ML14007A084

Byron, Units 1 and 2, Response to NRC Request for Additional Information, Dated November 21, 2013, Related to the Byron and Braidwood Stations, Units 1 and 2 License Renewal Application, Byron Station Applicant'S Environmental Report. Part

ML14007A084
Person / Time
Site:	Byron, Braidwood
Issue date:	12/19/2013
From:	Exelon Generation Co, Exelon Nuclear
To:	Office of Nuclear Reactor Regulation
Shared Package
ML14007A078	List: ML14007A080 ML14007A081 ML14007A082 ML14007A083 ML14007A084 ML14007A085 ML14007A086 ML14007A088 ML14007A089 ML14007A090 ML14007A091 ML14007A092 ML14007A094 ML14007A105 RS-13-282, Response to NRC Request for Additional Information, Dated November 21, 2013, Related to the Byron and Braidwood Stations, Units 1 and 2 License Renewal Application, Byron Station Applicants Environmental Report. Part 4 of 15
References
RS-13-282
Download: ML14007A084 (343)

Text

Byron Environmental Audit -Request for Additional Information ResponseQuestion

1. HCR-1 Category:

Historical and Cultural Resources Statement of Question:

Provide a series of aerial photographs of the entire plant site and associated transmission line(s) (during pre-construction, construction, and post-construction periods) looking at levels of disturbance that occurred during construction or sinceoperation, whether any historic structures or possible sites are present on the property, and identifying any recent projects that will require a review of additional documentation.

Response

Aerial photographs of the plant site during the pre-construction and construction timeframes are attached to this response.

Also, in a letter dated February 1974, the IllinoisSHPO stated that no cultural or historical sites of significance were located within theByron project boundaries.

A copy of the 1974 letter from the Illinois SHPO to the U.S.Atomic Energy Commission is attached to this response.

There are no ongoing or anticipated construction projects at Byron that would requirereview of additional documentation.

List Attachments Provided:

1. Aerial photographs

2. Letter from Illinois State Historic Preservation Officer (A. Dean) to U.S. AtomicEnergy Commission (D. Muller) regarding review of environmental reports forBraidwood, Byron, and Clinton Stations, February 1974.

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The following drawingspecifically reference MapOfArchaeological SiteDOI STAT I LLI NHotSDEPARTMENT OF CONSERVATION SPRINGFIELD 62706AAI> N *FEB 1 197Docket Nos.:STN 50-454, STN 50-455ST) 50-456, STN 50-457STN 50-461, STN 50-462Mr. Daniel R. MullerAssistant Director for Envircnmental Directorate of Licensing U. S. Atomic Energy Coi.ission W~ashington, D. C. 20545Proj ects

Dear M!r. Muller:

The envirorn.ntal reports prepared by Co-orvealth Ed+/-son cn Braidwood Staticn (Units 1 acd 2, Will Ccunty) and Byron Sta-ion (Units 1 ard 2,Ogle County) and Illinois Power Co=pany's environmental report on theClinton Power Station (Units 1 and 2, De Witt County) have been reviewed.

This review was made to deter-_ine what effect, if any, undertaking theEvrom, 3raid-ood, or Clinton projects would have on cultural and histori-cal si:es of significance within or adjacent to project work boundaries.

Archaeological, studies conducted on the project sites by members of theIllinois Archeeclcgical Survey for Illinois Power and Co=onwealth Edison indicate the existence of archaeological sites within the boundaries of each of the three projects.

Results of the archaeological surveys foreach site should be included in the final environmental statements.

Thefinal statements should also indicate Co=onwealth Edison's and IllinoisPower's plans for archaeological salvage of the lochted sites and theirplans for recording and salvage of archaeological sites which may bediscovered during project construction.

It has been deternined that, with the exception of the aforementioned archaeological sites, no cultural or historical sites of significance are located within the projects' boundaries.

No National Register ofRECYCLED PAPERH-1 Mr. Daniel R. Muller-2-FebruaryHistoric Places sites are found w4thin the project boundaries of theBraidwood, Byron, or Clinton Power Stations,..

DirectorState Historic Preservation OfficerATD:gjfcc. Ir. George Monret, Building l-A, Environmental Statem.ent Projects.

Argonne National Laboratory, 9700 South Cass Avenue, Argonne,Illinois 60439Hr. Charles Bareis, Illinois Archaeolcgical Survey, IC9 Davp.nporz Hall, University of Illinois, Urbana,.

Illinois 61601.Mrs. Ann Webster Smith, Director, Office of Cozpliance, AdvisoryCou..cil on Historic Preservation, Washington, D. C. 20240H-2 Byron Environmental Audit -Request for Additional Information ResponseQuestion

1. HCR-2 Category:

Historical and Cultural Resources Statement of Question:

Provide a copy of the avoidance measures recommended by the Illinois State HistoricPreservation Office (IL SHPO) for construction of Byron as referenced in Section 2.11.2of the ER.Response:

Attached is Section 2.6.1 from the Byron Station ER-OL, as amended January 1983(CoinEd 1981 a, p. 2.6-1). This section states (1) that "[i]t was recommended

[in the1974 Phase II Archaeological Report] that the sites along the Rock River in the riverscreenhouse area be fenced and construction crews be instructed to remain 50 feet fromthe fence in order to avoid impact during construction activities,"

and (2) that"[a]rchaeological site Oq-1 53 [sic], the only site near any construction

activity, wasfenced in the fall of 1976." [Note: While the ER-OL refers to archaeological site Oq-1 53,current SHPO records refer to the same site as 11OG153.]

Also attached is a letter dated September 18, 1974, in which the Illinois SHPOacknowledged receipt and review of the Phase II Archaeological Report for the ByronStation site. The letter notes that "safeguards are being taken to protect the knownarchaeological sites and that construction crews will be instructed to remain a minimumof 50 feet from them."A copy of the Phase II Archaeological Report is attached to the response to Audit NeedsQuestion HCR-12.List Attachments Provided:

1. Section 2.6.1 from the Byron Station ER-OL, as amended January 1983 (CoinEd1981a, p. 2.6-1).2. Letter from Illinois SHPO (A. Dean) to Commonwealth Edison (J.McCluskey),

September 18, 1974.

Byron ER-OLS AMENDMENT NO. 4JANUARY 19832.6 REGIONAL

HISTORIC, ARCHAEOLOGICAL, ARCHITECTURAL, SCENIC,CUTURAL, AND NATURAL FEATURESThis section reviews the findings of the historical study and thearchaelogical surveys of both the Byron Nuclear Generating Station -Units 1 & 2 (Byron Station) site and the transmission line rights-of-way.

2.6.1 Plant SiteThere are no sites on the station property that are included orare eligible for inclusion in the "National Register of HistoricPlaces" (Federal Register 1977a, 1977b), the "National Registryof Natural Landmarks" (Federal Register 1975; Resseguie 1977), orthe other listings of locally significant sites.Although six historic sites were listed for Ogle County in the"National Register of Historic Places" (see Table 2.6-1), none ofthese will be affected by the Byron Station.

The "Historic American Buildings Survey" (Ison 1977) lists three structures inOgle County (see Table 2.6-1), and again none of these will beaffected by the Byron Station.

The "Pictorial Archives of EarlyAmerican Architecture" (Ison 1977) lists four buildings in OgleCounty, none of which will be affected by Byron Station (seeTable 2.6-1).Many areas of local historical

interest, however, do exist in thearea. Table 2.6-2 lists and briefly describes these historicsites and markers located within 10 miles of the site as suppliedby information from various local sources (see references).

In February 1974, Anthony T. Dean, State Historic Preservation Officer for Illinois, stated that no cultural or historical sitesin the area would be affected by Byron Station.

A copy of hiscomments is included in Appendix 2.6A.An archaeological survey of Byron Station was conducted in June1973 by the University of Wisconsin

-Milwaukee, a memberinstitution of the Illinois Archaeological Survey. Sevenpreviously unrecorded archaeological sites and one previously recorded site were encountered.

In 1974 test excavations wereperformed to further evaluate the sites so that procedures couldbe developed that would preclude any potentially harmful effects.It was recommended that the sites along the Rock River in theriver screenhouse area be fenced and construction crews beinstructed to remain 50 feet from the fence in order to avoidimpact during construction activities.

Archaeological siteOq-153, the only site near any construction

activity, was fencedin the fall of 1976. In September 1974, the State HistoricPreservation Officer of Illinois stated that no archaeological sites would be disturbed by the construction of the ByronStation.

A copy of his comments is included in Appendix 2.6A.2.6-1 Byron ER-OLS AMENDMENT NO. 3MARCH 1982AMENDMENT NO. 4JANUARY 19832.6.2 Transmission Line Rights-of-Way The historical sites of interest for the Byron East to CherryValley-Nelson transmission line right-of-way and the Byron Southto Cherry Valley-Nelson transmission line right-of-way are thesame as those listed in Subsection 2.6.1. The "Camling-Cline Mound Group," an archaeological site located in Section 10 ofRockvale Township in Ogle County, is being considered fornomination to the "National Registor of Historic Places."

TheByron North to Wempletown right-of-way is adjacent to the site 4but does not impact on it. This right-of-way also crosses intoWinnebago County where the "National Register of Historic Places"lists 13 sites (see Table 2.6-3). These sites will not beaffected by the Byron North to Wempletown right-of-way.

Thereare no sites listed on the "National Registry of NaturalLandmarks" for Winnebago County.Archaeological surveys were conducted on these transmission linerights-of-way out of Byron Station.

The results of the surveyswere submitted to the Illinois State Historic Preservation

Officer, and his assessment of transmission line impacts on 3historic and cultural resources is contained in letters dated May12 and July 16, 1981. Copies of these letters were submitted inresponse to NRC Question 310.4, which is part of Amendment No. 1to this ER-OLS.The Byron North to Wempletown transmission line will be visibleat the Rock River crossing.

2.6-2 Byron UR-OLSSTATE OF ILLINOISS 'o1914Wy HIUiIlDEPARTMENT OF CONSERVATION I.4t% .SIAEII ('I~ll I II III 9Ip.Jlc 11% SIA 111111 14CIIII III. 1".-iI'IINGIFIFILn 62706ChIICAGO tIrImc.-hiin

s. MICIhIGAN AVE. 6l060SSeptember 18, 1974Mr. J. P. McCluskey Director of Environmental AffairsConmionwcalth EdisonPost Office Box 767Chicago, Illinois 60690

Dear Mr. McCluskey:

On August 22, a his office received the Phase II Archaeological Report forthe Byron Station sitc. The Report has been reviewed and the Department is satis~led that no archaeological sites will be d.Lsturbecd by coi1StrUt:tion activiLies dtaiIL.1ed in your transmittal leiter and survoyor's

mi

p. It iSnoted that safeguards are being taken to protect 0tW kno,'n arh.eological sites and that construction cre%.:s will be iinstructed Lo remain a u1inimniu,:

of 50 feet from them. Thank you for this opportunity of review and comment.( S: w rely,Di re/. torStatre listorlc Preservaition offierATD:tmmYk- )aw Byron Environmental Audit -Request for Additional Information ResponseQuestion

1. HCR-3 Category:

Historical and Cultural Resources Statement of Question:

Provide any maintenance or avoidance measures currently in place for site 11 OG153, orany other site within Byron site boundaries.

Response

Specific avoidance measures have not been implemented for site 11OG153 or otherarchaeological sites within the Byron owner-controlled area because the FinalEnvironmental Statement related to operation of Byron specifies no mitigation requirements for historic and archaeological sites on the Byron plant site (NRC 1982, p.9-5) and states that "[o]peration of the plant will not result in any significant impact onhistoric and archeological sites in the area" (NRC 1982, pp. iv and 5-17).Copies of the pertinent pages from NRC 1982 are attached.

List Attachments Provided:

1. Page iv from NRC 19822. Page 5-17 from NRC 19823. Page 9-5 from NRC 1982

a. The additional generating capacity provided by operation of Units Iand 2 of the Byron station will result in a significant savings insystem production costs and will assist CECo in maintaining adiverse i'&A of generating resources (Sec. 2).b. The land use impacts will be small (Sec. 5.2).c. The Byron station will draw most of the water it consumes in oper-ation from the Rock River; a small portion for the makeup watersystem will be pumped from wells. The average net use will be about1.3 m3/sec (47 cfs), which is about 1% of the average annual flow;therefore, no water-use impacts are expected (Sec. 5.3.1).d. The chemical,

thermal, and other waste discharges into the Rock Riverwill be rapidly assimilated; hence, no adverse impacts on downstream water users or aquatic biota are expected (Secs. 5.3.2 and 5.5.2).The staff expects that applicable standards will be met.e. The plant area does not alter the flood plain of the Rock River orits tributaries in the vicinity to affect their flood-prone areas(Sec. 5.3.3)f. There will be a visible plume extending from the cooling tower mostof the time; however, the ground-level fogging and icing caused bythis plume will be negligible (Sec. 5.4.1).g. The potential for impacts on the terrestrial ecosystem, which couldbe caused by operation of the cooling-tower emissions, bird impaction, noise, or trar,imission-1inp

pffpcts, ha, hPen e, JT cnd no ddi-tional impacts are expected (Sec. 5.5.1).h. The potential for impacts on the aquatic ecosystem, which could becaused by impingement or entrainment, thermal discharges, or dis-charges of chemical and sanitary wastes, has been examined and areexpected to be small (Sec. 5.5.2).i. Operation of the plant will not have an adverse effect on any rare,endangered, or threatened species (Sec. 5.6).j. Operation of the plant will not result in any significant impact on.'--istoric and archeological sites in the ar :Re r along the transmi s-Jýs~iqn,,qrr idors" (S kk. The staff concludes that the primary socioeconomic impacts of plantoperations are tax benefits and employment.

Other socioeconomic impacts of operation are expected to be small (Sec. 5.8).1. No significant environmental impacts are anticipated from normaloperational releases of radioactive materials.

The estimated max-imum individual dose for a member of the public subject to themaximum exposure will be very small compared to natural-background doses. As a result, the staff concludes that there should be nomeasurable radiological impact on members of the public from routineoperation of the plan~t (Sec. 5.9.3).3yron FESiv 5.S.I s toric.,and rArheologica Ii Sites)Opera tion of the station wi not result in,;in any cant .1. mpac t". on?.,ý historicnd.0 archeological itesO n ;teiarea(FES-.Section.

5.1)) nor along the trans-mission corridors (ER-OL. PQ 3104). However, as directed-in a letter from theState Historic Preservation Officer to the applicant (See Appendix H), caremust be taken to avoid the known archeological sites in the transmission corridors during maintenance activities, and in the event that a future majorground disturbance related to the operation and maintenance of the transmission lines is anticipated at the sites, the applicant is required to consult theSHPO before taking action. The applicant shall provide copies of thiscorreý,,,,1denc_

to NRC.5.8 Socioeconomics The socioeconomic impacts of station operation are analyzed in Section 5.5 ofthe FES-CP with visual impacts covered in 'Section 5.1.2. lhe primary impactsof plant operation are tax benefits and employment.

[the tax benefits areestimated to be approximately

$11 million (1981 dollars) in 1985 when thestation is scheduled to be completed.

These annual revenues will be paid tonine local jurisdictions ranging in amount from $4.9 million to $10,900 (1981doli.r_.)

as shown in Table 5.5. The plant wfli employ about 400 personnel whenoperatirn,,

with an annual payroll of S10.9 million (1981. dollars).

Approxi-mately 25o of these will be local hires. There will also be 100 security forceemployees with an annual payroll of $1,450,000 (1981 dollars).

It is estimated that al.l of the security staff will be hired locally.

(ER-OL, RQ 310.7.) Theinflow of operating personnel will not significantly affect local services7- .L L' -t j.': .JI ýý C!, i'eqI'U i I Io LIu L , L -UL, L u Iphase of the station.Table 5.5 Byron station property taxesTaxing .urisdiction 1985 Estimated*

Ogle County $ 2,022,800 Rockvale Township 1,322,600 School District U-226 4,944,300 Byron Fire District 1,516,000 Junior College District 511 629.200Oregon Park District 313,300Byron Library District 45,900School District U-220 199,200Junior College District 52' 10,900$11,004,200 A198; 1.c1la ,'s.Sour'ce:

ER-OL. No:met J. 1. I, fable 8'.2-1.l -yvr ; Lrb-/i on the Byron station property had been buried by others prior to the acquisition of the property by Commonwealth Edison and has been reported to be cleaned upin a satisfactory manner by the Illinois EPA. Additional monitoring of ground-water wells will be conducted by the Illinois EPA to monitor the effeýcts ofdumping,:on.adjacent property.

9.5.3.1 Aquatic (01-2, CECo-29, CECo-32)DI commented on Section 5.5.2.1.

This section has been revised based oncomments received from the applicant (see Appendix A). The applicant pointsout that neither the operational Section 316(b) demonstration study nor theconcerns of the IDOC to be studied include entrainment..

The applicant hascommitted to keep the Rock Island Field Office of the Fisn and Wildlife Serviceinformed of the findings from both the NPDES monitoring program and the specialstudy addressing the IDOC concerns (according to a letter from C. L. McDonough, Commonwealth Edison Director of Environmental Assessment, to S. Chesnut, NRCLicensing Project Manager, March 9, 1982).In response to the applicant'-.

comments, the first sentence on page 5-16 hasbeen deleted.

Corrected information is in Sectinn F.5.2.2.Section 5.5.2.2 has been revised to reflect the monitoring requirements speci-fied by the NPDES permit and the applicant's agreement with the IDOC.However, while Section 5.5.2.2 has been revised, the title has not been alteredas suggested because the applicability of the information is stated in thefi-rst sentence of the revised text.A new Section 5.5.Z.3 has beeo auded tc clarify the separate monitoring programbeing conducted under the agreemeitt between the applicant and the [DOC.%9:4' Histori Archeollogical Sites CECo-33Ita sU not': the s taf f 's 1intent~

to e.1 imi nate~l CECb61'sý communicati on witt) the SH-P(bu,, 6i`ý!SHOan.

NRCýIb6Vfnformned if:archeologi'cail) s'Aesln the tra~nsm~issiori 0rri ,,re ~aeto 4!ý4f e ,bf tr-aivfe,)e cionX15 179.5.5 Radiological (CECo-35; HHS-1, -2; EPA-1, -2, -5; IDNS-3, -4, -5)In response to CECo and IONS, the staff's judgment that the calculated resultsof the consequences are more likely overestimates is based upon the following:

(1) The release fractions of fission products, shown in Table 5.11, arebelieved to be conservatively high for those radionuclides that aredominant risk contributors.

This is due to the complexities of modelling more accurately natural plate-out and aerosol agglomeration and settlingtendencies within containment.

(2) The meteorological dispersion model employed is believed to beconservative.

(3) The staff's estimates of the effectiveness of protective actions,particul~arly evaCUation times, are believed to be conservative.

Byron FES.9-5 Byron Environmental Audit -Request for Additional Information ResponseQuestion

1. HCR-4 Category:

Historical and Cultural Resources Statement of Question:

Provide a description of how historic and cultural resources are considered in land disturbing activities.

Response

Exelon Generation has adopted a procedure applicable to nuclear power plants that provides aprocess for screening of proposed activities by responsible individuals to determine whetherfurther evaluations for environmental impacts are warranted.

[EN-AA-103]

Examples ofactivities that would qualify for further evaluation and that could involve land disturbance include[EN-AA-103-F-02]:

• Changes to or installation of storm drains, ditches or swales (e.g., changes to culverts, removal/addition of vegetative cover, changes to grade, blocking stormwater pathways)

" Changes to or installation of dikes, dams or appurtenances

" Construction, demolition or abandonment in place of any site or non-generating facilitybuildings or structures

" Dredging or silt removal from intake structures or other structures

• Land disturbance of >1 acre for any one activity, well drilling, soil boring, or changes thatwould alter storm water runoff* Paving of previously unpaved areasActivities determined to warrant further evaluation are reviewed by Environmental personnel todetermine whether the actual or potential environmental impacts of the activity are bounded bythe environmental basis for the nuclear power plant. [EN-AA-103-F-02]

In the case of a landdisturbing

activity, the cultural, historical and paleontological resources environmental basis forByron Station has been summarized in a Cultural Resources Management Plan (CRMP), whichidentifies previously disturbed areas and the locations of known archaeological sites within theStation's boundaries.

If the actual or potential impacts of excavation associated with the activityare not bounded by the environmental basis, then a supplemental cultural resources surveymay be performed based on consultation with the State Historic Preservation Officer.

[EN-AA-103-0001]

List Attachments Provided:

None Byron Environmental Audit -Request for Additional Information ResponseQuestion

1. HCR-5 Category:

Historical and Cultural Resources Statement of Question:

Provide a description of the process for inadvertent discovery of historic and cultural resources.

Response

If cultural, historic or paleontological resources are uncovered during an ongoing excavation atthe Byron Station, the work would be stopped, appropriate notifications would be made, a coverwould be positioned to protect the exposed resources from the elements, access to the areawould be controlled with barriers and/or signs, and work would not resume until authorized byEnvironmental personnel.

Also, Environmental personnel would coordinate the salvage ordisposition of any recovered resources.

[SA-AA-1 17]List Attachments Provided:

None Byron Environmental Audit -Request for Additional Information ResponseQuestion

1. HCR-6 Category:

Historical and Cultural Resources Statement of Question:

Provide a description of ComEd's transmission line management plan, including:

timingof activities, danger tree removal and other clearing, inspections and repair activities conducted by ground vehicles, standard operating procedures or guidelines for theapplicant and any contractors; erosion control procedures, technician training

programs, and any regulations that restrict maintenance activities (e.g., looking for activities thatcould affect depth of disturbance, if any disturbance is necessary along the corridor).

Response

In the Byron Station License Renewal ER, Exelon Generation applied the NRCregulations and guidance that were in effect at the time the Byron and Braidwood License Renewal Application (LRA) was submitted (May 2013) to define for whichtransmission lines environmental impacts should be analyzed.

Under the previousregulations and guidance, the in-scope transmission lines for Byron license renewalincluded the transmission lines that were constructed with the station to connect it to theregional electricity grid. Such lines, which are all owned and operated by CornEd, areidentified in the Byron License Renewal ER as follows:* Byron to Wempleton (345-kV line extending north from the Byron switchyard)

• Byron to Cherry Valley (double circuit 345-kV lines extending east from Byronswitchyard)

• Byron South (345-kv line extending south from Byron switchyard)

In June 2013, after the Byron and Braidwood LRA was submitted, the NRC finalized regulations that changed the requirements and guidance defining which transmission lines would be within the scope of license renewal environmental review. Under the newregulations, in-scope transmission lines are defined as transmission lines that connectthe nuclear power plant to the substation where electricity is fed into the regional powerdistribution system and transmission lines that supply power to the nuclear plant fromthe grid [10 CFR 51, Appendix B to Subpart A, Table B-i, Footnote 4]. This definition isfurther explained in the Statement of Considerations for the final rule, which states that"those transmission lines that would not be impacted by a license renewal decision (i.e.,those lines that would not be dismantled or otherwise decommissioned as a result of aplant terminating operations because its operating license had not been renewed) areconsidered beyond the scope" for the license renewal environmental review. [78 FederalRegister 37296 -37297; June 20, 2013]Because the NRC will now apply the new regulations to define the scope of transmission lines for which environmental impacts are analyzed in the License RenewalSupplemental Environmental Impact Statement for Byron Station, Exelon Generation has revisited its original evaluation of the in-scope lines. Electricity generated at ByronStation is transformed from generator voltage to a nominal 345-kV transmission systemvoltage by the main power transformers.

The main power transformers are connected via intermediate, on-site transmission lines to the on-site 345-kV Byron Station switchyard.

The location of the intermediate transmission towers on the site property isshown in Byron UFSAR (Exelon Nuclear 2010a), Figure 8.2-3. For ease of reference, acopy of the figure is attached to this response.

Based on this information and that thereare no other transmission lines that would be dismantled or otherwise decommissioned as a result of terminating operations at Byron, Exelon concludes that, under the newregulations, the intermediate, on-site transmission lines are the only in-scopetransmission lines for the Byron license renewal environmental review. Thesetransmission lines are located entirely within the station's protected area. Groundsmanagement practices for that area are described in the Request for Additional Information Response HCR-7.List Attachments Provided:

Byron UFSAR (Exelon Nuclear 2010a), Figure 8.2-3 REVISION 9DECEMBER 2002WEMPLETOWN z F2KCE0Un-JIL se, L zIN L=G, 0.9" 310"EL 230*-*0)z0CE53ISAL I :*CIRCULATING La.J IflY. IIATER I ' WATERcoOIN j :: _pWupOUSt 31i0K STAlIONUPDATED FINAL SAFETY AALT= REPORTsa- -g.-FlGU9 234VOE1 PLAN Byron Environmental Audit -Request for Additional Information ResponseQuestion

1. HCR-7 Category.

Historical and Cultural Resources Statement of Question:

Provide information on management around less-developed areas of the plant site,especially near known historic and cultural resources or near unsurveyed areas, ifapplicable.

Response

Vegetation control at Byron station is the responsibility of the Facilities Maintenance Department.

The following guidelines are used as the basis of operation for this activity.

• Regular -"Yard" areas both inside and outside of the PA are generally mowed ona regular basis to maintain a height of 6" or less. (e.g., training, plant entrance, shooting range)* Secondary

-Security sensitive areas inside and outside the PA are mowed lessfrequently to maintain vegetation at 12" to 16" or less. These areas are locatedoutside from the center of the plant, and their boundaries depend on defensive strategies of the security force. Security supervision contacts facilities maintenance if the vegetation becomes overgrown to a point that it may hindertheir activities.

Facilities staff and security management tour these areas asneeded to discuss possible issues or special requests.

( e.g., along south road,natural draft cooling towers -- East side)* Outlying

-These are areas that are of less significance to security and theoverall aesthetics of the site, but warrant some degree of vegetation control forwork access, security inspections, or noxious weed control.

These areas have agoal of being mowed twice per year. ( e.g., North of main parking lot, outlyingareas of shooting range)* Blowdown

-The blowdown line and 345 kv line to RSH areas have a goal ofbeing mowed at least twice per year with more frequent mowing dependent onwork activities and inspection access. These areas are also monitored for treegrowth/infringement on the power lines." Less developed

-Less developed, unsurveyed areas of station property notencompassed in the areas previously described are maintained only in responseto special requests.

Note: The frequency of mowing activities is subject to weather, other work load, plantpriorities, and staffing levels.Note: The known historic and cultural resources indicated on the map in the CulturalResources Management Plan are not maintained in any way differently than any of theother landscape in the immediate surrounding area.Ust Attachments Provided:

None Byron Environmental Audit -Request for Additional Information ResponseQuestion

1. HCR-8 Category:

Historical and Cultural Resources Statement of Question:

Provide documentation of construction projects that have occurred on the property sincethe construction of Byron to determine how historic and cultural resources wereconsidered.

Any documentation demonstrating compliance with existing environmental procedures would be useful. What materials are used by the staff to determine whetherthe SHPO should be consulted?

Response

No construction projects have occurred at the Byron Station since existing procedures requiring environmental review of such projects were implemented, which occurred afew years after the merger in October 2000 of Unicorn Corporation and PECO EnergyCompany to form Exelon Corporation.

Prior to the merger, documentation ofenvironmental reviews associated with construction on the Byron owner-controlled property was not archived.

For future reviews of proposed land-disturbing construction

projects, Byronenvironmental personnel will review the cultural, historical and paleontological resources environmental basis for Byron Station, which has been summarized in a CulturalResources Management Plan (CRMP). The CRMP identifies previously disturbed areasand the locations of known archaeological sites within the Station's boundaries.

If theactual or potential impacts of excavation associated with the project are not bounded bythe environmental basis, then the State Historic Preservation Officer would be consulted concerning the need for a supplemental cultural resources survey. [EN-AA-103-0001]

List Attachments Provided:

None Byron Environmental Audit -Request for Additional Information ResponseQuestion

1. HCR-9 Category:

Historical and Cultural Resources Statement of Question:

Provide a percentage of disturbed and undisturbed land within the Byron Site.Response:

Exelon Generation believes that areas occupied by the power block, switchyard, and othersupporting facilities (approximately 154 acres) [Byron UFSAR Section 2.4.2.3, pp. 2.4-6a to2.4-7] as well as the pipeline corridor (approximately 384 acres) [Byron UFSAR Section 2.1.1.2,p. 2.1-2] were all disturbed by original construction of Byron Station.

These areas(approximately 538 acres total) represent 30 percent of the total Byron Station land area(approximately 1,782 acres) [Byron UFSAR Section 2.1.1.2,

p. 2.1-2]. Approximately 47percent of the total Byron Station land area (840 acres) has been leased for agricultural purposes.

Such land is considered disturbed because most of it is tilled. The remaining 23percent of the Byron Station land area (404 acres) is undisturbed land.List Attachments Provided:

None Byron Environmental Audit -Request for Additional Information ResponseQuestion

1. HCR-10 Category:

Historical and Cultural Resources Statement of Question:

Provide information about the percent of leased land within the Byron site; how much of the landwithin the Byron site is directly owner-controlled?

Response

The Byron Station occupies approximately 1,782 acres of land. This area consists of the mainsite area and the pipeline corridor to the Rock River. The main site area occupies approximately 1,398 acres, while the corridor occupies the remaining 384 acres. [Byron UFSAR Section2.1.1.2,

p. 2.1-2] Approximately 840 acres (47 percent) of the total land area occupied by theByron Station is leased for agricultural use. The power block, switchyard, and other supporting facilities under continuous surveillance occupy approximately 154 acres (9 percent) of the totalstation land area. [Byron UFSAR Section 2.4.2.3, pp. 2.4-6a to 2.4-7]Regarding control of leased land within the Byron site, Exelon Generation generally retains anunrestricted right to enter, use, and dispose of the leased land for its business purposes and inthe event of emergencies.

Also, subleases are not allowed, and leases typically restrict use ofthe leased land solely to a designated

purpose, such as for farming and agricultural

purposes, for cultivating crops, and/or for pastureland.

In addition, some leases may prohibit certainspecific activities on the leased land, such as removing top soil, changing the original groundgrade level, altering the natural water drainage

pattern, and installing irrigation systems.List Attachments Provided:

None Byron Environmental Audit -Request for Additional Information ResponseQuestion

1. HCR-11 Category:

Historical and Cultural Resources Statement of Question:

Is there any formal cultural resource training for Byron staff?Response:

Byron Station personnel receive no formal cultural resources training.

List Attachments Provided:

None.

Byron Environmental Audit -Request for Additional Information ResponseQuestion

1. HH-1 Category:

Human HealthStatement of Question:

Provide NPDES monthly discharge monitoring reports for the past five years.Response:

The NPDES monthly discharge monitoring reports for all months of years 2008 through 2012and January through July 2013 are provided.

List Attachments Provided:

1. NPDES monthly discharge monitoring reports for January 1, 2013 through July 31, 2013.2. NPDES monthly discharge monitoring reports for January 1, 2012 through December31,20123. NPDES monthly discharge monitoring reports for January 1, 2011 through December31,20114. NPDES monthly discharge monitoring reports for January 1, 2010 through December31,20105. NPDES monthly discharge monitoring reports for January 1, 2009 through December31,20096. NPDES monthly discharge monitoring reports for January 1, 2008 through December31, 2008 Exelkn.Exelon Generation

Company, LLC www.exeloncorp.com Byron Station445o North German Church RoadByron. IL 61010-9794 February 25, 2013LTR: BYRON 2013-0029 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyWater Pollution ControlCompliance Assurance Section #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring Report.In accordance with National Pollutant Discharge Elimination System (NPDES) Permit NumberIL0048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report forByron Station, Units 1 and 2. This report covers the period of January 1, 2013 throughJanuary 31, 2013.Special Condition 14 of the NPDES permit requires the station to weigh the copper anodes atthe end of the zebra mussel control season and to include the total mass of copper used in thedischarge monitoring report. The zebra mussel copper ion skids were shut down on December26, 2012. The anodes of the OA copper ion skid were removed and weighed on January 24,2013. The anodes of the OB copper ion skid were removed and weighed on January 24, 2013.The total mass of copper used for zebra mussel control was 221 pounds.If there are any questions regarding this report, please contact Ms. Zoe Cox,Environmental/Radwaste Supervisor, at (815) 406-3035.

Respectfully, Benj M.2 aPlant ManagerByron Nuclear Generating StationBPY/ZC/eh Attachments NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAMEIADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN. 7.. r",.,I/l:MU OMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERA01 -0DISCHARGE NUMBERMONITORING PERIODMMI/D/YYYY MM/DDFYYYY FROM 01/01/2013 TO _ 01/31/2013 1DEMINERAUZER REGENERATE WASTE (001A)External OutfallNO DISCHARGE ED ...PRMTRVALUE VALUE UIS VALUE VALUE VALUE UNIASYSXIO TYPESld .T tlS s e d dSAM PLE .. .....< .3 <11.3 19001/30 08Soilds, Total Su d MEASUREMENT Effluent Gross toQIRMD.AG

Chromium, hexavalent SAMPLE(as Cr) MEASUREMENT Effluent Gross EQIMChromium, total SAMPLE(as Cr) MEASUREMENT 010341 0Effluent GrossCopper, total SAMPLE(as Cu) MEASUREMENT 0104210Effluent Grossiron. total SAMPLE(as Fe) MEASUREMENT 010451r0Effluent Gross WRE lIEILead, Total SAMPLE(as Pb) MEASUREMENT 01051 10Effluent Gross ELI-Nickel, total SAMPLE ....500(as Ni) MEASUREMENT Effluent Gross wm, 9N AM E lrTTL E I *:e dfy und erpnl ty o f taw t sat ft do mum e rd an d al an, ctuncif w er e pre ard under m y T E L E P H O N E D A TEPRINCIPAL EXECUTIVE OPFRCER d uraction or auislo in a ce with a system designed to assre thst qualied peimonepropert gamfer anm evakft the information suxmated Based an mil hmfy of the person or persons-El Benjamin P. Youmnan who manage the system, or stose persons dfmt"y easpos for gathering the informatin, Uthe -0212512013 inotmwsti submitted Is. to the best of my Iknowledge and belef. true. accurate.

and captle 9 I am IGNA RE AINCIPLEPlant Manager aware tha the am ssgnificant penalties for sutm)ing false inmation, bi1dkng the possbey of EXECUTIVE CER OR MMIDDJYYYY

• rEe OR PMMTW fe and lt f violations.

AUTHORIZED AGENT CDCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Relevence all attachments her)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow exIsted 31 of 31 days durng this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAMI&ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfietd RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoo CoxIENV SPECDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERA01-0DISCHARGE NUMBERMONITORING PERIODMM/DD/IYYYY MM/DDIYYYY FROM 01/01/2013 TO 01/31/2013 DEMINERALIZER REGENERATE WASTE (001A)External Ouffell* NO DISCHARGE

...IMEASUREMENT SAMPLEMEASUREMENT PRINCIPAL.

EJCECU'IVE OFFICER :gectiort or eupervioim m accordance walt a system disrned to msure that qzattted petsonret

____ ____________

Benjamin P. Youman who manage the system, or those persons ¢re~ty reSlones gasrertg the Intomialim.

the SNA. E .PIILE02/25/2013

• mfomelr eutimitted In. to the best of my knowledge end belief, truJe, acctiraete end comrpiete.I aint SGA E PI IPE_ __oPlant oManagerlmr eawaretandmnCt mnthem re 81sgnirhcant per nawltn e sihtI~ng fa]se Ittnfomltlon, Indlud~g the peabutot EXECUTlVY OFFICERuTOID AGNOR NUMBER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)I. Flows for January 2013 are estmated based on July 2012 values due to totalizers being Out of Service.

The totahizers are an obsolete model and work orders are in place to findreplacement totutizers and get them installed in the system.EPA Form 3320-1 (Rev 01/06) Previous ediIions may be used. 1/6/2012 PAGE 2 NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)OMR Maeling ZIP CODE.61010PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 r*FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010MAJOR] (SUBR 01)I IL0048313 i1B01-0CSI PERMIT NUMBERDISCHARGE NUMBERIMONITORING PERIODMIMWDDYYYY I I MM/DD/YYYY STP PLANT EFFLUENT (FORMER 0019)External Outfall* * ' NO DISCHARGE rJFROMI01/01/2013 ITol01/31/2013 pHI I7.08 1 I 7.52 I 12 1 0 1 02/o30 I GR I00400 10Effluent GrossSolids. total suspended 00530 10Effluent Gross-Unr , oslt or dllY 0,tL, 0.005 0.011 3 ...... U;01/01 CUNtreatment plant MEASUREMENT 50050 10Effluent Gross ,R_______

.SAMPLESAMPLESAMPLEMEASUREMENT NAMEFMITILE ICertify under penalty oflamw that this document and an anach~menft were prepared under nq TELEPHONE DATEPRINCPAL EXECUTIE OFFICER direction or supe,,fWWion accoranc wth a system designed to assure tha qualfied Persornnel________________

ropery gather and evalute the Inforrarton

submited, Based an ny ntqur ato the person or persons 7Benjamin P. Youman who manage the system, or those persons directly responsitle for gathering tne ionniation.

the 02t25/2013 bnfonnatio submitted Is. to the boest o my knowKedp and beWee. mw acorae. and comlpete.

I am SIGNAinE 0RINCIPLE Plant Manager aware hat there are stgnfficant paafaties for a atnining ase tornanb, InCtudnog the poesly d EXECUTIVE OFFICER OR AREA NUMBER DOR PNI ' ine and innnprlonment for Mowiag vtationat

.AUTORIZED AGENT MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flow existed through this outfall 29 of 31 days during tlis month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. .. 1/6/2012 PAGE 1 PERMflTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvile, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoe Cox/EV SPECNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR),L0048313 i I C01-0PERMIT NUMBER DISCHARGE NUMBERMONITORING PERIODMMJDD/YYYY MMIDD/YYYY FROM 01/01/2013 TOI 01/31/2013 DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010WWTP (FORMER 001C)External Outfall'" NO DISCHARGE PAAEE QUANTITY OR LOADING QUANTITY OR CONCENTRATION N. FIREOUENCY SMLVALUE VALUE UIS VALUE VALUE VALUE UNIALYSISO TYPESolids, total suspended MPLE 4.6 6.6 19 0 02130 24Effluent Gross I,Chromium, hexavalent SAMPLE(as Cr) MEASUREMENT SooChromium, total SAMPLE ......(as Cr) MEASUREMENT Soo01034510Copper, total SAMPLE ......(as Cu) MEASUREMENT 5001051 1 0Efflnt GrossL a ,ttlSAMPLE

..... ...... Soolt50Effluent Gross ME f&M1(as Nil MEASUREMENT50 010671 0#"EnTnE I ceoify under penalty of law that this documet and arl acfl were peJere under my TELEPHONE DATEPRNCIPAL EFXECUinVE OFFICER diectin or supervsion In ecordance with a system designed to assure that quaffed personnel propedy gather and evalute the inforrmaonl Based on my nuiry of the person or persons 406-3700Benjamin P. Youmen who manage the system, or those persons directly tor gathering the Infonna9on, the 815 02/25/2013 Inflonnaton submitted is. to the best of my knowledge and beloef, true, accurate.

and complete.

lam SIGNAn 0 RI 7Plant Manager aware that them are significant penalties for submfting faise lformatilon, incluing ithe possablfty of E %CU OFICER OR AREA NUMBER MM/DD/YYYY onEo OR P nWirpEtfinenaed for nowing AUTHORIZED AGENT ODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hare)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow exsted through this outfall 12 of 31 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/2012 PAGE 1II NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010A'r-'N- 7nw r.~/N~tV RPI=C.DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERC01-DISCHARGE NUMBERMONITORING PERIODMMIDD/YYYY I I MM/DD/YYYY WWTP (FORMER 001C)External Outfall* *" NO DISCHARGE lFROMI011101t2013 TO01/31/2013 iQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. SAMPLEPARAMETER OVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS OTYPEZinc, total SAMPLE(as Zn) MEASUREMENT 50001092 1 0Effluent GrossI -iFlow, In conduit or thru SAMPLEtreatment plant MEASUREMENT 35005010 --Effluent Gross RUN O liSAMPLEMEASUREMENT SAMPLEMEASUREMENT SAMPLEMEASUREMENT SAMPLEMEASUREMENTAM EnITL.E t carlifyund~er enall oa law thatifi kn doumnt and all attachments were prpae under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER mcton or supenisl~

n In accance wth a system designed to assure that qualified personnel

-prpe rty gathe r and eva th e in f ormna tin su b mit'tec B sd. on m y bnq by °f te p e rson or per sons -" Ski ' I 4 0 L-3 7 0 0Benjamin P. Youman who manage the system, or those peosos directly responsible for gathering the Inforto, the 0225/2013 informatlon submitted is, to tha best l myt Itotaedge and beief, true. accurate, and complete.

I am SIGNA- E 0 RINCIPLEPlant Manager aware that them am significant penaliles for submtg [alse Inftrmation.

including the posstiliy of EXEC E FICER OR AREATVPED ON PR ftie and ilprislorment tor Imowltg volations.

AUTHORIZED AGENT CODE NUMBER MMIDO/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachmenta here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE-2 NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN' 7rm. P~,wI::V QPI:tPDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERD01-0DISCHARGE NUMBERMONITORING PERIODIi MMIDDIyYYYY MMIDDIYYYY RADWASTE TREATMENT (FORMER 001 D)External Outfall**NODISCHARGE FROM[ 01/01/2013 TOl01/31/2013 iPRMTRQUANTITY OR LOADING QUANTITY OR CONCENTRATION N. FREQUENCY SMLPARAMETEROFAML Solids, total suspended MEASUREMENT 0053010 0Effluent Gross REQ0lFlow, In conduit or thru SAMPLEtreatment plant MEASUREMENT 0.022 0.022 3 0 01/01 CN5005010 1.Effluent Gross I. .iREM.. 1-_ AM ,SAMPLEMEASUREMENT SAMiPLEMEASUREMENT SAMPLEMEASUREMENT "1 SAMPLE INAM, IE/1'LJE I Cr,

• under Penalty dl law thi this document and all were prepared under my i TLPOED EPRIWCIPAL EXECUTIVE OFFICER drettion or superesion Itn ac ce wtdtM a swsore designed to assure ttat te persmw TELEPHrONE DATproperty gather and evalute the Information sub itt. Based on my Inquiry dl the perso or peron 406-3700.

Benjamin P. Youman who manage the system, or those persons &Bcdy respons.be fix gatherng the Wonnadon, Ie SG-n-'Ef./ 02125/2013 Information submttied Ks to the best of my ito~wiedge and belief, ltree, aceurte, and complete, I am SIN 7R "RNILPlant Manager aware thdat thre ame sgnificant peonafes

.fr submittn false infimatlon.

Including the possitety of EXECUTIVE O FFICER OR AREA NUMBER MMIDD/YYYY TVN cwýW ý ~ fbe and toptluetfor nWing volataions.

ZDAET CDCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flow existed through this outfati 2 of 31 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1//2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIT1EE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4480 North German Church RoadByron, IL 61010A'TTN- 7nn SPECDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 3I PERMIT NUMBERE01-0DISCHARGE NUMBERM Y MONITORING PERIODMMIY MMDDYYYYSTORMWATER (FORMER 001E)External Outfall* * *NO DISCHARGE E ...FROMI01/01/2013 TO]01/31/2013 I IQUANTITY OR LOADING QUANTITY OR CONCENTRATION FREQUENCY SMLPARAMETER N OFSA>1 VALUE VALUE UIS VALUE VALUE VALUE UNT X ANALYSIS TPSolids, total suspended SAMPLENT0053010Effluent GrossSolids. total suspended MEASUREMENT Other Treatment, ProcessChromium, hexavalent SAMPLEChromium, total SAMPLE ......(as Cr) MEASUREMENT Effluent GrossCopper, total SAMPLE(as Cu) MEASUREMENT Effluent Gross I 1(as Pb) MEASUREMENT Effluent Gross I cardl/y under penalty of ~ thawtg this document and al were prpae under my [

'AET [TEL"EPHONE DATEBenjamin P. Youman who manage the syste. or those persons irecly respons0e for gathering the tfornatlmr the 02M/2013information submtedl Is. to the bet of my Imowledge and belil, true. ac-,rate, and compviee I SIGNnRE RINCIPLEPlant Manager aware that there are signtrrcant penalies for submittttng false infornatin.

inclutng the possibrblttyi

EErn FFICER OR ATTE GF .tOW lne and hrrprisiornmont for Imowtng vildations.

AUThORIZED AGENT CODE NUMBER MMIDDIYV'IY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hare)1. There was no discharge of processed steam generator chemical cleaning wastewater during the month.2. Flow eisted through this outfall 0of 31 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/162012 PAGE 1]

PERMITrEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoe CoxfENV SPECNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR),L0048313

[ EOl-0PERMrT NUMBER DISCHARGE NUMBERMONITORING PERIODMM/DD/YYYY MMIDDfYYYY FROMI 01/01/2013 ITo[ 01/3112013 OMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010STORMWATER (FORMER DO1E)External Ouffall*

• NO DISCHARGE E ...QUANTITY OR LOADING QUANTITY OR CONCENTr'RATION N.FREQUENCY

ýSMLPRMTRVALUE VALUE UIS VALUE VALUE VALUE UNIASYEXIO TYPENickel, total SAMPLE .........

(as NJ) MEASUREMENT 0106710 J REffluent GrossZinc, total (as Zn) MEASUREMENT OEflue0nJt 10ros If NowFlow, In conduit or thru SAMPLEtreatment plant MEASUREMENT 500501 0Effluent Gross R 'SAMPLE SO VSAMPLEMEASUREMENT MEASUREMENT NAMENTS LE I ceA undEL penaAAy OF law tIat this do(R uent an all attachments were )epared under my ONE DATE1. No .EXECUose E OFFICER drmcai of supervision In ascordance with i system designed to assure that quaoinhed perso.l2 prope Sdr gather and evaPre theInfornain was disared ts monf the.pmonorpens8 Benjamin P. Yournan who manage the system. orthose peos= directly responsibl the, inform'ation.

the 02/25/2013 Information submitted Is, to the best of my knweg and bedef true. accurate, and complete.

IlamI GNPlant Manager aware got there amsre can penatdes for subndltbg false Inormation, Incuding the pa~ossbiy df EX lqTE OFAFFIC ORBE EAD/YY.. wOR and h One for knowing Violations.

AUTHORIZED AGENTERM/~fYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. No Closed Cooling System Drain Water was discharged this month.2. No Service Water System drain water or Fire Protection drain water was discharged this month.3. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Cleaning wastewater was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 118=12 PAGE 2I1 PERMrTrEE NAME/ADDRESS NAME Exelon Generation Co., LLC.ADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010AT'rM. 7- r'n.=IEJM CO1flNATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)1L0048313 I 1 001-0PERMIT NUMBER DISCHARGE NUMBERMONITORING PERIODMMIDDFYYYY

_//] TO MM1DD/YYYY FROM I 01/01/2013 IO 01/31/2013I DMR Mailing ZIP CODE:MAJOR61010(SUBR 01) CSCOOUNG SYSTEM BLOWDOWNExternal Outfall* *

• NO DISCHARGE EJ"

• RL~ QUANTITY OR LOADING QUANTITY OR CONCEN7TRATION N.FREQUENCY SAMPLE> <VALUE VALUE UNT VALUE VALUE VALUE UNT X ANALYSIS TYPETemperature.

water dog. SAMPLE ....... ..... 83.1 i 01/01 ONFahrenheit MEASUREMENT pH ~~~~SAMPLE.......

Effluent GrossSolids, total suspended SAMPLE .9 3.9 19 0 01/30 OROOS301 0MEASUREMENT Effluent Gross A_ N wChromium, total (as Cr) SAMPLE "O"002<01900101/07 ORMEASUREMENT 01034 1 0Copper, total (as CS) SAMPLE en....500 MEASUREMENT Gross 19 0_01_07_O Cpnc,rtotal (as Zn) M PU flBLENTi.....

f 0.004 0.008 01/07 OR01042 10Effluent Gross Bpope4 gather midevaluate i~ntwnafli jsirfttedL Based on myInquiry oftheperson orpersona "7 f/85463Benjamin P. Vouman who manage tie system, or tine p0erawia dirctl repoali for gathein the bitonnatlon the- 02/25/2013 InZin, bned is to te nes of my brow'ette an te ., cut wmorete m SN F PRINCIPLE Zn) BAMPLEPlant Manager aware that theme are signiticani penaltes for submItting ilse Infomsitlon, Including the poassettyof EXECUTnV OFFICER OR AREA NUMBER El ente and npdomen fo knowing v.latRona.

A R AGCOMMENTS AND EXPLANA tON OF ANY VIOflATIOhs (Reference all attachments here)1. MonitoPing data for outfall001-0 is icluded on attachment.

EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 1I.a:-..4f.it NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMrrTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBER001-0DISCHARGE NUMBERMONITORING PERIODMMIDDIYYYY

=ý I MMIDDYYYY FROM 1 01/01/2013 TOI 01/31/2013 COOLING SYSTEM BLOWDOWNExternal Outfall* *NO DISCHARGE "J

NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMRT-EE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010IL0048313 PERMIT NUMBER002-0DISCHARGE NUMBERDMR Mailing ZIP CODE:MAJOR(SUBR 01) CSSTORMWATER RUNOFF BASINExternal Outfall61010MONITORING PERIODi MMIDD/YYYY IFROM 01/01/2013 TOMMIDD/YYYY I----- f01/31/2013 I* * *NO DISCHARGE M ..t IIQUANTITY OR LOADING QUAN1TTY OR CONCENTRATION FREQUENCY PARAMETER

.-_OF SAMPLEPRMTRVALUE VALUE UIS VALUE VALUE VALUE UNT X ANALYSIS TYPESolids. Total Suspended MEASUREMENT

.eEASUREMEN 0053010Effluent Gross .R-ETSolids, Total Suspended SAMPLEOhrTreatment, Process.Complete

Chromium, hexavalent SAMPLE ........(as Cr) MEASUREMENT Effluent Gross REG. ~ -. VGL .Chromium.

total SAMPLE(as Cr) MEASUREMENT E~ffluent Gross LEGUIRREM MICopper, total SAMPLE(as Cu) MEASUREMENT Iran, total SAMPLEo.,,

.(as Fe) MEASUREMENT 01045 1 0Lead, total SAMPLE ....(as Pb) MEASUREMENT Effluent Gross NMUErTLE Icertify under iena th ddme d all and mftrrt were under my ONE DATEPRINCIPAL EXECUTIVE OFRFCEIR

, recliion of supervision in ac~ordance wthU a system designied to assure tha Quaffied personnel IEHNmprletly gather and evablte the tntfonraton subiutrrifd.

BaGM on my hnquhy od the person or person A4Benjamin P. Youman who manirage the system. or those parns decuy resporsble for gathering the M ai te 0225/2013 Infonnaton Is. to the best of my Inowledge and belief. tnhre. accurate, and cmlete, lan SIGN RE AP PRINCIPLE Plant Manager aware thait ther are significant penalfes for subnrtiltng faise Inflonnaion.

cMluding ltle possbrty of EXE UTIY OFFICER OR AREA MM/DD/YYYY IVM end Inprslonrent for knowing vi AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments herm)1. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Metal Cleaning Wastawater was discharged this month.2. No Fire Protection, Service Water or Closed Cooling System Drain Water was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/62012 PAGE 1.

PERMITIEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, 1160555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)IL0048313 002-0PERMIT NUMBER DISCHARGE NUMBERMONITORING PERIODMMMDDIYYYY MMMDD/YYYY FROM 01/01/213 1 F 01/31/2013 DMR Malling ZIP CODE-MAJOR(SUBR 01) CS61010STORMWATER RUNOFF BASINExternal Outfall* *

• NO DISCHARGE I ""P'-I 1 I'.~ Lg :lV orr-QUANT17TY OR LOADING QUANTITY OR CONCENTRATION NO._FREQUENCYSAMPLE PARAMETER OFSAMPLPRMTRVALUE VALUE UIS VALUE VALUE VALUE ANALYO I TYPENickel, total SAMPLE(as NI) MEASUREMENT 0106710 IVRZinc, total SAMPLE(as Zn) MEASUREMENT 0109210FEffluent Gross X ,Oil end Grease SAMPLE ...MEASUREMENT 035621 0Fltow. in conduit or tinni SAMPLEtreatment plant MEASUREMENT Effluent Gross 11REUMt ,. DA.!G WENT!SAMPLEMEASUREMENT NAM~rrllrLE Icurty under penalty d awJ that tiles dooarnent ali at eta~enenls were prepared under my TLPOEDTPRINCIPAL EXECU~lrVE OFFICER diretion or srrpervlonr In accuntance wvdh a system designed to ssure that quatfied perssat____n______________

Benjamin P. Youman manage the system, or those persons decl responsible (or gahrn the lnfo~mstlon, the SIN, ..-F02521Plant Manager aware that there are sign~acnt penaltlea for submitting false lrrmrnalin.

Includng the posblt of EXECI1V OFFICER OR ARIEAIM/DYY sypemi psas late hen Iniprsbirnment lot knowig blh.b AUTHORIZED AGENT cOD] NUMERMMD/Y_

COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments haem)1. This discharge point was not used this month.2. There was no discharge of processed steam generator chemical cleaning wastawater during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/1/'2012 PAGE 2I ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 January 2013Page 1 of 3MONITORING DATA:WBD CRock RiverDATE Temperature mgd Flowdeg F cfs01/01/2013 67.9 19.52 3,75001/02/2013 68.9 21.18 3,37001/03/2013 71.8 17.65 4,07001/04/2013 74.7 20.20 3,75001/05/2013 74.7 25.48 3,91001/06/2013 73.3 20.23 3,91001/07/2013 74.9 15.29 3,42001/08/2013 75.8 20.81 3,62001/09/2013 75.8 20.44 3,45001/10/2013 74.7 19.42 3,07001/11/2013 81.5 20.22 3,30001/12/2013 81.5 24.77 2,93001/13/2013 68.8 20.69 3,10001/14/2013 67.5 15.92 3,51001/15/2013 70.6 22.20 4,54001/16/2013 76.5 17.72 5,42001/17/2013 76.5 20.55- .5,68001/18/2013 76.0 19'91' 5,51001/19/2013 77.2 25.65 3,94001/20/2013 73.3 19.96 5,06001/21/2013 67.3 13.94 5,85001/22/2013 62.0 24.35 4,78001/23/2013 64.6 20.06 5,04001/24/2013 66.0 18.68 4,75001/25/2013 72.0 19.19 4,58001/26/2013 72.0 24.96 4,23001/27/2013 74.7 20.43 4,00001/28/2013 76.7 17.04 4,06001/29/2013 83.1 18.76 4,34001/30/2013 83.1 20.20 6,29001/31/2013 71.6 22.90 11,300K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2013\January 2013ATTACH01.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 January 2013Page 2 of 3HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (or associated rinses) containing hydrazine discharged to the Cooling System Blowdownduring the month of January 2013.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite and Bromine compounds were used this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 31 of 31 days.4. Per Special Condition 24 the influent from the Rock River and effluent fromOutfall 001-0 was monitored for Total Suspended Solids (TSS) this month.The Rock River TSS value was 4.3 mg/L on 01/14/2013.

The CWBD TSSvalue was 3.9 mg/L on 01/1 4/2013.5. Rock River flow for January 2013 was >2400 cfs therefore dailytemperature calculations were not required this month. (Special Condition 12).6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in January 2013. (Special Condition 15).K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2013\January 2013ATTACHO1.doc Exelkn.Exelon Generation

Company, LLC www.exeloncorp.com Byron Station.4450 North German Church RoadByron, IL 61010-9794 March 26, 2013LTR: BYRON 2013-0042 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyBOW CAS #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring ReportIn accordance with National Pollutant Discharge Elimination System (NPDES) Permit NumberI1L0048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report forByron Station, Units 1 and 2. This report covers the period of February 1, 2013 throughFebruary 28, 2013.If there are any questions regarding this report, please contact Ms. Zoe Cox,Environmental/Radwaste Supervisor, at (815) 406-3035.

Respectfully, in P."Plant ManagerByron Nuclear Generating StationBPY/ZC/eh Attachments NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIlTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoe CoxIENV SPECDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IIL0048313 PERMIT NUMBERA01-0DISCHARGE NUMBER[ MONITORING PERIODswwwwI MrDEMINERALIZER REGENERATE WASTE (001A)External Outfall***NODISCHARGE EJFROMI02/01/2013 ITO02/28/2013 IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER

-- OF_ _ __ __ __ _ SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS E TYPESolids, Total Suspended SAMPLE 2.2 2.3 19 0 01/30 08MEASUREMENT Effluent Gross w oChromium, hexavalent SAMPLE ...(as Cr) MEASUREMENT SIX0Effluent Gross R .M1 Mai" W- =1-_. AChromium, total SAMPLE(as Cr) MEASUREMENT Soo... ...o * .9.- -f"U. Cj.. ---Effluent GrossmaCopper, total SAMPLE(as Cu) MEASUREMENT

5000104210Effluent GrossIron, total SAMPLE.......

(as Fe) MEASUREMENT 0104510 .~ 'rr~ (A *j. -~Effluent GrossLead, Total SAMPLE(as Pb) MEASUREMENT.

50Effluent Gross. ... .. .... ..."n .. ,..Nickel, total SAMPLE ...(as Ni) MEASUREMENT 500Effluent Gross NAME/TTR.E Icandy under pennfy d law that Oft document and afl attachments were prepardLunderNmyDATE PRINCIPAL EXECUTIVE OFFICER dUtecaton or seupevisa In accordance with a system desged to assure thia quaified personnel prTpNey gather and evalue Vie uiom ation suWmed. Be on my lnqLt d t persco or persons 815 DATEBenjamin P. Youman who manage te system, or those piesonm dweoy mspwont for gathe Vn .Vh 03W26/2013 bdonimnm Is, to the best a my and be iel. t ,rue accu, SaF PRINCIPLE coplte Iam_______PRNCIPL Plant Manager aware Va there are sIgnificant pensaies far subminOttig ltae kdonnatai WIudg the EXECUIT OFFICER ORinn and inWpsnmen for lowing violaons.

AUTHORIZED AGENT MMDDYYYYnsa. pma AU~ORIZEDAGENT coo ___COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hare)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow eidsted 28 of 28 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/682012 PAGE 1LUcCU)M:

0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DUR)PERM17TEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarenvtille, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, L 61010DMR Mailing ZIP CODE;MAJOR(SUBR 01) CS61010I IL0048313 PERMIT NUMBERA01-ODISCHARGE NUMBERI MONITORING PERIODMMIDD/YYYY

_____ MMIDNMYYDEMINERALIZER REGENERATE WASTE (001A)External OutfallI NO DISCHARGE EJ 'l .........

!FROMI02/01/2013 ITO021281013 I--iQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. F SAMPLEPARAMETER EOF TYPE> <VALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSISZinc. Total SAMPLE ... ........(as Zn) MEASUREMENT 0109210Effluent GrossFlow, in conduit or thru SAMPLE 0.057 0243 3 ..01.Benami5P7Vom0.243maag3th m 03212013 Etreatment plant MEASUREMENT Efneuent Gross e-d n ... bowIoat"o-s.

SAMPLEMEASUREMENT MEASUREMENT MEASUREMENT SAMPLEMEASUREMENT SAMPL.ENAMENTLE I CeEA lt under penO aAy, law dLthis (Rcumeen and at mtchmerns ere) TELEPHONE DATEPRImc'PAL EXECUTIV OFRCF-R dircton or sueso in accordlnoe with a syte dam~nd to assredud quagired persrnnel Benjamin P. Youmnan ;who manage the system, or those persons drectly responsble for gahf the the 40-7003/26=13 sude is..to, the be ol my lax he an U.=m aart. an compete I, amIS E OF Plant Manager aware thn there are soilicant peruitie lor sulxtittift fase iordarnffm, intu the possMt d EX1ECUTIVER 0FFCER OR AE UBRM/DYYni(PHRVE on finm e and hmpdsburen for lour~ft vlllos AUTHORIZE AGENT MCODEYYCOMMENTS AND EXPLANA71ON OF ANY VIOLATIONS (Referenc all attac:hments here)1. Flows for February 2013 ar estimated based on July 2012 values due to totaJizers being Out of Service.

The totalizars ar an obsolete model and work orders am in place to findreplacement totalizers and got them installed in the system.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 1/6/2012 PAGE 2mo0n NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWanrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoe Cox/ENV SPECIL0048313 PERMIT NUMBERB01-0DISCHARGE NUMBERDMR Mailing Zt.p CODE-MAJOR(SUBR 01) CSSTP PLANT EFFLUENT (FORMER 0018)External OutalilNO DISCHARGE-"

61010MONITORING PERIODMM/DDJYYYI MM/DD/YVYYY FROMI02/0112013 1 ToE02128/2013 II Il IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF_____PRMTRVALUE VALUE UNITS VALUE VALUE VALUE EX OFTYPE> < UNITSANALYSIS BOD, 5-Day SAMPLE(20 Dog. C) MEASUREMENT 0031010 -Effluent Gross 9PH SAMPLE..7.6

' 7.36 12 0 02/30 ORMEASUREM4ENT Effluent GrossSolids, total suspended ESAMPLE 0.50 0.67 26 9.0 9.7 19 0 02/30 24005301 0Effluent GrosstFlow, in conduit or thru SAMPLEtreatment plant MEASUREMENT 0.006 0.00p 3 res.on..b"e0 01/01 CNEffluent Gross.....

...- -*SAMPLEMEASUREMENT SAMPLEMEASUREMENT lnomtonsbite

.t it et at my .+ le :.'ledge an e, ..ti.re :+ .. ... " .., .

.... .cw.s.o.

ad.c....et.

am____-,-___

__ _ __ _..__ _SAMPLEMEASUREMENT C MMEnTS LE I ceAN under penaEL I law NtA I tO documenraned all attachmntras here)pared uder T HPWKWALEXE~~iu'WE0 lMcp te-tin a, amsim in acdac with a strn esmi~i~gec to assure that wualied iWewnnelBenjamin P. Youman who manage tMe spswM or Urme iosms directy mrimeodgi for galtefig Vie Waiai the86 0-30 0342612D13 infanafm subnitt~d is, to te bsoo fmy knowledieanclbefie, true, a¢uraw, and owniete, lain SGNfE Cr PFRINCIPLE,,

Plant Manager aware do t~here am penalfes for subidln false hibnalotatn, Ircludx the OFIERO AREANUERM//YY n~mm r~n an Imds~rnm fr AUTHORIZED AGENT CODE1. Flow exdsted through this oulfall 27 of 28 days durng this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/1/2012 PAGE 1m0m 0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITrEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenviie.

IL 60655-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR Mailing ZIP CODE-MAJOR(SUOR 01) CS61010,L0048313 PERMIT NUMBEREZZZCZZZZ MONITORING PERIODAMMIDDIYYYY WWVTP (FORMER ODIC)Exdernal Outtal"*NO DISCHARGE E *"FROMI02/01/2013 02/28/2013 IS QUANTITY OR LOADING QUANTITY OR CONCENTRATION N.FREQUENCY SAMPLEPARAMETER EXOFTYPE> <VALUE VALUE UIS VALUE VALUE VALUE UISANALYSIS "PESolids. total suspended SAMPLE N..... 8.2 10.6 10230 24MEASUREMENT 0053 10 A1.Effluent GrossChromium, hexavalent SAMPLE Soo(as Cr) MEASUREMENT 0103210Effluent GrossChromium.

total SAMPLE(as Cr) MEASUREMENT 0103410Effluent GrossCopper. total SAMPLE(as Cu) MEASUREMENT 0104210Effluent GrossIron. total ampL ...(as Fe) MEASUREMENT 0104510Effluent GrossNicead, total SAMPLE Soo.... 0(as Ni) MEASUREMENT Effluent Gr-oss ..

u....AMEn.eI catil under penmap eawo ft docturent and allatuachnue were prepared anerndy TELEPHONE DATEwapeft gathe and evalute the inonatioan submitted.

Based an mvy mqLftol ft permn or persons, 8'- i4,6-37,'

BenWan9n P. Youmnan hof mtanagie ft system, of mine paw~ns dirmctly responsl for' ,aftmMn the infontation, p,.r..L 0=26=113Irdornatin umite I s. to the baest anlyn kolati and bdl inse, acouate, and cwwlalte lain SGAR FPA LmPlant Manager fe idipso'4 IIow aware Me #we are stificsant penwtare = suabe Ifornisti.

lakln th posbhy d EXECUTIVE OFFCER OR AUARZEAGNT UME M/DYYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Refernce all attachments hem,)1. There was no discharge of processed steam generator chemical cleaning wastawater durng this month.2. Flow existed through this outfall 16 of 28 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1A/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITEE NAME/ADDRESS NAME Extlon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvile, IL 60655-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoe Cox/ENV SPECIL0048313 PERMIT NUMBERC01-0DISCHARGE NUMBERDMR Mailing ZIP CODE.MAJOR(SUBR 01) CSWWTP (FORMER 001 C)External Outfal61010 cmco)C)aI MONITORING PERIOD I I MMIDD/YYYY I .... ...-I' ......IFROMI0Zo0112013 TO0=1112013

' NO DISCHARGE J --II lQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETE-rR OFPAMLVALUE VALUE UNITS VALUE VALUE VALUE uN ALYSIS TYPEZinc, tol SAMPLE ......t...o(as Zn) MEASUREMENT 0109210Effluent GrossFlow, in conduit or thill SAMPLE --I3 --nf .. 0 101SAMPLEMEASUREMENT SAMPLEMEASUREMENT MEASUREMENT SAMPLEMEASUREMENT SAMPLEMEASUREMENT NAMElfT.E I certify under penally l law that the n en al e were p arpaed under myPRiNCIPAL EXECUlvE OFFICER dictn or supenison I accordnce wih a systn des" to assur tha TE ONE DATEProperty gather and evadtee the Waffoation submlted.

Based on my inquiry of the or persons ,rAiAa 815 406-3700Behn P. Youran who manage the syatem or mt. pomse descy mespnmsPbe lr gathering the Wnom --n. te 4012M13kIlatian aubm-led is, to the best my mowtedge and beNe, true. acurate, and comple. I am SIGNAIRE o PRINCIPLE Plant Manager aware ta there ae SniW Penalties for Sut" false bnrnnatbt m.rddng the pmsall of EXECUTIVE OFFICER OR AREATomm and irnpriouninet fr vioan AUTHORIZED AGENT CODE NUMBER MM/mD/YYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachmeants hem)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/612012 PAGE 2cC1=m NATIONAL POLLUTANT DISIRGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR MaIling ZIP CODE.MAJOR(SUOR 01) CS61010 mIL0048313 PERMIT NUMBER001-0DISCHARGE NUMBERMONITORING PERIODMJWYY MMIDD/YYYY I1111100yy RADWASTE TREATMENT (FORMER 0010)Extrmnal OutfallFROMI02/01/2013 1 TOl0240=13I* *NO DISCHARGE M- ..--lnC NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMiTTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarnenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010ATTWJ 7 fwIkiI D-DMAR Mailing ZIP CODE.MAJOR(SUBR 01) CS61010 U0IL0048313 PERMIT NUMBERE01-0DISCHARGE NUMONITORING PERIODMMIDWIYYYY L_ MM/DDJYYYY STORMWATER (FORMER 001E)External Outfall*.. NO DISCHARGEE JFROM]V02(0112013 ITOl02/28/2013 II ll lS QUANTITY OR LOADING QUANTITY OR CONCENTRATION N.FREQUENCY SAMPLEPARAMETER

[ > A U A U NT A U A U A U NT XOF TrYPEVALU VALE VLUE ALU VALE iANALYSIS Solids, total suspended SAMPLEO~f~ethGrosslt.Pocs (as Cu) MEASUREMENT 01053010Effluent GrossSolids.,

total s peddSAMPLE

.....[as Cu)MEASUREMENT anocs e.aComplete MASEENBmenja i P.os ......m.nae..hes..te.

a hs -oison dired -- ruo .b to gat.enn...i.....o--atl-.

.03/26-201 Crmu, total SAMPLE .o.s. odgn.. a(as Pb) MEASUREMENT Effluent GrossM n ea ae ht e,. nh an e.. ...u.t. ... ...............

..EO I.O....COMNTSAND1.EXPAAIO OF~ ANYe VIOLATIyONS (Referendcem all attacments hem)peae

.hreium.

wotasllchE OF procssed stAMP gen chemalceaning s aste water dute month.2. FTohersed thr og thisc outarge of p 28essdaystemgnrtrceia laigws e during the month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 116/2012 PAGE 1]

NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010Af"TIJ 7nofl,Wst.vlMUL '1DMR Mailing ZIP CODE.MAJOR(SUDR 01) CSI 1L0048313 1 IE01-0I !I PERMIT NUMBERI I DISCHARGE NUMBER1MONITORING PERIODE MIDWYI MMIDWIYYVY 61010 MC2)CDSTORMWATER (FORMER 001E)External Outfall* *' NO DISCHARGE

""FROIl02101/2013 I TOI02/2812013 Il JI IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPENickel, total SAMPLE(as Ni) MEASUREMENT 0106710Effluent GrossZinc, tow SAMPLE(as Zn) MEASUREMENT 0109210Effluent GrossFlow, In conduit or thru SAMPLEtreatment plant MEASUREMENT 5006010 1., .. cvs-Effluent Gross SAMPLEMEASUREMENT

_ ___SAMPLEMEASUREMENT SAMPLEMEASUREMENT t?SAMPLE lil tMEASU REMENTkAMF.~m.E I una al law that On document and aD atchments pr d my TELEPHONE DATE.XEcUnnWE OFFCER direcatn or supervvisi In accordance r th a system desgned to assure that quatfied pesatnaepropety gather and evalte the IWnlonon subnitted.

iosyhe peunpai a 815 "406-3700P0rson1 Benjamin P. Youman who manage the sysiem. o those peasans dikr* resomsnLbl or gathering the bdonnutis.

Me 032013mlonnati sa ied Is. to Vie bestS my awaedge and beldS. two. =caste. end owat. lam SIGNAIYT V O RI CIPLEPlant Manager aware da there am significasn penaties tar submtg alnse ai onamsn. bc0ianI the posýy St EXECUTE OFFICER OR AREAInman -1 finae and imptsionment for Wowing viadedos AUTHORIZEDAGENT NUMBERCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reerence all attachments here)I. No Closed Cooling System Drain Water was discharged this month.2. No Service Water System dra-n water or Fire Protection drain water was discharged this month.3. No Turbine Buildin Fire and Oil Sump or Generic Non-Chemical Cleaning wastewater was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 28=m NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarsenville, IL 60555-5701 FACILITY Byron Nucdear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR Mailing ZIP CODE*MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBER001-0DISCHARGE NUMBERMONITORING PERIODMMIDD/YYYY MMIDWYYYY COOLING SYSTEM BLOWDOWNExternal Outfall* NO DISCHARGE FROM I02/01/2013 I TOI02/2812013 ATTN: Zoe Cox/ENV SPEC FREQUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FRSAEQ CPYPAAETROFPARAMETER

[ VALUE VALUE UNITS VALUE VALUE VALUE UNITSANALYSIS TYPETemperature, water deg. SAMPLE ............

...... 78.3 15 0 01/01 CNFahrenheit MEASUREMENT,' , ' ' :'Effluent Grosso wpH SAMPLE --- 8.47 8.68 12 0 01/07 GRMEASUREMENT 0040010 .r --&.r-.-Effluent GrossSolids, total suspended A E6 56 19 0 01/30 ROi & Grease SAMPLE -.5 1.7 19 0 01/07 GRMEASUREMENT 00566 10Effluent GrossC_,o'aiurm, total (as 0.0021 19 0 01/07AGRMEASUREMENT

...001170103410Effluent GrossCopper, total (as Cu) SAMPLE .500MEASUREMENT

.. 00104210 -A~%, ~ --"' ' %.1~Effluent GrossZinc, total (as Zn) 0009 0016 19 0 01/07 OR0109210 7W.A. n-.Effluent Gross=EfLE I cartiy uidet penalty ot law tha the document and all attachments were prepared uinder my TLPOEDAWF PRMPAL EXECUTVE OFM dclon or supenvi~o In acconsance with a system des to assure that qualified pwera'dpiperly gather and e u the itonnmadan auft tted. Based on my nquiry o fte peorson of Nam4ns37Benjamin P. Youman who manage the system, or thme persons drectly spoxWae for gattering the notniabon.

the 03/26/2013 Infonnatlon subNotted

a. to the beat o my Iknowedge and belif, trUe. sccuran and o=0"te. I am WSN UEC7 PICIPLEEPlant Manager aware at them are s!naM penas for sWnng false WnarmatftL Kding the poasility o EXEbEJFFICEROR 1vpWa -1 p , and muns~rmen for kwi vioabons.

AUTHORIZED AGENT coo NUMBER MMIDD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Monitoring data for outfall 001-0 is included on attachment EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 1Cn NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITrEE NAME/ADDRESS NAME txelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvile.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010DMR Mailing ZIP CODE.MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBER001-0DISCHARGE NUMBER iMONITORING PERIODMMIDD/YYYY

_MWDWYYYY COOLING SYSTEM SLOWDOWNExternal Outhdl* *' NO DISCHARGE E".'.FROMI02/0112013 I TOI02128/2013 Il I1I lAt I I rv: 40 OW tEoJNlV XQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY OF SAMPLEPARAMETER VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OF TYPEOxidants.

total residual MEASUREMENT

.... 0.05 19 0 01/07 GR3404 10-n.r...r I -0Effluent GrossPriority pollutants total effluent SAMPLENT5000810 ." " " .Effluent GrossRow, in conduit or lhnu SAMPLE 20.1..26.33 3 -0 0treatment plant MEASUREMENT 50050 10 Mt -.~.~*~4 .~~'Effluent GrossChlorine, total residual 5AMPLE ...... o00MEASUREMENT 6131310 .... k... i-Effluent GrossHyraUe APLE 500MEASUREMENT SAMPLE -MEASUREMENT PRxIN IAl IEX :CW11VE o FwICEF dlreetsin o ' supwvlsson in accosdance wiC a sia desge to assure stha qualilted peorisorl

___ _ _TE EP ON DATEproesly gasheand evaluese mtonal~m sunnissad Bad s dmy biuhSthe pesnioapeace 1<1 0630Benjamin P. Youman wiso e shse SUn5 or those pemass dhreosy m&G1M for game9thein SIGNA p~E OF P 03/26/13Plannlaaasesalaiaon submiftd t,. to She best of my knowledgde and baioS. trim. acosret, and casplta I a _aiPlnaaae ware that mhere are ahgnrnlcam peaies for autrssn aiseO Isslomiaio, nag m0he poesi~sy~

s ~ :IIE 0F fER OR AREA !NUMBER M/DYYow peatia fe and ipbnvtlnmn for Imowina violaions.

AU11hORIZED AGENT C.ODEMI~YY COMMENTS8 AND EXPLANATION OF ANY VIOLATIONS (Refernce all attachments here)EPA Form (Rev 01/06) Previous editions may be used.1/202PG2 NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DUR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, iL 60555-5701 FACILITY Byron Nuclear Power StationLOCAlION 4450 North German Church RoadByron, IL 61010I1lUX48313 I ---Ill.002-0DISCHARGE NUMBERIiDMR Mailing ZIP CODE.MAJOR(SUBR 01) CS61010I PERMIT NUMBERSTORMWATER RUNOFF BASINExternal Outdallm0nIMONITORING PERIODII M/DWYYYYI TO[MMIDO/YY-iFROM I02101/2013 02r2SM13*** NO DISCHARGE a] ..I IO UIANTIITY OR LOADING QUANTITY OR CONCENTRATION N.FREQUENCY SAMPLEPARAMETER OF_____PRMTRVALUE VALUE UIS VALUE VALUE VALUE OFLYI TYPESAMPLE .......Solids. Total Suspended MEASUREMENT 00530 10Effluent GrossSolids. Total SuspendedSAPE...

Chromium, henavalant SAMPLE ......(as Cr) MEASUREMENT 0103210oEffluent Gross qChromiu, total

,.....1(as Fe) MEASUREMENT Effluent Grossc ra w -o n .w pp o .d.mCopper total SAMPLE(as Cu) :MEASUREMENT Effluent Gross ... .EPEgNcIPAL EXEC~fllVE OFFICER cremcttn or aup~er~skm bi acoance with a syasem des~gned to a~sasur reat quaffed persstnel r ___gahe an evaue th bronntw eae an minquiry t the peso or pe 'ru ", ,,sBejrinP oua s li, lm m ead ~l U manage the sysan., or those pem dircty rospatit fo gatherng the Intonnal.

th lan

'0/621Plant Manager swas ma these ass siitn pewe for aubnritirg false inoIm.sn me P~ssUY EXECUIWVE OFFICER OR NUMBER IMMIDDIYYYY COMME.NTS AND EX(PLANAT1ION OF ANY VIOLATIONS (Reference all attachments here)1. No Tudeine Building Fire and Oil Sump or Generic Non-Chemical Metal Cleaning Wastewatar was discharged thi month.2. No Fire Protection.

Service Waler or Closed Cooling System Drain Water was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11612012 PAGE 1 0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

U 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR Mailing ZIP COOE:MAJOR(SUBR 01) CS610101L0048313

-PERMIT NUMBER002-0DISCHARGE NUMBERMONITORING PERIODMMIDDJYYYY I I MMIDD-YYVY STORMWATER RUNOFF BASINExternal OutfallI

• NO DISCHARGE ...III" .........

FROMI02/01r2013 ITOU2/2/2013 IP M QUANTITY OR LOADING QUANITIY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SAMdPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX A Y TYPEANALYSISNickel, total SAMPLE. ...... .....(as Ni) MEASUREMENT Effluent GrossZ11c. total SAMPLE(as Zn) MEASUREMENT

_____0109210___--...

-.*.'t"Effluent GrossOil and Grease M AMPLE ,. ,, ,,,,.MEASUREMENT 063582 10Effluent GrossFlow, in conduit or thri SAMPLEtreatment plant MEASUREMENT Effluent GrossSAMPLE ""'MEASUREMENT SAMPLEMEASUREMENT

.... .*t............'

-4SAMPLEMEASUREMENT NAMETIT1L.E I cenriy under penalty of law that is documeot and all attadmmmers wor prepared wide my TELEPHONE DATEPNIAL EXECUIlVE OFI:CER direomn or supevsion In accordance with a system dsged to assure its qualiied personnel prolgather and evathe Information submtted.

Based on my inquiry S the person or Per.ons815406-3700N03128/2013 Benjamin P. Youan wh manage the system. or those persons d~rect reponrae for gathering me the 03A2M213Informalion

&ubetod is. tot e best of my knowedge and befel. tare, accurate and caoplte.

am I RINCIPLEPlant Manager -taw red tere ar slicant penatltes for submtitIng fale Inc wudhg the o EXEC =rEVFCER OR,I tne and krpdslonnient for kneeinag vldations.

BRM DYvnPanmem R IM AUTHORIZED AGENT CODE NUMBER ___ DD/Yt ___COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. This discharge point was not used this month.2. There was no discharge Of Processed steam generator chemical cleaning wastewater during the month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 1/1/2012" PAGE 210C)

ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 February 2013Page I of 2MONITORING DATA:WBD CRock RiverDATE Temperature mgd Flowdeg F cfs02/01/2013 65.3 20.28 1330002/02/2013 69.7 23.64 1350002/03/2013 66.0 20.00 1470002/04/2013 68.3 15.26 1490002/05/2013 74.5 20.77 1430002/06/2013 74.5 18.78 1450002/07/2013 72.8 23.83 1430002/08/2013 72.8 18.08 1320002/09/2013 72.8 24.85 1260002/10/2013 75.3 20.16 1250002/11/2013 75.3 16.74 1540002/12/2013 68.6 19.62 1560002/13/2013 68.6 19.29 1530002/14/2013 78.3 21.55 1450002/15/2013 74.2 18.42 1170002/16/2013 67.9 26.33 896002/17/2013 67.9 20.17 909002/18/2013 76.4 15.18 848002/19/2013 76.4 23.65 913002/20/2013 64.1 16.80 733002/21/2013 71.5 19.83 698002/22/2013 74.1 20.92 1340002/23/2013 74.1 24.90 1320002/24/2013 70.8 20.02 981002/25/2013 75.6 15.29 639002/26/2013 75.6 24.28 567402/27/2013 75.6 16.40 492002/28/2013 75.6 20.44 4770K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2013\FebruaryWebruary 2013 ATTACH01.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit 1L0048313 February 2013Page 2 of 2HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (or associated rinses) containing hydrazine discharged to the Cooling System Blowdownduring the month of February 2013.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochiorite and Bromine compounds were used this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 28 of 28 days.4. Per Special Condition 24 the influent from the Rock River and effluent fromOutfall 001--0 was monitored for Total Suspended Solids (TSS) this month.The Rock River TSS value was 160.7 mg/L on 02/11/2013.

The CWBDTSS value was 5.6 mg/L on 02/11/2013.

5. Rock River flow for February 2013 was >2400 cfs therefore dailytemperature calculations were not required this month. (Special Condition 12).6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in February 2013. (Special Condition 15).K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt2013\FebruaryWebruary 2013 ATTACHO1.doc Exelon.Exelon Generation

Company, LIC www.exeloncorp.com NuceByron Station ear.445o North German Church RoadByron, IL 61010-9794 April 18, 2013LTR: BYRON 2013-0049 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyBOW CAS #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring ReportIn accordance with National Pollutant Discharge Elimination System (NPDES) Permit NumberIL0048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report forByron Station, Units 1 and 2. This report covers the period of March 1, 2013 through March 31,2013.If there are any questions regarding this report, please contact Ms. Zoe Cox,Environmental/Radwaste Supervisor, at (815) 406-3035.

Respectfully, Plant ManagerByron Nuclear Generating StationBPY/ZC/eh Attachments BEST COPY AVASLA VPERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenviie, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)OMR Mailing ZIP CODE'MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERDI S A01-0DISCHARGE NUMBER[ MONITORING PERIODMMIDD/YYYyI MMA)DDYYYV DEMINERALIZER REGENERATE WASTE (081A)External Outhfll* NO DISCHARGE EJFROMI03/01/2013 TOI03131/2013 IByron. IL 61010ArlN: Zoo CoyJENV SPEC ______________

___________________

___QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF 8MLVALUE VALUE UNITS VALUE VALUE VALUE UNIT EX TYPESAMPLE...

.........

<0.8 <0.9 19 0 01/30 08Solids. Total upened MEASUREMENT 00530 10 , p T T -Effluent Gross .m-4 ý~AtChromium.

hexavalent SAMPLE ... ..(as Cr) MEASUREMENT SooEffluent Gross awn.___,

f'-,Chiromium, total SAMPLE ...(as Cr) MEASUREMENT So-0103410 14 j7.~Effluent Gross -Agj ~ '-Icopper, total5P0(as Cu) MEASUREMENT 500Effluent Gross n. .......,-- ,?..Iron. total SAMPLE ..... .(as Fe) MEASUREMENT 5000104510 .-&" .. ..,,-Effluent Gross ...:. ,. __, ___ -' 7. ... ,Lead, Total SAMPLE If* ....(as Pb) MEASUREMENT0 0105110 .4'.'-mi

.,,.DavEffluent Gross Z. R. ....~. -, -.... __. ,._Nickel. total PLE ..........

.. .... .....(as Ni) MEASUREMENT, 5000106710 B '. IMPEffluent Gross 1. 1. 41411 '- ~ .~ DILNAHEnTrLE I cetny under penalty of law that thi document and a atachments were prepared under my TELEPHONE DATEPRPICIPAL EXECUTIVE OFFICER direct OFUP in in accdance a system designed to assure that qualified persmWl *Benjamin P. Younan ,who manage the system, or those persons directly respon.be for gatheamg the Wao.at8n.

the 04/182013 informtirato submitteid is. to the besw of my lotowiedge and belief. true. accurate.

and complete.

Iam SIGNATURE 0 ORINCIPLE

___Plant Manager aware tht0 there are signricant penalts for soubiting false Wlomaimn, hudKWg the Possibity d EXECUTIVE OFFICER OR AREA NUMBER MMIDWYYY.. an aMe and imprilionmerndtor owin violmions AUTHORIZED AGENT CODENCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow e)dsted 31 of 31 days during this month.EPA Form 3320-1 (Rev 01/08) Previous editions may be used. 1/612012 PAGE 10 B3 COPY AVANLA8L' PERMrrTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarranville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 610100NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)DMR Malting ZIP CODE:MAJOR(SUBR 01) CS61010I IL0048313 PERMIT NUMBERA01-0DISCHARGE NUMBERMONITORING PERIODUMDO/VYVY MMIDDJYYYY DEMINERALJZER REGENERATE WASTE (001A)External Outaell* "NO DISCHARGE

[-] .lFROMII03101/2013 TI o03/31/2013 I-Il lQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS ( ANALYSIS TYPEZinc, Total SAMPLE ..........

u...... 500(as Zn) MEASUREMENT 0109210 .:3,_ .. '/ "" -" Effluent Gross ... -A. .. .,'*,, .. ... ---" ___Flow. In conduit or thru SAMPLE 0.057 0243 3 .. 0 01/01 EStreatment plant MEASUREMENT 500501 0 q. q. g.to-E~ffluent Gross 'jjjý -______ ýo .. ~ ... ~ '.*..*..

.....:. .. ... .SAMPLEMEASUREMENT MEASUREMENT MEASUREMENT

.: ..........

.... ................4 , ,. ..;: .. .4, .SAMPLEMEASUREMENT V ...,l , ..4 P .;: ~ & & 2._ _. 4.. ....-_ _ -SAMPLEMEASUREMENT NAME/TITLE I cay under penalty l law that this document and alI attachmentS wre prepared under W TELEPHONE DATEPRINCIPAL EXECUTIVE OFRCER directo or supervsio in accadwne wM a System desigTed EP aHON Eat quaDilAm pTnEelproperty gather and avalte the Wniation subrmied.

Basedl on my inquby d the peosn or persons J, 815 406-3700Benjamin P. Youman who manage te system, or fhse persons responsible for gathr" the intdoratlon.

theIPLE 04/18213inlonmaliat submned Is to the best ol my knomledge and beliet, true, accurate, and complete.

lam bIGRWHEOFrJII__

Plant Manager aware thal there are significant palies sbnb false tftotnat.

bt Incluig the pilby of EXEdUTIVE OFFICER OR AREA NUMBER MMIDDJYYYY WOA Rp le and lnowing vltoltlms, AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)1. Rows for March 2013 are estimated based on July 2012 values due to totalizers being Out of Service.

The totatizers are an obsolete model and work orders are in place to findreplacement totalizers and get them installed in the system.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/612012 PAGE 2 BEST COPY AVAILABLE PERMITFEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenviUe, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North Gennan Church RoadByron. IL 61010NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)OMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010I L0048313PERMIT NUMBERB01-0DISCHARGE NUMBERMONITORING PERIODF MM/DDJYYYY L- m~oMID/YSTP PLANT EFFLUENT (FORMER 0018)Extenal Ouffall' NO DISCHARGE FROMI03/01/2013 J TOI03/31/2013 III BE*COPY AVAILABRV.

PERMITrEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvilie.

IL 60555.5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 610100NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)DMR MaIling ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERC01-0DISCHARGE NUMBERMONITORING PERIODMMIWDIYYY

_J I MMIDDVYVYY WWTP (FORMER 001C)External Outfall' **NO DISCHARGE FROMI03101/2013 I0103131/2013 II aATTN:QENC ZooCMPLE PEQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FFEQUENCV S PPARAMETEROF AMLVALUE VALUE UNITS VALUE VALUE VALUE UNrIT EX ANLYISPEANALYSISSolids, total suspended SAMPLE .........

5.A 7.2 Is 0 02/30 24SMEASUREMENT

......Effluent Gross --4Chromium, hexavalent SAMPLE ...... S00(as Cr) MEASUREMENT_500 0103210 -- -Effluent Gross EVA"Chromun.

total SAMPLE SIX.(as Cr) MEASUREMENT 50001034 1 0 '.... , .- -" " -" " --J -,".. .fla. ..' .....Effluent Gross ____Copper, total SAMPLE ........

........00(as Cu) MEASUREMENT_50_

0104210 -,-1Effluent.Gross.-

- "..:.Iron, total SAMPLE ...... 500(as Fe) MEASUREMENT__

Effuent Gross -~~~~~-~

~-Lead. total SA.... ...(as Pb) MEASUREMENT 50001051 10 ~ ~ pt___ ~ -' ~ ~Effluent Gross J~l ..- .Nickel, total SAMPLE ....(as Ni) MEASUREMENT SooEffluent Gross ,JIll mx,. .4t- i ---. --. -NAME/TrI'LE I ceWsj unere penally of law thatthis document and all afttahments were prepared under myPARINCIPAL EXECUTiVE OFFICER direction or suervsion in accoarance Wtth a systemn designed to assure that qeafed ersone TELEPHONE DATEBenjamin P. Youman who manage the System, or thane persons directly respnsble fmr gatherItg the birma on. W1he2013Wonaeban sulmitted Is, to the best oa my knotedge end befief, tnue, accurate.

and ompilet.

I am OF OUCIPLEPlant Manager aware that there am significant penates Ifo submitting lale Infomationa, Icluding the PGSbm d EXECUTIVE OFFICER OR AREAiwsn o n -Ase b _e and _ mp_ _ _ _ _ _ _ _ _ for _n v_ __a_ __. AUTHO RIZED AG EN T CODE NUM BER M M /D D/YYYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed through this outfail 17 of 31 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editons may be used. 1/6/2012 PAGE 1 BEST COPY AVAiLABLeF PERMI7TEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)DMR Mailing ZIP CODE,MAJOR(SUBR 01) CS61010I IL0048313 I PERMIT NUMBERC01-0DISCHARGE NUMBERI MONITORING PERIODI MM/DDYYYY I I MMrDDIYYYY WWTP (FORMER ODIC)External OutfallI *" NO DISCHARGE ED ...I II _ IFROMI03/01/2013 I TOl03/31/2013 Byron. IL 61010ATTN: Zoo CoxIENV SPEC_______________

_____________________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER EX OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS E ANALYSIS TYPEZinc, total SAMPLE ....(as Zn) ME.ASUREMENT 01092 1 0 ** ~, --... ... ........~ ..dl' .'*..Ewffiuent Gross ;'g.Flow.Inconduitorthru SAM 0025 0.046 3 0 01/01 CNtreatnent plant MEAREMENT 500501 0 Ui.. 'fv& .Effluent Gross F 1 .1 W all-~~SAMPLEMEASUREMENT SAMPLEMEASUREMENT SAMPLEMEASUREMENT SAMPLEMEASUREMENT SAMPLEME ASU REMENTNAMFnTn.LE certify under penafty of law that dus document and al aladhmwnts were prepaed unwder my TELEPHONE DATEPAINPAL EXECUlIVE OFCFIER directlon or superveion In accordance with a system designed to assure that qualiied pesmonnel popefy gathe and e#a It ft iroimalia

,ubmed. Based an my Inquir 01 tha pero o _ 04/18/2013 Benjamin P. Youman wino manage tne systerm, or tmse perons direcuy responsIe br gahern the Information.

the 8 15 406-3700 04/18,13Iniomntm submitted Is. to Me beat 01 my knoW g and belief. true, accurate.

and Cmplee. I am SIGAp#. OFP#NCIPLE Plant Manager aware that teare a pn tor sulbmitig false Ionnafmin.

mdtuding Me posslly EXECUIJVE OFFICER OR AREANUMBER

/DDYYYtlu end Inprislonment for wmowln vileatlons.

NMEIMIDYY r'IM OR PndsMf AUTHORIZED AGENT ]CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference al attachments here)EPA Form 3320-1 (Rev 01/06) Previous edtions may be used. 116212 PAGE 2 0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)0PDýJSQPYAVAOLAB10.

NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4480 North German Church RoadByron, IL 61010DMR Mailing ZIP CODE-MAJOR(SUER 01) CS610101L0048313 PERMIT NUMBERD01-ODISCHARGE NUMBERMONITORING PERIODMUIDDIVYYY I MM/DD/YVYY RADWASTE TREATMENT (FORMER 001D)External Outfall* **NODISCHARGE D ...FROM I03/01/2013 I TOI 03/31/2013 INAMEIlhlTE PRINCIPAL EXECUTIVE OFFICERBenjamin P. YoumanPlant Manager1iFmOA , NmmEDI ceti"y under penalty ol law that his document and all attachments were prepared under mydirecion or superviso In acordance with a system designed to assure Utat qWalified personnel property gather and evalute the information subminted.

Based on my Inquy of the person or personswho manage the system, or tose persons responsie tor gateng the intonmatlon, theInformation submitted is. to the best of my knowledge and bedef, tnre. accurate.

and complete.

I arnaware that tere are sirllcarn penalties lor submitting false intonrmaon. g ft possWEt ofrme and Imprislonment for nowing violations.

AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)F. low existed through this outfall 10 of 31 days during the month.

BEST COPY AVAILA.,_.

PERMIrTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. UL 61010NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)IL0048313 PERMIT NUMBERE01-0DISCHARGE NUMBEROMR Mailing ZIP CODE.MAJOR(SUBR 01) CSSTORMWATER (FORMER 001 E)External Outfall61010IMONITORING PERIODI MMIDD/YYYY I I MMADD/YYYY

! II __ _ IFROMi03/01/2013 I TO103131/2013 I* NO DISCHARGE F-1 """-I IATTN: Zoo CoxIENV SPEC_____________________________

__________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TPVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OFYTYPESois oa up ne AMPLE ..".. .............

.... So"o"50Solid, total suspended MEASUREMENT 00530 10 .15~~- ~ .~.t~~' tladEffluent Gross 1T 0,,pops_..

." .." .Solids, total suspended MEASUREMENT 2.3 2.6 Is 0 01/07 ORChromium, hexavalent SAMPLE 500.. .....50(as Cr) MEASUREMENT Effluent Gross ____ ,Chromium, total AMPLE ........(as Cr) MEASUREMENT 0103410 ! .....av 4....Effluent Gross -" .Copper, total SAMPLE SIX.(as Cu) MEASU REMENT0104210 1. .... I... A ... , .5 1 , ."" "Effluent Gross -mims i 2 1a ~~ awIron, total SAMPLE ............

.....(as Fe) MEASUREMENT

_"_5000104510 Dg. ktL : 'Effluent Gross ;" , ne0,i, .

'.".-Lead, total SAMPLE ....... 500(as Pb) MEASUREMENT 01051 1 .

-Effluent Gross ":'- QC"4': -4 , " ...... :-_ AME_____E I c__tty under al of law OW Oft docurnent and all efachnmnts were prepared under my TELEPHONE DATEPRUCPAL EXECllVE OFRCER __ econ or supevson In acordance wth a system designed to assure that qualified pe.onne_propety gte and evalute fte tWmaoa subintiad.

Based an my Inqury of Me person o personsBenjamIn P. Youman who manage the syem or those petswis dnchy responsible tar gather the Itnration.

the 04/16/2013 Inration submitted is. to Ba beat of my knowledge and belie,. ue, accurate, and I am SIGNATU§I OF P PLEPlant Manager aware that Bare amre snrcant pMenast toa subnihng false infonnaon, intdin the p Ysaw wo EXECUTIVE OFFICER OR AREAan hMm fine and bipiW'iit for no'wing vaioaions.

AUTHORIZED AGENT CODE NUMBER MMD_/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Them was no discharge of processed steam generator chemical cleaning wastewater during the month.2. Flow existed through this outfall 2 of 31 days during the month.3. Fire Protection drain water was discharged this monthEPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 1 BL1 COPY .V 0:' .,PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvilie, IL 60555-5701 FACILITY

-Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)DMR Mailing ZIP CODE*61010IL0048313 PERMIT NUMBERE01-0DISCHARGE NUMBERMAJOR(SUBR 01)CSI MONITORING PERIODI MMIDO/yVy I I MMIDDYYYY STORMWATER (FORMER 001E)Extenal Outfell* NO DISCHARGE EJI II .... ..... IFROMI03/01/2013 I TOI03/31/2013 II Il !"I.

BEST COPY AVADLA1BLE PERMITrEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010I IL0048313 PERMIT NUMBER001-0DISCHARGE NUMBERMONITORING PERIODMM1DWnYYYYI MMIDDWYYYY COOLING SYSTEM SLOWDOWNExternal Outfall***NO DISCHARGE E 'FROM I03/01/2013

.TOI03131/2013 l III IByron, IL 61010ATrN: Zoo CoxIENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS E ANALYSIS TYPETemperature.

water dog. SAMPLE ...... ....... 79.0 15 0 01/01 CNFahrenheit MEASUREMENT 00011 10 iw~ " ~ e~ --lv~~~O~MEffluent Gross. .... .pH SAMPLE N.8.41 8.62 12 0 01/07 GR;)H MEASUREMENT 0040010 A. ...6 ,. 19 0REffluent GrsW ..Solids, total suspended AME6 56 19 0 010 ORMEASUREMENT_______________

______00530 10 -,Pmp&Mtn iE~ffluent Gross .~-.Oil & Grease SAMPLE ............

....... <2.0 3.8 19 0 01)07 ORMEASUREMENT 00556 10 PtjEffluent Gross NIX' .... .-*,1-., .' .. ....... .tf ...l.......At.. .l .,. .:. .AMPLE ...... ... ... <0.0021 19 0 01/07 ORChromium, total (as Cr) MEASUREMENT 0103410 "" ... .,2Copper, total (as Cu) AMPLE ...... ........

5MEASUREMENT""50 01042 10 .." ..... ....EffluentGros

-41 m_____:V

~~.___Zinc. total (as Zn) SAMPLE ...... ...... 0.... 0.009 19 0 01/07 ORMEASUREMENT"0.60.9 19 01/7G0109210 o ...E ff l u e n t G r o s s : -' .' ; ' ..', .4#, ...- " "'.MEnTLE I ceay under panaty od law thta ts documea and AD attachments wetre prepared under my TELEPHONE DATEPRINCIPAL EXECUnVE OFFICER dimbctin or supeorsin In acmcrdance with a system designed to assure owm qua1led personDAl pmpety gater and evakute information submitmtd.

Based n my inqui d te person of personBenjamin P. Youman w manage the system, orthosepeisons drectlymrMesporgaheingtheWmannatmln 04/18te13 mlonrnabon suwtsnfed is. to the basst r my Maledloage and baelef tnwo. amcurae, and coniplete.

I am SIýGNA EOF P M.E 0/821Plant Manager aware Mat there we sgnfca penalties for s&u b g fale Infonnation.

icktding tMe possitlity d EXEC E OFFCER OR AREAER MMIDDYYYY ED OR ON ,the and 5ICfsmflwit for Icnowing vlalm AUTHORIZED AGENTENCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hwe)1. Monitorng data for outfall 001-0 is included on attachment

!EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11612012 PAGE 1 BES .OPY AVAOLABLE PERMATTEE NAME/ADDRESS NAME Exulon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010ATTN: Zoe Cox/ENV SPECNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)IDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IIL0048313 Il`--I001-0I1I IfWCrMI I 5' nuro-IIUIQPrvInUEWCIUMVIDEn

!MONITORING PERIODMMIDDIYYYY I I MMIDDJYYYY COOUNG SYSTEM BLOWDOWNExtermal Outlall611NODISCHARGE r iFROMI03/01/2013 TOI03/31/2013 Il IIk pQUANTITY OR LOADING QUANITFY OR CONCENTRATION NO.FREQUENCY PAAEERIN.

OF SAMPLEP I VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPEOxidants.

total residual AMPLE ...... ...... ......0.04 19 0 0107 GRMEASUREMENT

0.0 4__9_0_01__7_GR

340441 0 ! ! ,j, : ...-..mp......

Effluent Gross :in1II-.

'"Priority pollutants total effluent SAMPLE ...... SooMEASUREMENT

_____________

05000510Effluent Gross -EJ,., ' -:-Flow. in conduit or thru SAMPLEtreatment plant MEASUREMENT 5005010Effluent GrossChlorine, totail residual SAMPLE ..... .Soo....MEASUREMENT H-ydrazine SAMPLE .........

MEASUREMENT 5008,13131 0 , ..:, ,,_,.." ,0 1 * : :

..." D ' .... W ke Effluent Gross WIT,: "*,.SAMPLEMEASUREMENT SAMPLEMEASUREMENT I/AME/trrLEcear uncer permaty l aw that true doc~unein anm auJ atanac ents wegre prepared unm rrmyPRINCIPAL EXECUTIVE OFFICER diection or supealon n acc=dance wth a systemn desned to aasans that quaatfe

% TELEPHONE DATEBpejezy agather evaute the Wnn3matln SMd. ased On OyW It d the 815 406-3700 peBenjamin P. Youman no me" the system or those persons dircly respoe for 0gatheUmt f te thG RNCIPLE01he Plnt Manaeron subesnfed Is. to the best o my ImwledPe and b10e1. tWe. accurate, and complete, I em U- .04/18 13P awanIMaagrere a a ea o lt UTIVEreCER OR 4F NUMBER MM/DDtYYYY MI 1 fine and irsionrnient for kwwinot vioatim s AUTHORIZED AGENT CODE NUMBER I__________

COMMENTS AND EXPLANATION OF ANY VIOLATIONS (RefeMnco all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1162012 PAGE 2 BEST COPY AVAILALr' PERM7T'EE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Wintield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)IL0048313 PERMIT NUMBER002-0DISCHARGE NUMBERDMR Mailing ZIP CODE:MAJOR(SUBR 01) CSSTORMWATER RUNOFF BASINExtemal Outfal* 16NODISCHARGE Eji .J .61010IMONITORING PERIODiI MM/DD/YYYY ITO[MMIDDWYYYY IFROM I03/01/2013 03/31/2013 Il !& lByron, IL 61010ATTN: Zoe Cox/ENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPESolids. Total Suspended SAMPLE ......MEASUREMENT Effluent Gross ______ _____Solids, Total Suspended MEASURAMPLEN 0053080 -OthterTreatmnent Process 44 1. '-* ~Chromium.

hexavalen!

SAMPLE .............

e(as Cr) MEASUREMENT Effluent Gross ...,.,,Chromium, total SAMPLE ......(as Cr) MEASUREMENT 0103410 "... .. "Effluent Gross -i -. -W-. .., .' ., i .-..'" ,._,.Copper. totalSAPLE (as Cu) MEASUREMENT 0104210 ..,,,.Q411Effluent Gross cilia.,'. -..' " " _ " =-' L,Iron. total AMPLE ........(as Fe) MEASUREMENT_______

_ ___ __Effluent Gross 1/2 &- \ Ld + -Lead, total SAMPLE .... ........(as Pb) MEASUREMENT 0105110 ý. ... , ... 043.Effluent Gross MAN ___ ~ ,~INIPLAL FTILE I oatiy undr penaly of lw 00 thi documen and al a were prepared under my TELEPHONE DATEPRINCtIPAL EXC TV OFFIC-R drectilon or 5upervis m n 8=rdartc wit a syste desotd to assreO qua iie peromenn

% property gaMer and evaute the Information subrned.

Based my inquiry of the peim ofrs 8615s 4)-37Benjamin P. Youman who manage the system or those persons direcay rasponsae for gaitienng Me Infoimnatin.

Me 04/18=13informatim is, to the best of my Wwwleda and belef, tnue. accuate, and I am SIGNA ,"F PR LE_Plant Manager aware that tere are sinificant penalties for sutumitg false Informatio.

Inluding the possiblity d EXECULTIVE OFFICER OR AREANUMBER MMDDYYYYMID) OR PRWMD -1ftne and lmprisionnent tar kowtng vilations.

AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Metal Cleaning Wastewater was discharged this month.2. No Fire Protection, Service Water or Closed Cooling System Drain Water was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11612012 PAGE 1 B*CPY AVALAO[A!

PERMITrEE NAME/ADDRESS NAME Exeton Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvilte, U 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 610100NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)I IL0048313

]I PERMIT NUMBER002-0I DISCHARGE NUMBER1 MONITORING PERIODI MM/DDJYYYY I I MMIDDYYYY DMR Mailing ZIP CODE:MAJOR(SUBR 01) CSSTORMWATER RUNOFF BASINExternal Outfall* ' NO DISCHARGE

( ...61010I II .....FROM I03/01/2013 I TOI0313112013 1QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPENickel, total SAMPLE ...... ...... ......(as Ni) MEASUREMENT Effluent Gross -r-Zinc,- total SAPLE(as Zn)MEASUREMENT Effluent Gross Z""GOil and Grease MEASRMPET_____

_________

_________

___________

Effluent Gross 111 R 60 1A. A 0,.VFlow, in conduil or thru SAMPLE ......treatment plant MEF...ASUREMENT Effluent Gross -". ...' '- .Z. .-' ... "MEASUREMENT

_____ -'SAMPLEMEASUREMENT SAMPLEMEASUREMENT NAMEMII1E I rmw* unde penalty of law that t1is docunent and sn artlactirents were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER dirction or supervisio In accorance wttm a systemn designed to msum that qualified pesonnelBenjamin P. Yournen who0 Manage the s1ptem. or ftse persona dbacWy responsia for 90eg Me fifnfm ation, th1e40-30 04/11/213 ilo..alcen su~mfted

b. to the best of ray knowiedlge andI WMl. true. accurate, and cqM~e. I ain ,SIGiaI--OF P IC!PLEPlant Manager towa we wemm signifcant peruws for asmrnittin flse Iwonmk% ax",

of EXCTEOFCER OR AE1-ir o pml In ab rpsofianar tw knowing violailns.

AUHOIEDAGN CD NUMBER COMMENTSI' AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments heow)"1. This discharge point was not used this month.2. There was no discharge of processed steam generator chemical cleaning wastewater during the month.!EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/212 PAE:

ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 March 2013Page 1 of 2MONITORING DATA:CWBD Rock RiverDATE Temperature CWBD Flow Flowdeg F mgd cfs03/01/2013 75.0 21.95 4,50003/02/2013 71.6 23.79 4,41003/03/2013 69.6 20.25 4,23003/04/2013 71.2 15.85 4,11003/05/2013 71.2 20.63 4,36903/06/2013 72.8 19.84 4,13003/07/2013 72.8 21.23 4,02003/08/2013 71.9 19.37 4,02003/09/2013 71.7 25.34 3,87003/10/2013 78.3 20.19 5,37003/11/2013 74.9 15.24 17,00003/12/2013 74.0 20.96 23,50003/13/2013 68.2 20.83 20,40003/14/2013 69.3 20.14 17,30003/15/2013 68.6 18.85 15,50003/16/2013 72.5 25.66 15,70003/17/2013 71.9 20.16 16,00003/18/2013 74.7 15.88 15,80003/19/2013 74.7 21.08 15,40003/20/2013 70.3 19.73 14,30003/21/2013 63.8 22.50 13,60003/22/2013 63.1 18.06 12,80003/23/2013 66.0 24.78 11,90003/24/2013 74.5 20.05 11,40003/25/2013 74.3 17.76 10,70003/26/2013 76.1 19.53 10,30003/27/2013 75.0 19.64 10,90003/28/2013 79.0 18.84 11,40003/29/2013 76.3 18.57 11,90003/30/2013 77.5 23.73 12,30003/31/2013 77.5 19.10 12,600K:\BYR_CH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2013\March\March 2013 ATTACHO1.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 March 2013Page 2 of 2HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (or associated rinses) containing hydrazine discharged to the Cooling System Blowdownduring the month of March 2013.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite and Bromine compounds were used this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 31 of 31 days.4. Per Special Condition 24 the influent from the Rock River and effluent fromOutfall 001-0 was monitored for Total Suspended Solids (TSS) this month.The Rock River TSS value was 10.0 mg/L on 03/04/2013.

The CWBD TSSvalue was 5.6 mg/L on 03/04/2013.

5. Rock River flow for March 2013 was >2400 cfs therefore daily temperature calculations were not required this month. (Special Condition 12).6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in March 2013. (Special Condition 15).K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2013\March\March 2013 ATTACH01.doc Exelon.Exelon Generation www.exeloncorp.com NucleaTByron Generating Station.4450 North German Church RoadByron. IL 61010-9794 Tel 815-234-5441 May 23, 2013LTR: BYRON 2013-0070 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyWater Pollution ControlCompliance Assurance Section #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring ReportIn accordance with National Pollutant Discharge Elimination System (NPDES) PermitNumber IL0048313, issued January 24, 2011, we are submitting the Discharge

.Monitoring Report for Byron Station, Units I and 2. This report covers the period ofApril 1, 2013 through April 30, 2013.On 4/17/13 at 13:57, the Stormwater Runoff Basin Overflow (Outfall 002) of ByronStation's NPDES permit began to experience flow conditions due to the excessive rainfall in the vicinity.

This flow event lasted until 17:20 on 4/17/13.

The estimated flowrate was 1000 gallons per minute for a total flow of 203,000 gallons discharged viaOutfall 002. As required per the permit, Total Suspended Solids (TSS) and Oil andGrease samples were obtained and analyzed.

The TSS results were 198 ppm and 195ppm for an average concentration of 197 ppm. This exceeds the permit 30-day averageconcentration limit of 30 ppm and the daily maximum concentration limit of 100 ppm.The Oil and Grease result was 2.3 ppm. On 4/17/13 at 21:31 Outfall 002 againexperienced flow conditions due to another extremely heavy rain event in the vicinity ofByron Station.

This flow event lasted until 10:50 on 4/18/13.

The estimated flowratewas 1000 gallons per minute for a total flow of 800,000 gallons discharged from Outfall002 for this event. The total amount of discharge from Outfall 002 for the 2 events is1,003,000 gallons.

As required per the permit, an Oil and Grease sample was obtainedand analyzed on 4/18/13.

The Oil and Grease result was <1.40 ppm which whenaveraged with the previous result is an average concentration of <1.9 ppm. The Oil andGrease concentration met the 30-day average concentration limit of 15 ppm and thedaily maximum concentration limit of 20 ppm listed in the permit.

Page 2 of 2BYR LTR 2013-0070 File: 2.09.0411 and 1.10.0101 In anticipation of the forecasted rain events Byron Station undertook proactive measures to reduce the water elevation in the Stormwater Runoff Basin by installing anadditional pump, to supplement the pumping capacity of the existing installed pumps.Unfortunately the volume of water received overwhelmed the storage capacity of theStormwater Runoff Basin and the capacity of the installed and supplemental pumpingsystems.

In accordance with the station's NPDES permit on April 18, 2013 the Agencywas notified of this Upset event by Mr. Zigmund Karpa, in accordance with SpecialCondition 11 and Standard Condition 12(f)(2) of the permit. Byron Letter 2013-0057, dated 4/22/13, was sent to the Agency to meet the 5-day follow-up reporting requirement of the permit conditions.

If there are any questions regarding this report, please contact Ms. Zoe Cox,Environmental/Radwaste Supervisor, at (815) 406-3035.

Respectfully, Ben VoumanPlant ManagerByron Nuclear Generating StationBPY/ZC/eh Attachments bcc: K. Hersey -Environmental

-Cantera (electronic)

Z. Cox -Chemistry

-Byron NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DUR)PERMITTEE NAMEIADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60655-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010OMR MaIling ZIP CODE:MAJOR(SUOR 01) CS61010IL0048313 PERMIT NUMBERA01-0DISCHARGE NUMBERMONITORING PERIODI MMIODDYYYY I .MM/DD/YYYYI DEMINERALIZER REGENERATE WASTE (001A)External Outfall***NODISCHARGE j JFROMI04/01/2013 ITol04/30/2013 II *ATTN: Zoo Cox _ENV SPEC __FREQUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER

-EX OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPESAMPLE 2-..8 2.9 19 0 01/30 08S~ldS ToalSusened MEASUREMENT

Chromium, hexavalent SAMPLE .....So....(as Cr) ZMEASUREMENT7-Effluent GrossChromium.

total SAMPLE ...... Soo(as Cr) MEASUREMENT Effluent Gross MUM_____Copper, total SAMPLE .............

500(as C u) M E A S U R EM E N T _ "_ ",. "- "0104210 .-.Effluent Gross N ,4- WW "i.. L :-D Y ýs-Iron, total SAMfPLE ....... .0(as Fe) MEASUREMENT__________

______________

010451 0 ~ W~I~ 1,~Effluent Gross W",-I~ ~ -. ~ ~ -...~ -Lead. Total 500(as Pb) MEASUREMENT 01045110 A 4:g~ w qRV ,,..:.,:.:..., *'o ....I.. ..Effluent Gross big .ci2; '"-, : 4 y .--N!"e, total SAMPLE ...... ... ......500(as Ni) MEASUREMENT Effluent GrossKAMFnnLE i cIWilly under pWetay d lw tha1 this doument and al attacuments were prepared under U TELEPHONE DATEPRNWiPAL EXcVE OFRCER f or supervisio in an wfth a system des to a6ssure bt qafied persoTnnel prpe*y gatier and evalute the Informata submined.

Base a my inqiy the pe rm or personsBenjamin P. Younan who manage the system. or foe persms direcly ressaptie for gaitefng the the 40&37 231W03Bmeamiin P.Vomned is, to ftan best d my Wxinae and bfiel f, true. am, geand ', I am SIGNA E OF PRI LE 05/l3/201i Plant Manager aware ha tmere am sigitkcant penaltes submitting false Inomalion.

cilding the pasalhhty d EXECUTIVE OFFIZOR O AEA NUMBER MMDDIYYY1 n Se and e anment for kng vms. AUTHORIZED AGENT ogOCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2- Flow exdsted 30 of 30 days durng this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1652012 PAGE 1* 4 ,0U0X NATIONAL POLLUTANT DIS!CARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITrEE NAME/ADDRESS NAME Exglon Generation Co., LLCADDRESS 4300 Winfleld RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010A"Tmi, 7- t%/l.CSJI COCO%IL0048313 PERMIT NUMBERIDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IA01-0I ......lI DISCHARGE NUMBER IMONITORING PERIODMMIDD/YYYY I MMIDDJYYYY DEMINERALIZER REGENERATE WASTE (001 A)EFxtle Outa~lU*NO DISCHARGE EJ3 ...*1FROMI04101/2013 I TOI04/30/2013 I! IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER EX TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSISZinc, Total SAMPLE ..........

(as Zn) MEASUREMENT 01092 1 0 2- <" '- -, ,U-, , .-.1/4.'Effluent Gross Amt.,%Flow, in conduit or thru SAMPLE 0.057 0.243 3 -. 0 01/01 EStreabnent pant MEASUREMENT

'Effluent GrossSAMPLEMEASUREMENT

.o....s & -,..-.-.

, a.5e4. a.>j-..,.

.. 4 .. " ..... .. o"SAMPLEMEASUREMENT SAMPLE.MEASUREMENT MEASUREMENT NAKE/TITLE I costly widler penaly of law trial s documnent and all aflhadvmnls were prepared under myTLEHN DATEPA1INCIPAL EXECUTIE OFFICER d~rection or supe~sveon in accordance wait a aswam designed to assure Via quape peisonrnel

-property gatrier and avaitot fth mlorruima autnifled.

Based on my siqu of the person of persons 4630Benjamin P. Youmnan who manage fth system or the peisons directly responsailef (or gaihefn the hionaton 05IN REOr CPE________________

nwioan, sujtirntatl is. to the beao ofmy nwwledg and b".S true, accurae.

and wnpleta.

I 05/23/2013O PINCPLPlant Manager swame tha there sie sigificant penalties tor submtehig ini flseInfornllon, Inkiduling the powbstly of EXECUTIVE OFFICER ORNUBRMDDY Ynna O a W rm fine and foibiinttr blowing vidallomns.

I AUTHORIZED AGENT COD NUMBER MM/____________

COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Refernee all attachments here)1. Flows for April 2013 ame estimated based on July 2012 values due to totalizers being Out of Service.

The totalizers ame an obsolete model and work orders ame hin place to findreplacement totalizers and get them installed hin the system.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11/12012 PG-a00 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIT"EE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010AI-r'I:.

7-J--.1v/=&1%1 QDPI:LTU0048313 PERmIT NUMB3ERB01-ODISCHARGE NUMBERDMR Mailing ZIP CODE-MAJOR(SUER 01) CSSIP PLANT EFFLUENT (FORMER 0018)External Outfall*"* *NO DISCHARGE E '61010MONITORING PERIODC MMJDONMYYYI MMIDDIYYYY FROMI04/01/2013 ToI04/30/2013 II lQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF IVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX AALYSIS TYPEBOD. 5-Day SAMPLE 102 9.5 109..2(20 Doeg. C) MEASUREMENT 26r ___ 1101___f__

0031010 Q,1 -: ____ ___Effluent Gross 'AIX,_ ______ ________pH SAMPLE 7.54 7.90 12 0 02130 GRMEASUREMENT Effluent Gross I T Q 4Solids, totall suspended MESR NSAMPLE .r ,1.13 26 9.8 11.3 19 .24MEASUREMENT

_____ _____ _ _ _ _ _ _ _ _Effluent Gross -WMV-0JEMI Fkrow. In conduit or thin SAPLEtreatment plant MEASUREMENT 00200630 0/1 C500601 0 m~ .. : -" .; '" ,,, , " I -- ' -" -4 i. " "- ... .. ..:. .-~ -;weEffluent Gross IMA Mt

,

SAMPLEMEASUREMENT SAMPLEMEASUREMENT CO MENTS AND EPA TIO OF AY VnerpIOaydlaTI1ONS (Rfeecew andll attachments hem re)ae ~ yTLPOEDT1.Flw dsedthouh hi outal l e and of0 aysduing fthis kv mon mth. t ae nmyiwydtepssr tpr P. 010m,) P.e ediion may be used. 1/.,2012.PAG.'

,WhoM111119 M syte .

Pets='-..

&e: .sp-"df fm am " the ;

ft -:Spi ..

.064"2M13

,-,Waraton ub ite i. to t .he b -.st .... .y bw g ,ai,. .. t '

, :.:,:,r ac. -rteai-..--,,.nSINA I E F& ICIPlant anagerawaeMat L~EWeWliatPeatefo u)1=LI r=9 t nk"O oslqd E CU VE FIER R%TYPM n 113awd ME andUREtcMENT frWoigvlaos UHRZDAET

'o UBRMIDVCOMMENT .'"D EXPLANATION OF ..NY VIOLATIONS

...e.e...c.

all attacment

.......Fl.ow .-xi..te. throughi,'-,-.

thi "u l .30' of. 3.0 ."a"ys. .d--ing, this month. " , -.. .

330- (Rv0/6 rvoseiin a eue.16 1 A E1-M0000z NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAMEIADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Wmfie RoadWarrenville.

IL 60655-5701 FACILUTY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010;110048313 PERMIT NUMBERC01-0DISCHARGE NUMBERDMR Mailing ZIP CODE:MAJOR(SUOR 01) CSWwTP (FORMER OD1C)External OutfallI IINODISCHARGE 61010MONITORING PERIODMMIDDNYYY LMDJYYFROM04101/2013 TO04/30/2013 II,,I lAI I N.* Ol L.JwCI"V br0.,/ _ _FREUENCY QUANTIY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESolidsEtotal p.nded ...... 1.4 2.4 19 0 02/30 24sore. MEASUREMENT OO 30 0. ':o .......Effl~uent Gross rChromium.

hexavalent SAMPLE ...... S00(as Cr) MEASUREMENT 0103210 I+. ." ..E~ffluent GrossChromium, total SAMPLE......

(as Cr) MEASUREMENT S_01034'10 N"' : ... ++-. *-. *-4: "*.... " ""Effluent Gross. .C r, total SAMPLE ............

(as Cu) MEASUREMENT 0104210 ag:- ..... .---;'. .. ...... r .. i.>..."..4.'

E~ffluent Gross rIron. total SAMPLE ...... Soo(as Fe) MEASUREMENT 0104510 -" .'- nn:, .. '.Effluent Gross __.-_.- .., ..'. " .._-. .,Lead, total AMPLE 500(as Pb) MEASUREMENT

'Eff luent Gross V.'t .2Q~Q~ A1Y~Nickel, total SAMPLE ............

...... .....(as Ni) MEASUREMENT

___Effluent G ro ss '4 l "". ..- ..NAMEInTLE I cer id w udraIZy of law Ut. doCmunnU and a taclum were prepard under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER cikecior supension in acrance with a SystDm dAmE to assur Ml qua persnelproperly gather an evalute btlaonnmaion suaundled.

Basd an "my vpily of het person or personsBenjamin P. Youman who manag tea systo. or thoe persons drectly mWWW atfor gaow e-a n he 40intatbi.,

05h3e13intormadin is. to fie best ol my MknAeag and bellef. true. accurate, and catIpaele.

l ai GNA E OF CIPLEPlant Manager aware that te am signiftm panttiles tor ,ubrn fabs kioman. Wudt ft pmsVof EXECUTEl R AREA NUMBER MMIDD/YYYY iw -oan xU If and lapalowMA for Wwwbg violatns.

AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Raference all attachment here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow eAdstel through this outall 20 o130 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/162012 PAGE 1-0000z NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITrEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR Mailing ZIP CODE:MAJOR(SUOR 01) CS61010IL0048313 PERMIT NUMBERC01-0DISCHARGE NUMBERMONITORING PERIODMMIDDIYYYY I MIDDIYYYY WWWP (FORMER ODIC)Extemral Outfall* NO DISCHARGE EJ "'FROMIl04/01/2013 TOI04/30/2013 Il l-13000M0)F4111 NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADORESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACIUITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERD01-0DISCHARGE NUMBERMONITORING PERIODMM1DD/YYYY I MM/DDWYYYY RADWASTE TREATMENT (FORMER 0010)External OutfallFROMI04101/2013 I TOI04/3012013

!"IINO DISCHARGE ED ..-vI JMEASUREMENT egpwr~:nww uneucazp14J1I.....~s. ..h..1 i.daL...a&~.ba.....

I ~ y I isi~at~ II.N*ME11nTLE PRFIcIPAL OFFICERBenjamin P. YoumanI certly Under penaft d law that fis docufmlen and at atlachments were prepared under Mydijaction or spemvWo In accordance with a system designed to assure Unat quafted per-amniproperly gather and evakie the inonrmaion submitted.

Basedn my Inquiry a thie perso pesmonswho manage the system or tlase persons drecty responsibe for gathering Me informatio.

MeIntonmata subeted is. to"e best al my knowledge and befie, rue. acmrate.

and complete.

I amaware a thre are penalties far suWMig fase infomatim, te poassby atfme and mpasimment for kowing violatios.

TELEPHONE 406-3700Plant ManagerEaR -nimITl)MMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)Row existed through this outtall 12 of 30 days during the month.

NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfeld RoadWarrenville.

IL 60655-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadIL0048313 PERMIT NUMBERE01-0DISCHARGE NUMBEROUR Mailing ZIP CODE:MAJOR(SUSH 01) CSSTORMWATER (FORMER 001E)External Outfall9

• NO DISCHARGE 61010MONITORING PERIODUM/DOVYVYYr MMIDDI1YYYY FROMI04/0112013 ITO04r30/2013 Il r lByron, IL 61010ATTN: Zoo COXIENV SPEC ______________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER EX OF TPVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPESAMPLE ........

00Solids, total suspended MEASUREMENT 0053010-'z.

.0 ,. .Effluent Gross W.- Si .rSolPtotal suspended SAM28.7 57.2 19 0 01/07 GRSolids, tol suspended MEASUREMENT 00530804vIR Other Treatment.

Process %rrcompleteChromium.

hexavalent SAMPLE .... .... 5I(as Cr) MEASUREMENT I0103210 :Effluent GrossChromium, total SAMPLE ...... 500(as Cr) MEASUREMENT

_0103410 Ys tCopper, total SAMPLE ...... S..(as Cu) MEASUREMENT 0104210 tw5MKt ,. r -- -.~4 4 -V:Iron, total SAMPLE ...... .. ...... ....5(as Fe) MEASUREMENT 0104510 v PTj .... .. ... : "M...,___...

Effluent Gross _OEM ~l~r ~~t.--Lead, total SAMPLE .. *...(as Pb) MEASUREMENT 0105110 ~' .~pr s ~ .~ :'-- >pUEffluent Gross '.. ..119 "*1/4 ." 'I ' " ' ". -: >-

" -- NAME/TnlE I ceiy under penafy o law t n is document and a all nuemns were parMed under my TELEPHONE DATEPRINCIPAL EXECUWnE OFIRCER direction or supervbso in accordae with a system designed to assure th qua pervannel gather and evakite the information submitted Based an my inquiry of te person or person A..' 815 406-3700Benjamin P. Youman who manage the systmn. or tose persons Wocty reponsbe gathra g t inoametion the 00232013ilotnisbon submitead is. to the boe d my knowledge and b--al. tnre. awcuate, and complete.

I am NAVE-X OF C 05/C2 1Plant Manager aware that there am signifcant penaflis for sabmliting lase informatimn.

Inciuing the possalldy EXECUTIV NUMBER MM/DDYYYon a1 ine and nimpuontnent 1 knowing violatons.

AUTHORIZE AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference ail attachments hem)1. There was no discharge of processed steam generator chemical cleaning wastewater during the month.2. Flow eidsted through Oth outfal 15 of 30 days during the month.3. Are Proection drain water was discharged this monthEPA Foem 3320-1 (Rev 01106) Previous editions may be used. 1/6/2012 PAGE 1I* 0 0 NATIONAL POLLUTANT DISCIGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)0PERMfTTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadOMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERE01-0DISCHARGE NUMBERMONITORING PERIODMMIDD/YYYY J I MMIDDJYYYY STORMWATER (FORMER 001E)External Outfail* *NO DISCHARGE

• 0FROMI04/01/2013 ITOI04/30/2013 Byron. IL 61010ATTN: Zoo CoxIENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF YPVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPENickel. total SAMPLE Soo.. ...(as Ni) MEASUREMENT 010671 0

.E~ffluent Gross AR ~2Zinc. total SAMPLE 500(as Zn) MEASUREMENT 0109210 R.,+ ... ' -. :. '.1+ .. +. ' '+ """ " '""Flow, In conduit or thru SAMPLE 0.564 1.701 3 0 02130 .CNtreatment plant MEASUREMENT SAMPLEMEASUREMENT

+,~A .., ., --v.SAMPLEMEASUdJREME-NT

__ _ __-__ _ _ N -I -1£.. -"+.. ..-. :+. : ...MEASUREMENT

-__ _.-.__ _. :.'.+ .. .. j.~~~~4 -4t**~t~,~

KiE/IT.E I cattify under penalty d law dhu tihs documemt and al anuadeuntas were prepared und my TELEPHONE DATEPRINCIPAL EXECUTIVE OFPCER Wiean or supev i with a system desiged to assur thd qualifed WenelSpmperly gather and evatlla the Ionsoatm submitted Based mo my nquty of the pesmu of personsBenjamin P. Youman who manage the system. or atse pers" directly mspmnsbe tor gathme"Og the malman. fte T F"13inforritim submntd is to the besto my WwWedge and betef, true. acoirata end =pMits. Iam SIGNA1UAR OF PNUMBERPlant Manager aware hat tere are Winfant penalties for sunTdi9 false ingla o ,mato. i 0 ft ia of EXECUTIVE OFFtheR OR MAREA/YYY f nIne and Wlriint for Mknw vdalaons.

AUTHORIZED AGENT CODE MMIDDYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Raefernce all attachments hem)1. No Closed Cooling System Drain Water was discharged this month.2. Service Water System drain water was discharged this month.3. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Cleaning wastewater was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11612012 PAGE 20U0C:0 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAMEJADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACIL1TY Byron Nuclear Power StationLOCATION 4450 North German Church Roadi I.0048313 PERMIT NUMBER001-0DISCHARGE NUMBERDER Malfing ZIP CODE: 61010MAJOR(SUDR 01) CSCOOUNG SYSTEM BLOWDOWNExternal OutfallI* NO DISCHARGE EJE MONITORING PERIODMMIDD/YYYY I MMIDDJYYYY FROM I04101/2013 ITOI04130/2013 II IByron, IL 61010ATTN: Zoe CoxIENV SPEC ______________

___________________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER

_________________N.

OF SAMPL.EVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX TYPE[>< IANALYSIS Temperature, water dog. SAMPLE ............

.............

82.8 15 0 01/01 CNFahrenheit MEAURMENT pH MPLE ...... 8.48 8.70 12 0 01/07 A GRMEASUREMENT 0040010 7. -7 7Solids, lotaluspended S 10.9 11.1 19 0 01/30 GRSolds toalsusened MEASUREMENT Oil & Grease SAMPLE .4 <1.4 19 0 01/07 GRMEASUREMENT EffluentGross

-. "Co , total (as C)... ... 0.011 19 0 01/07 GRMEASUREMENT ZCo ta (aC SAMPLE .. 00 0.02B 19 0 01/07 GRMEASUREMENT Zinc. total (as Zn) SAMPLE ....... 0.1 .06i,.0/7G 0109210 4 k 15AEffluent Gross Elk "... .9 0 0N*MEMTITLE I cany under Iwpenayf law that this document and a attachienrt wers purpanted y TELEPHONE DATEPRINCILPAL EX-CUTIVE OFFICER dWCOM W Supem,,=

in accordace with a system desgn1ed to astsri that qualed personnel pmpety Sgathae end evaritU ntiormaton.

submted.

Basecd n my nui b e d the person ma peons8Benjamin P. Youman who manage the system, or throe persaons dimcy rsmsponsM for arhemO e ing die ----- 4-FPR I7 05/23d2013 inoimation sularnited

a. to the best d my knowledge and beief, true. acrte, and ca*myete.

I am SIGNAnlJ OF P PLEPlant Manager aware diat there am sil'rat pename for submitlbn false Infonnb.

bidzdng the posaiksty d EXECUTIVE OFFICER OR AREA UMBibis and imprislomt for knowug viclalba.

Cuoz AGN No ER _______________

TvOPOCI I iead I AUTHORIZED AGENT COENME0M/DrY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)1. Monftonng data for outfall 001-0 is included on attachment.

EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/0/2012 PAGE 10 ,'a00C0o NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exulon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCA1ON 4450 North Genman Church RoadByron, IL 61010A1r'r'J-7 PrimfJ-UA~l QOD::'DMR Mailing ZIP CODE:MAJOR(SUOR 01) CS61010IL0048313 PERMIT NUMBER001-0DISCHARGE NUMBERMONITORING PERIODI MMIDDWYYYY I........

!ITolIMM/DD/YYYY ICOOLING SYSTEM SLOWDOWNExternal Outfall**'NO DISCHARGE "I lFROMi04/01/2013 II04130)2013 II IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEARAMETER VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OF TAMPLEE5 ANALYSIS

, ___Oxidants, total residual AMPLE ............

0.04 19 0 01/07 GRMEASUREMENT 34044108AMPL

.. 50'Priority pollutants total effluent MEASUREMENT 500081 0 -oIn..:- .Effluent Gross _ ... ,..Flow, In conduit or thru SAMPLEtreatment plant MEASUREMENT 50050 10 ~- *Effluent Gross = -T .4 m.Chlorine, total residual SAMPLE .....500MEASUREMENT Effluent Gross -W AS ;Hydrazine SAMPL..E SI........0 MEASUREMENT50 Effluent Gross O1 , QTMEASUREMENT MEASUREMENTLE I certia nder penaly 01 law 0a this er and afl anadmunas wet preparetd wider my NONEPRINCIPAL.

EXECUIWU OFFICER tlrectimi at aupevislo in accotdance with_____a__

_ sstem desined to asasur that waffed persamat 1,.,J LE H DATEBejmi P roperly gather and evahfla tea Infomavaon submaled.

Based atmy avy Wqf of the person at persons -V/damiP.Yw na the syte t persons dreofty resportsm for gaftfl t SI F P _______815 406_3700________

Plant Manager kdinfor n eutmued AI. to the eao of my knowlmedge and bee. rem.

and omlplu ar i am SI--= ---F P'iP--lwarM that thge amo srulkant peae t subonittnri false inlonnadi.

includitg me posemay of EXIE E OFFICER OR AR NUMBER MM/DO/YYYY

__ _ _m _ _ ,.e aON hnrnfninlm.n.t for knowing violaions AUTHORIZED AGENT COD NCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Raference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 2"D00003X NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenvide.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4460 North German Church RoadDMR MailIng ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBER002-0F DISCHARGE NUMBERMONITORING PERIODMM/DDN/YYY I I MM/DD/YYYY STORMWATER RUNOFF BASINExternal Outfall* *" NO DISCHARGE"7

...FROM 104/01/2013 I TOI04/30/2013 Byron, IL 61010ATTN: Zoo Cox/ENV SPEC QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER EOF TAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS E ANALYSISSolids. Total Suspended MEASUREMENT

.... -- -.00530 10 ." ",."Effluent Grossw~'

4 i 61 i ,,fSolids, TotalSuspended SAM 197 198 19 2 01/07 GRSolds ToalSusened MEASUREMENT 0053080 " " W 4 : .** .' .' .: ..." "" " " "Other Teatmnent, Process .-Chromium, hexavatent SAMPLE ...... ........0(as Cr) MEASUREMENT 0.1021"0

....... ..' " ' .... ....:,01. .. -" ., ""..Effluent Gross NO N -Chromium, total SAMPLE Soo........

(as Cr) MEASUREMENT 010341 0 .Effluent Gross 2I., .Copper, total SAMPLE ... 500(as Cu) MEASUREMENT

..... .- .. ..... .., "Iran .total SAMIPLIE 500......

.(as Fe) MEASUREMENT

.. 00104810 Zm-.ff.IT:zu

,... ;Lead, total SAMPLE ..... ...... ....500(as Pb) MEASUREMENT 5000105110 8 W~_ _ __NAMEIT'LE I canldy under penarly of law thai this document and ats allchments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFRCER direclon or supensisa in accordance with a sytem designed to assure thao qualifed pearsaiel pedy gather and evatfe the ibonnation subnaed.

Based on my ht of the pmon of peoons 15 03700Benjamin P. Youan who manage the systen. o those persons diredtly esponsbe for gathering the Iomadon.

theg 05232013Dormal s P Is. to the bow d my knowegede and bdel. tMe, accurate, and comp"e lam SIGNATUV E OF P7062C0PLE Plant Manager aware that here ae signficant penalties for sulang Idee idonnaton.

Includg the possaft EXECUTIVE ER OR AREAlrmE o a sxn m FIN__Onn and __ _ _ _ _ _ _ _ _ _ for __Wahl% vi__ms. AUTHORIZED AGENT CO NUM BER M M IDD YYYYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. No Turbine Building Fire and Ol Sump or Generic Non-Chemical Metal Cleaning Wastewater was discharged this month.2. Fire Protection and Service Water System Drain Water was discharged this month.3. No Closed Cootinq System Drain Water was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/612012 PAGE 10 0 000 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMI'TEE NAMEIADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarmnvlte.

u 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron,IL 61010DMR Mailing ZIP CODE.MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBER002-0I _DISCHARGE NUMBERMONITORING PERIODMMIDDIYYYY I MMIDDIYYYY STORKWATER RUNOFF BASINExternal Outdall*NODISCHARGE FROM I04/01/2013 I TOI04130/2013 l iQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSISNickel, total SAMPLE 500(as Ni) MEASUREMENT 0106710 ASR I~ ~v*TEffluent Gross I"- ...;'Zinc. total SAMPLE .......(as Zn) MEASUREMENT Effluent Gross" ". A.. ..: ..-, ..O and Grease SAMPLE ..........

... 4.9 2.3 19 0 DL/DS GRMEASUREMENT Effluent Gross' .... " f' ..Flow, in conduit or thru SAMPLEtreatment plant MEASUREMENT Effuent Gross ýMwm

..::.:, +SAMPLEMEASUREMENT

.4..^ "-,.- > + .+ .,. ,,, + ...-..3 412.44, .1.....

~ ~ ...... ; ... ....SAMIPLEMEASUREMENT

, iNMFITr I cetity under penatk d law thathis doment and al allaezenl were prepared Undler my TELEPHONE DATEPRINCIPAL EMCUMV OFFR *lcton of spervsion in a wah system designed to assure that quatfWied personner prope gather and evwke thetIdormatin subttentsd.l BasndIN thperP- , O-M15 40-3a7Benjamin P. Youran who manage the system. or those persons directly esponsble for gathier the fte ,13ionmatim vulnduea is. to the botw o my knowld and betef. tree. a=ret. and *OMpete.

I am SiGNA1Uo OF P 051J3/....

Plant Manager aware dhat there are srgni-at tor somating false odoi hindul lte ft hd EXECUtjE OFFICER OR NMEAmManager ine and rnprslonment for Iknowing vkAUaOZDs.

GTE NUMBER M/D/YYYYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flow existed through this outfall 2 of 30 days during the month.2. There was no discharge of processed steam generator chemical cleaning wastewater during the month.3. Upset defense used lor TSS concentration exceeding limits. See DMR cover sheet for additional details.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/2012 PAGE 2-00000G)

ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 April 2013Page 1 of 2MONITORING DATA:WBD CRock RiverDATE Temperature mgd Flowdeg F cfs04/01/2013 74.1 14.27 12,80004/02/2013 78.2 21.11 12,90004/03/2013 78.2 17.82 12,90004/04/2013 82.7 18.58 13,00004/05/2013 82.7 20.82 12,90004/06/2013 82.6 24.65 12,90004/07/2013 82.8 15.29 12,70004/08/2013 73.7 14.96 12,50004/09/2013 73.3 19.13 12,90004/10/2013 70.4 18.74 14,90004/11/2013 68.4 20.40 17,60004/12/2013 67.2 22.95 19,80004/13/2013 59.8 20.09 20,20004/14/2013 72.6 24.15 19,90004/15/2013 72.6 11.69 20,00004/16/2013 68.5 11.35 19,90004/17/2013 62.4 10.82 21,00004/18/2013 70.0 11.90 31,80004/19/2013 70.0 14.63 39,00004/20/2013 59.7 13.53 39,80004/21/2013 63.8 13.10 36,80004/22/2013 68.7 11.87 33,20004/23/2013 73.9 12.36 30,60004/24/2013 67.3 13.45 28,40004/25/2013 67.3 11.94 26,50004/26/2013 68.1 13.48 24,70004/27/2013 70.2 13.40 23,10004/28/2013 70.2 10.63 21,80004/29/2013 73.6 11.63 20,70004/30/2013 81.1 14.43 19,500K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2013\April\April 2013ATTACH01.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 April 2013Page 2 of 2HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (or associated rinses) containing hydrazine discharged to the Cooling System Blowdownduring the month of April 2013.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite and Bromine compounds were used this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 30 of 30 days.4. Per Special Condition 24 the influent from the Rock River and effluent fromOutfall 001-0 was monitored for Total Suspended Solids (TSS) this month.The Rock River TSS value was 38.1 mg/L on 04/08/2013.

The CWBD TSSvalue was 11.1 mg/L on 04/08/2013.

5. Rock River flow for April 2013 was >2400 cfs therefore daily temperature calculations were not required this month. (Special Condition 12).6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in April 2013. (Special Condition 15).K:\BYR_CH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2013\April\April 2013ATTACHO1.doc Exelon Generation

Company, LLC www.exeloncorp.com Byron Station4450 North German Church RoadByron, IL 61010-9794 June 21,2013LTR: BYRON 2013-0082 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyWater Pollution ControlCompliance Assurance Section #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring ReportIn accordance with National Pollutant Discharge Elimination System (NPDES) PermitNumber IL0048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report for Byron Station, Units 1 and 2. This report covers the period of May1, 2013 through May 31, 2013.If there are any questions regarding this report, please contact Ms. Zoe Cox,Environmental/Radwaste Supervisor, at (815) 406-3035.

Respectfully, Benja~eaPlant ManagerByron Nuclear Generating StationBPY/ZC/eh Attachments bcc: Kevin Hersey -Sr. Environmental Specialist

-Cantera (electronic)

Zoe Cox -Environmental/Radwaste Supervisor

-Byron POOR QUALITY ORIGINALNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIrTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenvWlle, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadDMR Mailing ZIP CODE:MAJOR(SUOR 01) CS61010I IL0048313 PERMIT NUMBERA01-0DISCHARGE NUMBERMONITORING PERIODMMIDD/YYYY I MMWDDWYYYY DEMINERAUIZER REGENERATE WASTE (001 A)External OutfallI *" NO DISCHARGE

-*FROMI05/01/2013 I TOI05/31/2013 IByron, IL 61010ATTN: Zoe Cox/ENV SPEC QUANTITY OR LOADING QUANITIY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESolids, Total Suspended SAMPLE 1.6 2.1 19 0 01o30 08MEASUREMENT 0053010 P"PR.IT -15 30Effluent Gross -REQUIREMENT

."-" ...__ -30DAAVG DAILY MX M,. C P,Chromium.

hexavalent SAMPLE Soo ""." ..-5(as Cr) MEASUREMENT 0103210 ' :GRERRAT

...1,,Efuent Gross REQUIR'EMENT

...._. :_ G PAJL .... .-, ...D. GRAChromium, total SAMPLE S.......

... 5o(as Cr) MEASUREMENT 01o3410 .2. .. ' , ... .... GRAEffluent Gros sE.UIRE-

" SODA AVG DAILY ..ma., Da"Oy GRABCopper. total SAMPLE ...... Soo(as Cu) MEASUREMENT 0104210 .e.. PW.. z ...s ..mL -aly GRABEffluent Gross .'-RE , _R.. , SODA AVG DAILY MX -Iron, total SAMPLE .500(as Fo) MEASUREMENT

_010451 0 POW DORY 1Effluent Gross R ,MEM , , , DALY MXLead, Total SAMPLE S...o ,. ......(as Pb) MEASUREMENT 01051 10 ;.E rr ~.. ..', ,., " .,, ".- , "." ." .4 7 ." al0105110'

..................

_ SODAAVG.I

• DAILYMX.

2".. -':'Daily GRABEffluent Gross REQUIREMENT L30DA "V: ,I MX,Nickel, total SAMPLE Soo ....... 500(as NI) MEASUREMENT 0106710 PERMIT -,,,e. -.e i .e,.. !e 'Effluent Gross REQUIREMENT

.PDAAVG.

ODAYMX ...... GRABNAME.,TlLE I certify wue penaly of law OhW Vi documem and W we prepared

-nder my TELEPHONE DATEPRIINPAL EXECUTIVE OWFCER O:don in scoode arm a a'sstem damged to aure Vil wquLaffed peaona 1vopedy garn erw eneaP Me ftodrrndan wdx~nfta.

8ased an myr kqukv d the P~ron= Of P -,1 46370Benjamin P. Youman v" nmpW the syn or th-se pene dircty eoside 1w gada f I'me0 ft _815 406-370W 06/21P2013 lienwan m&WMW i. to to bw of my wwwww wn l@W, Mo. acuae and conle.I am SIG V-RE O&INCIPLE Plant Manager awam Via these are titntfim penarles for umalnlrt false bte pua at o E XUTIVE OFFICER OR AR NUMBER MDD/YYYYpfswm _i;W wpbiwm for lbwo alorm. AUTHORIZED AGENT CODE NUMBE _ _________

COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow e)dsted 31 of 31 days during this month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 1/6/2012 PAGE 1 POOR QUALITY ORIGINALNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 610107nn (-.jwdI=NV RPI:=t'OUR Mailing ZiP CODE:MAJOR(SUBR 01) CS61010I IL0048313 PERMIT NUMBERA011-0DISCHARGE NUMBERMONITORING PERIOD,M/OD1YVY

___ I MMIDDIYYYY DEMINERALIZER REGENERATE WASTE (001A)External Outlall* ** NODISCHARGE

-FROMI 05/01/2013 1TOI i-05131/2013 Iq IA TQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OF TAMPLELý<ANALYSIS TPZinc. Total SAMPLE .500(as Zn) MEASUREMENT Effluent Gross -INEQREMENT:

",_,"___

' -"..__"

30DA VG DAILY MX"GFlow, In conduit or thru SAMPLEtreaiment plant MEASUREMENT 50050*10

". moD AVG0 DALY -. : V".. Daily CONTINEffluent Gross REQUIREMENT

_.-30DAAVG_

DALY UK_,_ ' " _ _ _ ________SAMPLEMEASUREMENT REQUIREMENT

-SAMPLEMEASUREMENT

........

"___ ____ ___ ___ __SAMPLEMEASUREMENT

• PERMITREQUIREMENT

_____ _____ _____ __________

SAMPLEMEASUREMENT

• _ __ _REQUIREMENT

_SAMPLEMEASUREMENT

• PERMITREQUIREMENT-__________

_____ ____ ___KAKEPITLE I cltify was petafty law diat oft domarmmd and all elaclwrita wereS prepared wider my TLPOEDTPRIlINPALECUIVE OFFICER Oadooraeimin 4~ scwac wftm a systm dosigia to ast V tad Wd p TLEHOE ATWampafty gather anid evahite ft e Wmmatia submitted.

Based onmy bftiar of thie perso or per~s 11 0630Benjamin P. Youmnan who manage the sysfem or ftose persona dradly reapwonbie tor gafheutn do tntonarsimwr AA e 06121/213

il -miation aidrtted W to fte be of my otedge '.- be"d. rm. ,ac "ate. and c Ie .am FG "E OF P IPLE " ' ::'Plant Manager EE EO tEROR ARENUMAER "M"D" "COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flows for May 2013 are estimated based on July 2012 values due to totalizers being Out at Service.

The totalizers are an obsolete model and work orders are in place to findreplacement totalizers and got them Installed in the system.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11111=112 PAGE 200 0 POOR QUALITY ORIGINALPERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWaffenvllle, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010Ar... n~~ne^rNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)DMR Mailing ZIP CODE:MAJOR61010IL0048313 PERMIT NUMBER5B51-ODISCHARGE NUMBER(SUBR 01)CSMONITORING PERIOD[__ MMIDDWYYYY L_ u/DDJvYYYV STP PLANT EFFLUENT (FORMER 0015)External OutfallI I*NODISCHARGE FROMI 05/01/2013 TO05/31/2013 II mQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FEQUENCY SAMPLEPARAMETER

__F__TYPE_

VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX AFY TYPESOD. 5-Day SAMPLESOD, 5.CayMEAME 0.49 0.53 26 12.5 16.0 19 0 02/30 24(20 Deg. C) MEASUREMENT 003101 0 ,PEMT .. ..,- 10.5 3 60Effluent Gross ..RRQUIREMET M G DAILY MX _._-, :, 30DA AVG" -DAILYMX n: .. TwIce.PerMonthCOMP24 SAMPLE ... .7.53 7.80 12 0 02M30 GRpH MEASUREMENT oo~~~~oo~

....r ........_...G.Effluent Gross -REQUIREMEM "T .."":- ________.

...... :.".. MINIMUM 6 !. .". .. " ' I- .A)CJlJM

__P, _ M____hSolids,total suspended SAMPLE 0.15 0.18 26 -2.8 3.6 19 0 02/30 24MEASUREMENT

__________________

____0053010 MST3 10.6 30 60_Effluent Gross REQUIREMENT

".,300A`

AVG, DAILYMX _,_... .,,30:AAV.ALX":

TwIce r .Month C P2Flow. In conduit or thru SAMPLEtreatment plant MEASUREMENT 0.006 0.011 3 0 01/01 CN5005010 o..ERMI RfTMO.. Re ._.. -, .Effluent Gross REQUIREMENT-S30DA AVG -DAILY MX .* Daily CONTINSAMPLEMEASUREMENT

_______________REQUIREMENT________________

SAMPLEMEASUREMENT

_____________

P"qMrr.-REQUIREMENT

...... ......_______ __ ___SAMPLEMEASUREMENT

=_REQUIREMENT NAME/Tn.TE I certy under penally oa law doat th document and alU hmenD wr prpard under my TELEPHONE DATEPRINCIPAL EXECUA lVE OFFICER d of v Wm in e whh -ey~en *l i to assure O W q led pemTrEnel Benjamidn P. Youra proerl gather1 Nd evlt the Inonelr satre aa niyb fd esno esn 815 T406-3700 0/121BjrnP.Yumnan wto menage the or uft persons drecy iesponsite for 0&mer, dwth kdommilr to 06/21/2013 knnodon s&bWwW Is. to OF boo o my laowiedge

" bete. trueP acust. anoste. ILEm _ _ OFPlant Manager awarm that tSU U patltes amtn*h false biloaln, hckftG the b F CER OR AR'EAo NUMBER MM/DD/YYYY TOW ON I and knPalionnt for bwnoag vitorm AUTHORIZED AGENT CODEJCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flow existed through this outfall 27 of 31 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/2012 PAGE1" POOR QUALITY ORIGINALNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DUR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN* ona t"=nxIFlNV RPI:fDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERC01-0DISCHARGE NUMBERMONITORING PERIODMMIDDYYYY I MMIDDYYYWWTP (FORMER 001C)External Outfall* *

• NO DISCHARGE FROMI05/01/2013 ITOI05/31/2013 IPARAM..ER QUANITrY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNEIT OF TYPE....IT ANALYSISSolids. total suspended SA-PLE8.2 12,4 19 0 02/30 24Solds toalsusened MEASUREMENT 00530 10 "MIT 1 -. 30Effluent Gross ,REQUIREMENT

-,, .," ..30,DAAVG

.-DAILYMX JTc,'PerMonth COMP24Chromium, hexavalent SAMPLE 500(as Cr) MEASUREMENT_500 0103210 PERMIT Daily GRASEffluent Gross ;00E#QUIREMENT

_

" 3-.A DAILY M).(Chromium, total SAMPLE ..--- -.(as Cr) MEASUREMENT 5000103410 PIRml,. * :- "A*Effluent Gross -' '- ." ._ _ _ D A D " yCopper, total SAM PLE .. ... ..(as Cu) MEASUREMENT 5000104210 -...; ":" -' -: .3DAG5 -- 1AL X gL ..""Diy GAEffuent Gross RIEQUIREMENT

.., "" "" .-. ...(asflent Gross 300__ __ _ _ _ __ _ _ OA AVG DAILY MXC m g/. Daily GRASIron. total SAMPLE -p(as F e) M E A SU R EM EN T 500__010451 0 0ERMIT ,Effluent Gross REQUIREME.T

,_ .. L ...GLead, total SAMPLE DAIL ....(as Pb) MEASUREMENT 5000105110 1PERMFF11 SIXAF eENue.t.Gross"REQUIREMENT

.4-* __, DAILY MX .,.. .._.., GRANickel, total SAMPLE ..(as Ni) MEASUREMENT 5000106710 500:" --".. 2 GS URE.-A DAILY MX -GRASNALECTIVE ceRrty under penaty at law Mi fot cocunemwd and ,. aftachdenta were Prepared unde; my tELEPHONE DATEPRNCPA EEO~hE F~CuR~reacdn or aajpwvwn in a mdencer vm a aYWtni daalgnad to mague gola mflie F.e-raTLEPONEDAT Benamn .ouna rpeilgaflixer a udmaaVe bilonnab ahltd. Asadon ny fmiy of Ve pumaonopemom 815 408-3700 0/121Benjamin P. Youran who -rga fte y-am, or Vim pnmm dWlreofy eponWtns for galheb the V.dolmaVn.

Vie 21/0'rtf n nailon Ited b ,to ft beae ofmy knowki d and b*ef. true. a nu as. and m qoet. jam -4W7RE000CIPLE P la n t M a n a g e r a w a re t h a mere a re dl nmcarV p e n a, le fo r s u ba t ln g as e kf o mi" a tb i k nc g n 0 # W p o e saw y o l E X E C U T IV E O F R IC E R O R 0N BM 1 / Y0 1 YflPWMPROUMelE fo an I5nOv*A-tor www~dei elaldwa.m

____________,_________________________________

~r=.AUTHORIZED AGENT CODl NUMBER ____ ___ ___ ___ __COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments tere)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed through this outfall 14 of 31 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1162012 PAGE 1

.POOR QUALITY ORIGINALPERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWaxrenvije, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010A3"rl- 7,u ('V/w~IUNI OIO::tNATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)I IL0048313 PERMIT NUMBERC01-0DISCHARGE NUMBERDMR Mailing 33P CODE:MAJOR(SUBR 01) CSWWTP (FORMER ODIC)External Outfall***NO DISCHARGE r "61010MONITORING PERIODE MMIDDN1YYY

• _ MMIDDNYYYY FROMI05/01/2013 I TOI05131/2013 Il ll IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLE* PARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS E ANALYSIS TYPEZinc, total SAMPLE .,(as Zn) MEASUREMENT 0109210 P NI4IT'. -" --,, ..:.-T " ." 1- 2-- .. ,,_ GEffluent Gross REQUIREMENT xu AVG DALY Di -GRAB IFlow. in conduit or thru SAMPLEtramn ln.MAIEET 0.022 0.037 3 .... 0 01/01 CNtreatment plant. MEASUREMENT

______________

50050 10 PMW lq o, N.0oue Gro0s *:: PERMIT.'"

Req. Mon... .,ReOI. ",. ..',,m "Daily CONTINEffluent Gross REQUIREMENT.

30DA AVG DAILY MX .. .... ."* .."SAMPLEMEASUREMENT

..:PERMIT.:

REQUIREM "NT -..... ...SAMPLEMEASUREMENT PERMIT

.____ _SAMPLEMEASUREMENT P9RMlIT_______________REQUIREMEN

_______________________

_____ _________

SAMPLEMEASUREMENT

-PERMIT'

.__REQUIREMENTr

" .:. _ .... _.:_"_"_"_"_'"""

SAMPLEMEASUREMENT

_.REQUIREMENT.

.., ._ _ _ __-_.,_,_.

NAEXTIVnE fI *artiy under inalty o law Vat me document and d, aftadunuft w pxapad under my TELEPHONE DATEPRKWAL EXECUmleVE OFFR corMcsdn ooi accolnce th a systenm designwd to that qiad personneprcp gathr and e~lue the kInormation eubaufed.

Based an my bwpfti of me* person or personsBenjamin P. Youman Vo rmanage "a sysm. of ft" persons drecdy esaporute tot me Intannallon.

me 06421/2013 kItomtallo eutmiftted W. to meo best of my Noleeedge anid Meel. tnae. a~rrmw ant comlee. lam SIGNORE OF CPCPlant Manager a~ware ft~ro ame 90fl-M penW for aftntklin fB~w kdonnedon, blk~dbV the poess:)y of EXII&UTIVE OFRCER OR AREAa-- Mae I , n m lt AUTHORIZED AGENT iCODdNUMBER MMIDD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 146=212 PAGE 21 POOR QUALITY ORIGINALNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfleld RoadWarrenville, IL 60558-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTM- DMR Mailing P CODE:MAJOR(USBR 01) CS61010IL0048313 PERMIT NUMBERI01-0DISCHARGE NUMBERIIMONITORING PERIODRADWASTE TREATMENT (FORMER 001 D)Extenrai OutfallFROMJMMIDOIYI I UMIODNIYVY 05101/2013 I ToI05131/2013 I* N ISHREJ .I *ARAMETER QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX O TYPE1 <IANALYSIS Solids, total suspended 9.3 18.0 19 0 02/30 CPSolds toalsusened MEASUREMENT 0053010 -"M.7..0:--

T P "Mo -MPSEffluent Gross REQUIREMENT A _ ...._"OAAVG AMPFlow. In conduit or thiu SAMPLE -0treamen65 0.048 3 " "* 0 01101 CNtreatment plant MEASUREMENT 5006010 o ! ...Req.. ... -*~~ ~ ~~~ ..... -4.4..1.4

CONTINEffluent Gross REOUIRWENT S-

O)DA AVG DAILY MX 7.. ..... .NNSAMPLEMEASUREMENT PERIIT______________RE0JIREMIENT

.cj::>-..

SAMPLEMEASUREMENT

___ _____________

____ ___,PRM ... ... ....SAMPLEMEASUREMENT PERMIT_REQUIREMENT

." .-. .. .- "SAMPLEMEASUREMENT

PERI T .: ...,... .--_______________REQUIREMENT

.. -SAMPLEMEASUREMENT

-REQUIREMENT

.-. ._ _,_. ." " -' ' ..', -.NAMEITIME I cemy undr U P1ay of WI 11 11* docUm and ad nerchmwft

-Prefd vaide my J TELEPHONE DATEPAINCWAL EXECIIUhI OFFICER d con orjj 0, per~sim In a~m rdicu w4it a *W orn danigna to masue M qmat ai ed Parsonno J -Ipnopady gnawe en evahti f bUfrn nosmatn sutinftta Based an myr Mhiqiy of the permon of penwoin85

-30W123Benjamin P. Youman who mrnag the Uyrernu or Urtem pos dndy raspwanbe r geIhe tihe Irdworelbm o 06/21/2013 wwnftomnib euteriuwites.

to ftn bean of nV bwewadg andt betel tmu, accrate, and 0Wsrqe*Wt&

I. am___ _____________RE_

Plant Manager awawe & mtathere tnd pefnae for Siflt lain kdonrafm kWiie E)JyCU1T OFRCER OR AR NDSim o R p m f ._i _ _an d _ _ _ _ _ _ _ _ _ _ _ _ __Nf_ _v"_l__ A U T H O R IZ E D A G E N T C O D N U M B E R I_ MMD DY Y Y YCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flow existed through this outfall 6 o131 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/1/2012 PAGE 1 0 POOR QUALITY ORIGINALPERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvilWe.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010NATIONAL POLLUTANT DISRGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERE01-0DISCHARGE NUMBER-MONITORING PERIODMMIDDIYYYY MMIDDJYYYY STORMWATER (FORMER 001E)External Outfal* **NO DISCHARGE

-JFROMI05/01/2013 ITOI05/31/2013 II eATTN: Zoo Cox/ENV SPECI QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO.' FREQUENCY SAMPLEPARAMETER EX OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPESolids, total suspended MEASUREMENT 00530 10 PERMIT .-.... s15 30GRABEffluent Gross -REQUIREMENT 300AAVG DAILY MX* .So.toa ssene AMPLE ....o-5oSolids, total suspended MEASUREMENT 0053080+ l

• i. " " ' 30 '100Other Treatment.

Process -t PERIT -.... GRABComplete

" wi .. AVG. D,,L. .GChromium, hexavalent SAMPLE 500..(as Cr) MEASUREMENT 0103210 , MI .- -- ,OAAVG MX "taJL Daily GRABEffluent Gross .REQUIREfE,

-. .. .'", .-.Chromium, total SAMPLE 0 .....(as Cr) MEASUREMENT 01034 10 P9RMIT .... 1 2OWEffluent Gross RM -- DA AVG DAILY I4X , mOIL Daily GRABCopper. total SAMPLE .....(as Cu) MEASUREMENT 01042 10 .. PERMIT ..., ., .5 1Effluent Gross REQUIRBIENT

,_-__ _____, __

• DAV DAILY MX GRABIron, total SAMPLE 500.. ......5(as Fe) MEASUREMENT 0104510 PERMIT: ...... ..1Effluent G ross R EQ UIR EM EN T7 ' _ " _." '_ .. ._ __. .....". ", DAILY M X angIl "all/ G RABLead, total SAMPLE ..... .500(as Pb) MEASUREMENT 0105110 PERMIT ... .2 .4Effluent Gross REQUIREM"NT.

30DA AVG .'DAILYMX (i Daily'. GRABNAMElMTLE I cedit urune penafty of ku Ow Oft documen al a-"acih.les m puivad urdMr my TELEPHONE DATEPRINCIAL.

EXECUTIVE OFFICER cszuctimtor apez~ton iaccoranc

,1a ftoavu 'iag~t inxs w toswiaiqimi.

P-0Mo! DTpapesygamm and evaluta the kdomviilon mmfed. omnm o mynquy of the ped orpwwm 815 406-3700Benjamin P. Youman va, manage tue fystwm, or tmose perm dhreey rasponulble tfo gathmng the bdofmZn 112013titommaton smintt is. o to ft b my aW e aind belef, tm. agmeu.ue and I arn SI=GN RE RINCIEPlant Manager awm thl fte ase aditca penalles tIa tab. Istont , la kditof ft a EARRO NUMBER MMoDCEYYYY

o. ai I O Eaifo AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemlcal cleaning wastewater during the month.2. Flow existed through this outfall 5 of 31 days during the month.1. Therm was no discharge of Fre Protection drain water during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11612012 PAGE 1I POOR QUALITY ORIGINALNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenvile.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010I IL0048313 I PERMIT NUMBERE01-0DISCHARGE NUMBERMONITORING PERIODMMIDDIYYYY I I MYDWYYYDMR Mailing ZIP CODE:MAJOR(SUBR 01) CSSTORMWATER (FORMER 001E)External Outfall***NODISCHARGE 61010FROMII05/01/2013 ITOlI05&31/2013_

I IOUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREOUEUPY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPENickel, total SAMPLE ..(as NI) MEASUREMENT Soo0106710 PRM -1 2..Effluent Gross REDUVREMENTG.'

DLY MX ' -"..pa ly G*Zinc, total SAMPLE * -.***** -- 50(as Zn) MEASUREMENT

__0109210 ...... .... -I 2Effluent Gross REQUIREMENT

--., _.'______

-,. __ j00AV.' DAILY MX .__.____Flow. In conduit or thau SAMPLE .3.D4 3 --0 02/30RABtetetpat0.103 0.243 3... ""* 0 02'0Ctreatment plant MEASUREMENT 50050 10 Refl I .:R h ;N. 0 0230..Req.

M n.Effluent Gross REQURReq. ,V .AILYMX M. , ..Twice Per Month CONTINSAMPLEMEASUREMENT PERMIT. --I.. .REQUIREMENT

"_ ' " ,,_"_" _ " '_ " " _ _ "_ ' __"_"_"_"

SAMPLEMEASUREMENT PERMIT'REQUIREMENT SAMPLEMEASUREMENT PERMIT .REQUIREMENT

' '_. --_.. ._ _,_"._, _ ..SAMPLEMEASUREMENT

.__ _ _ _ _ _ _ _ REQUIREMENT

_______:

_ ......,_._" .__ _ _ __ _ _ "_...:.__.___

NAM~~tITLE E I cetlty uider peflefy at low dW W t e doomnenarid end a efleceents wr rprdwdrmPRINCPAL EXECUTIVE OFR irecriori or aup@M*jon In a mdtirx whh a 6 we r prpae unde TEEaNEDTYe eindt su 0qabdprewm TELEPHONE DATEBnadnP om pn*ropry 0ailer arid evaltre die. Wroaelri adnild Base On my biqudry dl the pinion or prwBenjamin P. Youman ahoe mOeleys.

o- pe-ons drectly MsWpolble f, gaheMai*

kft 8151on406lu 062/2Pln angr ildomuar 8Avftarld Wa to the beat of my bwowledgenard beblef tnre. accndei.

erid =ronuete.

aern 1/2013__

_ __ _ __ _ __ _ _Plant Manager aware fe met e ala p e for abmg lafe uornation, r Ut p y of EXEiTIVE CER OR ARpmoz NUMBER MMfDD/YYYY T ,orftrFW fine and qpdsioloment jar keou vlofallOnR.

A H Z D G TDCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference aU attachments here)1. No Closed Cooling System Drain Water was discharged this month.2. No Servico Water System drain water was discharged this month.3. No Turbine Building Fire and Oil Sump or Generic Non-Chem"cal Cleaning wastewater was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 2

• POOR QUALITY ORIGINALPERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenvlle, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)IL0048313 PERMIT NUMBER001-0DISCHARGE NUMBERMONITORING PERIODMMIDD/YYYY I I MMIDDJYYYY 0MR MaUlng ZIP CODE: 61010MAJOR(SUBR 01) CSCOOLING SYSTEM SLOWDOWNExtenal OutfallNODISCHARGE EZII.FROM I05/01/2013 ITol--I0&31/2013 Ia -Byron. IL 61010ATTN: Zoe Cox/ENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS E ANALYSISTemperature.

water deg. SAMPLE ,- -,88.3 15 0 01/01 CNFahrenheit MWA5LRgEMEMT-miii, " " "iTR q. Mon1::.

O~I0 0 01 1 1 0 o p ally.C O. ,N. : ..T. ...Effluent Gross IMEATUIREME.T

..-*,Rq. -q .aly;CO-TIN pH SAMPLE --- 8.42 8.59 12 0 01/07 GRMEASUREMENT

"-Woekly GRABEffluent Gross IREQUIREMENT'

-MAXIM .* .: -"0040010 .0 '. MINIMUM __" ____. MAXUM ________

___Solids total suspended AMPLE ....- 3.1 3.1 19 0 01/30 GRMEASUREMENT

.0053010 PERMIT.

• u MW. eqR eong : Re. Mon. Monly GRABEffluent Gross

.A. p ..b L *A ... *Oil & Grase SAMPLE ..4 01.4 19 0 01/07 GRMEASUREMENT

,__0055610 PRm -T,' ." -16 .20Effluent Gross

_ __r_-

• _,_ ,_" SODA AVG DAILY MX edGChromium, total (as C SAMPLE -.. <0.0021 19 0 01/07 GRMEASUREMENT 0103410 PEI T02 We" --GRABEffluent Gross REQUIREMENT

, "_ -'_"_-:"

-. ___ _"_"" -DAILY MX L .,SAMPLE ..... .,...., .2 9 0 0/7GCopper, total (as Cu) MAUREME 0.024 19 0 01/07 GR0104210 .-:; GpRAMB *.,-$ "!QEffluent Gross REQUIREMENT

... ....-.-m..L. -Weely GRABZinc total (as Zn) AMPLE --- 0.003 0.004 19 0 01/07 GRMEASUREMENT 0109210 -PERMiT'-

..* -..-. .213 ..433Effluent Gross REQUIREMENT:*

_ --V DAILY Mg".J ---4 " .* ... -NAMEflTTLE I ceffiy under penalty od lw tU documam and all aachunm imwe prupared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER iren a supeaon Inaccordance fth a stm designed to mstau didt qumllied peneil_Benjamin P. Younan who manage the syst h o dose persom nsirectly respotsnbe for gadlihang die kdomallon.

te 06/21=e13 bzdormallon wialubmlld I to thde be ot my lvowldege and IoM. Inte. nomade. and ompnlole.

Iam Sl15FRINCInPLE Plant Manager aware Mat dire ame algnticam penaf for lo tng taoe bUormallor.

Indcslnkg the postaly of I CUTIV OFFICER OR AREA NUMBER MWDDIYYYY TMOR PpOFF'o -m laend Inftslonment lor knmn violatins.

AUTHORIZED AGENT CODENME MIDYYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hers)1. Monitoring data for outfall 001-0 Is Included on attachment.

EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1AM2012 PAGE 1 POOR QUALITY ORIGINALNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

IL 6055S-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron.:.IL 61010IL0048313 PERMIT NUMBER001-0DISCHARGE NUMBERDMR Mailing ZIP CODE: 61010MAJOR(SUBR 01) CSCOOUNG SYSTEM BLOWDOWNExternal Outfall* *

• NO DISCHARGE j*MONITORING PERIODMMDIYYYY T MMIDDIYYYY FROM I05101/2013 I TOI05/31/2013 IAI IN: ,I/:V il"FR UECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OF TYPE>< ANALYSISOxidants, total residual SAMPLE 0.03 19 0 01/07 GRMEASUREMENT 3404410 PE.RMI .0534441 .-m : '-.* " -l,,p m .- Wekldy GRASEffluent Gross REQUIREMENT DAI_____

_-_'__..

-NLY MX -- .e.y G.Priority pollutants total effluent EAUMLE 50050008 10 .Req Mon.*. Req. G..AEffluent Gross REQUIREMENT

-DAILY MX, IWd -DAILY MX WwY GRABFlow, In condui or thin SAMPLES 20.16 274 3 ..... 0 01/01 CNtreatment plant MEASUREMENT 2.62.630 011C5005010 P1 0eq. Mon- Rec. Idbn-Effluent Gross REQUIREMENT SPOA AVG DAILY W.id/d .-Dany CONTMNChlorine, total residual SAMPLE500 50060 10 PEMTA"EUIE

... MXEffluent Gross REREMET ANT .__ _.__ ._ ...._ _ _ _ __ ____ __ __ __ __ _ __ __ __ _ -"___" __ " __ __" _ _____*__

___.. ..... DAILY MX .-Weekly GRABHriSAMPLE 5Hydrazine MEASUREMENT 5008131310 PERMIT **,., .011 .m27 m. Daly WhenEffluent Gross REQUIREMEINT 3"_ _ *_"_,_ODA AVG DAILY MX Discarn GRABSAMPLEMEASUREMENT

• PERMIT .REQUIREMENT'

• _ !. _SAMPLEMEASUREMENT,

• PERMITREQwREMENT:

"_ __ _ " _ _..... _. ._"_. ._"NAMEIIT.E I cWity under penaly of law Va thOf documnt and 5 atmr were pepared undertTELPHONE DATEPRINCIPAL EXECUTIVE OFFICER ltcIJon or supe slonlnaccordance w.ith a B dten to asueaM qMalifiedI p -If -,ae--o_.PHONE4I6-3TE Benjamin P. Youman propet 95111and evaluOs the Informatin srubmited.

Based an fly WqIry of tMe pesmon or peros011 e 815 4030 0-2/2013whr o manage th syWUaI. at those perons directly respomib for gatodn the ftInformation.

the /S! E1F"LIEPtant~na~er Ivn~ht~mm Pniismu subirad I.to the best ofmy Inowede nd befie. tue. ac=WA. andcnit lan ARANUB5nMD Plant Manager .lr ~ o ~ ~ ~ ~ ~ ~ iw ~1ICiI E FCER OR REA W_______ n md b t for knano viorm AUTHORIZED AGENT C NDiYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/08) Previous editions may be used. 1A/2012 PAGE 2 O POOR QUALITY ORIGINALPERMITTEE NAMEJADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvllle, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 Norlh German Church RoadNATIONAL POLLUTANT DI*ARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)OMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBER002-0DISCHARGE NUMEMONITORING PERIODMM/DONYYY

-j I MMDD/YYYY STORMWATER RUNOFF BASINExternal Outfall*NO DISCHARGE E .FROM I05/01/2013 05/31/2013 IIByron. IL 61010ATTN: Zoe Cox/ENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSISSolids, Total Suspended SAMPLE 500MEASUREMENT 0053010 PERMIT. .' .15 30m:..' "". ' " O8DfAVA ..-DAILY MX° , .-.w GRAEffluent Gross REUILREMENT

, ,*D, ,G- DM-GRSAMPLE -Solids. Total Susp I MEASUREMENT 0053080 a- -_-.... .. *.-.R T .-R..Uoo " GRABOther Treatment.

Process 3" We. AP..Complete

., -" ... .""__....Chromium.

hexavadent SAMPLE "500(as Cr) MEASUREMENT

-_01032 10 -R .. -, , ... .. ..___ ,__ ,01 .OAAG .0LYX inq30 IDaI RAEffluent Gross REQUIREMENT YOf .041DilChromium, o SAMPLE Soo(as Cr) MEASUREMENT 0103410 PERMOI, T"2 mg/L GRABEffluent Gross REQUIREMENT 30DA AVG DALY MX RCopper, total SAMPLE .5(as Cu) MEASUREMENT 01042 10 PERMIT =025 .041Effluent Gross REQUIREMENT 0 -,,DA AVG DAILY MX. m.... Daly GRASIron. total SAMPLE .. .. ... --I500(as Fe) MEASUREMENT 0141 PERMIT GRA0104510 "- R.EQUIRMEN

_...._._,

______ ,, -::.',**

.. ",,, .I .....YM...Da.l~y GRASEffluent Gross ,REQU-REMENT

--." DAILY I1 ,Lead, total SAMPLE Soo(as Pb) MEASUREMENT 0105110 PERMIT 1 "' .063 :.298Effluent Gross REQUIREMENT'-

-. *.-

MX Da""""GRAS NAMEnM.E I centy under penalty of law Ow Ofl docurnme and al attachmentar m prepard widar my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction a, supevisiotn in accodance vaU a system designed to assure Me~ qiiUm parsonnel

__propelty gamer and evakluea ft Inom uftinmed.

Based an my kfrquiy of the pemon or pemrsons 9Y5 406-3700Benjamin P. Yoursn who managmem system or mose persona dkly r*spwoaato fr goal-e-g

-the idomionf 06/21/2013 enformatn

__ftntid Is to ft bo o my loled and blief. lim, acuMLand Cmplte. Iain SI RE,0yPRINCIPLE Plant Manager aware haI tere am signiicarU penalties for jbkftkn false Information.

icamdng the pos.syol ofITI OFFICER OR AREA-Ean PAhN fione mand inprs sio'arM for bwowig vfalatons.

AUTHORIZED AGENT CODE NUMBER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference oll attachments hers)1. No Turbine Building Fire and Oil Sump or Generic Non-Chemlcal Metal Cleaning Wastewater was discharged this month.2. No Fire Protection or Service Water System Drain Water was discharged this month.3. No Closed Cooling System Drain Water was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/612012 PAGE 1 POOR QUALITY ORIAIIN1.

PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, 1 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010ATTNM 7n rm n.JFNV RP::NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)OMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBER002-0DISCHARGE NUMBERMONITORING PERIODI HMMDJu n I I MWDD/YYYY STORMWATER RUNOFF BASINExternal OutfallNODISCHARGE EZJFROM I05601/2013 I TOI405&31/2013 IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSISNickel, total SAMPLE ....... So(as Ni) MEASUREMENT 0106710 *E0AV .V8 DAILY'MX

..il. .-Day- GRA.Effluent Gross REQUIREMENT 300A AVG _ __ _ _ __Zinc, total SAMPLE 5...00(as Zn) MEASUREMENT

..____ _-_5_00109210 PERMIT. .04. -. ;AMaly. GRABEffluent Gross REQUIREMENT

-. -300A AVG DAILY M.X t g/I. , D AOil and Grease SAMPLE ....... ..... 500MEASUREMENT 03582 10 5PERIT 2D* 1.2 When* "* "300 AV " DAILY MX ," .-D ischargling9 RAEffluent Gross REQUIREMENT:

__________

___ SDA AVG DIYM oi IAFlow, in conduit or thru SAMPLE ...... 500treatment plant MEASUREMENT 500501 0 PFMIWT Req. Mon. " Req.DAi.

EST.MAEffluent Gross REQUIREMENT, 3DAAVG DAILY MX- F -'*:" ESTIMASAMPLEMEASUREMENT PERMITREQUIREMENT SAMPLEMEASUREMENT REQUIREMENT:

..I___.____.___-___-_

SAMPLEMEASUREMENT REQUIREMENT

" .-"__"_"..

" ""___"_""'

MNAMTIE I Certify under penalty of law mt this docwner and an sfladitrnerl were Papd Uwder my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER directon or upevion in accordance with a systemr desgned to assure qud PemrTonnELPeONElD pmpedy gather and evalute suibrred.

Based on my iqtyf o Person o Pesons 815 406-3700Benjamin P. Youman ft, "mange systeme or Ose persons dirctly rasponsria for gathein te Onlomtatondo.

06/21=013 tratmiasion aubridua Is. to ft beoo of nay knasriedg arid balief. true. accurateana d cple.Iami Sir ' RI~IINCIPLE Plant Manager ware Iat them re alsignfIcant pertaites lot sunbtnrg tabse Infonnation, indudtrag me posaslityof (ECaC E OFFICER OR AREATYPED OR Sfe and risnVfo nm vlo AUTHORIZED AGENT CODE NUMBER MM/DDYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. This discharge point was not used this month.2. There was no discharge of processed steam generator chemical cleaning wastewater during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/120"2 PAGE 2 ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 May 2013Page 1 of 2MONITORING DATA:WBD CRock RiverDATE Temperature mgd Flowdeg F cfs05/01/2013 81.1 11.34 18,60005/02/2013 79.7 16.04 17,50005/03/2013 66.2 23.76 17,00005/04/2013 75.2 26.19 16,60005/05/2013 75.2 22.02 15,90005/06/2013 76.4 14.84 15,20005/07/2013 74.9 23.10 14,50005/08/2013 78.7 16.67 14,00005/09/2013 78.7 22.51 13,40005/10/2013 77.5 17.36 13,80005/11/2013 80.4 26.58 13,80005/12/2013 80.4 21.63 13,60005/13/2013 78.3 16.68 13,50005/14/2013 88.3 21.31 13,40005/15/2013 88.3 18.98 13,20005/16/2013 83.8 19.21 12,80005/17/2013 80.4 14.09 12,20005/18/2013 84.0 26.77 11,70005/19/2013 85.7 21.37 11,40005/20/2013 87.2 14.24 11,20005/21/2013 87.2 21.13 10,90005/22/2013 86.0 19.06 10,50005/23/2013 82.3 20.79 10,30005/24/2013 76.1 21.60 10,20005/25/2013 75.0 27.46 10,00005/26/2013 77.4 15.05 9,81005/27/2013 79.0 22.63 9,74005/28/2013 85.8 18.72 9,79005/29/2013 86.5 20.27 10,20005/30/2013 88.2 22.09 10,20005/31/2013 87.8 21.36 10,300K:\BYR_CH\BYRON.DB\Clerk\4onthly Discharge Monitor Rpt\2013\May\May 2013ATTACHOI.docx ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 May 2013Page 2 of 2HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (or associated rinses) containing hydrazine discharged to the Cooling System Blowdownduring the month of May 2013.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite and Bromine compounds were used this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 31 of 31 days.4. Per Special Condition 24 the influent from the Rock River and effluent fromOutfall 001-0 was monitored for Total Suspended Solids (TSS) this month.The Rock River TSS value was 11.2 mg/L on 05/06/2013.

The CWBD TSSvalue was 3.1 mg/L on 05/06/2013.

5. Rock River flow for May 2013 was >2400 cfs therefore daily temperature calculations were not required this month. (Special Condition 12).6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in May 2013. (Special Condition 15).K:\BYR_CH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\20133\May\May 2013ATI'ACHO1.docx Exelon.Exelon Generation

Company, LLC www.exeloncorp.com Byron Station Nuclear445o North German Church RoadByron. IL 61010-9794 July 18, 2013LTR: BYRON 2013-0096 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyWater Pollution ControlCompliance Assurance Section #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring ReportIn accordance with National Pollutant Discharge Elimination System (NPDES) PermitNumber IL0048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report for Byron Station, Units 1 and 2. This report covers the period ofJune 1,2013 through June 30, 2013.If there are any questions regarding this report, please contact Ms. Zoe Cox,EnvironmentaVRadwaste Supervisor, at (815) 406-3035.

Respectfully, Benjamin P. Voum?Plant ManagerByron Nuclear Generating StationBPY/ZC/eh Attachments bcc: Kevin Hersey -Sr. Environmental Specialist

-Cantera (electronic)

Zoe Cox -Environmental/Radwaste Supervisor

-Byron NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMrrrEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010IL0048313 PERMIT NUMBERA01-0-DISCHARGE NUMBERMONITORING PERIOD IMMIDWYYYY

_ MMIDDJYYYY DMR Mailing ZIP CODE: 61010MAJOR(SUBR 01) CSDEMINERALIZER REGENERATE WASTE (001A)External Outfall* NO DISCHARGE

[ 'FROMI06/01/2013 I TOI0&/30/2013 I enATTu: Zoo CoxIENV SPEf'PARAMETER QUANTITY OR LOADING1 r 1VALUEVALUEUNITSVALUEI 6 4 I ISolids. Total Suspended 0053 10SAMPLEUPACIIAURI1:PT MEASUREMENT1..

FERW T,:...,FChromium.

hexavalent SAMPLE ......(as Cr) MEASUREMENT 01032 1 0 PERMIT .' ",***Effluent Gross REQUIREME

---Chromium, total SAMPLE ......(as Cr) MEASUREMENT 01034 10 EMT*Effluent Gross ..UIREMENT

-I -=Copper, total SAMPLE ....(as Cu) MEASUREMENT 010421 0 .- .,. .,., -, -.. ,rn.Effluent Gross REAUIREMENT

" .," "'Iron. total SAMPLE ...................

(as Fe) MEASUREMENT 0 1 0 4 5 1 0 -I .I ..I, -, -.. : -..... ..Effluent Gross REQUIREMENT

,Lead. Total SAMPLE ........................

(as Pb) MEASUREMENT 01051 1 0 PR. PEMIT ._. ...'. 21 .-'.Effluent Gross REWUIREME T * --.T-.. ---Nickel, total(as Ni)0106710C~HI SAMPLEMEASUREMENT It NtMEASUEMEN

--iIPPRMrr NAM.~ ..== .........

llýNAMErnTrLE PRINCIPAL EXECUTIVE OFtICERBenjamin P. YounanPlant Manager1Mw oR PRINrMI cattify under penalty of law that t=ds document and all attachments worn pnqeae under mydirection of supervision at accordance with a system designed to assure thaO qualited personnel property gather and evalute the inf onnation subnfed.

Based on my inquity of the poeson or personswho manage the system, or those pers"os d W responsi for gathedng the nf ormation, theInformation submitted is. to the best of my knowlodge and bewef, tree, accurate, and complete.

I amaware that there are sinlfica penalties lot submtltting false Islomialn, Incltefudjng the poesitbliy oftee and IMrpslonmen for knowing violations.

COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed 30 of 30 days during this month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 1/6/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4460 North German Church RoadByron, IL 61010ATTN: Zoo Cox/ENV SPECDMR Mailing ZiP CODE:MAJOR(SUDR 01) CS61010110048313 PERMIT NUMBERA01-0DISCHARGE NUMBERMONITORING PERIODMMIDDIYYYY I MMIDDIYYYY DEMINERALIZER REGENERATE WASTE (001A)External Outfall* *NO DISCHARGE FROMI06/01/2013 I TOI06130/2013 IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER

___ __N. OF SMLVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPEZinc. Total SAMPLE ... .(as Zn) MEASUREMENT Soo0109210o..

PERMIT ..., ......._.. .. ....-2 , -. :Effluent Gross RQUIR EuNT , 0 _ ." bDA AVG. DALY MX" , ' : : " -.AFlow, in conduit or thru SAMPLE 0057 0.301Etreatment plant MEASUREMENT 0.057 0.243 3 .........

0 01101 ES50050 10 RPEReT , *.q. Mqn; Re, e, Mon: ..... -. .Effluent Gross REQUIRdENT

• AVG PAILY:1..

"T " -" -': ":"'"" * " " NISAMPLE ------MEASUREMENT

________

__________

REQUIREMENT

.p ... .. ..SAMPLEMEASUREMENT

" ..___- .___"_. ... .REQUIREMENT

--:; .... ...-.... ._ ....PE M T. ...... ......... .., ..., .... .. :, ..i .: ' : ! ' :SAMPLEMEASUREMENT Sp.EQUIR.EM T -F -.-. .:,:_.SAMPLEMEASUREMENT

'__._'_'.

_"_" _-_ "PERM .... ... , ...._ _.-. .....SAMPLEMEASUREMENT I. I : ...., ..... .LEAUREMENT

-.,-,Y -.-.....MESREMIIENT NAME/fTILE I cetiy under penaly o law that this document and all atladunents were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER d irecun m a supe wao in accordance with a system " to .th i qua led peT EonnLEPHO properly gather and evetute the m ormnatlon aubmitted.

Based an my irnqusY of the person or p 81 4E06-370Benjamin P. Youman who manage the system, or those persons directly responstote for gathering the mtomalion, tte F 0--.- =.1 07/18/2013 nformatlon submitted.

to the beet ci my knowledg, and bfllf. true. accurate, and complete.

an SIGNAEOFVM CIPL TPlant Manager aware that there are signiftant penates for submitting false Information, Unudn tle posis 4 of EXE TIVE OFFICER OR AREA N 13Sa ne and for knowing vdaliea.ns, AUTHORIZED AGENT COD NUMBER MM/DDYYY_

COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flows for June 2013 are estimated based on July 2012 values due to totalizers being Out of Service.

The totalizers are an obsolete model and work orders are In place to findreplacement totalizers and get them installed in the system.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)DMR Mailing ZIP CODE:MAJOR61010PERMWTrEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010ATTNW 7n IL0048313 PERMIT NUMBERIB01-OI (SUBR 01) CSI DISCHARGE NUMBERD_ýISCHKARGE NUMBER IMONITORING PERIODMMIDDINI MMIDDIYYYY STP PLANT EFFLUENT (FORMER 0018)External Outfall* 6

• NO DISCHARGE FROMI06/01/2013 I TOI06/30/2013 Il iQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPEBOO. -Day SAMPLE 0.38 0.40 26 ...... 5.5 7.0 19 0 02/30 24(20 Deg. C) MEASUREMENT 0031010 I5.3 10.5- .0 T.Effluentt Gross REQUIREMElNT 300&6RA A I AILY.MX ._____ OA AVG. PAILY W:~ wi~~rMpf O~pH SAMPLE .............

7.52 7.60 12 0 02/30 GRMEASUREMENT 0040010 " "-PER4II

.." .* .' " * " o --,Effluent Gross REQUIREMENT

.. > .N UM :."__:__".

.,..MUM -........

.,Solids, total suspended SAMPLE 0.23 0.31 26 2.9 3.1 19 0 02/30 24MEASUREMENT______________

_____Effluent Gross REQUIREMENT S,,A vG .PALYMX -

AjLY. " i--g.. ..r .C '205ow 1 in conduit or thrR SA3,IMPLE*.

.... .FwinodtrhrSAPE 0.008 0.014 3 ...0 01/01 CNtreatment plant MEASUREMENT 0____ 0.014 3 0 01_01 _ _50050 10 a..*- ,p. ., -R=. -=,, Req. h" ...... -'- ' ...Effluent Gross REQWRMU IT 300A AVG. .-DALY MX 73;_____

_____~SAMPLEMEASUREMENT

.. .. -......... -SAMPLEMEASUREMENT

• PERMIT-.

."- .-. ". "_____________

R"EQUIREM04T

._ __________

SAMPLEMEASUREMENT,

..PER .. ..: , -..- -.-* P*:: .:.. : -: .,, ".......

__._:____

NAMETL..E I cattly under penaty of law dhud ds document and all attachms were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction or SupeMWlniin acordance with a system designed to assure that qualied personnel Spcoperly gauer and aletyo lae tht e nfdonsubmittent a Sed a n myentquryd epe-onorpem,

.815 406-3700Benjamin P. Youman who manage p te systemr on 1aute persomans auy msponsit ad gatherng te SnINatR, the 07118/2013 information submitted is., to tie best of my knotedge and belief. true, accurate.

and complete.

I am SIGNN _URE O0_ __NCIP-LE Plant Manager sware that there are slgndicant penalties for umnittmg false infomnati, Includin the porsllty ao EXECUTIVE OFFICER OR AREA NUMBER M/DD/YYYY TWDOR PIMM ,~ line and imprisionmest for knowving AUTH'ORIZED AGENT CODE N M E MD)Y YCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flow existed through this outfall 29 of 30 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITrEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCAT1ON 4450 North German Church RoadIL0048313 PERMIT NUMBERC01-0I DISCHARGE NUMBERDMR Mailing ZIP CODE:MAJOR(SUBR 01) CSWWTP (FORMER 001C)External Outfall61010I MONITORING PERIODMMIDDIYYYI MM1DDIfYYYY FROMI06/01/2013 I TOI06130/2013

• NO DISCHARGE

= ...IByron. IL 61010ATTN: Zoe CoxIENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF YPVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALY TYPESolids total suspended SM......

6.4 7.4 19 0 02/30 24MEASUREMENT 0053010 7 PERIT --pMM 36*.' "' "'.*. 1 0Effluent Gross REQUIREMENT-

._._., 300DA AVGChromium, hexavalent SAMPLE .. ...... 500(as Cr) MEASUREMENT 0103210 .P"MjT .2...."-"-

" "e" .v- : '.. *l AEffluent Gross 7 R5,UIIUEMEIl'

"... ' A V... .' ..- K -..Chromium, total SAMPLE ............

.....(as Cr) MEASUREMENT 0103410 2 ". * * ... ..- -: ... , .Effluent Gross .300A AVG -AILYXI " " " ......" -Copper, total SAMPLE 50......

S(as Cu) MEASUREMENT 0104210 77* PERi * +.. *.*..* .!..q. -.1Effluent Gross REQUIREIEN..

,.....-......

.--..." 30DA"AV%

... '.- LY.MX ",......Iron. total SAMPLE .... .(as Fe) MEASUREMENT 0104510 pE1wrr .--,- .., .* " .... ... -,- -Effluent Gross XR..IREMENT

-_.. ..,. -..." " -.-.-Lead, total SAMPLE ... ... 50S(as Pb) MEASUREMENT 0105110 2-. P " .AAV" ",D J'YM- m _'__ _"-.,Effluent Gross REQUIREMENT

" .0DA.V D:-.A.LYNickel, total SAMPLE ...... ...... 500(as NQ MEASUREMENT 0106710 OIT .*.,_ 1 2'.Effluent Gross :.REQUIREMENT

" 0-' --4, .O.... DA.LY......

• ....IAME/'TTLl.E I certify under penalty of law that this docwnent and all attachments were prepared under my TELEPHONE DATEPRINCI,1PAL EXECUTIVE OFIFcERfi direction supervisma In accoorance with a system designed to assure #a0 iuafi'id persnnelPprey gather and evalute Me infonnation submitted.

Based on my inquy of the pero or persons , 815 1406-3700 Benjamin P. Youmnan who manage Ing systern, or those persons directl resposb lot gathrn the wlornlation, th 07/18/2013 information submitted is, to the best of my kowledge and belief. true. accurate, and complete.

I am MG_'__F I_-CIPLEPlant Manager aware that there are significant for subnftg false infomation.

including.the possiblily of EXECTIVE OFFICER OR AREA fi ne and imprisionmant for Mowin violaiias.

AUHRZDAET C4D NUMBER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed through this outfall 20 of 30 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIT'EE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 44S0 North German Church RoadByron. IL 61010DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS610101L0048313 PERMIT NUMBERCo010I _DISCHARGE NUMBERF MONITORING PERIODMMIDDIYYYY I MMIDDIYYYY WWTP (FORMER 0O1C)External Outfall** NO DISCHARGE E ...FROMI06/01)2013 I TOI06/30/2013 QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS F ANALYSISE Zinc, total SAMPLE .............

500(as Zn) MEASUREMENT Effluent Gross RlUIREMENT

.........

_"_ T30DA AVG. DAILY MXRow. In conduit or thru SAMPLE 0,024 ...... ......treatment plant MEASUREMENT 0024 0.041 3 0 01101 CNMEASUREMENT Effluent Gross MXEURMN PD V ~ ~~* Mg ~1*SAMPLEMEASUREMENT SAMPLEMEASUREMENT MEAQUIREMENT-SAMPLEMEASUREMENT

• -, PERMIT .... ..: "__ _ _ _ _ _ REQUIREMEW.

A___SAMPLEMEASUREMENT____

--PRMIT-. .SAMPLEMEASUREMENT_____

_____ _____________________

_____"~MIT .... .. 7.-K.NAME/TITLE I cartRy under penalty of law hat to documenm and al attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUiVE OFFICER drecbln Of SpMiOn in accarance with a system designed to assure dao qualified permonnel r P.perty gather and evahl fte Information submitted.

Based an my Inquiryof md th pero or persons 81 407/37002 Benjamin P. Youan whosmanageteSystem, or mose persons dIrectly responsbwe lor the iomatl. 07/18m013 mformadon submitted Is. to mae best of mtr bnowledge and belle'. true, accurate, and complete.

Ilam SIGNAV OF P CPLE____________

Plant Manager aware that there are aignffea penales tor submftng talse infortaio.

ic me posalt EXECUTIVE OFFICER OR AREAOR PCTE tne and kntpsoent tof knowing vilations.

AUTHORIZED AGENT [CODE NUMBER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/2012 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITrEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

L 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERD01-0F DISCHARGE NUMBERMONITORING PERIODI MMIDDINYYYY I MM/DDJVYYYY RADWASTE TREATMENT (FORMER 001D)External Outfall*I*NODISCHARGE E: ...FROMI06/01/2013 1 TOI06/30/2013 I iI IATrN: Zoo CoxIENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS E ANALYSIS TYPESAMPLE ...... 2.4 4.1 19 0 02/30 CPSolids tota suspenda MEASUREMENT 0053010 PERMfIT.

.. .,.T*- , 15- .'. " .. ..Effluent Gross .eQuiReENT

-""" .." -300. AVG PNYMX :..Row, in conduit or thru SAMPLE ...002 ......0..30 11tetetpatMAUEET 0.022 0.024 3 ...0 01/01 CNtreatment plant MEASUREMENT

_____ _____ ___ _____5 0 0 5 0 1 o0 P-. u M i T "., R eq .M o R eq. 7o. .-.... -.' .". ."--Effluent Gross -REQUIREMAENT 39W j AY -. AlYX __SAMPLEMEASUREMENT

__ _ _ __ _ _ _ R QUIREME T ..;... .-: ... -- ....:- ._ .... ....-,*.. -... -,.:..SAMPLEMEASUREMENT D m u ' " .-..."-" ' -." I .:"1 " ,." '- ." I. **S*-,m E , .,, ....... ,.. .-. .:, t.. .,SAMPLEMEASUREMENT

, .. .* .-.... , I ". .: -' , :... ..-: `::. _,__ _ REQUIR -.. *_". .: , _ _.._-'_...

... .. ...-SAMPLEMEASUREMENT P. "MFr. ...*.

...: ... ............ .- ...... .- ... .. ,. -. -.-, ...- -. ..... .. .... ...... ' .::-':::

-:. ..,______________REQUIREMENT A. ____ ______ ---------

__________

____SAMPLEMEASUREMENT PERW .-.NAMEa .E I cedy under penalty o law that due document and al attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER or supervtslon in accordance with a system designed to assure that quaified B gather and evalute the info.mauton submited.

Based on my Iily d the person Or persons8151406.3700107/1 Benjamin P. Youman wh'o manage tUe system.n or those persons dirctly for gathering the inforlmabn, the 07/118=13 Information submitted!

is. to Ehe bes of my Icowleoe and befiet. tue. accura, and complete.

Iam OF PI CIPLE _ _ _Plant Manager aware that there am signilicant penalties for sutning false lnformaion.

including the PmMY of EXECUTIVE OFFICER OR AREAOR -fne and lo owing violations.

AUTHORIZED AGENT CODE NUMBER MM/DDjYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flow existed through this outfall 5 of 30 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/8/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60655-5701.

FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010IL0048313 PERMIT NUMBERE01-0DISCHARGE NUMBERDMR Mailing ZIP CODE.MAJOR(SUOR 01) CSSTORMWATER (FORMER 001 E)External Outfall... NO DISCHARGE 61010S.MONITORING PERIODUM/DD1WYYYV M M1DDYYYFROMI06/01/2013 I TOI06/30/2013 IATlN: Zoe Cox/ENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER

____OF SMLVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESolis. total i SAMPLE .........

5..MEASUREMENT 0053010 1PE5rI" m. , .30Effluent Gross REQUIREMENT

... .___"_""__

300A AVG DAILY'M).

' * ........Solids,SAMPLE

...... ...... ...... 25.2 27.0 19 0 01/07 GRMEASUREMENT 0053080Other Treatment.

Process R1U -e G+.Complete

_____ _____ 4~~DA( Ath ~- ____Chromium.

hexavalent SAMPLE ..500(as Cr) MEASUREMENT

...... ...... ......_Soo0103210 :p -"+ * -" ...... ....- ' : 2 '" ily" " ,: "Effluent Gross .REQUIREMENT-

" --. ., .", ' 3ODAAV Q DAILY M ,, _,"Chromium, total SAMPLE 0(as Cr) MEASUREMENT

...... 5000103410

, ..... .1 .".....Effluent Gross RE"UIEP ..-..- ' -..ODA AVQ ..ILYM '- .Copper, total SAMPLE ..... 5(as Cu) MEASUREMENT

..- 5000104210 >:P IIT..IT '" "'- " -"' .s- :Effluent Gross REQUIREMENT

, " .:;,A V ,L , ,. .Iron, total SAMPLE ...00(a e A P E.... ..... ......nl(as Fe) MEASUREMENT 5.001045 1 0 " I " " .-.- ,:" .. .5Effluent Gross .RE UI.EME"T

" " .". : -OA.j" Y".X* ..Lead, total SAMPLE ......................

.'1(as Pb) MEASUREMENT 5000105110 " , -- .2Effluent Gross REQUIREMENTS',

."'" -... -. ,....- -30DA AVG --WNAMEITITLE I centfy under penalty Of Law thaO tho docmeun and al anachrents were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER drectlon 0r Sup o I aMo-dance with a system designed to assure that quamted personnel

__PNDApropery gai11W and evaue fte mitomma subnmt .BaSe on my hquiry d the persm o, pemrsona1 406-3700Benjamin P. Youman who manehystem te person directly spo tor atengnoe iomon. the , 815 406-3700 07/18/2013 Wmatinaon subrmeite is. to fte best as my knoattede and belef. t=u, accrate, and compete I am S GNA E OF PPICIPLE

________________

Plant Manager awam th'i tre arm sgdiant penatoes for subrnttkg the pos14telty EOFER OR AREATWED.O OR PMCD_1 rine and pfnionment for knowing violations.

AUTHORIZED AGENT MODE NUMBER M/D/YYYYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during the month.2. Flow existed through this outfall 6 of 30 days during the month.,3. Theem was discharge of Fire Protection drain water durina the month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 116/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010IL0048313 PERMIT NUMBERE01-0F DISCHARGE NUMBERDMR Mailing ZIP CODE:MAJOR(SUIR 01) CSSTORMWATER (FORMER 001 E).External Outfall61010MONITORING PERIODMMIDDIYYYY MMIDDMYYY FROMI06/01/2013 JTOI06/30/2013

• *

• NO DISCHARGE

= ...QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS E ANALYSIS TYPENickel, total SAMPLE ..........

(as Ni) MEASUREMENT 0106710...,

.... .... ,., 1 2Effluent Gross REQUIREMENT

..300A AVG DAILY " : D.lyG'A'Zinc, total SAMPLE ...... ....... 500(as Zn) MEASUREMENT

.: .T... I.. ........... .... .... .-. -.0109210 " RERMIF .": " ...;. ,... .. ..*, 1 .. ..Effluent Gross REQUIREMENT..

._.-_300AAVG DAILYMX':

"- " " -. -Flow in conduit or thru SAMPLE 0.355 0.731 3 ...............

0 02/30 CNtreatment plant MEASUREMENT 500501 0 P.. PIRIl1" Re* .P 4,. Req. Monm. ".'.," CN'.""Effluent Gross REQUIREMENT

,QA AVG. 'ALY.,M.

" ........

" ..T.. : " " Month'.SAMPLEMEASUREMENT SAMPLEMEASUREMENT

.,REQUIREMEN

., .. , , ..SAMPLEMEASUREMENT p w .r ... .-.-.*.. ..... " ... -,':" REQUIRE ENT .. "" ..... .:..J-.-

, "-,_ "" ": " _..

.. ... .. ... ..... ........."..',...:...".'.

-..... ........

.... .SAMPLEMEASUREMENT

.R M .,: : -. .-.- -' :, -!. ..- , ..]'- .: '-: ..: .. i .... -. : I.: : -: " ..-.' .. : , , ..-"... .-1... 0.. .' : ._ ,. V.. .,.- 'A:.:.;'NAME/TtT1.E I certify under penafly of law tha this document and all attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUtIVE OFFICER drection or supeision in accordance wia a system designed to assure What quailed personnel Iproperly gather and evabute the infonnation submitted. an my inqky of tre person at persons El, '# 8546370Benjamin P. Youmnan who manage the system. or Viose persons dlrctly responsible for gatherang the information, the 07/18013information submitted Is. to the best of my knowledge and be lef, true. ac irate, and com plete. Inam SIG N --RE O F " P P "Plant Manager aware tat here are signhtcAnt penalties for subawling lalse mfonmati, Incding the possifbty ci EXECUTIVE 0 ICER OR AREAUMB.-lme and pnnl nowg wsts AUTHORIZED AGENT COD NUMBER M_/DD/__YY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)1. No Closed Cooling System Drain Water was discharged this month.2. No Service Water System drain water was discharged this month.3. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Cleaning wastewater was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 2 NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMJTTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010OMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010L IL0048313 PERMIT NUMBERI 1 001-0I DISCHARGE NUMBERMONITORING PERIOD MCOOLING SYSTEM BLOWDOWNExternal Outfatl* *

• NO DISCHARGE FROM I06101/2013 I TOI060=13IATTN: Zoe Coy]ENV SPEC______________

____________________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER FO. OF TYPE* VALUE VALUE UNITS VALUE VALUE VALUE UNITS AALYSISTemperature, water deg. SAMPLE ... .. 91.6 1 0 01/01 ONFahrenheit MEASUREMENT

_........._91.6_15 0_00001110 ... IMII Fq. M11.Effluent Gross MOEQUIR EMEN "_r"_ "_"... _.. __.... ,'. * .-" ,F .' :? 11'" "pH SAMPLE ...... ... ..... 8.46 ...... 8.76 12 0 01/07 GR0040010 'z-':.PER..

I .. .*": --: 'SU -6'. eI -...Effluent Gross REQUIR.EM" MINIMUM ..MAIMU .Solids, total suspended SAMPLE ....... .. 3.0 30 19 0 01130 ORMEASUREMENT

...... ... ...._.0_,0_90_0____

00,53010

-.:..J. ' " ,.ER.' :: ., ..-'MOn...-.

'..: e: , " :ýý .:: .;': ... " .; .-."r ... :zEffluent Gross .REQUIREMENT

.....301)A VG

.. ..:. fR..- .tt ... L.-Q ,Oil & Grease SAMPLE ...... .1.4 -1.4 19 0 01/07 ORMEASUREMENT

<.<119 017_.- *. ... , ..-- .,. -.... -.. 7.o 700556 10 '* 10z1M- .' .:.1 ,, -.. Effluent Gross "0 , .-",:, ,.-..., _" ODA AVG DA, LY MX. Wa... ....Chromium, total (as Cr) SAMPLE .... 21.07.MEASUREMENT

_.002_19 0 01/07 GR1.... nu .. : : -I --o -.:. , : ,01034 0 " .'Effluent Gross .REQUIREMIff..

-, .-,..W..-.

.A'.Copper. total (as Cu) SAMPLE ..01900R.. .....REM"NT 0.024 19 0 01/07 GRMEASUREMENT 40___1 017_010421.0 0 ' .'-"_ _ _ _"_ _*_ ._ _ ._ _ ,. n",.I ; .... ~ 9. ky. O Zin.C, to ala (as Zn) *fliJ .. ... -.. ...0 0 8 90 07OMEASUREMENT

__.__4__008___0____7__

01092 107, 7 .. ,,,. ...... .4 -IEffluent Gross RIQUIRUSENT ...:_____-.

"....QDA AVG DALY -:L ....M..' ."..NPAME/TITLE I catr*y under penalty ot law that alf docun, and all aeaclments were prepared my TELEPHONE DATEPRMWALEXECUTVE OFRFR dirction or superviion in accoomance with a systemn dege to assure tha qualroad pesornnel prolxS4 gather and evalute the ilorthation subn~ted.

Basen rmy bwutry at the person or peron 815 140-30'

,..Benjamin P. Youtman who manage the system Of Vtcs. persons drectly responsabe tor gathertngtle tnfomatla, te GP 8mtoomatton submitted is. to the best of my knowledge and beaea, true, accurate.

and complete.

I a SIGNAnE OF PCLPlant Manager aware that there are signilicant penalties for subding slatseo nonmam, hcdng Mte pessay ol EXECUTIVE OFFYCER OR NREA, ao RPWM fine and ltnpiltonmeit flor lotvatri9 vloalions.

AUTHORIZED AGENT ODNUMBER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hers)IA MonitForm da0- (r ou0fal1 001 -0 is included on attachmenu 1EPA Form 3320-1 (Rev 01/06) Previous editions; May be used. I!stm12 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 6055 -5701FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadDMR Mailing ZIP CODE:MAJOR(SBUR 01) CS61010110048313 PERMIT NUMBER001-0DISCHARGE NUMBERMONITORING PERIODMMIDDYYYI MMIDDJYYYY COOLING SYSTEM BLOWDOWNExternal Outfall, ..NO DISCHARGEEJ FROMI06/01/2013 TOI06/30/2013 Byron, IL 61010ATTN: Zoo Cox/ENV SPEC QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OF TYPE1 <ANALYSIS

____Oxidants.

total residual SAMPLE .............

....... 0.05 19 0 01/07 GRMEASUREMENT 34044 10 "pF!M ...* ,,, .05 --*Effluent Gross REQUIREMENT.

' ." ." .QALY.M ."'e'. .(3RSAMPLE .........

500Priority pollutants total effluent MEASUREMENT

... e500081 0 IERT .1 -I-. SJL 'Effluent Gross " QRE jiji lEM ___f_'" '. *.... ,AI&YM)(

D.AN... X. .Flow. in conduit or thru SAMPLE 21 3 2154 3.......

0 01/01 CNtreatment plant MEASUREMENT

., '. .'_r -_,5_ _ _'" .. .._" ' .NEffluent Gross ".REIOUIREMEINIT WqAAV-k ..,__ ...... ..Chlorine.

total residual SAMPLE ........

.........

500MEASUREMENT

'Effluent Gross REQU __________

.PAll-VMX' mgIHydazneSAMPLE

...... ...... ......." Soo0Hydrazine MEASUREMENT 8131310 N T * ." -__________

.0AAV ;"- 7 Wln.Effluent Gross ;"EQUIR EMW T .".:." _".-' " ..._ .- ': ' " AAVG.II-,.

SAMPLEMEASUREMENT OPUMIT ....REQUIREMENT

• _"'" *_" "_ " "" " " ' : " 'SAMPLEMEASUREMENT P.: ER-. rr°-L ..:.- .... ... ... ......;- ,. .. ... ' " ." " '-..__ _ _ REQUIREMENT

,. ...... .NAMEnnM.E I certify under penaly of law hat docunentad all attachmens were pelpre under my TELEPHONE DATEPRINCIPAL EXECLlVE OFFICER direction or superion in accordance with a system designed to assure hat TualE O perTnnelE properly gars and evalute the Inlormation submitted.

Based on my inquiry of tte person orpesns 815 406-3700who manage tle system, or those persons directy responsibe for gathering mte informaton.

SIGNmRE.

1R20CIPLE_

Plant Marnagler infonmaion submitted is. to the best at my inowiedge and betel, true. accurate.

and compiete am EX TIE IPFFI ERwa that ther ar significant penalties for submitting fals Infornation including the posablily of NUMBER, MM/DDYYYr line and imnrisionment for knowrnn Uintarionn AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hers)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITIEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN:, 7,-d "--=NV/I:k

-QD=I'DUR Mailing ZIP CODE:MAJOR(SUOR 01) CS61010IL0048313 PERMIT NUMBER002-0DISCHARGE NUMBERMONITORING PERIODMMIDDIYYYY I I MMIDDYYYY STORMWATER RUNOFF BASINExternal Outfall* * "NO DISCHARGE fMJ1 .1FROM I 06/01/2013

---

--- 4ITOI06/30/2013 IrPARAMETER QUANTITY OR LOADINGVALUEVALUEUNITSVALUESolids. Total Suspended EAMPLE ......MEASUREMENT 0053010 EITEff luent GrossREIRMN_____

SAMPLE ......Solids, Total Suspended MEASUREMENT 00530 80 .Other Trealment.

ProcessComolete 1 / __- -_, _ ..-.- ..:-Chromium, hexavalent SAMPLE .......(as Cr) MEASUREMENT

_________

01032 1 0 .~ .:.-::,Effluent Gross REQUIRE.ENT

_ ., .Chromium.

total SAMPLE .... .... ......(as Cr) MEASUREMENT 010341 : .. .t. ..1.Effluent Gross REQUIREMENT.'

.uopper, loutd(as Cu)0104210Fftluant flrnLssSAMPLEMEASUREMENT

-4.... 1Prm (T.I --Eflun Grosss~,~.~4

..J--iorn. total(as Fe)0104510SAMPLEMEASUREMENT ttHtt-.4- .1 J.-.---J.

IP114411R~OUIR~UrnJT Lead, total SAMPLE ..(as Pb) MEASUREMENT t*et0105110 'PR I- -..Effluent Gross REQUIREMENT

` ________

-.NAMEInTTLE I cariy under penalty of law that tis document and al attachments were prepared under myPRINCIPAL EXECUTVE OFFICER direction or supevision in accordance with a system designed to assure th qualified pesonnelproperty gather and evalute the information subminted.

Based on my tiquliy of tie pensi or personsBenjamin P. Youman who manage the system, or those persons directly respaons tot gathering the information.

theinformation subimitted Is. to the best of my knowledge and beef. true. accurate, and comtlete.

I amPlant Manager aware that there are sncant penalties fotr SuMIting false inlormatimo.

including the poesilty ofTVPED OR PARME I we and Imprisieru lot Itario g violsats.

U0;MMENT1 AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Metal Cleaning Wastewater was discharged this month.2. No Fire Protection or Service Water System Drain Water was discharged this month.3. No Closed Cooling System Drain Water dlisharnnd ithis mnnlhEPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/8/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvilla, 1160555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBER002-0DISCHARGE NUMBERMONITORING PERIODMMIDDYYYY I I MM/DD/YYY STORMWATER RUNOFF BASINExternal OutfallNOOISCHARGE I-FROM I06/01/2013 I TOI06/30/2013 ATTN: Zoo Cox/ENV SPEC FREQUENCY_____________________________

QUANWTTY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER

________

____________

__NOOF SAPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPENickel, total SAMPLE ..........

...... ......(as Ni) MEASUREMENT 500010671 0 pRI 01.Effluent Gross REQUIREMET'IT

.__.__ -__.._" __ -_. ..- -3)DA.'AVG QAILY MX .. * --.ra-"- -GRABZinc, total SAMPLE ...... 500..(as Zn) MEASUREMENT 5000109210 PEMT-*...

.047.2 RAEffluent Gross REQUIREM-ENT

..., _-. .300A AVG.. PjIlYNI, M91 L ....-. .Oil and Grease SAMPLE .........

...... ....MEASUREMENT 035821 0 ". PEMIT"" -: G " F.IAB .5 0 ;. ...

DALYMX .- ..--.: , n -. -.Effluent Gross REQUIREMENT, 150i"" .1 DAIL -M".. "Flow, in conduit or thru SAMPLE ......treatment plant MEASUREMENT 5005010 le, -" " ." " .. .'Mon.Effluent Gross .EQUGIEe T .PAILY MX g. ;" * " -,.ismm'.,qn SAMPLEMEASUREMENT PERMIT .v ....SAMPLEMEASUREMENT.

" 'SAMPLEMEASUREMENT NMETIE I certify under penalty al law that his document and all atta ments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER d5mctlon or euPefvision in accordance with a system designed to assure that qualffed personnel TPropert 9gather and evalute te information submitted.

Based on my inquiy of fte persones 815 4 07/8701Benjamin P. Youman who manage the system, or those persons direcly responsilue for gatherin the inforna theo d 07/18/2013 inlormation submitted Is. to the best of my knowledge and belief. true. accurat, an complete.

1 am SIGNOURE OFPINCIPLE Plant Manager aware that there are significant penalties for tse ocludin the poasiblily of EXECUTIVE OFFICER OR AREN"rM oR wfumm faM and imprsiomet fr knom~g violations.

AUTHORIZED AGENT coo NUMBER MMDD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. This discharge point was not used this month.2. There was no discharge ol processed steam generator chemical cleaning wastewater durng the month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 1/612012 PAGE 2 ATrACHMENT TOCOOLING SYSTEM BLOWDOWN (Ouffall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 June 2013Page 1 of 2MONITORING DATA:WBD CRock RiverCWBD FlowDATE Temperature mgd Flowdeg F cfs06/01/2013 86.1 21.55 10,40006/02/2013 85.0 18.66 10,40006/03/2013 77.8 19.69 10,10006/04/2013 78.2 20.64 9,67006/05/2013 79.4 19.29 9,39006/06/2013 79.4 19.67 9,43006/07/2013 79.0 21.51 9,27006/08/2013 77.5 24.99 9,02006/09/2013 85.7 25.38 8,71006/10/2013 85.7 10.59 8,50006/11/2013 86.0 20.54 8,21006/12/2013 88.9 20.74 7,99006/13/2013 88.9 20.33 8,42006/14/2013 84.1 20.42 8,51006/15/2013 87.2 25.44 8,32006/16/2013 87.2 25.22 8,08006/17/2013 86.6 16.76 7,78006/18/2013 85.6 21.17 7,56006/19/2013 78.7 20.58 7,43006/20/2013 88.2 25.40 7,19006/21/2013 88.4 19.89 7,28006/22/2013 88.3 26.03 10,50006/23/2013 88.3 20.86 13,60006/24/2013 88.3 14.89 14,10006/25/2013 91.6 22.95 15,30006/26/2013 89.9 21.49 20,10006/27/2013 89.4 23.09 26,80006/28/2013 88.8 22.27 28,60006/29/2013 85.9 28.54 25,60006/30/2013 83.6 22.90 25,900K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2013\June'June 2013ATTACH01.docx ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 June 2013Page 2 of 2HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (or associated rinses) containing hydrazine discharged to the Cooling System Blowdownduring the month of June 2013.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite and Bromine compounds were used this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 30 of 30 days.4. Per Special Condition 24 the influent from the Rock River and effluent fromOutfall 001-0 was monitored for Total Suspended Solids (TSS) this month.The Rock River TSS value was 29.3 mg/L on 06/10/2013.

The CWBD TSSvalue was 3.0 mg/L on 06/10/2013.

5. Rock River flow for June 2013 was >2400 cfs therefore daily temperature calculations were not required this month. (Special Condition 12).6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in June 2013. (Special Condition 15).K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor RptA2013'June\June 2013ATTACHO1.docx Exelon.Exelon Generation

Company, LLC www.exeloncorp.com Byron Station Nuclear445o North German Church RoadByron, IL 6101o-9794 August 26, 2013LTR: BYRON 2013-0114 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyWater Pollution ControlCompliance Assurance Section #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring ReportIn accordance with National Pollutant Discharge Elimination System (NPDES) PermitNumber 1L0048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report for Byron Station, Units 1 and 2. This report covers the period ofJuly 1, 2013 through July 31, 2013.If there are any questions regarding this report, please contact Ms. Zoe Cox,Environmental/Radwaste Supervisor, at (815) 406-3035.

Respectfully, Beai~nP.

Y aPlant ManagerByron Nuclear Generating StationBPY/ZC/eh Attachments NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)

NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60655-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010ATTN: Zoo CoxiENV SPECDMAR Mailing ZIP CODE.MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERAo0-0DISCHARGE NUMBERMONITORING PERIODMM/DD/YYYY MMIDD/YYYY DEMINERALIZER REGENERATE WASTE (001A)External Outfall*NO DISCHARGE FROMI07/0112013 I TOI07/31/2013 PARAMETER

><QUANTITY OR LOADINGVALUEVALUEUNITSVALUESAMPLE ...... ......Solds, Total Suspended MEASUREMENT 0053010 .r ." ......Effluent Gross REQUIREMENT

-.- ..... .Chromium, hexavaient SAMPLE ...................

(as Cr) MEASUREMENT 0103210 jPER! ..... ....Effluent Gross REQUIREMENT

':Chromium, total SAMPLE .........

......(as Cr) MEASUREMENT 0103410 ., R " .E.. ..*.IE ff l u e n t G r o s s R 6 Q U I R E M El T _ ._ _ ._ ._ _ _._ _. ..Copper, total SAMPLE ... ... ....(as Cu) MEASUREMENT 0104210 -.. ., ....Effluent Gross REQUIREMENT,

-. ......'IIron. total(as Fe)01045 1 0Fi:fh. rnt Arri.w.SAMPLEMEASUREMENT

, 41J2 PWTAEOUIRRII.IT

-I* :: .....;.tmptI.Effluent

______ Gross, 4 1Lead, Total(as Pb)01051 1 0MEAMPLEMEASUREMENT4 -- ~4 .I -* pERMr~.'DerAIaIaE!Ethr'v C-,*iE lluent, tmGos .-_____Nickel, total(as Ni)0106710i::fhac~t rsMEAMPLEMEASUREMENT S4 1 -+ -p..-.*I.iEff luent Gross 'REQUIREMENT F:NAMEnlTTLE PRINCIPAL EXECUTlVE OFFICERBenjamin P. YoumanPlant ManagerSnTYE OR PMUMcertity under penalty of law that thos document and all attachnments were prepared under mylietiaon or supeoson in accordance with a system designed to eissure that quafled personnel Propenly gather and evalute the information submitted.

Based on my inqutiy of Mte person or persons0no manage the systeM, or those pemona directly responsible for gathering the Information.

thenformation submitted is. to the bfet ol my knowledge and bel, true, accurate, and complete.

I amaware tt there are sigftcant penalties for sub9ittin laabe Information.

hiudding the posatlbity of.ine and imprlsionment for knowing violations.

TELEPHONE DATE-.7 IiU m W W WU m 815406-3700 08/26/2013 SIGNAlJ'E OF PRIf1LEEXECUTIVE OFFICUh ORAUTHORIZED AGENT-4 ICOEv NUMBERMM/DD[YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)1. There was no discharge of processed steam generator chemical cleaning wastawater during this month.2. Flow existed 31 of 31 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6I2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAMEIADDRESS NAME Exeton Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvite, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010IL0048313 "PERMIT NUMBERIA01-0IOMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010I DISCHARGE NUMBERIMONITORING PERIODI MMIDDYYYY I MMDoiYYYY DEMINERALIZER REGENERATE WASTE (001A)External Outfall* **NODISCHARGE

! I! .4FROMI07/01/2013 I TOI107/31/2013

-I lQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SMLVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPEZinc. Total SAMPLE..

..(as Zn) MEASUREMENT 01002 1 0 vRM' I'.i " -I 2 .Effluent Gross REQUIREMENT

"" .: -. .. .30DAD,, A:GM4jYM)

"ia',"Flow. in conduit or thru SAMPLE 0057 0243 3 0 01101 EStreatment plant MEASUREMENT 5005010 PERI MIT " Rqq. Mon. sq-Mon..."".

" .' D.. ." -CONT IEffluent Gross 0EQUIAEMENr

.DAGYI MX ..-__..,,..

SAMPLEMEASUREMENT

______________

• REQUIREMENT,___________-

--SAMPLEMEASUREMENT______________________

-_ _ -. I vsSAMPLEMEASUREMENT

_____________________

"__ _ _. W p , .-... .- .._ _ _ _* _. .. .., .... .. .... ., -... ., ... .. -. ,._ _.SAMPLEMEASUREMENT

• ......dr r... ... ..,.. 4 * ,-I:

, .- .'_"____"""_

." ' ."" ...;; ."SAMPLEMEASUREMENT

.........

..... .... ....................

,..........

.........

--.-r'.-" ., -..: .... .-.. .- * ' : ' Y :: :i. 2::" ,'. ,- .; .- :<0 *""

__ _ _ _ _ _ RQuIRM ENT- *-"-""-_

.. .. ", ."_,. -___ .."----.NAMEITTTLE I certif under Penally df law that Oth document and anl eladhtenrts ware prepared under mtyTLPOEDT PRO41CIPAL EXECUTIVE OFFICER direch or superetsiminsordw=c wilth system designed to assure tat qualified peromonae 82621.UAMPLEPL infomation suib:mited is. to the beo of ..y knwle and belief. true. accurate.

and complete.

I am SIGNA1F.-...

FI.... P. .... ...;, ____. __. ___._.--.....

Plant Manager -daware tha there are significanit Penalties for stubmitting false informataion ncluding the posality d XC VE 0 CER OR AR UMEREAD/YY TYPIED OR pfwnw fne and lmprisioavnenl for knowing viciationsTOIE)

GN OENMBRMIDYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Refernence all attachments hers)1. Flows for July 2013 are estimated based on July 2012 values due to totalizers being Out of Service.

The totalizers are an obsolete model and work orders are in place to findreplacement totalizers end gal them installed in the system.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE?2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIR"E NAMEIADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenvile, IL 60555-5701 FACIIJTY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010IL0048313 PERMIT NUMBERB01-0DISCHARGE NUMBERDMR Mailing ZIP CODE.MAJOR(SUBR 01) CSS"P PLANT EFFLUENT (FORMER 001B)External OutfallI *

• NO DISCHARGE 61010MONITORING PERIOD[ MMIDDIYYYY MM.DDIYYYY FROMI07101/2013 I TOI07131=2013 l IATTN: Zoo CoxIENV SPEC _ FREUENCYQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPEBOD, S-Day SAMPLE 0.28 0.33 26 ...... 3.5 4.0 19 0 02530 24(20 Dog. C) MEASUREMENT 0031010 .o.... 5, , 10.5 30 ,. .... ,Effluent Gross REQUIREMENT 3 WPA op A v .____: '-" DA AVG- D 9 TpH SAMPLE ....... ...... 7.31 ...... 7.47 12 0 02130 GRMEASUREMENT 0040010 -. P- .6IT .: .--.Effluent Gross REQUIREMENT

.-.." ..MINIMUM

....._._*_..MAXIMUM

" ' .Tw -ce e r Month-.?:.

Solids. total suspended 0.12 0.19 26 .<1.3 2.3 19 0 02130 24MEASUREMENT 00530 10 ,PoWT 5.3 10.5 '..,-. 3 " " -? `6Effluent Gross REQUIREM

......... " .Y .. .*: -ODAAV..

DALY. -TITO '.Flow. in conduit or thru SAMPLE 0006 ..... 0.101.treatment plant MEASUREMENT 000013 .........

0 0101 N5005010 PEFr .Ieq. Mon. 'Req. Mon. --..,Efiuent Gross MEQUIREMENT 300A AVG. * ._.SAMPLEMEASUREMENT

... -~~~~. " " .".. ..-."...I. .".".~~~~~~~~~~~~~~~~~.

..-....,.. *.. ..:,.. .-. ..... ... ...... ... :. ....-..:... ,:... ,: .:RPEREQUIREMENT.

SAMPLE-MEASUREMENT

___________

_ _ _ _ _ _ _ _ _ R Q I E E T -......_ _ _ _-_.. ........ -.. .,._._.' ._ : .. , ; ,. :- '.: ...:.. ..' SAMPLEMEASUREMENT A ...:.r. ..-y -__ __ __ __ __ __ RE ulRE -l.... "-- .: ....... _ _ _ _ _ _NALEEUE I certify under penalty of law that this document and aOt atadunchtns were prepard under my TELEPHONE DATEPANCIPAL 1XECUTIVE OPFtEr" Of supervao in accordance wth a system desgne to assure tha quafited pensonnel properly gather and evatute the intonniaton submitted.

Be on my mquhy oP the person or personsBenjamin P. Youman who manage the system. or those pemons directly responsible for gathering the intonnatbn.

the t,:7 01/2C213informaton submitted is. to the best of my knowledge and betiel. true. accurate, and conplete.

I am IG RE OF P iCIPLEPlant Manager aware that there am significant penalties for submitting false tim0lomln.

including the possftty d EXECUTIVE OFFICER OR AREAUMBlime and inpisionent for knowing v~latbis.

AUTHORIZED AGENT CODE NM_/_COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flow existed through this outfal 30 of 31 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/612012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 610107AA trrnyFl:NV R.PIF:tIDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010I1LPMN4833E r- PERMIT NUMBEIC01-0DISCHARGE NUMBERIMONITORING PERIODMMIDDJYYYYL MMIDDIYYYY WWTP (FORMER ODIC)External Outfall* NO DISCHARGE FROMI07/01/2013 I TOe07/3112013 QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF SMLVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ALYS TYPEsos total suspended

..................

3.0 3.5 19 0 02/30 24Solds toalsusened MEASUREMENT 0 0 5 3 0 1 0 i --.P r r ... ............: ... ...: .. ..: * * " .." , ,m .l1 ...-.3 ..- .' ...,-.' ." ..." I : -_ -.-.00530 100Effluent Gross REQUIREMENT

-,- .., ..___AAV_....

D '.X m -; *W.: T -rMot ...:Chromium.

hexavalent SAMPLE ..........

...... ......(as Cr) MEASUREMENT 5000103210 P:.. PERMIT. -.1 .-. ,2-. " o '" iEffluent Gross R.QUIF.EMENW t , .... A , ... M%.Chromium, total SAMPLE ......(as Cr) MEASUREMENT 01034 10 "fERWp. ..2-Effluent Gross REQUIREMENT,

,.. ....._"' ,0A AVC -DAIy- .. ,- ..Copper. total SAMPLE ...........

(as Cu) MEASUREMENT 5000104210 .77 ... .. .-, ,a-y.Effluent Gross -REQUIREMENT

, .: .. ...:. ... .:3DOPAAVG

.QAJLYMX.

'" "Iron, total SAMPLE ............

..(as Fe) MEASUREMENT 500Effluent Gross REQUIREMEN"

,, .'"- ..".... .., y --Lead. total SAMPLE .........

.......(as Pb) MEASUREMENT 5000105110 ,.. r r -T ."Effluent Gross UElrEbtMENT

, .-'."... J 3 A "DA"LYM " !'

DNickel, total SAMPLE ........

.... .....(as Ni) MEASUREMENT Soo0106710 '.. .. .... "- 1 2Effluent Gross XREOiREMEIT

...A ...... .-. .-. , .., , .NAME/TILE I Cerfly unlder penalty oi law tral vids domument and all achmenls were prepared under my TELEPHONE DATEPINCIPAL EXECUTIVE OFFICER drectin or supeman in accodance with a system deslied to assure Mtt qualifl pedMOnalBenjamin P. Youman who manage the system. oat tose persons directly spomisible ta gathering the infomatia.

the 08/2612013 nWontatim submitted is. to the best di my krowledge and beliel, true, ancurate, and ctilmpeta.

I in SIamANURE

?)F'PRINCIPLE Plant Manager aware that them are sgnificant penalties for submiting false no'matin, the pos..ety of EXECUTIVE OFFICER OR AREATnYEo oR MimT lee and biroraknnei for knowing v AUTHORIZED AGENT CODE NUMBER MM/DDYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed through this outfal 16 of 31 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11/62012 PAGE 1 NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERCH1-8I -DISCHARGE NUM-BER-ý MONITORING PERIODMM/DDYYYY I MMDDJYYYY WWTP (FORMER 001C)External OuttallI NO DISCHARGE FROMI 07/01/2013 1 TOr07/31/2013 III lByron, IL 61010ATTN: Zoe CoxIENV SPEC ______ ____________________

PARAMETER QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER

-________

NO. OF SMLVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPEZinc, total SAMPLE ...... ...... 500(as Zn) MEASUREMENT 0109210 , .,r -,.. " .Effluent Gross REQUIREMENT 3- .-.. ..__.-_.__-

.AVG .... * .... GRABK.Flow, In conduit or thru SAMPLEtreatment plant MEASUREMENT 0.024 0.041 3 0 01/01 CN50=5O10 PEM IT " .'Mon......34-5005010............................................

....... ..-....................................

......Effluent Gross PREQUIREMENT..

36AAVG DAILY MX ".Wl.. -' "7 * , ....SAMPLEMEASUREMENT "REQUIREME.T_..

.SAMPLEMEASUREMENT

-r ps,. .. .. ... .....,. ... ,. 4 _______________REQUIREM

____________

SAMPLEMEASUREMENT

.... , .". ;, ' ,.. ......................................:--:SAMPLEMEASUREMENT REQUIREMENT

__________

_____ .<:. .-____SAMPLEMEASUREMENT

____R._ _;_ _ REQUIP........

._-_NAiEnlLE I certfy under penalty of law that this document and an attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction or supervislon In accordance with a system desiged to assure am qualified personnel properly gather andl evalute th Irwrmadn submaxi.

Based an my inquiy d it pme an or persans .'iBenjamin P. Youman who manage the syster. or those peasons directly respmsie for gathering the informatio n..4 08/t2013information sutd Is. to the best of my knowledge and belef, true, accurate, and carmpete.

I am oIGNATE OF O PLEr.Plant Manager aware that Ute are sionificant penalties for sultting false Ifomnation, including the poasiity of EXECTIVE OFFICER OR N ERRA____an pre___d ______fine and ____ fu_ __nv_ AUTHORIZED AGENT COID NUMBER MM/DDYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITfEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadOMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010I 11.0048313 PERMIT NUMBERDOI-0DISCHARGE NUMBER[ MONITORING PERIODUMMW/YW I MMIDDIYYYY RADWASTE TREATMENT (FORMER 001 D)External Outfal* * *NO DISCHARGE MFROMI07/01/2013 I TOI07/31/2013 II IByron. IL 61010ATTN: Zoe Cox/ENV SPEC QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESAMPLE t..al ....d. 2.0 3.3 19 0 02/30 CPSolids. total suspended MEASUREMENT 0053010 Pe. M!T 'IT Rq..th COM0PO, " RE EN ... " .30DA.AVO

" ., MX. ."~ .i! .!] le M p Effluent Gross REQUIREMENT

, .AV""DA.L.

M , g. ..-.,- .. .MothFlow, In conduit or thru SAMPLE 0.= 0.0m 3 .............

0 01/01 CNtreatment plant MEASUREMENT 500501 0 FOOgjq.Mon 0e. Pmonp, gId -Oth C~1Effluent Gross REQUIREMENT 3MDA AVG , ...SAMPLEMEASUREMENT PERMIT-.MREASUIREMENT

________SAMPLEMEASUREMENT P.RMrT .,________________

REQUIREMN91.11

_____ _____ _____ ____SAMPLEMEASUREMENT rER U".N- :'-." " K" .' ." "' ' "r:-SAMPLEMEASUREMENT SAMPLEMEASUREMENT NAMEnTITLE I cerfty under penalty of law that this document and all antachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUT1E OFFRCER of supevmsion accoadance with a system desg to assure that qualified personnel Iproperly gather and evakft the kdormalion submitted Based on my lnquibV o theMpersn perso s Or ,a.. 815 3700 08/26/2013 Benjamin P. Youmnan who manage fte Systaf Of d1060 pesons dwy esmsap="

for ft iwormaon, mte "*082/01mlonr kailm submitted Is. to the best of my Io woledge and betel. true. acc rate, and complete.

I am SIGNA OF CIPLE :::;[ NUMBERPlant Manager aware hat them are sindca penalt for submbn false infoimtam.

inchrdrng the pobafity of EXEClTIVEO0 CER OR Ar MMIDD/YYYY

.M fine and iprisltmoment for fatowing vlatiMo.

AUTHORIZED AGENT 4COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flow existed through this outfall 6 of 31 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116=2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES]DISCHARGE MONITORING REPORT (DMR)PERMIrTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010ATTN: Zoe Cox/ENV SPECIL0048313 PERMIT NUMBERE01-0DISCHARGE NUMBERDMR Mailing ZIP CODE:MAJOR(SUBR 01) CSSTORMWATER (FORMER 001E)External Outfall61010IMONITORING PERIODI MMIDDYYYY I1o4MM/DDIYYYY IFROMF07/01/2013 07/31/2013 I"NO DISCHARGE rll lI l-VPARAMETER 7><:ýQUANTITY OR LOADING-4VALUEVALUEUNITSVALUESolids, total suspended MSUMENTMEASUREMEN~j

.~ j,,,.,,,..,

053010 0Effluent Gross REQUIREMENT F. ......Solids, total suspended 0053080Other Treatment, ProcessCompleteSAMPLEMEASUREMENT pEfwrr'30'l 00dy%~RA5.i " " " i " 1 , .~~~~~. .. .b .. .. .... .... r .,. .....* -..-.. ..--. ..-. .Chromium.

hexavalent SAMPLE ........

5...... ......0(as Cr) MEASUREMENT 5000103210 P I T .A..q.

A.. " ".- "Effluent Gross REQU ...N.T -- .-_- .... AVG".DA-L.,"-

mg'LC- AVGa .. "." ,Chromium, total SAMPLE ...... 500(as Cr) MEASUREMENT 5000103410 PERMIT ..*..,..*1*2-mt- *Effluent Gross REQUIREMENT

" .".'... " " .30DA AVd DA[IYMX :_ -.., " ..-'Copper, tolal SAMPLE ......(as Cu) MEASUREMENT 5000104210 PERMIT. EMIR. .I -- U 4AEffluent Gross 0REQUIREMENT

-,3Q" .; ____ _ " " "AAVQ. XD M".Iron, total SAMPLE .............

..........

500(as Fe) MEASUREMENT 5__0104510 ." ., ,., ." "a""Effluent Gross .REQUIREMENT

..t_____ ' .JI .'. ." , --" ."..i.*Lead, total SAMPLE ...... ...... 500(a s P b ) M E A S U R E M E N T 5___ __ _0105110 'PEfIMIT1 VMSEffluent Gross ,."A'REQUIEMET

,, " " '__ _ " " .-jpAAVQ " DAILYM;X

.m. ... a: ..II, under penalty o law that this document end all alactamnets were prepared under "'y TELEPHONE DATEPRINCIPAL EXECUTlVE OFRCF.R direction or superesmn tn accordance with a system designed to assure tha qualified personnel

" I,B nop"o gather and evalute the Iomatin subrrited.

Based an my lnr of the peson o815 406-37Benjamin P. Youran who manage the sem, or those persons duectV reprnsibe for gathering the Information.

Uheinformation submitted is. to the best of my knowiedge and belef. tre. accurate.

and complete.

I ame iNATE OF P IPLEPlant Manager aware that mare are sificart penalties for sunlitting false information, ncludkg the posily of EXECUI1VE OFF ER OR NUMBER MM/DDIYYYY TWPOR CA PED fine and imprisonment for blaming vi__ a__ __s. AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during the month.2. Flow existed through this oulfall 2 of 31 days during the month.3. There was no discharge of Fire Protection drain water during the month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 1/6/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMI'rEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenvite, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010ATTN: Zn Cnx/ENV SPECDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERE01-0DISCHARGE NUMBERMONITORING PERIODMMFY I I MMIDr YSTORMWATER (FORMER 001E)External Outfall* I

• NO DISCHARGE

--- ...! IFROMI07/01/2013 I TOI07/31/2013 IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER V OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS E ANALYSIS TYPENickel, total SAMPLE .(as Ni) MEASUREMENT 0106710 .,- r .2*E_,u _,._,or___

.-R.=,=,REME,,=,,

_ __......__-_.,,,-

,: , .300AAV_.

.. ...Y..... .Effluent Gross *-& "IRMN ..*AW PA MX _______ ______zinc, total SAMPLE ...... ......5So(as Zn) MEASUREMENT 0109210 ,.PER?41T,-

... ..m ,..

• mg",.-: ,'eal .Effluent Gross REQUIREMENT r -.-, _ ...oAAVG o* Wa 0-- "_,-' __" _ "_Row, in condluit or thru SAMPLJE...

reatmentndlat SUME 0.178 0.209 3 0 02/30 CNtreatmnent ptant MEASUREMENT_____

__________

__________

500501 0 .o T Req. ,r,. ...Reg.,M_..*

, .. Tc -4r' neq. ( OeqMoT.ýEffluent Gross RmQ umv E T .W, " a. .,-. __ _ -._.. .. .. .... ,...SAMPLEMEASUREMENT

_______________REQUIREMENT..*.--_____

____SAMPLEMEASUREMENT_____

!.PEl MIT -I_____________REQUIREiMEN

___ ___ __ ___ __SAMPLEMEASUREMENT

________

____,.PEMR!REQUIREMENT

________________

_____ ____SAMPLEMEASUREMENT

!g, ..l.,. .-,,.. ,.. .,MEASUREMN

-NAMEnTTILE Icerituy under penalty of law that the documentand aM allttachmnents were prepared under my EEHOEDTPRINcPAL O=EU'iVE oFRCERditio of TELEPHONE DATErac wt yt dsge oasuedmqaife esneBenjaminYprepeity gather and evaMe he ntwmatinsauftated.

Based on my mqury of the person or p--oa j..j/~ 8151 4008/6/201

...manage ft heyste. th .e perso directly responsible for gathering the In-..mati..

lth e. ".i...sation autndted

i. to the beg of my Mnwledge and befe. true. accurate.

and c:nplete.

em IGNA&fKEOF fIIPLEPlant Manager aware that there are algnftant penafties For eubdn" falea Intotmatlat Including fth possiblft of EXECUTIVE OFINCER OR ARESNMRTMDO PUE --fine end inipramoment tor knlowing violatiors.

AUTH4ORIZED AGENT coo NUBE MMIDDJYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments herm)1. No Closed Cooling System Drain Water was discharged this month.2. No Service Water System drain water was discharged this month.3. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Metal Cleaning wastewater was discharged this month.EPA Formt 3320-1 (Rev 01/06) Previous editions may be used. 116/212 --PAGE 21 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)I IL0048313 I I 001-0PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010I PERMIT NUMBERI DISCHARGE NUMBER IMONITORING PERIODMWMMIDIIYYI MIWDDIYYYY DMR Mailing ZIP CODE: 61010MAJOR(SUBR 01) CSCOOLING SYSTEM SLOWDOWNExternal Outfall* NO DISCHARGE F ...FROM I07/01/2013 I ToI07/31/2013 IL II lATTN. Zoe Cox/ENV SPEC ___________________________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS Ex ANALYSIS TYPETemperature, water deg. SAMPLE ...........

...... ........94.2 15 0 01/01 CNFahrenheit

.MEAUREM.NT 00011 10 .... "" -: ' , C ' .: .- 'Effluent Gross REQUIREMENT "Mo-X J-0pH SAMPLE ........

..... 8.30 ...... 8.63 12 0 01/07 GRMEASUREMENT 0040010 U hf6~8S~I

~ ~ d~REffluent Gross :REQUI1REMENT

---MINIMUM

-MAXI'U ~SolidsSAMPLE

.......d ...... 42-0 42.0 19 0 01/30 GRMEASUREMENT 005301 .. -.' -n: .-Effluent Gross R IEQUIRK E -- '- , ,-W. ., ". ... .on: " A .---...O&Grease............

.........

1.4 <1.4 19 0 01/07 ORMEASUREMENT 005561 0 .; :..P4IT " ...." -".-l .20' " , m.... ..Effluent Gross R IIR lEI4T ., ..." .., 0DA AVG.-'" DAIl.YM "_.___'I

-__" ____Chromium, total (as Cr) SAMPLE ...... ...... ...... ... ... 0.005 19 0 01/07 ORMEASUREMENT 0103410 ' ".0;2.'Effluent Gross REQ7JIREME.T

" .._.o_....

... "' ' " , ..---Copper, total (as Cu) SAMPLE ............

...... .. ..... 0.025 19 0 01/07 ORMEASUREMENT 0104210 o -r5E~MITr

-..,-. .... *0.071 -*."Effluent Gross REQUIR"MENT

.77 V ... " .DALY, IAB-'- ..SAMPLE ,* ..........

000 .21 0 007RZinc, total (as Zn) MEASUREMENT 0008 0.02 19 0 01/07 OR01092 1 0 3.. _ ..-:.. , ... : ..-. -T.., ..3.-....Effluent Gross R..M 1 .: -I --I 300AAVG -.DI LW P( --. NAMEI nerLE I leny under penalty of law that ft document and al attachments were prepared under my TELEPHONE DATEproperty gather and evalute the bItonnation submitted.

Based on my inquiy of the person or persons1Benjamin P. Youman who manage the system. or those persons drectly respornsibl 109 gathering Me information.

the 815 406-3700 08126/2013 inlomiation submnittd Is. to the of my Wkowtedge and belief. true. accurate, and complMet, I am SIGN#URE

___Plant Manager aware that there are significant penates Ar submiBEing alsa informatio.

incuding te poastat EXEUTIVEh1I=CER OR Ree fine and imprislonmrnt for Waniing violations.

AUHRZDAET CD UBRMM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Relfemree all attachments hem)1. Monitoring data for outfall 001-0 is Included on attachment.

EPA Form 3320-1 (Rev 01106) Previous editions may be used. 1/812012 PAGE 1 NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMriTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

L 60655-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, L 61010DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS610101L0048313 PERMIT NUMBER001-0DISCHARGE NUMBERMONITORING PERIODI MM/DDJYYYY MMIDD/YYYY COOLING SYSTEM BLOWDOWNExternal Outfall* -NODISCHARGE I IFROMI07/01/2013 I TOI07/31/2013 k -iiQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX AOAFS TYPEOxidants.

total residual SAMPLE. 0.04 19 0 01/07 GRMEASUREMENT Effluent Gross AEQUIRbI gT. .._ .___.___

.-.-.. .DT5 .. 9' I'.SAMPLE ...........

0Priority pollutants total effluent MEASUREMENT

... 55000810 .PERMIT".

-.Re"Effluent Gross ,REQUIRFME,?,,T

_*.".

• IL-. ..'-, ..XFlow, hi conduit or tltru SAMPLE PLM ~ ltloatmen clnt MEASUEE 22.48 32.58 3 .........

...... ...... 0 01/01 CNtreatment plant MEASUREMENT 5010 -R

"=_q.Effluent Gross -EURMN.ALY~

-.*. -- ~ .~';wChlorine.

totalE ...... SOOMEASUREMENT________

5006010 -P#IT..Effluent Gross REQUIREMENT..

'-, .." ". ?.v... ."-." .' .5 ...Hydrazine SAMPLE .............

....MEASUREMENT 5008131310 "..P Mr ", , , ..... ; .T .. ...- D l. --0.027E ff lu e n t G r o s s R [E Q U IR E M EA N T .--" _"'_"_"_*

.. ... ." --D. A V G .... .....; -.' .-.. -in g.SAMPLEMEASUREMENT

______________REQUIREMENT_____

______ _____________

SAMPLEMEASUREMENT

• ..., ~~~~... .... ... ... .o ; " ..REQUIREMENr

--." .-.. ... i .. , .._, .

I cently under penalty a law hat i docun'a aa atcment ware prepared umy TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER *nectbi or In accordance with a system designed to assure that qualfed TersEDeAl BenjaminP.

ouman prtygather anld evaft te he IonmaIIoA submiUed.

Based al my inquiry of Me person or pe062ns,1504/-370 who manage tMe system. or those persons direcly respoisible for gathering the infamatui the ;A OEM 1540-300OW2013

'SG 81NURE OTJRNCIPLE Plant Manager Information subittedI, t thebesto f myawedge and -i EXrlUTIVaIE VCER OR AREA NUMBER MM/DD/YYYY TVIPMORPR~law

-aware that there are significant penalties for submittning false Information.

Incuding the posslbliy of..UM E tIDYYi f *ine and imodrionment for knowin violtions AUTHOR AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITITEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvile, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 610107nn ("nvilFNV

.qPlFDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBER002-0DISCHARGE NUMBERMONITORING PERIODMM/DDJYYYY I MMIDD/YYYY STORMWATER RUNOFF BASINExternal Outfall""" NO DISCHARGE 5_ ...FROM I0710112013 ITOI07/31/2013 ATTN: Zoo Cox'ENV SPECPARAMETER QUANTITY OR LOADINGF r tVALUEVALUEUNITSVALUESAMPLE ..... .......Solids. Total Suspended MEASUREMENT 00 10 .PERMI" ..... "'"Effluent Gross RIEUIREEN

""Solids, Total Suspended MEAMPLE ............

......0053M ar -Other Treatment, Process PEFQUIM ET ptess __________

Complete

..~ ______Chromium, hexavalent SAMPLE ...........

......(as Cr) MEASUREMENT 010321 0 PEMlT .,.l ..., ....-Effluent Gross REQUIREM.NT

-Chromium, total SAMPLE ...... ......(as Cr) MEASUREMENT, 0103410 .I T...Effluent Gross "REQUIFRIkfIENT

_ __ _-_ .._-___copper. towal(as Cu)010421 0Pfth rantI flrrcSAMPLEMEASUREMENT II WHIIron. total SAMPLE I ..... ....(as Fe) MEASUREMENT

_ _ _ _______ _____0104510 77.7.- ER7MIT -Effluent Gross REQUIRIEMENT

______.,

_ __________

..____. .._ _w."_,___

Lead, total SAMPLE .....................

(as Pb) MEASUREMENT 01051 1 0 Pi4l

• i. ,, ,,,. 063Effluent Gross REQUIREMENT

'I, 30DA AVGNAME(nT1LE I Certy under penalty of law that this document and al attachmants were prepared under.myPMINCIPAL EXECUTIVE OFFICER direction or supevision in accordsnce wit a system designed to assure that qualified peronnelproperly gather and evaluto the Information submitted.

Based on my inquiry of the person or personBenjamin P. Youman who manage the system, or thos perss directly responsible for gathering the information, theinlornmtion submitted is, to the best of my knowledge and belet, true, accumate.

and complete.

I am SIGNAVRE Plant Manager aware that there are significant penalties for submitting false Inlonnation.

Including the pasltility of EXECUTIVE ORMr, OR o M ___~m 1 ine and imprisionmrnt for knowing violations.

AUTHORIZED I,COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference oll attachments here)1. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Metal Cleaning Wastewater was discharged this month.2. No Fire Protection or Service Water System Drain Water was discharged this month.3. No Closed Cooling System Drain Water was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS' 4300 Winfield RoadWarrenville, 1160555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010IL0048313 PERMIT NUMBER002-0DISCHARGE NUMBERDMR Mailing ZIP CODE:MAJOR(SUBR 01) CSSTORMWATER RUNOFF BASINExternal Outfall* I*NO DISCHARGE

[ "61010MONITORING PERIODMMIDDYYYY I MM/DD/YYYY FROM I07/01/2013

]I Tol07/31/2013 I-I Il lQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF YPVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS ONickel. total SAMPLE .............

500(as Ni) MEASUREMENT 0106710 P.. .011. .Effluent Gross REQUIREMENT T____ ____

• ____ ~AAG AYMC____Zinc, total SAMPLE .............

50(as Zn) MEASUREMENT 0109210 .07RMr ,..... * ...,. -"6. .... -...7 .,, -.. ' ; " 'Effluent Gross RRQUIREMENT..'-"-"

," 30DA A ."Oil and Grease SAMPLE ............

...... 00MEASUREMENT 03511210

..-..'...,. .15 20.. .,.6.. ... .....Effluent Gross RQUIREMENI

, ...-.. :', " )OArAYC3

' : AI.YL. MY : lrgn:'u-..

Flow, In conduit or thru SAMPLE 600treanment plant MEASUREMENT 5005010 Rea Mo .Effluent Gross "REQUIREMENT

" 3 .u)l:A A ". --" " ' ,*.SAMPLEMEASUREMENT REQUIREMENT

........

,_,_..._

__....._"_"

SAMPLEMEASUREMENT

.. .. .,.REOUIR M ENT -._,.,-.SAMPLEMEASUREMENT P*MT -- ....-..*..:. ... ._______________REQUIREMENT_____-

..______________

NAMFTPL"LE I ceOF ly under penally of law dust di documeant and attacments were preare under my TELEPHONE DATEPIFUNWAL EXE:CU11VE OFIFCF.R diection or supenrlson in accoidance withea sysim designed to assure tria qu alifed pmpeitygatherandevabAetheinfomationsubmitted.

Based on my 'quky of the person or persons 815 406-3700Benjamin P. Youman who manage the system. or those persons dilrectlys responsibe fr gathenng the Infonnation.

the 026/2013inloim~atin Is, to the best of my knowledge and belief. true, accurate, and complete.

Iam I GNA E OF NCIPLEPlant Manager aware at there are significant penafties for submitting false Information.

including me possutiy of EXE TIVE OFCER OR AREA NUMBER MMIDD/YYYY ow PRINTED tite and ilsiormeft for kflahla~ims.

AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. This discharge point was not used this month.2. There was no discharge of processed steam generator chemical cleaning wastewatir during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11612012 PAGE 2 ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 July 2013Page 1 of 2MONITORING DATA:CWBD CWBD Flow Rock RiverDATE Temperature mgd Flowdeg F cfs07/01/2013 83.1 18.27 24,60007/02/2013 83.1 25.50 22,50007/03/2013 82.4 21.44 20,70007/04/2013 86.9 21.57 19_30007/05/2013 86.9 20.88 18,00007/06/2013 88.1 32.58 16,90007/07/2013 90.2 19.23 15,80007/08/2013 91.4 16.71 15,10007/09/2013 92.0 25.87 14,30007/10/2013 89.7 17.99 13,30007/11/2013 89.7 23.51 12,10007/12/2013 83.0 25.17 11,00007/13/2013 84.5 31.08 10,20007/14/2013 89.8 19.37 9,57007/15/2013 92.2 18.13 9,08007/16/2013 93.2 22.68 8,66007/17/2013 93.6 20.35 8,19007/18/2013 94.2 19.58 7,86007/19/2013 94.2 20.38 7,44007/20/2013 92.2 27.77 6,99007/21/2013 88.7 21.79 6,77007/22/2013 88.7 18.63 6,75007/23/2013 86.9 26.72 6,73007/24/2013 84.8 19.11 6,50007/25/2013 84.7 24.83 6,39007/26/2013 85.6 21.20 6,43007/27/2013 84.2 27.37 6,69007/28/2013 77.6 16.76 6,45007/29/2013 79.6 25.69 6,20007/30/2013 80.5 24.63 6,04007/31/2013 83.1 21.99 5,970K:\BYR_CH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2013V3uly\July 2013ATTACH01.docx ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 July 2013Page 2 of 2HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (or associated rinses) containing hydrazine discharged to the Cooling System Blowdownduring the month of July 2013.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite and Bromine compounds were used this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 31 of 31 days.4. Per Special Condition 24 the influent from the Rock River and effluent fromOutfall 001-0 was monitored for Total Suspended Solids (TSS) this month.The Rock River TSS value was 32.0 mg/L on 07/08/2013.

The CWBD TSSvalue was 42.0 mg/L on 07/08/2013.

5. Rock River flow for July 2013 was >2400 cfs therefore daily temperature calculations were not required this month. (Special Condition 12).6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in July 2013. (Special Condition 15).K:\BYR_CH\.BYRON.DB\CIerk\Monthly Discharge Monitor Rpt\201 3UulyUuly 2013ATTACH01.docx Byron Environmental Audit -Request for Additional Information ResponseQuestion

1. HH-1 Category:

Human HealthStatement of Question:

Provide NPDES monthly discharge monitoring reports for the past five years.Response:

The NPDES monthly discharge monitoring reports for all months of years 2008 through 2012and January through July 2013 are provided.

List Attachments Provided:

1. NPDES monthly discharge monitoring reports for January 1, 2013 through July 31, 2013.2. NPDES monthly discharge monitoring reports for January 1, 2012 through December31,20123. NPDES monthly discharge monitoring reports for January 1, 2011 through December31,20114. NPDES monthly discharge monitoring reports for January 1, 2010 through December31,20105. NPDES monthly discharge monitoring reports for January 1, 2009 through December31,20096. NPDES monthly discharge monitoring reports for January 1, 2008 through December31,2008 Exeltn.Exelon Generation

Company, LLC wwwexeloncorp.com NuclearByron Station4450 North German Church RoadByron. It 61o1o-9794 February 24, 2012LTR: BYRON 2012-0023 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyWater Pollution ControlCompliance Assurance Section #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276 Subject Byron Station Monthly Discharge Monitoring ReportS In accordance with National Pollutant Discharge Elimination System (NPOES) Permit NumberIL0048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report forByron Station, Units I and 2. This report covers the period of January 1,2012 throughJanuary 31, 2012.Hf there are any questions regarding this report, please contact Ms. Zoe Cox,Environmental/Radwaste Supervisor, at (815) 406-3035.

Respectfully, Th~~yJ. TulonS~ice President B Nuclear Generating StationTJT/ZC/ca Attachments NATKINAL POLWLIANT DISCHARGE EJMIHATION SYSTEM (NPOES)-OOTE NA0UDRNMIMEE1sn Gmrm 00 LWAý 4300 Wbih RoadWanuws.b LUN0GWGAUO 4450NOMGWW Sh~f ReedDym% L W101NmecLtan No0 0-R REPORT p)Q --W4M r3 M14 (hNAM61010.210 .1VM O NO 000PAW NATK*AL POLUNTANT 0ISCHARIBE BJNAllONM SYSTEM (NPDES)mNXAin .wu1 m OWN RE I(DIPEVJFIE NAWADONAM Emn Os'amn Ca. LLCADMW 4300VsdWRoAd WaiOImbS L 406WPAIRYV yvan INdw Powo MaWOCAM 44 M olShm Omum Chwc Wed@VIMn L 61010-Iiunouw mooamKAM)61010I -0smsI IAMInI --.mm...m I~1m I -!I -AL!- -- AIIIN l4OiýnAi inwnA WAhlE (MA)NIrdtI-lllgm p-gII mlsummmIIl qITOIiWI -AkIm _ _ _ m-IomwusiJI0M11ID2I... wo minmin-l -ill HAWK PCLUWANT D.SCHARGE hUMNAIMO SYTM (NPOES)-NO M -wI -Dmummq~woam 61010-wAIMMAOIEn Nm boomstmWW C0.~ LL-DD m=VAWWAed WWOws LOWGUACKMJY3w ooiaar P 6MmLWA7M 4M6OoO0mm

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0ADý 43W VRW nWarwookfte5 0?LATO4AL POLLUTANT DISCHARGE EUMNA11ON SYSTEM (NPOES)mCAR~OOmawfp" L 3- 08"-lwfzcmNAlM I61010MOMFORMPEFOOD IFACWlY Bpwm OMa. Pow$ ~NOW IVv mWYYYY ILOGAION MW6 Peul "smm Clu" dt Road 0WmtU1 0WS2DPWn L 610109* 1, NOclf ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 January 2012Page 1 of 2MONITORING DATA.-CWBD CWBD Fow Rock RiverDATE Temperature CW D Flowdog IF edt01/01/2012 70.9 20.28 7,66001102/2012 68.6 15.24 7,54001/03/2012 68.8 20.60 6,65001/04/2012 69.4 17.71 6,73001/05/2012 69.4 19.70 6,83001/06/2012 75.5 19.98 6,65001/07/2012 75.5 23.83 6,57001/06/2012 72.0 19.69 6,46001/09/2012 69.0 17.46 6,42001/10/2012 73.4 17.56 6,28001/11/2012 74.6 18.69 6,15001112/2012 74.6 19.77 6,12001/13/2012 65.0 20.36 6,14001/14/2012 65.0 22.71 5,83001/15/2012 68.1 19.95 5,93001/16/2012 72.2 12.10 5,97001/17/2012 72.2 20.67 5,88001/18/2012 66.5 16.30 6,28001/19/2012 72.5 18.78 8,39001/20/2012 65.0 15.92 7,39001/21/2012 66.6 22.49 6,47001/2212012 69.7 17.40 7,87001/23=2012 75.0 14.19 9,62001/24/2012 67.7 16.86 9,73001/25/2012 66.0 18.11 9,13001/26/2012 68.7 16.46 8,70001/27/2012 68.7 18.01 8,42001/28/2012 70.2 21.31 7,44001/29/2012 66.5 18.58 6,75001/30/2012 63.3 12.67 6,09001/31/2012 76.5 17.91 5,840K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012ReportsJanuary\January 2012 ATTACHO1.doc I .IATTACHMENT TOCOOUNG SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 January 2012Page 2 of 2HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (orassociated rinses) containing hydrazine discharged to the Cooling SystemBlowdown during the month of January 2012.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite was used this month. Bromine compounds were notused this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 31 of 31 days.4. Per Special Condition 24 the influent from the Rock River and effluentfrom Outfall 001-0 was monitored for Total Suspended Solids (TSS) thismonth. The Rock River TSS value was 11.5 mg/1. on 01/02/2012.

TheCWBD TSS value was 16.5 mg/L on 01/02/2012.

5. Rock River flow for January 2012 was >2400 cfs therefore dailytemperature calculations were not required this month. (Special Condition 12).6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in January 2012. (Special Condition 15).KABYRCI-\BYRON.DB\ICerk\MonthIy Discharge Monitor Rpt\2012ReportsUanuary\anuary 2012 ATTACHO I.doc ExeloknExelon Generation

Company, LLC www.exeloncorp.com NuclearByron Station4450 North German Church RoadByron, IL 61o0o-9794 March 21, 2012LTR: BYRON 2012-0031 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyBOW CAS #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring ReportIn accordance with National Pollutant Discharge Elimination System (NPDES) Permit NumberIL0048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report forByron Station, Units 1 and 2. This report covers the period of February 1, 2012 throughFebruary 29, 2012.If there are any questions regarding this report, please contact Ms. Zoe Cox,Environmental/Radwaste Supervisor, at (815) 406-3035.

Respectfully, Plant ManagerByron Nuclear Generating StationBPY/ZC/ca Attachments PERWrlrEE NAWE/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FaC[LITV Byron Nuclear Power StationLOCATION 4450 North German Church RoadNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)SCc-lARGE MOKC7 ORýG REPORT PtMR)OL0483O13 AO-.0PERMIT NUMBER DISCHARGE NUMBERMONITORING PERIODMM/DD/YYYY MM/DD/YYYV FROM 02/01/2012 TO 02/29/2012 VMR Mwfling ZEP CODEU 0O)(SUOR 01) CS61010DEMINERALIZER REGENERATE WASTE (001A)Eternal OutfDtAByron, IL 61010ATTN: Zoe Cox/ENV SPEC _ _FREQUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX SM TYPE>_____ _<___ ANALYSISSolids Total Suspended

............

...... ...... 2.2 2.4 19 0 01/30 08MEASUREMENT 00530 1 0 PERMIT -15 30Effluent Gross _________

________

300A AVG DAILY MX mIoih COMP-8Chromium, hexavalent SAMPLE ......5......0......0......

(as Cr) MEASUREMENT 5_00103210 PERMIT -... ...1 .2Effluent Gross RmJU jT _________

S30A AVG .A...Y M fill ____GRAChromium, total SAMPLE ................

......0(as Cr) MEASUREMENT Soo0103,01 0 PERMI .. ..,r ., 2Effluent Gross Rr__U____l_

$_ODA AVQ DAILY MX n_ _ Daky GRASCopper, total SAMPLE ............

......(as Cu) MEASUREMENT

...... _ _ _01042 1 0 PERMIT-...-.

Effluent Gross RE=UIRiI,

., 300A AVG DALY W mL Daly GRASIron, total SAMPLE ......5......0......0............

(as Fe) MEASUREMENT Soo10451 10 PERMIT --.... 1 GRABEffluent Gross -_ * .DAINlY MX ....._w*GRALead, Total SAMPLE ............

...... ......(as Pb) MEASUREMENT Soo01051 1 0 PERMIT , ., .. .2 .4Effluent Gross R__QU__EME_

_ 30DA AVG DAILY MX m__" Daw GRABNickel, total SAMPLE ...... ...... ......(as Ni) MEASUREMENT Soo0106710 PERMIT -**.. * ... 1 2Effluent Gross __ __ __ __O AVG DAILY MX 1 DeJ*v GRABNAMEITTILE I cenity under penalty of law that this document and a3 altachmants were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER "tmctCon or superfiion in accordance with a system designed to assure that qualified personnel

,iropetty gather and evatute the information submitted.

Based on my inquiry of the person of persons~~40~7 Benjamin P. Youman who manage the system, or those persons directty responsibe for gathering the infoniatbon.

the 402112012 information submitted is. to the best ol my knowledge and babet. true, accurate, and conplete.

I am SIGNAI"RE OF PIIJ7ClPLE Plant Manager aware that there are significant penalties for submitting lalse intormation, including the possib.lty ot EXECUTIVE OFFICER OR AREAoi 0 r ne and impnsIonreent lor knowing violations.

AUTHORIZED AGENT CODE NUMBER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference eal attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed 27 o0 29 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 1 00NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)

NAME/ADDRESSExe~on Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4460 North German Church RoadByron, IL 61010CMR Wx-i!1nq ZEP CODE:(SUOA 01) CS61010PLEIT8313 NPERMIT NUMBERA01-ODISCHARGE NUMBERMONITORING PERIODMMIDDrYYY I L MMIDDIYYDEMINERAU.ZER REGENERATE WASTE (091A)External Outfall*

• NO DISCHARGE j* ]FROMI02/01/2012 I TOI02/29/2012 ATTN: Zoo Cox/ENV SPEC ______ _____________________________________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TZinc, Total SAMPLE ........................

(as Zn) MEASUREMENT 500010921 0 PERMIT ... ..1 2Effluent Gross ___ ___ __ ___ 300A AVG DALY MX WrnL Daily GRABFlow, in conduit or thru SAMPLE 0.08 0.2 3 0 01/01treatment plant MEASUREMENT 5005010 PERSNT Req. Mon. Req. Mort.Effluent Gross REQUUERINT 30DA AVG DAILY "X COTINSAMPLEMEASUREMENT SAMPLEMEASUREMENT PERMITSAMPLEMEASUREMENT PERMITSAMPLEMEASUREMENT PERMITREQUSIR3Af SAMPLEMEASUREMENT PERMTNAMEMTLE I certify under penalty of law that this document and all attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFRCER direction or supentvsion in accordance with a system designed to assure that qualied personnel property gather and evalute the information submitted.

Based on my inquy of the person or persons , 8,5 3700Benjamin P. Youman who manage the system, or those persons directly responsilge for gathering the information, the 03/21/12infonnalio subydnted is. to the best of my and beelf, tree, accurate, and comp.ee.

I am SIGN RE Ad PRINCIPLE

,.Plant Manager aware that there are significant penalties for submitting false information, including the possiblity of EXECUTIVE FFICER OR AREA NUMBER MM/DD/YYYY T OR PRITD mfine and impisionmment for knowing violations.

AUTHORIZED AGENT CODE NUMBER_ _______ ______COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 21

NAME/ADDRESS NAME Exelon Generation Co., LLCA0RRESS 4300 Winfie!d RoadWarrenville, IL 60655-5701 FACILITV Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATI'rN. Znr Cnrr/F:NV

.*plFC.NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIT NUMBER DISCHARGE NUMBERMONITORING PERIODRO[ MMIDDIYYYV MdDI/YYYY FRM02/01/2012 roI =229=120DMR Mali~ng Z?~ CODE:=fAOR(SUOR 01) CS61010STP PLANT EFFLUENT (FORMER 001 B)Enternal Outfall* *

• NO DISCHARGE QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS .X TYPEBOD, 5-Day SAMPLE 26 ......<4.0 <4.0 19 0 02/30 24(20 Deg. C) MEASUREMENT 02.2001 0200310 1 0 PERMIT 5.3 10.S 30 6OEffluent Gross RQUIROEWFT 30DA AVG DAILYMX 300AAV- DAILYMX m.L TWiePeMov0 COMP24SAMPLE ............

...... 7.28 ...... 7.43 12 0 02/30 GRMEASUREMENT I004001 0 PERMIT ...... 6 9 TwiceEffluent Gross IIW1R11iBIT

____ __ MINIM&UM MAXIMUM SU Per Month GRA3Solids, total suspended SAMPLE 0 14 0.23 26 ...... 2.1 2.7 19 0 02/30 24MEASUREMENT 0053010 PERITr 5.3 10.5 30 80Effluenl Gross RREOUMINT 3ODA AVG DALYMX Old SODA AVG DAILY MX rnm Twee Per COMP24Flow, in conduit or thru SAMPLE 0006 0.010 3 0.101.treatment plant MEASUREMENT

...... ...... ...... 0 01_01 __s o=010 PERMIT Feq. Mon. Req. Mort.Effluent Gross 30DA AVG DALY MX Ia ....... Doily CONTINSAMPLEMEASUREMENT PERLITSAMPLEMEASUREMENT PERWSAMPLEMEASUREMENT PERMITREQUIREMENT NARME'TtLE I certify under penalty of law that ttis documnem and a3 attachments wete prepared under my TELEPHONE DATEPRINAPAL E5CUI1VE OFFtCER tMroCben Or superision in accordance with a system designed to assure that quaffied personnel Benjamin P. Youmnan who manage the system. oa those persons directly resposibe tor gathering the into n s P 15 406-3700 t3/21/2012 information subritted is. to the best ot my nowltedge and beret. true, accurate.

and comp'!te.

I am SIGNA,_ _ _ _ _ P_ _ __IPLEPlant Manager aware that there are significant penalties tor submig talse informartin, including the posstibly of EXECUTIVE OFFICER OR AREATYE CH PstE fine and imoprsionment ftr knowing vioations.

AUTHORIZED AGENT CODE NUMBER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flow existed through this outfall 28 of 29 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/2012 PAGE 1i NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)PERMITTEE NAMEADDRESS k1.MS Exelori Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010CNR M1t!ltlno ZP CODE:(SUBR 01) CS61010L00483O13 PERMIT NUMBERC01-0DISCHARGE NUMBERMONITORING PERIODI MMJDD/YYYY I MMIDD/YYYY WWTP (FORMER ODIC)External Ouffell* *

• NO DISCHARGE

°FROMI02/01/2012 ITOI02/29/2012 AT TN: Zoo Cox/ENV SPEC FREQUENCY__

SAMPLE___

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETrER OF__AMPOF VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESAMPLE ............

...... ...... 4.2 5.1 19 0 02/30 24Solids, total suspended MEASUREMENT 00300 ERI ..,. ... ....300063010 PERMIGoI 300A AVG D3L0 X mgiL Twice Per Month COMP24Effluent Gross RUOCUIREUI

______A_

A________

_____ ________

______Chromium, hexavalenI SAMPLE ............

...... ...... 500(as Cr) MEASUREMENT I010321 0 PERMIT ...... .. D .1 .2Effluent Gross REUWJR1MEiT" 30OA AVG DALY MX OOID~ GRABChromium, total SAMPLE ............

...... ...... 500(as Cr) MEASUREMENT 0103M 0 PERIMIT 2.. M.WI.

• 1 2Effluent Gross RUI ....... 30DA AVG DALY MX g/L D...yDaiAy Copper, total SAMPLE ............

...... ...... 500(as Cu) MEASUREMENT"r 0104210 PERMIT -.....,. -i 5Effluent Gross REWREMET 30OA AVG DALY MX LDy GRABIron. total SAMPLE ........................

(as Fe) MEASUREMENT 5__010451 0 PERMIT ... ....., 1Effluent Gross REGQWRMB 1)4.. MXD ..WLead, total SAMPLE ............

...... ...... 500(as Pb) MEASUREMENT 0105110 PERMIT 2 .4 -..Da l2 .4Effluent Gross REQUIREIENT 300_A AVG DALY MIX LD (3RABNickel, total SAMPLE ............

....... Soo(as Ni) MEASUREMENT I0106710 PERMIT .. .... --D* 2Effluent Gross I_-_ AVG DALY MX mg/L Doily GRABAFIITLI ceriUfy under penalty oo law that this document and aD attachments were Prepared under my TELEPHONE DATEPRItNCIPAL EXECUTIVE OFFICER direction or supervision hi accordance witm a system designed to assure that personnel property gather and evalute the Iformation submitted.

Based on my inqury the person or persons 815 406-3700Benjamin P. Youman who manage the system, or those persons directly for gathering the inf ,on. the 03212012informt1ion submied is. to the best of my knowledge and DeOef, true, acCurate.

and complete I an SIGNii.jE 0W';PRINCIPLE

_ __IPlant Manager aware that them are significant penalties for submitting false informalion.

nftdauing the possiblty of EXECUTIVE OFFICER OR AREA NUMBER MM/DD/YYYY o- 1 fin'e and i 'npris io ntm ent for knowing vio a i n .A U H R D A E T C O D ETYPED op Rom AUTHORIZED AGENT 0o ___COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed through this outfall 16 of 29 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/GM2012 PAGE 1 PERMITTEE NA;E/ADDRESS N flflE Exelon Generation Co., LLC 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoe Cox/ENV SPECNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)

Col 0PERMIT NUMBER DISCHARGE NUMBERMONrTORING PERIODMM/DDOYYYW MM1DDNYYY FROM 02001/2012 TO 02129/2012 DMR ,alling MP CODE:(SUBR 01) CS61010WWTP (FORMER COIC)External Outfall** *NO DISCHARGE QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER I X OF SAMPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPEZinc, total SAMPLE ........................

500(as Zn) MEASUREMENT 0109210 PERMIT ....... 2Effluent Gross ______ ______ 300A AVG DAILY Mk V" p GRABFlownconduitorthru SAMPLE 0.023 0.034 3 ............

...... 01/01 CNtreatment plant MEASUREMENT 50050 0 PERI Req. Mon. 300A Req. Mion. Da* CONTINEffluent Gross I AVG DAILY MX ----SAMPLEMEASUREMENT SAMPLEMEASUREMEN E ___________

________"_____

SAMPLEMEASUREMENT PERMISAMPLEMEASUREMENT SAMPLEMEASUREMENT QIAMEfllTIIE cartl;'y under penarry ot tawe tna ttus document and an asacftrments were prepared under my TELEPHIONE DATEPRoN'CIPAL EXECUTIWE OFFRcER rtirection or supervrsin hraccordance wertl a system destgned to assure marl quafhedl personnel property gather and evalule the infotreatiop suhbmitted.

Based on my irqwryf t the peso or Benjamin P. Youman who Ianspe the system, or these petscns direotty responsibte for gatterrrg mer oiralc. th e SGNTUE , NIP, 03/1/12Plant Manager aware that theret are significant penalties tar submnitting false inforrnation.

including the possibuily of EXECUTIVE OFFICER OR AREA NUMBER MMIDD/YYYY

___rJ ie and itmprhrhonment tor knowing vitlrni.

AUTHORIZED AGENT CODE___COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01106) Previous editions may be used. ' ...1/6/2012 PAGE?2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)MvX)7CA ReFORCT (DMR)PERMITTEE NA/E/ADDRESS MA-AE Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCAliON 4450 North German Church RoadByron, IL 61010ATrN: Zoe CoxIENV SPEC0;19R [Veicfltn ZtP CODE:M~AJOR(SUBR 01) CS61010IL00M83¶3 PERMIT NUMBERI00¶0DISCHARGE NUMBERI MONITORING PERIODMMOD/DIYYYI MMIDDfYYYY RADWASTE (FORMER 001D)External Outfall°NODISCHARGE FROMI02/01/2012 I Tol02r29/2012 IR RQUANTITY OR LOADING QUANTITY OR CONCENTRATlON NO. FREQUENCY SAMPLEPARAMETER EX OF TMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSISSAMPLE ............

...... ...... <0.5 <0.5 19 0 02f30 CPSolids, total suspended MEASUREMENT 00530 1 0 PERWMIT ... ..15 30Effluent Gross _________E111 300___ OA AVG DAIY b4 MO& TI~ePrt~~

OOFow, in conduit or thru SAMPLE 0.023 0.023 3 ..................

0 01/01 CNtreatment plant MEASUREMENT 50050"10 PEMIT Req. Mont. 300A Req. Momt.Effluent Gross REQUIfREIT AVG DAILY MX WON Daily CONTINSAMPLEMEASUREMENT PERIMITREOUIRWIIII__II_

SAMPLEMEASUREMENT PERMITSAMPLEMEASUREMENT PEWmSAMPLEMEASUREMENT PERMWSAMPLEMEASUREMENTr PERMITNAME'TLE I centy under penalty of law that thits document and all attactMents were prepared under my TELEPHONE DATEPRD4CIPAL EXECUTIVE OFFICER erection or supenrision in accordance with a system designed to assuM that qualified personnel property gather and evalute the infomation submitted.

Based an my inquiry of the person or persons A /. .Benjamin P. Youman who manage the systern, or those persons drctly responsiv, f0 gahering me Information. G 815 406-3700 03121/2012 insotli~on subit'lted is. to the best of my knoa wedge and beliet, true.

and complete.

I amNPlant Manager aware that there are signirtant penalties for subming false information.

including the possbitlty of EXECUTIVE O'FFICER OR AREANTYPED oR aewla rine and imprnslonmenl for Knowing viotabors.

AUTHORIZED AGENT COE NUMBER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flow existed through this outfall 8 of 29 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1AI/2012 PAGE1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DSCRAG2 MCK170MSRW EP-CR (OIR)PERMITTEE NAM;EJADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, iL 60555-5701 FACILITY Byron Nuclear Power StationLOCATOMO 4450 North German Church RoadByron, IL 61010I CL0048313 DISCHARGE NUMBERI PERMIT NUMBERMAJUOR(SUBR 01) CSSTORMWATER (FORMER 001 E)External Outfall* -NO DISCHARGE Ex ...61010MONITORING PERIODMMIDDYYYY I MMDD/YYYY FROMI02/01/2012 J TO 02o2212ATTN: Zoe Coxl'ENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SMLVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OF TYPE> < -1ANALYSIS SAMPLE ............

...... ...... 500Solids, total suspended MEASUREMENT 00530 1 0 PERMIT s. 15 30 DALYEffluent Gross RErUIRIEMiT

... ..._ 30DA AVG MX tMgA. Wee*l _ GRABSAMPLE ............

...... ...... 5.5 6.0 19 0 01/07 GRSolids, total suspended MEASUREMENT 0053080 PERMIT 30 100Other Treatment, Process REQUIREMENT 30DA AVG DAILY MX mgl. Weekly GRABComplete 1Chromium, hexavalent SAMPLE .............

500(as Cr) MEASUREMENT 0103210 PERMIT .2,'* ... ....1 2Effluent Gross REOUWET _________

_1,__,_ 300A AVG DAILY MX MgIL Daly GRABChromium, total SAMPLE ............

...... ...... 500(as Cr) MEASUREMENT 010341 0 PERMIT ....... 1 2Effluent Gross R IIEWT _r 3110A AVG DALY MX mL Daily GRABCopper, total SAMPLE ............

...... ...... 500(as Cu) MEASUREMENT 0104210 PERMIT .5.. ........5 1Effluent Gross RErOUREMDET 30OA AVG DAILY MX 0-.L Dally GRABIron, total SAMPLE ............

............

500(as Fe) MEASUREMENT 0104510 PERMrl ...a... 1Effluent Gross REoUIRIEMEN DAILY MX m___ Daffy GRAB3Lead, total SAMPLE ...... ...... .(as Pb) MEASUREMENT I0105110 PERMIT ........

.. .2 4Effluent Gross RE.QUIltEMET 30DA AVG DAILY MX gL Daly GRABNAMTLE I cettify under penalty of law that this doiument and an attachments were prepared<

under my TELEPHONE DATEPRAINCIPAL EXECUTIVE OFFRCER direction or supenrison in accordance with a system designed to assure mtm quatred personnel property gather and eva.'ute the mfomation submitted.

eased on my inquiry of the pemon or personsBenjamin P. Youman r/to manage the system, or those persons responsible for gathering the intormabion.

8e..06..0 03e21/2012 information submined is. to the best of my krowledge and belef, true. accurate, and complete.

I am SIGNATU'JRO01 INCIPLEPlant Manager aware that there are significant penaties for submit"tg false Information, icicluding the possbhiy of EXECUTIVE O-FICER OR AREA NUMBER MM/DD/YYYY TVP O PR e and irinsiosmemnt for knowing volaons.

AUTHORIZED AGENT CODE NUMBER___M_/DD

____YCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during the month.2. Flow existed through this outfall 0 of 29 days during the month.3. There was no flow from this outfall this month however Fire Protection drain water was discharged to this ouffall this month which requires TSS sampling.

EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)(NSCMA!GE M oTORi REPCORT (OMRi)PERMmr-EE NAME/ADDRESS NAME, Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010IIL0048313 PERMIT NUMBERF_-E01-DISCHARGE NUMBERDMR MsI!'ng ZIP CODE:(SUBR 01) CSSTORMWATER (FORMER 001 E)Exteral Outfall""

• NO DISCHARGE r 7 ...61010MONITORING PERIODf MMMDU/YYY MWM/DDYYY FROMI02101/2012 IToi02129/2012 QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREUENCY SAMPLEPARAMETEROF PVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPENickel, total SAMPLE ............

...... ...... 500Jas Ni) MEASUREMENT 500106710 PERMIT ....1 2Effluent Gross RMIREMENT, 30OA AVG DAILY M L D GRABZinc, total SAMPLE ......5......0......0......

tas Zn) MEASUREMENT 500050921 0 PER3MT .e... 2Effluent Gross ROUMtEM0 30AADAVO DALLY MW mI Daily GRAOFlow , in conduit or th ru SAM PLE ...... ............ Saotreatment plant MEASUREMENT Sam 0," ; PEROMT Req. Iort. FReq. Mort. Mgai/d Twic Per Month CONTMEffluent Gross REUIOREMENT 30DA AVE DAILYM_SAMPLEMEASUREMENT IERNIhITSAMPLEMEASUREMENT PERMOTREQUIEMEN11111T

_ _ _ _ _ _ _ _ _ _ _SAMPLEMEASUREMENT PERMOTSAMPLEMEASUREMENT NMErnTLE I cerlity under penalty of law that this document and aD attachments were prepared under my TELEPHONE DATEPRIPCiPAL EXECUTIVE OFFICER directon or superrision in accordance with a system designed to assure thai Olailfled personnel p.roerly gather and evalute the ionotlation subriited.

Based on my Iwiry of the person or ersons 815 406-3700Benjamin P. Youman tho manage the system, or those persons directly responsible fr gathering the inormation, the J11-1 U 81541/2012 infonation submitted is, to the best of my knowledge and betel, true, accurate and Complete.

lam SIGNATPI.

OF P"$NCIPLE0 Plant Manager aware that there are signiticant penalties for submitt false intomation, incuding the possibity o EXECUTIVE OFFICER OR AREA* Mc OR PIRME r lne and Imprisionment for knowing vioatios.

AUTHORIZED AGENT COENUMBER MMDDYYYYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Metal Cleaning wastewater was discharged this month.2. Fire Protection, Service Water or Closed Cooling System drain water was discharged this month.3. There was no flow from this ouffall this month however Fire Protection drain water was discharged to this outfall this month which requires TSS sampling.

EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)(MSCHAR~ra MCK1CROK REPGRT {OMR)PERMITrEE NAE/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church Road0L0048313 PERMIT NUMBERF -001-0DISCHARGE NUMBERtOhlR Mr.King ZIP CODE:MAJOR(SUBR 01) CSCOOLUNG SYSTEM BLOWDOWMExternal Outall61010MONITORING PERIODMMIDDJYYY I I MM/DDIYYYY i!FROMI02/01r2012 1 TOFl 02/29212I* ' "NO DISCHARGE

= ...Byron, IL 61010ATFN: Zoo Cox/ENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER VALUE VALUE UNITS VALUE VLEAU UIS X OF TYSAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS E ANALYSISTemperature, water deg. SAMPLE ............

...... ............

75.5 15 0 01/01 CNFahrenheit MEASUREMENT 0001110 PERMT ..ql mT.NEffluent Gross R___U______

_,0 MAX___________

SAMPLE ............

...... 8.67 ...... 8.71 12 0 01/07 GRpH MEASUREMENT 00400 10 PERMIT S ..h.d6..R.Effluent Gross _ _ _ __ MAXMUM SU_ Wee"y GRABSldttlsseddSAMPLE

...... ...... ...... ...... 4.6 4.6 19 0 01/3D GRSolids, total suspended MEASUREMENT 00530 1 0 PERrT .... Req. Mort Req. MortEffluent Gross PAGUIWT liii 300A AVG DAILY MX Mo" GRABOil & Grease ASMPE ....... <1.4 <1.4 19 0 01107 GRMEASUREMENTI 0551 0Is 20Effluent Gross REOUIR1 T 300A AVG DALLY W_ _n Wee"ly GRA_Chromium, total (as Cr) ...........

...... ............

cO.0021 19 0 01/07 GRMEASUREMENT Glowz I] a PERMIT,,,...

,. ., .. 02 GAEffluent Gross 14140.111E113UT

,QAYMX MIAg Weekly GASAMPLE ...... ...... ...... ...... ...... 0.2Copper, total (as Cu) MEASUREMENT 50001042 10 PERMrr ... .........

0.071Effluent Gross AIWJ1IREM"T DAILY UX ML Weekly GRABZinc, total (as Zn) SAMPLE ............

...... ...... 0.004 0.008 19 0 01/07 GRMEASUREMENT 0109210 PERhST .... .213 .433Effluent Gross _ __,A AVI _____M__L Was_-y GRABNAMc/TITLE Candy under penalty of law that this document and a9 attachments were prepared under my TELEPHONE DATEPRINCtPAL EXECLUIVE OFFICER direction or supevision n accordance with a system designed to assure that quaffied personnel propeen u gather and evalute the Information subm2tted.

Based on my Inquiry of the person of 815 406-3700Benjamin P. Youman w1ho manage the system, or those persons dimrecty responsible tor gathering the infonration.

te 03t21/2012 information subm!tted is. to the best of my knowtedge and befief. true. accurate, and compWte.

I an SIGN F OpINCIPLE

_IPlant Manager aware that there am significant penalties for submitting false information.

linckuatg the possititty of EXECUTIVE OfFICER OR AREAlweOR PMED line and imprisionmant for knowing vioations.

AUTHORIZED AGENT CODE NUMBER MMoO/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Monitoring data for outfall 001-0 is included on attachment.

EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITCRWO REPORT PERW.I-TEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 Byron Nuclear Power StationLOCATION 44,0 North German Church RoadByron, IL 61010IL0048313 PERMIT NUMBER001-0DISCHARGE NUMBER0' MR M(zl!ng ZIP CODE:(SUBR 01) CSCOOIUNG SYSTEM SLOWDOWNOutfall61010MONITORING PERIODI MM/DD/YYYY I I MWIDDIYYYY IFROM I02/01/2012 I TOI02/29/2012 "NODISCHARGE F °l I1 !ATTN: Zoe Cox/FINV SPEC ______ _______________________________________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMMER VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OF TYPE> <IANALYSIS TPOxidants, total res;idual ESRMNSAMPLE

...... ...... ...... ...... .....So340441 0 PEMI .....0oSAMPLE ...........

-5.0Effluent

_____ Gross__ ___________

D_____ ALY MX m9&R Wceldy GRA13Pnority pollutants total effluent MEASUREMENT

...5000800 PE..IT, Req. Mom.. Req. Mon.Effluent Gross P4011,1111111011W DAILY MIX DALY GFlow, in conduit or thru SAMPLEFlw ncnu rtr APE18.15 26.31 3 ...... ... ... ...... 0 01/01 CHtreatment plant MEASUREMENT 5000PERMIT Mon. Req. Mon " Dy CONTINEffluent Gross REQUIRU1.4..1.WIT 300A AVG DAILY MXCfhlorne, total residual SAMPLE ............

...... ............

0.03 19 0 01/07 GRMJEASUREMEN'T Effluent Gross RECUN:43BIgkT DAILY UX m90L Wee*l GRABHydazneSAMPLE

...... ...... ...... ...... 5D0Hydfrazine MEASUREMENT 0I313 1 0 PERMIT ... ... ..... ..011 .027 DailyWhen Effluent Gross ___I____IR__

_,_ 300A AVG DALY MX GRABSAMPLEMEASUREMENT PERIMTSAMPLEMEASUREMENT PERMITrNAME/TITLE i cert./under p o ltscut and at attadmets were prepared u myPFNCIPPAL EXECUTIVE OFFICER direction or supervision in accordance with a system designed to assure that quasfiai personneltTELEPHONE DATEproperty gather and evatute the information sutrlted.

Based on my iquity of the person or psons 03,2815 406-3700Benjamin P. Youman who manage the system, or those persons directly responsitte tor gathering the winoum, SIGNhe OF I01NCIPLE12 infomation sutitted is. to the best Of my bowedg and beef. true, accurate, and comipeate.

I at IPlant Manaler aware that there are significant penalties (or submitting false tiformartion, Including the I t of EXEC E OF CER OR AREA NUMBER MM/DD/YYY 1wof PmiSm raie and imptisionment tor kinowmng violations.

AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)PERMITTEE NAME/ADDRESS 4AME Exelon Generat~on Co., LLCADORESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadPLT048313 NdPERMIT NUMBERD 02-0DISCHARGE NUMBERUNIR Vtaeffng zz? CODE:(SUBR 01) CSSTORMWATER RUNOFF BASINExternal Outfall*

• NO DISCHARGE IX '61010MONITORING PERIODMMJDD/YYYY L _ MMnDDJYYY FROM I02101/2012 I TOl 02/29)2012 IByron, IL 61010ATTN: Zoe Cox/ENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESAMPLE ........................

Solids, Total Suspended MEASUREMENT 0053010 PERMIT ..... 15 30Effluent Gross __,IRIT 300A AVO DAILY a MgL Wee*ly GRABSAMPLE ........................

Solids, Total Suspended MEASUREMENT 0053080 PER. ...... 30 100Other Treatment.

Process "V D Y9L W* GoAwComplete

_____ ____ .__G _____Chromium, hesavalent SAMPLE ............

...... ......(as Cr) MEASUREMENT" 0 PERlr .0............

..... ..011 .01Effluent Gross 3, ___A AV@ DAILY #A mg9L 0 GRABChromium, total SAMPLE ............

...... ......(as Cr) MEASUREMENT 0TOW 10 F T..1 2Effluent Gross _ _30DA AVG DAILY MU MI/L Daily GRABCopper, total MO VE ............

...... ......(as Cu) MEASUREMENT 0104210 PE.......02

.041Effluent Gross _ A A DAILY W m9L 01 GRASIron. total SAMPLE ...........

...... ......(as Fe) MEASUREMENT 0104510 PERM1T 0............

Effluent Gross R013REM5UfT DAILY LX __.____ALead, total SAMPLE ............

...... ......(as Pb) MEASUREMENT I01051 1 0 ......DA...063 A2W DY GRABEffluent Gross ____i_____0_A__A___GIL___

_ 300A AVG DDALy GRA4AM1"UTE I certify under penalty of law that this document and au attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFRCER lirection or supemision in accordance with a system designed to assure that qual~fed personnel property gather and evatute the infomation submitted.

Based on my of the person or persons "-.. 815 406-3700Benjamin P. Youman who manage the system. or those persons alrectty responsie Ior gathering the information.

the 0312112012 inntoalkon submitted is. to the best of my knowledge and belet, true, accurate, and complete.

I am SIGNAVUPE IO PRINCIPLE Plant Manager aware that there are significant penalties for subnmtting false informatimn, including the poesity of EXECbIWE OFFICER OR AREANtinm 0n PmmVeI 1fe and rnpnsionrmem for knowing violations.

AUTHORIZED AGENT CODE NUMBER MMDDYYYYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Metal Cleaning Wastewater was discharged this month.2. No Fire Protection, Service Water or Closed Cooling System Drain Water was discharged this month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 116M2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DiSCHARGE MOX70RNG R~EPORT (lOMR)PERMITTEE NAME/ADDRESSExelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, I160555-5701 Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010A'TrW- 7n,. flrurIhJ'l/N SPF:CDMR Malirtg TIP CODE:(SUBR 01) CS61010;L0048313 PERMIT NUMBER002-0DISCHARGE NUMBERMONITORING PERIODMMIDDIYM I MMIDDYYSTORMWATER RUNOFF BASINExternal Out/allI*

• NO DISCHARGE EKIFROM I02/011/2012 I TOI02/29=212 QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SMLVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPENickel. total SAMPLE ........................

(as Ni) MEASUREMENT 0106710 PWT -., .011 .176Effluent Gross .,RAQU.IR

... 30OA AVG DAILY MX mWL Daily GRASZinc, total SAMPLE ............

......(as Zn) MEASUREMENT 01092 T 0 PERMT ......047 .26Effluent Gross 30OA AVG DAILY MX .Dm GRASSAMPLEOil and Grease EA M E ...... ...... ...... ......MEASUREMENT 035821 O -... .15 20 WhenEffluent Gross REaUIRIIENT

.. ..DA AVG DALY MX MOIL GRASRow, in conduit or thru SAMPLE......

...... ......treatment plant MEASUREMENT 500510 Req. Mon. Req. Mort. .d- When ESTIMAEffluent Gross ,EQUIAME 300A AVG DAILY MX _ ESTIM_SAMPLEMEASUREMENT PERMITSAMPLEMEASUREMENT PERMITSAMPLEMEASUREMENT-PERMITNAEITTLE I certify under penalty of law that this document and a' attachments were prepared under my TELEPHONE DATEPRiCIPAL EXECUTIV OFRFR direction or supervision in accordance with a system designed to assure Mat quafried personnel property gather and evatutre the information submitted.

Based on my inquiry of the person or personsBenjamin P. Yournan who manage the system, or those perons drectly respensibe for gathering the information tre 815 40.3 03/21/2012 information submrtted is, to the best of my knowtedge and belel. true, accurate, and complete.

I am SIGN..IE C.frRINCIPLE Plant Manager aware that there are significant penalties for submitting false formation.

including the possbft of EXECUTIVE OFFICER OR AREAJSORRm -tine and imprisionrment tor knowing violations.

AUTHORIZED AGENT ODNUMBER MMDDYYYYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. This discharge point was not used this month.2. There was no discharge of processed steam generator chemical cleaning wastewater dunng the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11612012 PAGE 2 ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 February 2012Page 1 of 2MONITORING DATA:CWBD Rock RiverDATE Temperature mgd Flowdeg F cfs02/01/2012 75.5 16.09 6,40002/02/2012 67.3 17.45 6,97002/03/2012 67.5 16.69 7,01002/04/2012 69.6 26.31 6,95002/05/2012 69.5 11.88 6,87002/06/2012 67.7 19.48 6,80002/07/2012 68.6 18.60 6,58002/08/2012 64.5 14.24 6,46002/09/2012 68.8 18.72 6,38002/10/2012 68.8 20.01 6,24002/11/2012 66.6 21.36 5,95002/12/2012 73.0 11.51 6,26002/13/2012 73.0 20.80 6,60002/14/2012 66.7 17.60 6,45002/15/2012 71.1 18.10 5,98002/16/2012 71.1 17.07 5,90002/17/2012 70.6 17.79 5,89002/18/2012 70.5 22.73 5,77002/19/2012 67.4 18.42 5,66002/20/2012 67.4 15.50 5,54002/21/2012 71.1 19.60 5,55002/22/2012 72.5 15.94 5,51002/23/2012 72.5 18.45 5,42002/24/2012 68.8 18.86 5,65002/25/2012 68.8 22.70 5,64002/26/2012 71.8 18.55 5,51002/27/2012 71.8 13.84 5,57002/28/2012 67.0 19.60 5,57002/29/2012 75.5 18.36 6,250K:\BYR_CH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\FebruaryWebruary 2012 ATTACHO1.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 February 2012Page 2 of 2HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (orassociated rinses) containing hydrazine discharged to the Cooling SystemBlowdown during the month of February 2012.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite was used this month. Bromine compounds were notused this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 29 of 29 days.4. Per Special Condition 24 the influent from the Rock River and effluentfrom Outfall 001-0 was monitored for Total Suspended Solids (TSS) thismonth. The Rock River TSS value was 3.5 mg/L on 02/06/2012.

TheCWBD TSS value was 4.6 mg/L on 02/06/2012.

5. Rock River flow for February 2012 was >2400 cfs therefore dailytemperature calculations were not required this month. (Special Condition 12).6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in February 2012. (Special Condition 15).K:\BYR_CH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012ReportskFebruaryfebruary 2012 ATTACHOI.doc Exel n.Exelon Generation

Company, LLC www.exeloncorp.com NuclearByron Station4450 North German Church RoadByron, I161010-9794 April 19, 2012LTR: BYRON 2012-0045 File: c2:09.04--1:3 1.10.0101 Illinois Environmental Protection AgencyBOW CAS #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring ReportIn accordance with National Pollutant Discharge Elimination System (NPDES) Permit Number1L0048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report forSByron Station, Units 1 and 2. This report covers the period of March 1, 2012 through March 31,2012.Pursuant to Byron Station's NPDES permit, the Station monitors the Total Suspended Solids(TSS) result for Outfall C01 (Wastewater Treatment Plant Effluent) twice per month.On March 10, 2012, the TSS composite sample result for Outfall C01 was 37.9 mg/L and theduplicate result showed 39.6 mg/L. Reanalysis of the remainder of the March 10, 2012 sampleshowed 34.3 mg/L and 33.7 mg/L for the duplicate.

Once the original analysis results indicated greater than 30 mg/L TSS, the Wastewater Treatment Plant (TR) was shutdown.

On March 13, 2012, the TSS composite sample result for Ouffall C01 was 3.0 mg/L and theduplicate result was 2.5 mg/L.The elevated TSS of March 10, 2012, did not endanger health or the environment.

ByronStation has been reviewing potential causes of the elevated TSS at Outfall C01. The TRsystem uses two 30,000 gallon Collection Tanks to collect influent wastewater until enoughwater is collected to initiate the treatment process.

In addition to the collection tanks, foursettling ponds also collect influent wastewater for eventual TR processing.

On March 10, 2012the influent wastewater being processed at TR consisted primarily of TR settling pond water.The TR settling pond water often presents a challenge to the TR treatment system specific tothe removal of suspended solids. When processing TR settling pond water, additional operatorattention is required to assure that the system performs as designed.

Several actions are being taken to prevent this event from occurring in the future. Theseinclude:

implementation of operating procedure changes and creation of a new chemistry department procedure to perform a filter test of TR effluent approximately every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> April 19, 2012Byr Ltr 2012-0045 Page 2whenever TR is processing water. This event and all actions associated with the event arecaptured in Byron Station's Corrective Action Program under Issue Report 1339223.It appears lack of recognition of poor water quality being processed by the Wastewater Treatment (TR) plant is the main cause of the elevated TSS value.If there are any questions regarding this report, please contact Ms. Zoe Cox,Environmental/Radwaste Supervisor, at (815) 406-3035.

Respectfully, Benjmin MP.Youman Plant ManagerByron Nuclear Generating StationBPY/ZC/eh Attachments bcc: J. Gould -Environmental

-CanteraZ. Cox -. Chemistry

-Byron PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010ATTN: 7nn Cns/I:NV NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)IL0048313 A01-0PERMIT NUMBER DISCHARGE NUMBERMONITORING PERIODMMDD/YYYY MM1DD/YYYY DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010DEMINERALIZER REGENERATE WASTE (001A)External Outfall*

• NO DISCHARGE FROMI0310112012 ToI 0132o12 0I IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESolids, Total Suspended SAMPLE ............

...... ...... 1.8 1.9 19 0 01/30 08MEASUREMENT 005301 0 PERMIT- S i,,0..A AVG D3"Y COEffluent Gross REQUIREMENT 3 , __20DA AVG DAILY MIX_._m_/LMonthlyMP-

Chromium, hexavalent SAMPLE ............

...... ......(as Cr) MEASUREMENT 5000103210 PERMIT 2 .. .. -. ..Effluent Gross REQUIREMENT

' 30DA AVG DAILY MX __LDiyGA.

Chromium, total SAMPLE ............

...... ...... 500(as Cr) MEASUREMENT I0103410 PERMIT ........

...... 1 2 mgL Daily GRABEffluent Gross REQUIREMENT

"_3_DA AVG DAILY MX -....Copper, total SAMPLE ............

...... ...... 500(as Cu) MEASUREMENT 0104210 PERMIT ..... -.5 1 mGRABEffluent Gross REQUIREMENT

._30DA AVG DAILY MXIron, total SAMPLE ........................

500(as Fe) MEASUREMENT 010451 0 PERMIT ,.- .... -1.Dl GEffluent Gross REQUIREMENT

_ DAILY MX mg__ Daily GRABLead, Total SAMPLE ............

...... ...... 500(as Pb) MEASUREMENT 0105110 PERMIT ... .... .2 .4Effluent Gross REQUIREMENT 2_0DA_ AVG DAILY MX g/ Daily GRABNickel, total SAMPLE ........................

500(as Ni) MEASUREMENT 0106710 PERMIT .21 2Effluent Gross REQUIREM ENT "_ '"__" ...... " S30DA AVG DAILY MX g/L Daily GRABNAMEF.JTLE I cetify under penalty of law that this document and all attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction or supervision in accordance with a system designed to assure that qualified personnel propefy gather and evalute the information submitted.

Based on my inquiry of the person or persons ? -C.... = 815 406-3700Benjamin P. Yournan who manage the system. or those persons directly responsible for gathering the information, the 04119/2012 infonnatiom submitted is, to the best of my knowledge and belief. true. accurate, and complete.

I am SIGNATUS OF I.AINCIPLE Plant Manager aware that there are significant penalties for submitting false information.

including the possifbity of EXECUTIVE OFFICER OR AREAN-weD ot PrIED fio ne and imprisionment for knowing violations.

AUTHORIZED AGENT CODE NUMBER MM/DDYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed 31 of 31 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11612012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power SlationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoe Cox/ENV SPECIL0048313 PERMIT NUMBERIDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IA01-0DISCHARGE NUMBER1I MONITORING PERIODI MM/DD1YYYY I I MMfDD1YYYY DEMINERAUZER REGENERATE WASTE (O01A)External Outfall"NO DISCHARGE FROMI03/01/2012 I TOI03/3112012 QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OE SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS E ANALYSIS TYPEZinc, Total SAMPLE 500(as Zn) MEASUREMENT 500010921 0 PERMIT .. .... M 2mg& aily GRAEffluent Gross REQUIREMENT.

"-"_'_

• 30OA AVG DAILY.MX mg__. DaiyGRAFlow, in conduit or thru SAMPLERoi odi rtr APE 0.044 0.103 3 ........

...... ...... 0 01101 CNtreatment plant MEASUREMENT 500501 0 PERMIT Req. Mon. Req. Mon. Mgal/d Daily CONTINEffluent Gross REQUIREMENT 30DA AVG DAILY MX a _SAMPLEMEASUREMENT PERMfT.REQUIREMENT

" '_'_' "_""_"_"SAMPLEMEASUREMENT PERMITREQUIREMENT

_____.,__.._._.._.

SAMPLEMEASUREMENT PERMITREQUIREMENT

.,SAMPLEMEASUREMENT PERMITREQUIREMENT

"._-_._____._*

SAMPLEMEASUREMENT PERMITREQUIREMENT

.'NAMETITLE I certify under penalty of law that this document and at attachments were prepared under my TELEPHONE DATEPRJNCIPAL EXECUTIVE OFFICER direction or supervision in accordance with a system designed to assure that qualified personnel property gather and evalute the information submitted.

Based on my inquiry of the person or persons 4063I700Benjamin P. Youman who manage the system, or those persons directly responsible for gathering the information, the 815 406-3700 04/19/2012 inlormation submitted is. to the best of my knowledge and betel, true. accurate.

and complete.

I am SIGNAVRE PRINCIPLE Plant Manager aware that there are significant penaltes tar submitting faLse information, including the possabUty of EXECUTIVE OFFICER OR AREA UMBon emme fine and imprisionment for knowing violations.

AUTHORIZED AGENT CODE NUMBERMM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/8/2012 PAGE 2 PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PL004r13 I E H B01-0I PERMIT NUMBER I I DISCHARGE NUMBERDMR Mailing ZIP CODE:MAJOR61010(SUBR 01)CSMONITORING PERIODMMIDDIYYYY I MMIDDYYYY STP PLANT EFFLUENT (FORMER 001B)External Outfall-NO DISCHARGE FROMW 03/01/2012 l TO[03/31/2012 I IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESOD. 5-Day SAMPLEBD -aSAPE <0.28 0.39 26 ...... <6.7 9.3 19 0 02/30 24(20 Deg. C) MEASUREMENT 0031010 PERMIT 5.3 10;5 30 80Effluent Gross REQUIREMENT 30DA AVG DAILY MX' b/. 30DA AVG DAILY MX mg-L TWce Per Month wM-,24pH SAMPLE ............

...... 7.48 ...... 7.62 12 0 02/30 GRMEASUREMENT 00400 1 0 PERMIT 6 .....9.......

6 '.Effluent Gross REQUIREMENT

._MINIMUM MAXIMUM U Twice Per Month GRABSAMPLESolids, total suspended MEASUREMENT 0.12 0.13 26 ...... 2.8 3.2 19 0 02/30 2400530 1 0 PERMIT 5.3 10.5 30 60.Effluent Gross REQUIREMENT 30DA AVG DAILYMX -d30DAAVG D0AILYMXFlow, in conduit or thru SAMPLEFo .icodiortrSA PE0,006 0.011 3 ...... ...... ...... ...... 001101 CNItreatment plant MEASUREMENT 500501 0 PERMIT Req. Mon. Req. Mon.. ".." .'.. CONTINEffluent Gross REQUIREMENT 30DA AVG ODALYMX ............

"..'SAMPLEMEASUREMENT PERMITREQUIREMENT

.' "._"__ "SAMPLEMEASUREMENT PERMITREQUIREMENT SAMPLEMEASUREMENT PERMITREQUIREMENT

-NAMEMtMTLE I ceany under penalty of law that this document and all atlachments were prepared undet my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction or supervision in accordance with a system designed to assure thai qualiied personnel piroperty gather and evalute the inlormation submitted.

Based on my inquiry of the person or persons 8 467Benjamin P. Youman who manage tMe system, or those persons directty responsible for gathenng the Information, the , 815 406-3700 04/19/2012 Intormation submitted is, to the best of my knowledge and belief, true, accurate, and complete.

I am SIGNAIWE U. rRINCIPLE Plant Manager aware that there are significant penalties for submitting false information, including the possibilty of EXECUTIVE OFFICER OR AREAPrm-r ' [n'e and imprisionment for knowing violations.

AUTHORIZED AGENT CODE NUMB MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flow existed through this outfall 30 of 31 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/18/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010AT[N Zom, Corr/lNV ISPECDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERF -C010DISCHARGE NUMBER 7MONITORING PERIODMM/DD/YYYY I MM/DD/YYYY WWTP (FORMER 001C)External OutfallNODISCHARGE FROMI03/0112012 TOI03/31/2012 l ,IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESolids, total suspended SAMPLE ...... 14.7 39.6 19 1 02/30 24MEASUREMENT 0053010 PERMIT .s 30. .. .. Twice-pe..r M ,.,. 15 30Effluent Gross REQUIREMENT

• _______.30DA AVG DAILY , mol Twice-PerMonth

.COP24Chromium, hexavalent SAMPLE ...... 500(as Cr) MEASUREMENT 0103210 PERMIT ..1 mDaly GRABEffluent Gross REQUIREMENT

"__ .30DA AVG DAILY MX _ GRAB *Chromium, total SAMPLE ............

...... ...... 500(as Cr) MEASUREMENT 010341 0 PERMIT 2.. 1y2Effluent Gross REQUIREMENT

--ODA AVG,, DAILYMX ",Dal.RCopper, total SAMPLE 50......

S(as Cu) MEASUREMENT 0104210 PER ...... ...5Effluent Gross REQUIREMENT

."3A AVG .DAILY MX_- mg&L. Daily GRAB.--Iran, total SAMPLE ...... 500(as Fe) MEASUREMENT 010451 0 PERMIT .1 Daily GRABEffluent Gross REQUIREMENT DAILY MX .GALead, total SAMPLE ...... 500(as Pb) MEASUREMENT 0105110 PERMIT .. .. .... .2 .G4Effluent Gross REQUIREMENT

"_-_-_._.

_0ODA AVG DAILY MX rgL Dai GRABNickel, total SAMPLE ...... 500(as Ni) MEASUREMENT 0106710 PERMIT ...... .,. 1 2 mg1LEffluent Gross REQUIREMENT

"____"__

_____" ___ "" 30DA AVG DAILY MX m Daily .GRNAME/TITLE I certify under penalty of law that this document and all attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evalute the information submitted.

Based on my inquiry of the person or persons .815 406-3700Benjamin P. Youman who manage the system, or those persons directly responsible for gathering the information.

the 04/19/2012 information submitted is. to the best ot my knowledge and belief, true. accurate.

and complete.

I am SIGP URF.,' PRINCIPLE Plant Manager aware that there are significant penalties for submitting false Information, including the possiblity of EXECUTIVE OFFICER OR AREAoE -ine and imptisionmant for knowing violations.

AUTHORIZED AGENT CODE NUMBER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed through this ouffall 20 of 31 days during the month.3. See DMR cover letter for WWTP TSS exceedence details.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/612012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMrITEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoe Cox/ENV SPECDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERC01-0DISCHARGE NUMBERMONITORING PERIODMMIDD/YYYY I MMfDDIYYYY WWTP (FORMER 001C)External Outfall* I *NO DISCHARGE "JFROMI03/01/2012 I TOI03031/2012 QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPEZinc, total SAMPLE ........................

500(as Zn) MEASUREMENT 0109210 PERMIT ...... 1 2Effluent Gross REQUIREMENT

' 30DA AVG DAILY MX( mg/L Daily GRABFlow, in conduit or thru SAMPLERo.i odi rtr APE 0.015 0.030 3 .... ...........

...... 0 01/01 CNtreatment plant MEASUREMENT 50050 1 0 PERMIT Req. Mon. Req. Mon. -"Effluent Gross REQUIREMENT 30DA AVG DAILY MX Mga/d Daily CONTINSAMPLEMEASUREMENT PERMITREQUIREMENT SAMPLEMEASUREMENT PERMITREQUIREMENT-

,. ._._SAMPLEMEASUREMENT PERMITREQUIREMENT

-. *_'_'-_._,

SAMPLEMEASUREMENT PERMITREQUIREMENT SAMPLEMEASUREMENT PERMITREQUIREMENT NAMEMJITLE I ceaniy under penalty of law that this document and all attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECU1iVE OFFICER direction or supervision in accordance with a system designed to assure that qualified personnel pmpertygather anevalutethe nformationsubmittel.

Based on my inqur of the peron or persons,-

Benjamin P. Youman rho manage the systema or those persons sirectly responsible for gathering the Information, the 8151"2R14ý 4 6R37L 04/19/2012 information subnmtlted is, to the best of my knowledge and belief, true, accurate, and complete.

I am SIGN RE PRINCIPLE Plant Manager aware that them are significant penalties for submitting false Information, including the possibillty of EXECUTIVE OFFICER OR AR UMBED Oe P' eine and impesionment for knowing violations.

AUTHORIZED AGENT CODE ER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 20 0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIT-EE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERD01-0DISCHARGE NUMBERMONITORING PERIODMM/DD/YYYY I MMDD/YYYY RADWASTE TREATMENT (FORMER 001 D)External Outfall* *

• NO DISCHARGE G*IFROMI03/0112012 1 TO 03/31/2012

! IByron, IL 61010ATTN: Zoe Cox/ENV SPECSFREQUENCY SMLQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. OFRPNEPARAMETER

____________

__N. OF SAtPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESolids, total suspended SAMPLE ............

...... ...... <0.56 0.6 19 0 02/30 CPMEASUREMENT 005301 0 PERMIT. .. ........

-15 30Effluent Gross REQUIREMENT 30AAVG LY MX Twice PerMoth COMPOSFlow, in conduit or thru SAMPLEFoicodiortrSAPE 0.023 0.024 3 ...... ...... ...... ...... 0 01101 CNtreatment plant MEASUREMENT 500501 0 PERMIT Req. Mon. Req. Mon.. DMgald Da ,By. CONTINEffluent Gross REQUIREMENT 30DA AVG DALY MX " ', _NTISAMPLEMEASUREMENT PERMITREQUIREMENT

'.SAMPLEMEASUREMENT PERMITREQUIREMENT

....SAMPLEMEASUREMENT PERMITREQUIREMENT

__._ _"_ _- _-SAMPLEMEASUREMENT PERMITREQUIREMENT.

._"_.._.SAMPLEMEASUREMENT PERMIT 7_________________REQUIREM31ENT

______________

NAMFTImTLE I certify under penalty of law that this document and all attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evatute the information submitted.

Based on my inquiry of the person or persons 815 408-3700Benjamin P. Youman who manage the system, or those persons directly responsible for gathering the information.

the IfGAV- 815 406-370 04/1912012 information submitted is. to the best of my knowledge and belief. true, accurate, and complete.

I am SIGNATU"j;F

,MINCIPLE Plant Manager aware that there are significant penalties for submitting false information.

including the possiwrtty of EXECU1 OFFICER OR AREATVI.0 RPiEnaoie and Itmprisionment for knowing viotio.I AUTHORIZED AGENT CODE NUMBER MM/DDY_ _COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flow existed through this outfall 10 of 31 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010IL0048313 PERMIT NUMBERI E01-0IDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010I DISCHARGE NUMBERMONITORING PERIODMM/DD/YYYY MM/DD/YYYY STORMWATER (FORMER 001 E)External Outfall.". NO DISCHARGE i::iFROMIl03/0112012 ITOl03/31/2012 II !ATTN: Zoe CoxIENV SPECFREQUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESAMPLE ............

...... ......Solid, total suspended MEASUREMENT 500005301 0 PERMIT , 9.. 1W 30Effluent Gross ,tEQUIREMENT 3DAAVG DAILY MXSAMPLE ...... ...... 23.7 24.3 19 0 01/07 GRSolids, total suspended MEASUREMENT 0053080 PERMIT ..30 100 -mOther Treatment, Process REQUIREMENT 30DA AVG DAILYMX g" L Weekly GRABComplete

*_-_.._*Chromium, hexavalent SAMPLE 50.(as Cr) MEASUREMENT 0103210 PERMIT ... ... D ..1 .2Effluent Gross REQUIREMENT 300A AVG DAILY MX mg/L DeIty .GRABChromium, total SAMPLE ............

...... ...... 500(as Cr) MEASUREMENT 01034 10 PERMIT 2 1 Da2 GRABEffluent Gross REQUIREMENT 30DA AVG DAILY MX ._-Dy RCopper, total SAMPLE 500(as Cu) MEASUREMENT 01042 1 0 PERMIT ... .., .Dail .5 GREffluent Gross REQUIREMENT..

30DA AVG DAILY [a Vg. ..a.y .Iron, total SAMPLE ............

...... .500(as Fe) MEASUREMENT 014.0.ERIT.

...... ...... mo/L Daily GRAB"Effluent Gross REQUIREMENT DAILY MXLead, total SAMPLE ............

...... ...... 500(as Pb) MEASUREMENT 01051 10 PERMIT ...... 4.... ' .;,. ' ..." .mg/L DaIly GRABEffluent Gross REQUIREMENT

.__*_._._30DA AVG. DAILY MX -..INAME/iT1-E I certily under penalty of law that this document andi a! attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction or supervision in accordance with a system designed to assure that qualified personnel propedy gather and evaltute the intonmation submitted.

Based on my inquiry of the person or persons Benjamin P. YouFan who manage the systema or thoy persons dryecty responsible for gathering bhe Informatiun.

these815d40.-3700 0411912012 information submitted is, to the best or my knowledge an belief. true. accurate.

and complete.

I am SIGN- uE PRINCIELE Plant Manager aware that there are significant penalties for submitting false inforraot including the possibility of EXE=M11E OFICER O0R AREAf'lS A mnB ine and imprisiocnamnt for kinowing vioatons.

AUTHORIZED AGENT CODE NUMBER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Refenrence all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during the month.2. Flow existed through this outfall 2 of 31 days during the month.3. Flow is estimated due to replacement of installed totalizer duringq this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11W/212 PAGE 1I NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERE01-ODISCHARGE NUMBERMONITORING PERIODMM/DD/YYYY I MM/DD/YYYY STORMWATER (FORMER 001 E)External Outfall* *

• NO DISCHARGE

--' ...FROMI03/01/2012

] TOI03/31/2012 QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETR VAU NT AUX OF TPVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPENickel, total SAMPLE ............

...... ...... Soo(as Ni) MEASUREMENT 0106710 PERMIT 2

• 1.2Effluent Gross REQUIREMENT

" _.._" *_ .30DA AVG DAILY MX .... Daily GRABZinc, total SAMPLE ...... ...... Soo(as Zn) MEASUREMENT 0109210 PERMIT ...2*... 1 * *2Effluent Gross REQUIREMENT

"-30DA AVG DAILY.MX.

mg/L Daily GRABFlow, in conduit or thru SAMPLEtreatment plant MEASUREMENT 0.125 0.125 3 0 02/30 ES500501 0 PERMIT Req. Mon. Req. Mon.Effluent Gross REQUIREMENT 30DA AVG DALY MX Mgal/d f" Twice Per Month CONTINSAMPLEMEASUREMENT PERMITREQUIREMENT

". .SAMPLEMEASUREMENT PERMITREQUIREMENT

..... .. _- ._."_..-SAMPLEMEASUREMENT PERMITREQUIREMENT

._._"_"_""

SAMPLEMEASUREMENT PERMITREQUIREMENT-

_ ' _.... ,_ _NAMEI1TTLE I certify under penalty of Law that this document and as attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction or supervision in accordance with a system designed to assure that qualified personnel property gather and evalute the infornation submitted.

Based on my inquiry of the person or personsBenjamin P. Youman who manage the system. or those persons directly responsible for gathering the Infornation.

the 46-3700 04/19/2012 information submitted is. to the best of my knowledge and belief, true, accurate, and complete.

I am SIGN A6, hE P [PRINCIPLE

__5_=Plant Manager aware that there are significant penalties for submitting false information, including the possiblity of EXECUTIVE OFFICER OR AREA UMBOR IMM lne and imprislonment for knowing violations.

AUTHORIZED AGENT C'OD NU ER MM/I)D/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Metal Cleaning wastewater was discharged this month.2. Fire Protection drain water was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/2012 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadIL0048313 PERMIT NUMBER001-0DISCHARGE NUMBERMONITORING PERIODMM/DD/YYYY I MMIDDIYYYY DMR Mailing ZIP CODE: 61010MAJOR(SUBR 01) CSCOOLING SYSTEM SLOWDOWNExternal OutfallNODISCHARGE EDI n,,. FROM1 TOFI 03/31/2012 IIWC/VWPI4U I! lIByron, IL 61010ATTN: Zoe Cox/ENV SPEC _ FREUENCYQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSISTemperature, water deg. SAMPLE ............

...... ............

900 15 0 01/01 CNFahrenheit MEASUREMENT

____ ___00011 1 0 PERMIT M....,, Req. Mon. lyEffluent Gross REQUIREMENT

" '_" " O MX d F Dai CONTINSAMPLE ............

...... 8.62 ...... 8.80 12 0 01/07 GRpH MEASUREMENT 0040010 PERMIT ,.6 ,. 9 Weely GRABEffluent Gross REQUIREMENT

.." MINIMUM MAXIMUMSolids, total suspended SAMPLE ............

...... ...... 3.7 3.7 19 0 01/30 GRMEASUREMENT 00530 1 0 PERMIT ... Req. Mon. Req. Mon.Effluent Gross REQUIREMEN*'

• _._--_.

30DA AVG DAILY MX mo_., ROil & Grease SAMPLE ............

...... ...... <1.4 <1.4 19 0 01/07 GRMEASUREMENT 00556 10 PERMIT ... 20 mgL Weekly "GRA5Effluent Gross REQUIREMENT

-_ " 30DA AVG DAILY MX. .W yRChromium, total (as Cr) SAMPLE ............

...... ............

<0.0021 19 0 01/07 GRMEASUREMENT 01034 1 0 PERMIT 0.... " 0.2Effluent Gross REQUIREMENT DAILY MXWeCopper, total (as Cu) SAMPLE ............

...... ............

0.012 19 0 01/07 GRMEASUREMENT 01042 1 0 PERMIT.......

...., ..... ...,.. -0.071 m91I WeekGyEffluent Gross REQUIREMENT

..... " ___._. _* ._ _ .DAILY MX m " Wey RSAMPLE ...........

...... 0.003 0.005 19 0 01/07 GRZinc, total (as Zn) MEASUREMENT 0109210 PERMIT ..... .213 .433Effluent Gross REQUIREMENT

-3. AVG DAILY MX m,. WNAME/TITLE I certify under penalty of law that this document and asi attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction or supervision In accordance with a system designed to assure that qualified personnel property gather and evalute the informnation submitted.

Based on my inquiry at the person or personas 1 406-37d00 04/19201Benjamin P. Youman who manage the system, or those persons directly responsible for gathering the information, the i4/1 01information submitted is, to the best ot my knowledge and belief, true. accurate, and complete.

I am SIGN217REr PRINCIPLE Plant Manager aware that there are significant penalties tor submitting false informiation.

including the possib1ity of EX.QUJTIVE OFFICER OR AREA NUMBER MM/)D/YYYY TrPF.D OR PAIn-o fine and imprlslonment for knowing violations.

AUTHORIZED AGENT COD ECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachmenta here)1. Monitoring data for outfall 001-0 is included on attachment.

2. Copper ion skids started on 3/5/12.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/612012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIT'EE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadIL0048313 PERMIT NUMBER001-0DISCHARGE NUMBERDMR Mailing ZIP CODE: 61010MAJOR(SUOR 01) CSCOOLING SYSTEM BLOWDOWNExternal OutfallI *NO DISCHARGE EJ ...MONITORING PERIODI MM/DU/YYYY I MMIDD/YYYY FROM I03/01/2012 I TOI03/31/2012 Byron. IL 61010ATTN: Zoe Cox/ENV SPEC ______ _____________________________________

PARAMETER QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX* OF TYPE____________

I______ _____ ______ __________

ANALYSISOxidants, total residual SAMPLE ...........

500MEASUREMENT 340441 0 PERMIT" .... .05, ~ ~ ~ m/ * , NYX" iJ"Weekly GRAS.Effluent Gross REQUIREMENT

_. , DAILY MxPriority pollutants total effluent SAMPLE 500MEASUREMENT

__________

________500081 0 PERMIT ..R... Req. eq. mg/L Weekly GRABEffluent Gross REQUIREMENT'

" DAILY.MX

• DAILY MXFlow, in conduit or Ihru SAMPLEFoicodiortrSAPE 17.81 25.48 3 ...... ... ... ...... 0 01/01 CNtreatment plant MEASUREMENT 500501 0 PERMIT -Req. Mon. Req. Mon. ., Da...,,Effluent Gross REQUIREMENT 30DA AVG DAILY MK Mga/d ..Daily CONTINChlorine, total residual SAMPLE............

............

0.04 19 0 01/07 GRMEASUREMENT 500601 0 PERMIT .. 0. Week.l y-... oGRAB W0Effluent Gross REQUIREMENT DAILY-MX m"'oL W lSAMPLE ....... 5Hydrazine MEASUREMENT

..... 500813131 0 PERMIT ...... .... : ., 0DalyWhnEffluent Gross REQUIREMENT 300A AVG DAILY MX " Discharging SAMPLEMEASUREMENT PERMITREQUIREMENT

'___.__ _SAMPLEMEASUREMENT PERMIT_ REQUIRIMENT

• ._'_.NAME/1rTLE I cerly under penalty of 'w that MtRi documeut and ati attachments were prepared under myPRINCIPAL EXECUTIVE OFFICER rirection or supervision in accordance with a system designed to assure that qualified persornel TELEPHOTELEPHONE DATEpropery gather and evatute the intonration submitted.

eased on my inquiry of the person or persons 815 406-3700Benjamin P. Youman who manage the system, or those persons directly responsible for gathering the information.

the SiGN E 04/19/2012 information submitted is. to the best of my knowledge and beliel, true, accurate, and complate.

I am FF"CER ORNUBRERM Plant Manager aware that there are significant penalties for submitin~g false information.

includinhg the poss: fily of E I FIE R AE UBRM/DYYTYPOI PRINTED tine and irrtorisionment for knowing violations.

AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadOMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBER1 002-0I DISCHARGE NUMBERMONITORING PERIODMM[DD/YYYY I MMLDSTORMWATER RUNOFF BASINExternal Outfall* *

• NO DISCHARGE FROM I03/01/2012 TOI03/31/2012 Byron, IL 61010ATTN: Zoe Cox/ENV SPEC _ UANTITY ORLOADING__UANTITYORCONCENTRATIONNO._FREQUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS E ANALYSIS TYPESAMPLE ............

..... ......Solids, Total Suspended MEASUREMENT 0053010 PERMIT ..- ... 15 30Weekly. GRABEffluent Gross REQUIREMENT

_ _ -" .. _ "_: 3ODA AVG DAILYMx, WeeMlySAMPLE ...........

Solids. Total Suspended MEASUREMENT 0053080.

.100050 0PERMIIT .... :'....30

.100 : gLWeekly

" GRABOther Treatment, Process REQUIREMENT 30DA AVG DAILY MX mgIyCompleteChromium, hexavalent SAMPLE .............

......(as Cr) MEASUREMENT 01032 1 0 PERMIT ...... ,, ...... .011 .018: m101 Daily GRABEffluent Gross REQUIREMENT

.__30DA AVG DAILY MX ayChromium, total SAMPLE ...... ......(as Cr) MEASUREMENT 01034 1 0 PERMIT 2... ........

..... 1 2Effluent Gross REQUIREMENT 30- 0DA AVG DAILY MX mg/. Daily GRABCopper, total SAMPLE ...... ......(as Cu) MEASUREMENT 01042 1 0 PERMIT ......*. .. ... .025 .041 RAaEffluent Gross REQUIREMENT

" r ' '.

• 30DA'AVG.

DAILY MX mg/" Daly GRAB.Iron, total SAMPLE ...... ......(as Fe) MEASUREMENT 010451 0 PERMIT,,,,,

,,. ,..;, m., ., ' DailyEffluent Gross REQUIREMENT

_. ._ DAILY MX mg/, DGRABLead, total SAMPLE ........................

(as Pb) MEASUREMENT 01051 1 0 PERMIT ..063- .298Effluent Gross REQUIREMENT.

..T', 3ODA AVG DAILY MX mg/L. Daily GRABNAMEJ1TTLE I cettily under penalty of law that this document and alt attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction or supervision in accordance with a system designed to assure that qualified personnel

___________/_.,_

properly gather and evalute the Information submitted.

Based on my inquiry of the person or persons 8 4-Benjamin P. Youman who manage the system. or those persons directly responsible tor gathering the information.

e 815 406-3700 04/19/2012 information submitted is. to the best of my knowledge and belief, true, accurate, and complete.

I Em SIGN E A rE9YRINCIPLE Plant Manager aware that there are significant penalties for submitting lalse information, including the possiblity of EXEdTVbFFCER OR AREAN BM YTYPIED OR MN-,W fine and impnsionrnent for knowing violations.

AUTHORIZED AGENT CODE NUMBER MMDD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Metal Cleaning Wastewater was discharged this month.2. No Fire Protection, Service Water or Closed Cooling System Drain Water was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITIEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, 1160555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010A'T-TN! Znn Crn/IFNV 5PFCIL0048313 PERMIT NUMBER002-0DISCHARGE NUMBERDMR Mailing ZIP CODE:MAJOR(SUBR 01) CSSTORMWATER RUNOFF BASINExternal OutfallNODISCHARGEr

.61010MONITORING PERIODMM/DD/YYYY I MM/DD/YYYY FROM I03/01/2012 I ToI03/31/2012 X FREQUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FSAMPLEPARAMETER

____ ___N. OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPENickel, total SAMPLE ......(as Ni) MEASUREMENT 0106710 PERMIT ....,,,, ...011 .176Effluent Gross REQUIREMENT

'_"_"_30DA AVG DAILY MX Daily GRABZinc, total SAMPLE(as Zn) MEASUREMENT 0109210 PERMIT ..... : .,. .... ,047 .26Effluent Gross REQUIREMENT m9, __._- __ 0DA AVG DAILY MX .Daily GRAB.Oil and Grease SAMPLE ......MEASUREMENT 035821 0 PERMIT , ., ... ..15 20 When-Effluent Gross REQUIREMENT

"_______.

"_____" 30DA AVG -DAILY MX ..mg_ Discharging Row, in conduit or thru SAMPLE......

......treatment plant MEASUREMENT 500501 0 PERMIT Req. Mon. Req. Mon. Mld .'*" *"... WhenEffluent Gross REQUIREMENT 30DA AVG DAILY MX *

• Discharging ESAMPLEMEASUREMENT PERMIT .REQUIREMENT

-__ -, ,_ __,____,SAMPLEMEASUREMENT PERMITREQUIREMENT

,_ , ;_. 1_ ._-_._,_,_"_,.

SAMPLEMEASUREMENT_

PERMIT___________REQUIREMENT

"_"__ __*_NAME/TTLE I certify under penalty of law that this document and all attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction or supervision in accordance with a system designed to assure that qualified personnel

_____ __,_,_.__,,_,,__

properly gather and evalute the iaonnation submitted.

Based an my inquiry of the person ot persons E16370Benjamin P. Youman who manage the system, or those persons directly responsible for gathering the information, the..,-,.-

815 0 04/1963012 information submitled is. to the best of my knowledge and belief, true. accurate, and complete.

I am SIGNAT=yk OPrNRINCIPLE Plant Manager aware that there are significant penalties for submitting faise infonnation, including the poss"by of EXECbnVEM)FFICER OR AREA NUMBER MM/DD/YYYY TVPM Oine and imprrsionment for knowing violations.

AUTHORIZED AGENT CODE N ER __________

COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. This discharge point was not used this month.2. There was no discharge of processed steam generator chemical cleaning wastewater during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/0/2012 PAGE 2 ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit 1L0048313 March 2012Page 1 of 2MONITORING DATA:WBD CRock RiverDATE Temperature mgd Flowdeg F cfs03/01/2012 75.5 17.87 7,67003/02/2012 71.0 17.98 8,19003/03/2012 69.7 22.50 8,49003/04/2012 68.0 19.36 8,39003/05/2012 63.6 15.90 8,22003/06/2012 79.0 20.02 8,03003/07/2012 82.1 16.06 8,20003/08/2012 82.1 16.78 8,52003/09/2012 70.9 18.45 8,80003/10/2012 73.9 25.48 8,90003/11/2012 73.9 21.19 8,87003/12/2012 70.9 10.79 9,25003/13/2012 76.4 16.86 10,70003/14/2012 79.0 15.93 10,70003/15/2012 83.7 17.01 10,40003/16/2012 83.0 18.66 9,89003/17/2012 88.0 17.51 9,41003/18/2012 88.0 15.36 9,11003/19/2012 90.0 16.78 8,92003/20/2012 90.0 18.17 8,80003/21/2012 87.7 14.75 8,53003/22/2012 89.3 17.54 8,43003/23/2012 88.1 18.47 8,60003/24/2012 83.3 20.42 8,62003/25/2012 85.3 17.03 8,52003/26/2012 85.3 13.28 8,19003/27/2012 77.0 18.75 8,20003/28/2012 87.0 15.26 7,91003/29/2012 81.2 19.92 7,61003/30/2012 77.2 15.30 7,71003/31/2012 77.2 22.79. 7,730K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\March\March 2012 ATTACH01.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 March 2012Page 2 of 2HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (orassociated rinses) containing hydrazine discharged to the Cooling SystemBlowdown during the month of March 2012.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite was used this month. Bromine compounds were notused this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this ouffall 31 of 31 days.4. Per Special Condition 24 the influent from the Rock River and effluentfrom Outfall 001-0 was monitored for Total Suspended Solids (TSS) thismonth. The Rock River TSS value was 20.8 mg/L on 03/12/2012.

TheCWBD TSS value was 3.7 mg/L on 03/12/2012.

5. Rock River flow for March 2012 was >2400 cfs therefore daily temperature calculations were not required this month. (Special Condition 12).6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in March 2012. (Special Condition 15).K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\March\March 2012 ATTACHO1.doc Exelon.Exelo' Generation

Company, LLC www.exeloncorpcom Byron Station445o North German Church RoadByror, IL 61010-9794 May 21, 2012LTR: BYRON 2011-0059 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyWater Pollution ControlCompliance Assurance Section #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring ReportIn accordance with National Pollutant Discharge Elimination System (NPDES) Permit Number IL004831 3,issued January 24, 2011, we are submitting the Discharge Monitoring Report for Byron Station, Units 1and 2. This report covers the period of April 1, 2012 through April 30, 2012.On 4125/2012 at 18:30 hours the Unit 2 Natural Draft Cooling Tower (NDCT) basin exhibited a wave-type flow pattern that caused cooling tower water to overflow from the tower and flow into the storm water ditchlocated on the east side of German Church Road. The wave-type flow pattern is believed to have beencaused when the flow through the NDCT had to be re-configured due to a riser pipe break. The brokenriser pipe was bypassed so repairs could be made.The cooling tower basin overflow water flowed north in the storm water ditch and entered WoodlandCreek via storm water Outfall 003, East Station Area Runoff. The estimated duration of the overflow is30.7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> at a flow rate of approximately 25 gallons per minute resulting in an estimated 46,100 gallonsof cooling tower water flowing through Outfall 003. Analysis results of a sample of the cooling towerwater obtained prior to entering the storm water ditch are summarized in the following table:S pH Copper (mgL) I Zinc (mgL) Chromium (mg/L)8.75 0.011 0.007 <0.0021Byron Station Operators took immediate measures to lower the cooling tower water level in the basin ofthe NDCT to try to mitigate the effects of the wave-type flow pattern and reduce the flow of water from thebasin. Sandbags were also installed to stop the flow of cooling tower water to the storm water ditch.If there are any questions regarding this report, please contact Ms. Zoe Cox, Environmental/Radwaste Supervisor, at (815) 406-3035.

Respectfully, Benjamin P. YoumanPlant ManagerByron Nuclear Generating StationSBPY/ZC/eh Attachments bcc: Jennifer Gould -Environmental

-Cantera (electronic)

Zoe Cox -Environmental

-Byron NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMI"TEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfitld Rr drWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313

.PERMIT NUMBER ,A01-00!SCHAIOGENUMl IlOMONITORING PERIODMMIDD/YYYY I I MMDDYYYYDEMINERALIZER REGENERATE WASTE (001A)External Outfall*"

• NO DISCHARGE

[j ...FROMI04/01/2012 TOI04/30/2012 Ii lATTN: Zoo Cox/ENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPESolids.Total Suspended SAMPLE ...... <0.92 1.1 19 0 01/30 08MEASUREMENT 0053010 PERMIT -,.5 3Effluent Gross REQUIREMENT

• _ _"

• 30DA AVG DAILY MX. * .......Chromium, hexavalent SAMPLE ....... .,..,. .O(as Cr) MEASUREMENT 5000103210 PERMIT ---.1 .2 ; 7_____________________

______ igil.Daily GAEffluent Gross REQUIREMENT

":_"__. -_".30DAAVG DAILY MX " mg/__" ' _ ._.Chromium, total SAMPLE .... ...........

(as Cr) MEASUREMENT 5000103410 -PERMIT ,. ..I.. " ..... .-2Effluent Gross REQUIREMENT

" : .o , -..... 30DA AVG" DAY MX g/I Daily GRABCopper, total SAMPLE ...(as Cu) MEASUREMENT 5000104210 .PERMIT ". "."*. "" : " '" , .5 1Effluent Gros REQUIREMENT

• __,.....30OA AVG DAILY MX mg/I. Daily GRABIron, total SAMPLE ............

500(as Fe) MEASUREMENT 0104510 PERMIT ..1 ..Effluent Gross REQUIREMENT

...._'... --___. DAILY MX GRADLead. Total SAMPLE ..... 500(as Pb) MEASUREMENT 5000105110 PERMIT -4 .." .A VaL- " GAEffluent Gross REQUIREMENT q 30.DA AVG. DAILY.MX

..GRABNickel, total SAMPLE ...... 1(as Ni) MEASUREMENT Soo0106710 PERMIT -.-1 2 .Effluent Gross REQUIREMENT

.' _ "_ .. -" : ." :30DA AVG:,- DAILY MX. _g/_ " GR. ":NAME/TTTLE I certify under penaty of taw that this document and ae attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUniVE OFFICER direction or supervision in accordance with a system designed to sure that quaified personeL OBenjaminP.

Youman w lan d evter t theInrmont sd. my kqonyeof the pero.fersons 815 406-3700 05/21/2012 Benjamin P. Youman who manage the systemt.

or those persons directly responsible tor gathering the information, the 0/121Information subrmited Is. to the boes of my knowledge and belief. true. accurate.

and complete.

I am 916NAT&RE OF PRINCIPLE Plant Manager aware that there are sigtificent penalties or submitting false Information.

bicudng the possiblty of EXECUTIVE OFFICER OR ARMA'ryD DR Punmo fne and lmprlslmoment lor knowing violatons.

AUTHORIZED AGENT CODE NUMBER MIDD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference ell attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed 27 of 30 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL004831 3I PERMIT NUMBERI A01-0 NI DISCHARGEF Nli.MEtE

.MONITORING PERIODUMMDDIYYYY I I MMIDOJYYYY DEMINERAIZER REGENERATE WASTE (001A)External Outfall* *

• NO DISCHARGE

• ]FROMI04/01/2012 I TOI04/30/2012 l II IATTN: Zoo Cox1ENV SPEC ______________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPEZinc, Total SAMPLE ....... 500(as Zn) MEASUREMENT 0109210 PERMIT --. ..... 1 G2Effluent Gross REQUIREMENTI 30DA AVG. DAILY MX. GRAFlow, In conduit or thru SAMPLEtreatment plant MEASUREMENT 50050 10 PERMIT Req. Mon. Req. Mon. M,-. --l/ ." Daily CONTiNEffluent Gross REQUIREMENT 30DA AVG DALYM....

• M.. -" .-i .. -SAMPLEMEASUREMENT REQUIREMENT

.______...

• _ _ ... .... .. "SAMPLEMEASUREMENT PERMIT, ..." .IREQUIREMEN4T

... " ." :... " " ___:"_' __....SAMPLEMEASUREMENT PERMI, r .". ' -. .______________REQUIREMENT_____________

_____ __ _____________

SAMPLEMEASUREMENT PERMITREQUIREMENT

_ .I .- ........

"-. ..,_..._._

.-"SAMPLEMEASUREMENT PER MIT ., ." * -', " " " -".._ .. .REQUIREMENT

."T,. ' *: -, .. ..." "" " ...-'NAAIiFITTLE I ceftt under penalty of law thai thO document and all wars Prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction or supenrfion in accordance wi a system des4gned to smsue that qualified Personnel property gather and evalute the informalton subnllfted.

Based on my inquiry of the person or perons 815Z7/..,..."--81 406-3700Benjamin P. Youman who manage the system, or those persons directly responsible for gathering the nfomntlon, tire "-,,,O' ,WI,,-,,,

,.- -05/21/2012 Informnatiorn submitted Is, to the best of my loiuledge arid belet, true. accurate.

and complete.

I amir SG TUly OF PRINCIPLE Plant Manager aware that there are significant penalties for submitting false biformation, tIchxdrig the possibliy of EXECUTE OFFICER OR AREA16om 0fT fine andr impsiorment for knowing viojaton.

AUTHORIZED AGENT CODE NUMBER MM/_D/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/612012 PAGE 2 NATIONAL POLLUTANT DISO GE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)061010PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: zoe CoxdENV APECDMR Mailing ZIP CODE:MAJOR(SU BR 01) CSIL0048313 I PERMIT NUMBERE1101-0DISCHARGE NUMBERMM/DD/Y`YYY SfLWkI MM/DOIYYYY STP PLANT EFFLUENT (FORMER 001B)Externai Outiaii' "* NO DISCHARGE L °FROMI04/01/2012 TOI04/30/2012 1z !QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREUENCY SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPEBOO, 5-Oay SAMPLEMEASUREMENT

.54 0.85 26 <11 17.0 19 0 02/30 240031010 __ _ REQUREMENT 5ODA AVG5 DA0L M.__________

(2W .g ) MEASUEMEN 0030. E.Effluent Gross REQUIREMENT

.300A AVG' ,DAILY MX --DA AVG DAILY MX -Twice Per Month COMP24-SAME ...... 7.63 7.64 12 0 02/30 GR004001 0 PERMIT -.."" 6" 9-Effluent Gross REQUIREMENT

.______-_

MINIMUM .-- MAXIMUM.

SU .,wce Per Mo-th GRABSolids. total suspended SAMPLEMEASUREMENT 011 0.13 26 1.8 2.5 19 0 02/30 240053010 'PERMIT 5.3 -10.5 .... SOEffluent Gross REQUIREMENT 30DA. AVG .-DAILY MX " b0d SODA'AVG D"OLy MX, "g/_. Twice Per Month, COMP24Flow, in conduit or thru SAMPLEtreatment plant MEASUREMENT 0.005 0.007 3 ...... 0 01/01 CN500501 0 PERMIT Req. Mon. Req. Mon.Effluent Gross REQUIREMENT 30SDA AVG " DAILY MX M.gad .-" Daily .CONTI NSAMPLEMEASUREMENT PERMIT,REQUIREMENT

.*_._______"__.....__

SAMPLEMEASUREMENT PERMIT .REQUIREMENT.

_ __._". __.. .___ T ""________

SAMPLEMEASUREMENT PERMIT' ..7777 .-----*REQUIREMENT a __"__"__._

, -NAME/TITLE I cer* under penalty of law that Oft document and all ahttachents were prepared under my TELEPHONE PRINCIPAL EXECUTIVE OFFICER dirction or supervision n accodance with a system desWd to assure that qualied personneT DATEproperty gather evahfle the ',tonrmati subttmited.

Based on my Inquiry of th person oi persons 815 406-3700Benjamin P. Youman who manage te System, or thofm person direc resp for gathe" the Informatlon.

fthe 81 4-005/21/2012 informaion submitted Is, to the best of my Imowlede and behiel, tue. bcjurate.

and complete.

I am SIGN I-RE PRINCIPLE Plant Manager aware that there am sWltant penalties lot submtttini fal , t P EXEioTtVEnFFICER OR AREA N B MMJDNofPlant Manager fine and Imrisalorirnent for knowing; vloailaoris.

FIE R AE UBRM1~YYTMED on prmo _____ _________________________.AUTHORIZED AGENT CODE NMRM_COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flow existed through this outlall 29 of 30 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIT'EE NAME/ADDRESS NAME Exelon Generation Co., LLC-DRE"~ 430 a; 'e R oa dWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010DMR Malling ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 I EROLdIT NUMBEROCr- C01-0I I'IOVLARf 11 IE fMONITORING PERIODMM/DD/YYYY I I MM/DD/YYYY WWTP (FORMER 001C)External Outfall* **NO DISCHARGE EJI -I IFROMI04/01/2012 I TOI04/30/2012 Ii !i wI IATTN: Zoe Cox/ENV SPECFREUENC_

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF SMLVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESolids totalsuspended...

... 5.7 8.2 19 0 02/30 24Solds toalsusened MEASUREMENT 00530 10 PRI 53Effluent Gross REQUIREMENT.E T" '-. ... ."30DA1AVG.

"AILY MX mg/L.. .TwIce Per Mon. h COMP24Chromium, hexavalent SAMPLE ................

5(as Cr) MEASUREMENT 5000103210 PERMIT , ..-.1 .2 .Effluent Gross REQUIREMENT

"-,"ad__.-

.__ :.,__ SDAAVG DAIYMX -GRA""Chromium, total SAMPLE ...... ......(as Cr) MEASUREMENT 5000103410 PERMIT. 2. .****. ..0...1 *Effluent Gross 'REQUIREMENT

_______-

_ "_._.. ___ '.. .__ ". __"_"_-.

." ODA AVG .DALYMX GRABCopper, total SAMPLE 5...00(as Cu) MEASUREMENT 0104210 PERMITW,-

...., -.5 1REQUIREMENT-Da.5 GRABEffluent Gross REQUIREMEN"

..30OA AVG DAILY-Mx InQ/L DIron, total SAMPLE ...... 500(as Fe) MEASUREMENT 01045 10 PERMIT ... ..D.al --RA 1'__-_,,-_.___"____

_"__'. ____ DAILY " "mgfL Daly GRAB-Effluent Gross REQUIREMENT

-DAILY MX. ._ _ -___.,_Lead. total SAMPLE ...... S,... oo(as Pb) MEASUREMENT 010511 0 -. PERMIT ....4.. -.v... ....2"..4g/L DGRABEffluent Gross REQUIREMENT

.__ ______ 30DA AVG .'DAILY MX " " m y- ,GNickel, total SAMPLE ...... Soo.....

5(as Ni) MEASUREMENT 0106710 PERMIT ,. ' 2- mg. .Daily GRABEffluent Gross REQUIREMENT

-" _- _._" "_ .... -30DA AVG DAILYMW _ _ __ _NAMEITTLI.E I certify under penalty of law thai this document and al attactvments were prepared under my TELEPHONE DATEPRINCIPAL EXECIllVE OFFICER jreakiy or supenrisi in accondance with a sysem designed to assure th qualitted pesonnelprope rty gattier and evalute the biio mto n s utrtted.

Ba a on my uiry of ftpe rson orpe rsons 4JI -E1 6-370Benjamin P. Youman who manage the system, or fhse persons directly reapont tor gathertng the Information.

fte 0521/2012 i for mabon submit ted is. to the best of my knowledge and b elief, true. ac cur ate. and com plete. I am SIG N = PR IN C IPLEPlant Manager aware that thee aem significant penalttes tor submitting ftase Information.

biclutlg the possitilty EXof'UTI, OFFICER OR NAR MBmUR o N fine and risionme lfto knowing vUdns. AUTHORIZED AGENT COD NUMER MMJDD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater durng this month.2. Flow e~dsted through this outlall 22 of 30 days during the month.EPA Form 3320.1 (Rev 01/06) Previous editions may be used. 1/6=12 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLC=,,0RESS3 4=,, 'Wirn116 RoadWarrenvifle, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoo Cox/ENV SPECDMR Mailing ZiP CODE:MAJOR(SUOR 01) CS61010ILDD48313 C01-0oMONITORING PERIODMMIDD.YYY.I I MM!DDIYYYY FROMWWTP (FORMER 001C)External OutfallNOOISCHARGE I04101/2012

{ TO{04/30/2012 QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANTYYSIS PEZinc, total SAMPLE ...... ...... ...(as Zn) MEASUREMENT 5000109210 PERMIT --....... -1. 2GREffluent Gross REQUIREMENT

-300A AVG DAILY MX ,.AFlow. In conduit or thru SAMPLE 0016 0025 3 0 Olitl CNtreatment plant MEASUREMENT 50050 10 PERMIT

• Req. Mon.. Req. Mon Ma --Dally. CONTINEffluent Gross REQUIREMENT 300A AVG DAILY. MX .. _J/d " -_"SAMPLEMEASUREMENT PERMIT "REQUIREMENT

"_ _ _' ... ."_""_"_.....

..SAMPLEMEASUREMENT PERMITREQUIREMENT

_____ _____ _____SAMPLEMEASUREMENT PERMITREQUIREMENT:

...........................

SAMPLEMEASUREMENT PERMIT 7REQUIREMENT

,_. -_-.. ___.. .______..

.. .., ,SAMPLEMEASUREMENT

"..PERMIT-

'* REQUIREMENT

_'._-.___.._.___""_"

A .I cerfy under penalty of law that &ts docu, ment and afi attacttnents wr prepared

-ider my TELEPHONE DATEPRINCIPAL.

EXECUTlVE OFFICER irction or supervsion in eccodrance With a system designed 1o assure aw qualified personnel

-pop rtygatrad evaluef normatinSubmited.

BasedOn.m y o ~ , Of. the Person -P-,- .815 406-3700;

....Benjamin P. Y'ouman who manage "he system, or those persons dmrerty -9ste for gateringthe iftometon, tme ..1.. 05/21/2012 infornation submitted is. to the best of my knowledge and bel(, true. accurate, arid cnopete.,

arn PRINCIPLE Plant Manager aware tat there are soWlrcant penaties for submitting false informasion.

Including te posstbOty of E UTIVE OFFICER OR AREA NUMBER MM/O/YYYY

_ _ , _ _ _ oR Pitw= -e and Irisiona

,ent f ,av tions. AUTHORIZED AGENT CODE, N M R_COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. I",O/12 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCAi.DDRESS 43.W RtOadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR MailIng Z]P CODE:MAJOR(SUBR 01) CS61010FL004831 3i PERWs NUMBERfDOI1-0UMSCHARGEn5 N'UMBERMONITORING PERIODII MDYMM/DD/YYYY IRADWASTE TREATMENT (FORMER 001D)External Outfall*NO DISCHARGE FROMI04/01/2012

] TOI04/30/2012 I #i IATTN: Zoe Cox1ENV SPEC __FREQUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER

____OF SMLVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESolids, total suspended SAMPLE ...........

<0.8 1.2 19 0 02/30 CPMEASUREMENT 0053010 PERMIT -'15 30 TvoaPerMon COM-Effluent Gross 'REQUIREMENT

, .....30DAAVG OLYMXFlow, in conduit or thru SAMPLE 0 02 3 A 01L0 CpremntpatMAUEET 0.022 0.023 3 .........

... 0 01/01 CNtreatment plant MEASUREMENT 500501 0 PERMIT Req. Mom. Req. Mon. -C-NTINMg* Dai.l....y CONTINEffluent Gross REQUIREMENT

30DA.AVG DAILY MX. , .-.-SAMPLEMEASUREMENT PERMIT -_ REQUIREMENT.

._.___. ___ _.:.._._"._

_. .... .. ..SAMPLEMEASUREMENT 7 'PERMITREQUIREMENT

• _"_"_"--_

" "_ _ " _"_"_ "SAMPLEMEASUREMENT PERMIT'REQUIREMENT

" .._i -_. ._.--" .... -...SAMPLEMEASUREMENT

• PERMIT__....-__-__,___

PREQUIREMIET

". " ",,_.. ' _ :SAMPLEMEASUREMENT

.PERMIT-REQUIREMENT.

A. .-_.._..._NAMETITLE ceratty under penalty of law thai fts documsent and al allactmenwt were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction or supervsion In accordance with a system designed to essure that quarried personnel propeuty gathier arnd evalute fth Information submidtted.

Based on my bnqiry of Oem person of personsBenjamin P. Youman who manage the system. or those Perons directly responsle for gathteig the Infomation fti-37 05/21/2012 information submitted Is, to the best of my Imowledge aid belef. true, accurate, and complete.

i SIam OF PRINCIPLE Plant Manager aware tat tere are significant penafltes for subm1itdrn false inormation, ftktg fte possibity of SZ EC IvE OFFICER OR AR NATMD OR PROME i nne and fiornIent fon violwn ons. AUTHORIZED AGENT CO NUMBER MMDDYYYYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flow existed through this outfall 5 of 30 days durtng the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadIL0048313 PERMIT NUMBERFE01-0DISCHARGE NUMBER _OMR Mailing ZIP CODE:MAJOR(SUBR 01) CSSTORMWATER (FORMER 001E)Extemal Outfall* NO DISCHARGE

[]61010MONITORING PERIODMM/DD/YYYY I MM/DD/YYYY FROMI04/01/2012 TOI04/30/2012 t lIByron, IL 61010ATTN: Zoe CoxIENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESolids, total suspended SAMPLEMEASUREMENT 5000053010 PERMIT " --15 30Effluent Gross REQUIREMENT

.',DAAVG DAILY -IL Weeldy GRASSolids, total suspended SAMPLE .......MEASUREMENT

..... ..24.6 24.8 19 0 0107 GR0053080Other Treatment, Process PERMIT ...* " 30DAAV 100Complete REQUIREMENT

.. S0DA AVG DAILY. MX ,"mg-. Weel.y GRABChromium, hexavalent SAMPLE ........*(as Cr) MEASUREMENT Soo0103210 o

• PERMI, * .1 .2 DlGRABEffluent Gross REQUIREMENT

.30OA AVG.' DAILY MX rag4. G RAChromium.

total SAMPLE ........

..... 500(as Cr) MEASUREMENT 50001034 10 PERMIT -.-.2Effluenl Gross REQUIREMENT

"_""_30DA AVG "_ _ Daily GRABCopper, total SAMPLE ..................

5(as Cu) MEASUREMENT Soo010421 0 PERMIT ----.5 ,Effluent Gross _EUIREM.

.DAGX ll, Daily GRAIron, total SAMPLE(as Fe) MEASUREMENT 5000104510 PERMIT -IEffluent Gross RUIEET _ ___. ..DAILY.MX.

ml al RDLead, total SAMPLE ..... .... .5(as Pb) MEASUREMENT 5000105110 PERMIT --. * ' .... .2 A!.4 DGEffluent Gross -REQUIREMENT

.. -,. ,. ... -30DA AVG DAILY MX mg/L Dal.," R ..NAME/TITLE I Certily Uider penalty of law that this dooument and al attfChmert were prepared under my TELEPHONE DATEPRINCIPAL EXECUnVE OFFICER direction or supervsidon In accoidance with a system designed to assure that quaffed personnel TELEHON DATEproperty gather and evalule the Information submitted.

Based on my Inquiry of the person or persons 815 406-370Benjamin P. Youman who manage the system, or those persons directly respons ble for gathering the wlormnation, the 8 406.3700 05/21/2012 inforiation subrrdtted is. to the beast of my knowledge and tefel. true. accuuste, and oonpate, Iam SEIA OF PRINCIP LEPlant Manager aware that them are amrifrcant penalties mbttfttng 16se Wormaton.

ncluding the possaiity ot XECUTIVE OFFICER OR AR NUMBER MMEDDIYYYY r(M on PRIM= I..e arid bIprislanment for knowing violations.

AUTHORIZED AGENT CODCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during the month.2. Flow exdsted through this outfall 5 of 30 days during the month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 11f62012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 wintleld RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010OMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010= 1L0048313 i ERMiT NUMBERE01-00; G C HAR G 2l'JC 3lIUfMONITORING PERIODMM/DD/YYYY I I MM/DD/YYYY STORMWATER (FORMER 001 E)Extemal Outfall* * ' NO DISCHARGE

-*I 4FROMI104/01/2012 I To!04/30/2012 I JPAEEQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER

.E OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS E ANALYSISNickel, total SAMPLE ...500(as Ni) MEASUREMENT 0106710 PERMIT .,, G"RAB1"Effluent Gross REQUIREMENT

".'_,_"_I.

-.30DA AVG DAILY.MX

-.D. ..ABZinc. total SAMPLE ...... ....... 500(as Zn) MEASUREMENT 01092 1 0 PERMIT '2- ' .., -÷ t 2Effluent Gross REQUIREMENT

." -30DA AVG DAILY MX mgoL. -.. ly.Flow, in conduit or thru SAMPLE 0.237 0.8a5 3 .. .... 0 02/30 CNtreatment plant MEASUREMENT 500501 0 PEFRMIT:'

Re. Mon. Re.q. Mon. -,-"' -Twice Per Month CONTINEffluent Gross REQUIREMENT 30DA AVG -DAILY MX Mgel/d"-SAMPLEMEASUREMENT PERMITREQUIREMENT

"_._: _ _. ,.SAMPLEMEASUREMENT PERMITREQIOREMENT

-._ 'SAMPLEMEASUREMENT PERMIT'-

'REQUIREMENT

., .,.....SAMPLEMEASUREMENT PERMITREQUIR&MENfi "t" ' " .... ... .. " _: "NAMEJTTTLE I cartify under penalty of law that Wts document and alt attactments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTNE OFFICER direction or supervision in accordance with a system designed to ssmar tha quaifled personnel propery gather and evalrde fth information submitted.

Baed on my Inqfuiry of fte person or persona 46-70Benjamin P. Youman *to manage the system, or hose persons cdrectly responsale tar gatherig the inorratiorr SI 05t21/2012 information submitted Is. to the best of my owledg and blief, true, acourate.

and complete.

la1 m SIGN R F PRINCIPLE0 1Plant Manager aware Ma there am sigrniicant penalties for submitting false tormatim.

includig te possuly EXo UTIVE OFFICER OR AREAn~ ol ore anid l tof kI g AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Metal Cleaning wastewater was discharged this month.2. Fire Protection drain water was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/62012 PAGE 2 0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4S0U Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadSDMR Mailing ZIP CODE: 61010MAJOR(SUBR 01) CSCOOUNG SYSTEM BLOWDOWNExternal OutfallNO DISCHARGE mIL0048313 001.0lMONITORING PERIODMMDD/YYYY IMMIDD/YYYY FROM I04/01/2012 1 TOI 04/30/2012 Byron, IL 61010A'-rN: Zoe Cox/ENV SPEC _ _FREUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER EX OF SAPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPETemperature, water dog. SAMPLE -89.9 15 0 01/01 CNFahrenheit MEASUREMENT 0001110 PERMIT -- ' -- -Req. .... degF aOly CONNEffluent Gross -REQUIREMENT:

.,W._ ...._. ....... MO MAX -.______.pH SAMPLE 8.64 8.85 12 0 01/07 GRMEASUREMENT 0040010 We0l.PERMIT, 6 9 .- GRABEffluent Gross ._.REQUIREMENT

-_._.:_*__MINIMUM

......_ MAXIMUM,

.SU_._.._WeekyGRAB Solids, total suspended MAMUEE -1.9 1.9 19 0 01/30 GRSolds toaJsusened MEASUREMENT O0S30 10 .PERMIT .--, "' .., :-.. Req. Mon. Req. Mort.. "".. ....: .0053 0 SD300A AVG... DAILY MX mg/IL Monthly GRABEffluent Gross __________

________

--Oil & Grease SAMPLE <1.6 2.1 19 0 01/07 GRMEASUREMENT 0055610 .,PERMIT S 20, Weeldy GRABEffluent Gross REQUIREMENT 30DA AVG DAILY SAMPLE .... <0.0021 19 0 01/07 GRChromium, total (as Cr) MEASUREMENT

________

19 0 01/07 _ _0103410 PERMIT. 0. .we" --. -.0.2Effluent Gross -REQUIREMENT.

_"_._....

" _-_- _.. .DAILY M[X m9. -. e GRA .Copper, total (as Cu) SAMPLE 0.012 19 0 01/07 GRMEASUREMENT

_ _ -.-_ _010421 0 PERMIT '. -,..'.I.

.".... " 0.071 Wek.GAEffluent Gross -REQUIREMENT

,_ _"_" " DAILY.. .. _ ,I .. " " ..Zinc, total (as Zn) SAMPLE <0.0022 0.003 19 0 01/07 GRMEASUREMENT 0109210 PERMIT -...... .213- .433 m/L GRAB.Effluent Gross REQUIREMENT

-.- .SOA AVG. D ONLY m"I. Wee-ly GR.NAME I1T'LE I oCaty under penalty of taw OWa this docnm arid at attachments wer prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER dimxtion or suprAviW in a,,ordance with a system designed to assure that qualified personnel property gather and evalute mef Iormation subitrnted.

Based on my biquiry of ft peoton or persons 815 406-3700Benjamin P. Youman who manage te systeh m or mtoe persons drectly respoosae for gathering me Ifomation.

the 815 406-3700 05/21/2012 ktonrnation su mitated is, to the best ot my kgowledge and belief, true. acurate.

and oomplete.

am .1F PRINCIPLE

__Plant Manager aware that there are significant penalties for sutmltg slase iWotmiaon.

hrding the poSaibt ol EC E OFFICER OR AREATYEoD pao Ra and 1- --leonment for v .AUTHORIZED AGENT CODE NUMBER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Monitonng data for outfall 001-0 is included on attachment EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/12012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS

"'"" Exa,,' Gaa,, LL,,CADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 610101JDMR Mailing ZIP CODE:MAJORSwarn GI I a.61010I IS A(IAO~)4~

I -II001.0I PERMIT NUMBERI nercJ*cte

.,m,.bnea III,,/h,)

I*I U IIUIvIgl; r*1I MONITORING PERIODICOOLING SYSTEM SLOWDOWNExternal Outfall*"" NO DISCHARGE I MMWUIYYYY FROM F1 4MM/[DUITYY 04/01/2012 04/30/2012 I IQUANTITY OR LOADING QUANTITY OR CONCENTRATION

_ NO. FREQUENCY SAMPLEPARAMETER VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OF TYPE______________

______ ___ ANALYSISOxidanft, total residual SAMPLE .500MEASUREMENT 340441 0 PERMIT .. ...... ..,. ..... ..... .05GRAEffluent Gross REQUIREMENT'

-.,-

• _,-_,__ DAILYMX mgML -1Weely G .-Priority pollutants total effluent SAMPLE ...... .. ... 500MEASUREMENT 500081 0 PERMIT Rleq Mom. -. Pam. Req. Mon. mgl eky GRAS:Effluent Gross REQUIREMENT

..DAILY MX -_D 'mlI " 1 DAILEY.MX.

Mo___* "__

• __Flow, In conduit or thru SAMPLEtreatment plant MEASUREMENT 50050 1 0 PERMIT Req. Mon. Req. Mon. C " ONI * .Effluent Gross REQUIREMENT.

30OA AVG DAILY MX Mgalld -Daily.C""TI"

Chlorine, total residual SAMPLE 0.04 19 0 01/07 GRMEASUREMENT

....._0.04 19_0_01__7_OR 500601 0 PERMIT- --"- DA.L 0X Weekly 'GRABEffluent Gross REQUIREMENT.

DAILY MIX 111911. _e__-.,Hydrazine SAMPLE --- 500MEASUREMENT 5O_8131310 PERMIT '.-. .011 .027 DailyWhen.

GEffluent Gross REQUIREMENT

"*DAAVG:

DAILY MX -_" .--mWL GRABSAMPLEMEASUREMENT PERMITREQUIREMENT'

".'___ _" .-SAMPLEMEASUREMENT PERMIT.REQUIREMENT NAIM E fTrf i cartily under penalt of baw that docuetle mid* ai8q.l , attcmn ts were Prepared ef my TE EP ON DATEPRINCIPAL EXECUlrTVE OFFICER dection or supenrision in accordance with a systemn designed to assure tra qualified peonnel TELEPHONE DATEBenjamin P. Youman wo manage ft system. or 'Mse Perons diect respon815 ta gaft3 fthe 700omtat, 05/21/2012 Plant Mana ger Ioni subin i fed Is. to ft best of my Ivicniedge and belief. true. accurate.

and complete.

It r S IGTN' 1J RV V ICF PNRUIBNECI Pwa tate ,.r am s5fiareit penaftles for submrttnbg lalse mlormalhCkx*V fth posslito Af 6CUTIVE OFAGCER OR AREA NUMBERM_/DD/YY

_____ o______ Ifine and bunprisrrorment for knowin volatkons.

AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11602012 PAGE 20 0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADnDRESS 41-00 Winfitnff ReerdWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010I IL0048313 I -PERMIT NUMBERI002-0DISCHARGE NUMBERMONITORING PERIODMMIDD/YYYY I I MMfDD/YYYY STORMWATER RUNOFF BASINExternal Ouffall" NO DISCHARGE

! ..II IFROMI04/01/2012 I TOI04/30/2012 l II IATTN: Zoo CoY/ENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OFs TYPEANALYSISSolids, Total Suspended SAMPLEMEASUREMENT

________

__________

________005301 0 PERMT- 1 30Effluent Gross REGUIREM1ENT

-,. .. .... .. ...mg/ Wee. GRASSolids, Total Suspended SAMPLEMEASUREMENT

_____ ___ _____ _____0053080 .PERMITOther Treatment, Process 3. .30 -.100 -_GRAB__""

Comolete

,REQUIREMENT

.' 30DAAVG " DAILY MX 1 'W "ek" GRABChromium, hexavalent SAMPLE ............

.(as Cr) MEASUREMENT 0103210 PERMIT ...01.016 D ..Effluent Gross REQUIREMENT

...... _ _.. -.."" .. .. -,, -300A.AVG

-DAILY MX mg/L Da-Chromium, total SAMPLE(as Cr) MEASUREMENT 0103410 PERMIT 1 .2 * .Dtl, GRAEffluent Gross REQUIREMENT

" _ _ -.-, -30DAAVG DAILY MX -', GRASCopper, total SAMPLE .....(as Cu) MEASUREMENT 010421o0 PERMIT " -- -.02 -.041 D.GREffluent.Gross

-EUEMr ...... .,.PAAVG DAILYM( "mW. .Iron, total SAMPLE *.. .....(as Fe) MEASUREMENT 0104510 PERM... *.' 1XEffluent Gross REQUIREMENT Dmg/L DaBy GRABLead, total SAMPLE ......(as Pb) MEASUREMENT 01051 1 0 PERMIT ..063' .'.298Effluent Gross .REQUIREMENT X .30AAVG DAILY MX. ..NAME/lTrLE I centiy under penalty of law uml ths docume and all anachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER duectko or supenrslon in ntaccrdaffae with a symesined to assure &A fladw parsoneiproperty gather and evalute the Ilomtulon abrrrflled.

Based on my IqiJry ot te person orpero. .815 406-370persons Benjamin P. Youman who manage the sysem. or hos persons directly respornsble for gaWherg ft Wlruomrlon.

the 05/21/2012 Information submitted Is. to te bes of my knowlsege end 8eet, true. accurare.

and coarplte.

I am SIGU'FiPRiNCIPLE Plant Manager aware that Mtere er sgnhfkcaml penalties lot submillng false Infonrmaton. ng the post.ly of OFFICER OR AREAreoR ow peando _ __s__nmen_

__o_ _ __ow__ Violations.

AUTHORIZED AGENT CODE NUMBER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Metal Cleaning Wastewater was discharged this month.2. No Fire Protection, Service Water or Closed Cooling System Drain Water was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6=2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCAUUDDRESS 430 Winfieid RoadWerrenville, II 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTflJ 7hn flnvil=N' DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 iF ocoPER1Y'!

N*I ASEDF_ 002-0I niCpiiaGE NU'MBERMONITORING PERIODMMIDDYYYY L MMIDDIYYYY STORMWATER RUNOFF BASINExternal Outfall*NODISCHARGE FROM I04/01/2012 TOI04/30/2012 QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER EX OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSISNickel, total SAMPLE(as Ni) MEASUREMENT 0106710 PERMIT .011 .176Da8y GRADEffluent Gross REQUIREMENT_.

_"_* _. __"_,_300A AVG DAILY MX GRABZinc, total SAMPLE(as Zn) MEASUREMENT 0109210 PERMIT ...-..047 .26 GRABEffluent Gross REQUIREMENT

" _ ;.- _____ 300A AVG DAILY MX mtg/L DallyROil and Grease SAMPLEMEASUREMENT 0358210 PERMIT s 1 -20 When GAGRAEffluent Gross REQUIREMENT*.-"....-.

"___,.__

-. _-i ___... 30DA AVG DAILY MX -' L -'- GFlow, in conduit or thru SAMPLE .....treatment plant MEASUREMENT 50050 1 0 PERMIT Req. Mon. Req. Mon. When-Effluent Gross -REQUIREMENT 30DA AVG DAILY MX M ---Dlaciarging SAMPLEMEASUREMENT PERMIT_REQUIREMENT

..... _ _ _ _ _ __ _SAMPLEMEASUREMENT PERMITREQUIREMENT

_ _.. --, -SAMPLEMEASUREMENT

.PERMITREQUIREMENT r _ .-NANM'LE I certify under penalfy of law Mtat fts documend and all aftachnwts were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction or supervision in accordance with a system desgned to assure tw quaified psmoneoOproper egatsreand evaomerf thoseaonsn woied. ased on my cnyry of ft person or persons r. .wa..- 815 406-3700Benjamin P. Youman who manage thyehjster or mose persons 4ec'ty ryer the pa ft lnfonnaonr e85 05&21/2012 Information submitted la. to ftn best of my Iwledge and b"lt. Oue. accurate.

and copolete, I am IGN RE RINCIPLE

____Plant Manager aware ow fem ame agreant penatles tat s laftaton',onfb, iucng the posst of EXECUTE OFFICER OR AREA NUMBER MDDYYYYT O Ifrn and trrisomsvla for knowing violations.

AUTHORIZED AGENT CODE NM R__COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. This discharge point was not used this month.2. There was no discharge of processed steam generator chemical cleaning wastewater during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/612012 PAGE 20 ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 April 2012Page 1 of 2MONITORING DATA:CWBD C WB lw Rock RiverDATE Temperature mgd Flowdeg F cfs04/01/2012 82.5 15.02 6,88004/02/2012 81.7 14.38 6,86004/03/2012 83.6 16.80 6,93004/04/2012 83.6 17.00 6,80004/05/2012 77.6 15.63 6,63004/06/2012 75.1 17.27 6,51004/07/2012 76.4 21.46 6,38004/08/2012 79.6 17.00 6,17004/09/2012 80.8 12.47 5,93004/10/2012 78.7 16.48 5,77004/11/2012 73.5 16.79 5,68004/12/2012 79.5 17.40 5,61004/13/2012 79.0 16.16 5,49004/14/2012 85.3 22.60 5,38004/15/2012 89.9 16.13 7,59004/16/2012 89.9 12.77 8,41004/17/2012 82.3 18.26 8,17004/18/2012 81.8 15.13 8,00004/19/2012 87.2 18.33 7,35004/20/2012 86.2 15.58 7,12004/21/2012 77.7 22.24 6,97004/22/2012 79.1 21.17 6,63004/23/2012 82.5 16.50 6,43004/24/2012 83.4 21.37 6,33004/25/2012 86.4 19.51 6,16004/26/2012 86.4 21.41 6,10004/27/2012 81.3 22.92 5,94004/28/2012 81.3 24.83 5,84004/29/2012 82.2 20.47 5,93004/30/2012 85.2 15.69 6,130K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012]Reports\April\April 2012 ATTACHOI.doc VATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 April 2012Page 2 of 2HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (orassociated rinses) containing hydrazine discharged to the Cooling SystemBlowdown during the month of April 2012.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite was used this month. Bromine compounds were notused this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 30 of 30 days.4. Per Special Condition 24 the influent from the Rock River and effluentfrom Outfall 001-0 was monitored for Total Suspended Solids (TSS) thismonth. The Rock River TSS value was 44.3 mg/L on 04/09/2012.

TheCWBD TSS value was 1.9 mg/L on 04/09/2012.

5. Rock River flow for April 2012 was >2400 cfs therefore daily temperature calculations were not required this month. (Special Condition 12).6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in April 2012. (Special Condition 15).K:\BYR_CHXBYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\AprillApril 2012 ATTACHO1.doc Exek n.Exelon Generation

Company, LLC www.exeloncorp.com Byron Station4450 North German Church RoadByron, IL 61olo-9794 June 15, 2012LTR: BYRON 2012-0064 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyWater Pollution ControlCompliance Assurance Section #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring ReportIn accordance with National Pollutant Discharge Elimination System (NPDES) Permit Number 1L0048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report for Byron Station, Units 1and 2. This report covers the period of May 1, 2012 through May 31, 2012.On 05/03/2012 between 03:45 and 05:12 cooling tower water from the Unit 1 Natural Draft Cooling Tower(NDCT) basin flowed over the basin into the storm water ditch located on the east side of German ChurchRoad. The flow was approximately 1.1 gallons per minute for an estimated duration of 87 minutesresulting in approximately 92 gallons of cooling tower water flowing through storm water Outfall 003, EastStation Area Runoff. The cause of the overflow is a large number of NDCT fill packs fell into the coolingtower basin in a short period of time. This caused the delta level across the debris fence in the NDCT torapidly rise from 0.5 feet to 2 feet which pushed the water out of the basin. Byron Station Operations personnel took immediate measures to lower the cooling tower water level in the basin of the NDCT tostop the overflow.

In addition measures were taken to remove the fallen fill packs from the NDCT basindebris fence to lower the delta level across the fence.If there are any questions regarding this report, please contact Ms. Zoe Cox, Environmental/Radwaste Supervisor, at (815) 406-3035.

Respectfully, Benjamin P. YoumavPlant ManagerByron Nuclear Generating StationBPY/ZC/eh Attachments PERMrIrEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN. C'.wI1FNV RPFC:PNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)IL0046313 AD"-PERMIT NUMBER DISCHARGE NUMBERMONITORING PERIODMMIB WYYYY I MUMIDOYYYY DUR Mailing ZIP CODE: 61010MAJOR(SUBR 01) CSDEMINERALIZER REGENERATE WASTE (O01A)External Outfall* **NOOISCHARGE-

°FROMI06101/2012 I To05/31/2012 QUANTITY OR LOADING QUANITIY OR CONCETtON NO. FREQUENCY PARAMETER EX OF TY.PLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSISSolids, Total Suspended SAMPLE ....... 21 2.1 19 0 01/30 08MEASUREMENT Effluent Gross n xuChromium, hexavalent SAMPLE ........(as Cr) MEASUREMENT Effluent GrossC.hromium, total SAMPLE ..... ...500(as Cr) MEASUREMENT 0103410 ~ y:- -Effluent GrossCopper, total SAMPLE 500(as Cu) MEASUREMENT 0104210 ez- ..... ..2' *'-'-Effluent Gross 7Iron. total SAMPLE .. .... 50(as Fe) MEASUREMENT Effluent Gross Moog"Lead. Total SAMPLE ...... Soo(as Pb) MEASUREMENT Elffluent Gross-Nickel, total SAMPLE Soo(as Ni) MEASUREMENT____

010671 0 M --4.-7 -ýEffluent Gross iNAME/1TTLE I Derlity under penalty of law MtWa tks docueant alt Sttaflefts were prepared T, myL ONE DATEPRU414PAL EXECiLwVE OFFICER directi or supendsm bi accordance with a system to assure mat wuafid prpet g~r noeatt V romao sbmte a~sed m frinqur v*" perso or persons 815 406-3700Benjamin P. Youman wfo manage tite systm or tose pereonsi dtecy resporsWAe lor gaere erlolmat Vsnt t1e -152012inluomaw is. to ahe best of my knomtedge and be"et. tue. acrate. ant comrlete.

I amn SIGNPUREOF/NCIPLE Plant Manager aware tat &mere are sqndam penalties for faske informat.

wdudig owe p 0adt of EXECUTIVE OFFICER OR AREA-____n all _____- __o_________n__

(Or _ _i_ _ Vi_ _. AUTHORIZED AGENT CODE NUMBER MM/DD/YYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastowater during this month.2. Flow existed 31 of 31 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 1.0 0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DUR)PERMII-EE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvitle.

IL 60655-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATIN: Zoo Cox/ENV SPECIL0048313 PERMIT NUMBERA01-0DISCHARGE NUMBERMONITORING PERIODMM"1DYY I I "D/YYYYDMR MaIling ZIP CODE: 61010MAJOR(SUOR 01) CSDEMINERALIZER REGENERATE WASTE (001A)External Outfall*"NODISCHARGEE" FROMI05/01/2012 I ToI05/31/2012 IO QUANTITY OR LOADING OUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANAOFYSS TYPEZinc, Total SAMPLE ... .... ...00(as Zn) MEASUR.MENT So01092 10 4' r -.. .. ..... .....4'" "Wrb *" Effluent Gross = -- *S,Flow, in conduit or thru SAMPLE 3l 0 1/1CtetetpatMAUEET 0.033 0.094 3 ......* ...... 0 01/01 CNtreatment plant MEASUREMENT_________________

____________

50050 10 zT?~T -4~(~ 4lt ~~2L V;Effluent Gross- -inMEASUREMENT SAMPLE

.', " :SAMPLEMEASUREMENT

..- .. : ... ..t -W,SAMPLEMEASUREMENT SAMPLEMEASUREMENT NAMEmILMVE I cey under penty of law at this document and an aftactwents were prepared under mydimecton or upemn accordance with a system designed to a.ssur tat quati geonnet TELEHN Dpropery gatner and evabtie the itonfratioa submitted.

Based -i my hqiuy o te peeat or Benjamin P. Youman who manage the system. or ftse pemros direcdy mspnsase for gatherfg hme a oiona70n, 0 06/15e12iformiation subtited es. to the best O my and ke. mru. accurate, and Oomrete.

i am SUIVTUREft Of#MCIPLE Plant Manager aM tha ere ar signicant penaftes for submtig tate inormatwio frlotiding fth of EXECUTIVE OFFICER OR N EEYoE me and iipMantmit tor knowing vnioelns.

AUTHORIZED AGENT C NU MMIDD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 2,P©D Q&L fUAUV COWt7 PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadBron, t 61010NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (OUR)IL0048313 B301-0PERMIT NUMBER DISCHARGE NUMBERMONITORING PERIODMMIDWIYVYY L_ MMDD[YYYY DMR Mailing ZIP CODE:MAJOR(SUDR 01) CSSTP PLANT EFFLUENT (FORMER 0018)tdM Ouffall" NO DISCHARGE 61010FROMI 05/01/2012 I TOl05/311/2012 IATTN: Zoe CoxIENV SPECQUANTITY OR LOADING QUANTrrY OR CONCENTRATION NO. FREUENCY SAMPLEVALUE VALUE UNITIS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESODS0.38 0.50 26 5.5 6.0 19 0 020 24(20 Deg. C) 0031010 o ,.: 10E rs*"',.c

' ..-,- ...../ %0" SEffluent Gross " _ -mr. ..Mw000010- ~. ~ss. *0p '--too- +*Solids total suspnde0031010 7t~U ~ ~ -v- tttt uV;rr.Effluent Gross .""a, IFlow, in conduit or thru 0 0/0P CPHSAPEo...

O.L ... .....757...........1 0 OlrOI GRMEASUREMENT SAMPLAMEASUREMENT

______________________________________.. 4-MEASUREMENT,,

NAME/flfl.E r catty under peanty d law that tris doumeli and al atiachmfls were prpae under mty TLP EDTPRINCIPAL EXCUIE OPP1CEN erect'on ot suetso in --"ora.ew asl-ern asgne to asurema quae peTLEPONEDAT properl gather and evaleuthe mle oranf i aubrirted.

Based mi my inqur at the persis or persists , .-- 1 4230Benjamin P. Youman who manage die system, or tho~se persora directl reapoiwdil Ioa gasiarg oe b'Jorrnai mam 068155406470 Floomwano subitd e. to me atsty knowledge and ben. true. accurate, and crnrete , ani " SI0 4ATUR 0.0'PRINCIPLE 3 001Plant Manager aware hai there are sagnlcant genfltes tar submflm tatie entramabna.

Sichudg tIN posatktdy a EXfECUTIVE OFFICER OR JSA NMBRFMIWY trw mm " and kiprn~is~ma for mnowng Vi~litioniS AUTHORIZED AGENT CODE NUMBER ______________

COMMENTS AND EXPLAtATION OF ANY VIOLATIONS (Reference lS attMachments here)1. Flow existed through this outfall30 of31 days during this month.EPA Form 3320-1 (Rev 01/0'(6)

Previouseditions, may be used. ¶1uIb2012 PAGE 1(a IRQ PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvitle, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (OMR)IL0048313 C01-0PERMfT NUMBER DISCHARGE NUMBERDMR Mailing ZIP CODEtMAJOR(SUBR 01) CSWWTP (FORMER ODIC)Extenal Outfl.'.NO DISCHARGE "J "61010MONITORING PERIODMMIDWYYYYI MMIDWIYYYY FROMI05/01/2012 ITOI06/31/2012 IByron, IL 61010A't't': Zoo Cox/ENV SPEC ____ ________

_____________

__________

A : / SQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS SAMPLE ........u...d 3.9 6.5 19 0 o0230 2400530 10-. #, '.r a rSO'30 -~T ~$4-,-mEffluent Gross iChromium.

hexavalent SAMPLE Soo..........n5l (as Cr) MEASUREMENT 0103210 U~qy 4r tV$YX ~ rXk~d 1 ~-Effluent Gross A i aChromium.

total SAMPLE SI(as Cr) MEASUREMENT 500010341 0 44p ;Effluent Gross 1,Copper, total SAMPLE(as Cu) MEASUREMENT A-.010421 0 rz ~ ~ t'~ ~v"~Y' ,~eff'..tI tiYkfj 4YEff'l. ,. .-r--oss'

• A?2fl..,

', r ; ' -.-."-- .*-Iron, total SAMPLE ....... ... So(as Fe) MEASUREMENT 010451 0 .V-- #'* 4Effluent GrossLead. total SAMPLE(as Po) MEASUREMENT 0106110 ~~. ~ "' -~'S ;tEffluent Gross -,-'..-,

v.Nickel, total S..... ...... ......5.(as Ni) MEASUREMENT-5--

01067 10 so~r -A> )"~rr.- A~i k~ t:4 sN&-m~Effluent Gross 02 1 "1NANE1TnLE i certfy under penalty o law thit this doocment and a" aanes TELEPHONE DATEPAICPAL EXECUTIVE OFFCER riaction or supensvn m accordance with a system designed to assure tar qualired personnel I"doperty gater and evalute the uitonmation submitted.

Base an my tnuty of the person or persons 815 406-37I0Benjamin P. Youan who manage tro system. atrtose permons directly reaponsie icr gaitrerng the intonnaton.

mte 6W, rvI/2012informatiPn submtna ed is, to the best of my Ikowledge and beief. true. acoiate, and complete.

I am S0I6 01RE O2IRINCIPLE-Plant Manager aware that there am .signficant penaltis for s lubmitig false tomnrmnon, fIduic mhe possity of EXECUTIVE OFFICER OR AREA NUMBER MM/D YYYVSm O Pn jif and mrosmmfor kowmgviolain.

AUTHORIZED AGENT CODE NMRMDCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hee)1. There was no discharge ol processed steam generator chemical cleaning wastewater during this month.2. Flow existed through this outeall 24 of 31 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 14/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (OUR)PERMIT'EE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadIL0048313 PERMIT NUMBERC01-0DISCHARGE NUMBERI MONITORING PERIODI MMDYY I MMIu D/YYOUR MaIling ZIP CODE:MAJOR(SUBR 01) CSWWTP (FORMER 001C)Exemal Outtall***NO DISCHARGE 61010r-" .........

FROMI05/0112012 1 I06/31/2012 Il iByron. IL 61010ATTN: Zoo CoxIENV SPECQUANiTIY OR LOADING QUANTITY OR CONCENTRATION NO. FREUENCYPARAMETER OF SMLVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OF TYPEZinc. total SAMPLE(as Zn) MEASUREMENT

_ _I _ _50001092.10 3.... ý, ... .:. Z;E~ffluent GrossFlow, in conduit or thru Awicdulrtn APE 0.015 0.023 3 """......

0 01/01 CNtreatment plant MEASUREMENT 0.01_ 0.023 3_0_____O 50050 10 -'4i1 AOL 4.4f' -~Effluent Gros" "1J- -j .. ..... *SAMIPLEMEASUREMENT MEASUREMENT SAMPLEMEASUREMENT MEASUREMENT NAMEITITLE I C 10Y under p o law 0a On documen and al auftonts were pepared under myPRWCIPAL EXECUTIVE OFRCER doctn or supesion in acowdance wilh a system designed to assure 0l quailed persannM TELEHON DATEprOPe gather and evaklre sueated.

Based on my riqsy ofmf perso or personsBenjamin P. Youman who manae sWsTe or Vime peros diectly respnsl ff .te 4g0"-3-70Vie 06m15e2012 il ormatlon submittaed ito. tohVe boo of my Wowiedge and belief. tWAe waccrate, and corroleze l amn WUNGflREOF~PMhIlPLE Plant Manager aware 0V Viem am 50gificant penalt for wrmbmg false Womuo. kcx, V posesity of EXECUTIVE OFFICER OR N EEYORp RM fni a b u for f I .AUTHORIZED AGENT DE NUMBER M__ _ _ _ _ _ _COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/=2012 PAGE2a 0ORQAUWp 0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 610101L0048313 PERMIT NUMBERF 601-0DISCHARGE NUMBERFROMIMONITORING PERIODDMR Mailing ZIP CODE: 6MAJOR(SUBR 01) CSRADWASTE TREATMENT (FORMER 001 D)External Outfall* NO DISCHARGE EZJ1010MM/e D/YYYY05/01/2012

!UMIDDIYYYY 05/31/2012 1QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSISSolids, total suspended AMETCO cO 19 0 023M CMEASUREMENT

__________

____ ____ ____ ___Effluent Gross -..Flow, in conduit or thru SAMPlEtreatment plant MEASUREMENT

_ 0.021 0.023 3 ............

0 01/01 CN5005010 All,~ 2V 4~~~t%~IEffluent Gross si ' -.4MEASUREMENT

... t~.. eq`ýw-.J-au, A -h~j ! -4MEASUREMENT

____ ____________________________

SAMP MEASUREMENT A. 4yt v v ~ % 'l ~ ;A~ril ~y. ~SAMPLEMEASUREMENT mamwnnm.

i candty under penalty oS law thai the document and eli atauntt were prapare under ity LPOEDTBenjamin P. Youmnan who manage the stmn. at those pesoms asusal tow gatherig the mtormattw, the "IN IL 6I5mnfotmet,u etitldtta is.to ate beat oS my knowledge and belt ntree accurate.

and complete.

tamiEOnIL

__ _ ____________

Ptant Manager aware that thr are signifcant penaie tfuortrtkrlg tabse inam~adat.

having the ipmsrbuty EXECUTIVE 0FFIER OR ~ NME MDYYm end IccKuowing vidatiw.

AUTIhORIZED AGENT NUMBER MM/I)D/Y______Y COMMENTS AND OF ANY VIOLATIONS (Reference all auachmetmnta here)1. Flow existed through this ouflall S ot 31 days during the month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. --'1/6/2012 PAGE 1©XI PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60655-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoe Cox/ENV SPECNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)1L0048313 E0l-0PERMIT NUMBER DISCHARGE NUMBERI ~ MONITORING PERIODII MMIDDnYYYY IFROMITOlIMWD/YYYYl _ !0501I/2012 II05131/2012 DMR Mailing ZIP CODE:MAJOR(SUBR 01) CSSTORMWATER (FORMER 001E)Exteinal Outff**tNO DISCHARGE 61010-I IQUATMITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER EX OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPESolids, total suspended MEAMPLENT.

Solids, total suspended M0053010 j J'cOther Treatment, ProcesscompleteChromium, hexavalent SAMPLE ......(as Cr) MEASUREMENT 010321 0 A. 2;.,'Effluent GrossChromium, total SAMPLE ..... .(as Cr) MEASUREMENT 01034 10 T ' z A 4r?Effluent GrossCopper, total SAPL(as Cu) MEASUREMENT, SIMI0104210 'ASA "t""-. " ' -"Effluent Gross -L.', ,-,' LIron, total(as Fe) MEASUREMENT SooEffluent Gross k. -:4Lead. total SAM .....(as Pb) MEASUREMENT 50001051 10 ~ ? ' e'Af, :ct w.I*4 h r.Effluent GrossaNMf I Cerfady under penany of law Mat Me documern and an altadcments were prepared under my DATEPRInCPAL EXECUTIVE OFFICER dietion or aupertw in acmorance wem a sysaem designed to assure mat quaftled pertannel TELEHON DATE9g3a and evauite Via rormaion sufrnifed.

oadnht my ikxluy d te person or pem rizsC c 815 406-3700Benjamin P. Youman who manage ft sWe. or tose directly responsae for gam"ang ae onitrtw.

V6e -0615212Bomnan submfn is, to the bestS nVo'etd and betl, Ue, awrawe, andomwrs.

tam S1GWMuuRE OFýMCIPLE Plant Manager aware mat mere are penaties for infornatmon.

jfljfl the posa ilyS EXECUTIVE OFFICER OR AREA NU E MMDO/YYYY Sand prreo-mAnt for knowing a.UTHORIZED AGENTCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during the month.2. Flow existed through this outfall 2 of 31 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/2012 PAGE 11Cqr---)'Py P- a ey \ýý0 PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)IL0048313 EO1-0PERMIT NUMBER DISCHARGE NUMBERF MONITORING PERIODUMID/YYY I I -DwfYYYYDMR Mailing ZIP CODE,MAJOR(SUBR 01) CSSTORMWATER (FORMER 0OIE)External Outfall***NODISCHARGE 61010I .......FROMJ)l0510112012 To= o//201DI2 I IQUANTITY OR LOADING QUANITrY OR CONCENTRATION NO. FREQUENCY PARAMETER EX OF TYMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSINickel, total SAMPLE ...... ..... ...... 500(as Ni) MEASUREMENT 0109210 -- .Effluent Gross 1'~ 2,10 L a iZinc total SAMPLE ...... ...... 500(as Zn) MEASUREMENT 0109210 bye, en~ .Af-M'- ý W~N~5 F ,Effluent GrossFoicodiortrSAPE 0.314 0.575 3 .... ... 0 02/"3 CNtreatment plant MEASUREMENT MEASUREMENT

_____ _____ _____SAMPLEMEASUREMENT 4W.v~ --t Q~vtt~H.

i'V 41 7&3V@&MMEASUREMENT

• . -- .r _r .,& jf < -..- A 4 3. '%..rIMUE/I1TL.E canny under penally law vma mes doc~ment and all aeacflr~en warn prepared under my TELEPHONE DATEPfiCPL, EXECUTIE OPPICER dlrcha ow aupervmain i accordance wale a system deige to dial qualifed persmnne____

Benjamin P. Youman who manage the aystem r those peioss deafly resportaihe gatherig t~e miormasn, me SINR FIC- "u/ , J 06/15/2012 atomrnation aubmutad la, to the hemst my knowleg and hefler. tree, accurate, and complete.I amin ~ lRE~WILPlant Manager aware dial mere are peate Ice sulmziniti false inlomiainm.

kiM~s' mhe Pm~atity S EXECUTiVE OFFICER OR ARE UBR MM/DD/VYYY fle a xn la ne and bin utlrnmnn l for Igrowin vi a w .A U O R E D G N TO OCOMMENTS AND EXPLANATION OF ANY VIOLATIO)NS (Reference all attachmen~ts hem)1. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Metal Cleaning wastewater was discharged this month.2. Fire Protection drain water was not discharged this month.EPA Form 3320-1 (Rev 01106) Previous editions may be used.'...

1/6/2012 PAGE2Q QMLIW,='.

NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)OUR Maling ZIP CODE:61010PERMITTEE NAMEIADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Wintield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoo Cox/ENV SPECIL0048313 PERMIT NUMBERF 001-0DISCHARGE NUMBERMONITORING PERIODMMIDW0YYYY j I MM/ID/YYYY MAJOR(SUDR 01) CSCOOLING SYSTEM BLOWOOWNExternal Outfall"..NODISCHARGE FROM05/01/2012 J OL 06/31/2012 IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY VALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPETemperalure.

water dog. SAMPLE ...... ...... ...0Fahrenheit MEASUREMENT

.....9. 5 0 0/1C0001110-

_HSAMPLE ...... 8.25 8.73 12 0 01/07 ORpit MEASUREMENT

-Effluent Grossppv tr.'r. i -- .e A:Solds, total suspended

...... 1.6 2.1 19 0 01/30 GRSolds Ioalsusened MEASUREMENT 0053010 7, ., -.. 7" .,-. ITc. .. "7 Effluent Gross a Oil & Grease SAMPLE .. .... <1.4 c0.4 19 0 01/07 ORMEASUREMENT oflun Gros .-+ ----r +....

,t.," -- "........

Effluent GrossChromium, total (as Cr) SAME <0.0021 19 0 01/07 ORMEASUREMENT

_____________

____ ____01042 10 iiV Cj Za S4-Effluen Gos -:v '-;. ,: ....-.. -= .-... ---: --' ... .t4 ~ ~'-Effluent Gross .f-properl gaml ad e) SAMPLE t...... .. .. .... 0.013 19 0 01/07 mRColper toai as u) MEASUREMENT Effluent Gross _--- -: 1P+, ;-p .. '+" ....PAMLEr potal (as EXECUTIVEE<0.0022 0.ERO 24 19 0 01/07 ORZin, Effluent Gross :"' "+, °-+""...NCMENTS AND EXP.tLAN A uTI r PeOlty oL laT MOt (n R umef t al atftachmems were )maro uner m ONE DATEP1 .MnL EXdaCUtaE OFFCER outclt00 1 r sup edion attcorhaen with a system design to assur tha quatied PronelEPApFeoy ga330 an eva(e m0 1/rmaiono suednie.

Basen an my mauiry ou sde pe or .ons OD 0,1PAGE1Beniannin P. Yournan whg manage the system, or rhose Persos dir-t,'y repmb tm gaiemrn the infrmation, the 406-37PL 0615=212intonnabon submittdne is. t o am bowl of my knowmlede and 1belie. true, =,'cu,,ra.

andm =nmpMW.I m, SIN GR 1:nPlant Manager aware that there are sqgnificant penabaes for su latin e tabsnformtion fxing the postlf of EXECU TIME O~C ER OR AREAJTIM OaRm 1110110 em for knowin viltl AUTHORIZED AGENT 1COD NUMBER -MMIDD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Raefernce all attachments hem)1. Monitoring clata for outfali 001-0 is included on attachmrent EPA Form 3320-1 (Rev 01/06) Previous editions mnay be used. 1/6=212 PAGE 1QAO@DFfl (uQUA PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010A'f-Nz 7GB CinxIFNV SPECNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)IL0048313 001-0PERMIT NUMBER DISCHARGE NUMBERMONITORING PERIODMM,.D/YYYV I MMIDD/YYYY DMR Mailing ZIP CODE: 61010MAJOR(SUIR 01) CSCOOLING SYSTEM BLOWDOWNExternal Outfall*

• NO DISCHARGE

""FROM L05/01/2012 J TOI05/31/2012

-IQUANTITY OR LOADING QUANTITY OR CONCENTRATION

.FREQUENCY SAMPLEPARAMETER VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPEOxidants, total residual SAMPLE E500Priority pollutants total effluent MEASUREMENT500 Effluent Gross iFIAK r = 1 i aFlow, in conduit or thru SAMPLE 20.55 27.56 3 ....... 0 0101 CNtreatment plant MEASUREMENT 20;5650050 10goy txg1g es- 't .. -Effluent Gross m a 02=1.) 1ZChlorine, total residual SAMPLE ....... 003 19 0 01/07 GRMEASUREMENT Effluent G ross -: -i. -_-Hydrazine AMELE .50Effluent Gross M ~ SU M;. .81 18 : -'"k,& ,: " t' .i- "- , r,, NAM~fliTES rAMPLmSAMPLEMEASUREMENT properly gather anid evalula the Wnomutior sumttdM.

Based an Fmy binquii of the person or persons 1 40370615 2Benjamin P. Youmnan who manage Vve system, of fthee parsona directly reapomfle Icr gaMVterigte intorkone.

th SIGNJWIII OFYMNCIPLFl61521 Plant Manager int-rsrnteubmistted is, to tie betat 01r wmy tinoieg arid beirS, true. scoe, andl M0T1*51.

Itarn XCTVEOFCRR AEPlan Man er aware triat there are swinicant penalties tor aubrti falsgIe infrmiiation.

htflng the possiady s XCTVtOFCRO NUMBER MMMIDDYYYY

______ an__MINIM fin~e and irrrrisiermsnt tar mnowinG vioations AUTHORIZED AGENT CODE__ __ ____________

CMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all etutchnienta here)iEPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1621 AEPOOR UAL9fl ©©F%.

PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACIULTY Byron Nuclear Power StationLOCAliON 4450 North German Church RoadByron. IL 61010NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)IL0048313 002-0PERMIT NUMBER DISCHAR3GE NUMBERMONITORING PERIODFROM 06/01/2012 TOI 06/31/2012 DMR Mailing 13P CODE-MAJOR(SUBR 01) CSSTORMWATER RUNOFF BASINExternal Outfall* **NODISCHARGE 61010A I* I: -"=-V t awcn/ ~rlc, _ _ _ _ _ _ _ _ _FREQUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OF TYPE[ýý!<ANALYSIS SAMPLE .......Solds MEASUREMENT Colis, Total Suspended SAME(as Cu) MEASUREMENT 00o308 1 --.... ....Effluent GrossCome, oltalSMLe......

..Ihroniu.

toexaaltSML (as CF) MEASUREMENT 0103210 t* _Effluent Gross -.-r.ron,. tota SAMPLE .......(as Fe) MEASUREMENT (as Pb) MEASUREMENT Effluent GrossNAME/iTII1E ICertfy wnder pena~ly Cl law t'hai tys tclornmeit andi at alla'mens waee wnder' myTEEONDArl llINCIPAL EXCTV OPRICER ot m accaruarce with a systes desige to assue thai qpualfed pereonen_________________

Benjamin P. Youman who manage te ysem. r tiseepeisons duedy rsibetr gatherng te tdonmain.

the 1 0-70 61/21Iofonne.

submd is. t he best ol my knSAedPe end beel. true. ..cura.e. a1 lam WGNJ.URE OF7INCIPLEPlant Manager aware tha there em esignrtcant penaltis tar eutmoing talse etfomiabon.

erchdul the pcealbulty EXECUTIVE OFFICER OR NUMBER MM/DDJYYYY owe a wm and irlpflsraonlleltafr IImoWmiQ vidla~eS.

AUTHORIZED AGENT co ___ ___________

COMMENITS AND EXPLANATION OF ANY VIOLATIONS (Reeec ail attachments here)1. No Turbine Building Fire and Oil Sumnp or Generic Non-Chemical Metal Cleaning Wastawater was discharged this month.2. No Fire Protection, Service Water or Closed Cooling System Drain Water was discharged this month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. I/6/2112 PAGE 10ROUR-InA 0 -r y C 0'0)ý I P, NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)IL0048313 002-0PERMIT NUMBER DISCHARGE NUMBERMONITORING PERIODS MMIDDoYYYY MMIDONYYY PERMI'IEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenve, II 60H55-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoe Cox/IENV SPECOUR Malling ZIP CODE.MAJOR(SUBR 01) CSSTORMWATER RUNOFF BASINExternal Outfall"**NO DISCHARGE M ...61010FROM L05/01/2012 ITOl05/31/2012 QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPENickel, total SAMPLE ......(as Ni) MEASUREMENT 0105710 ' ----o #-M ., -* .-.,.Effluent Gross 21Zinc, total SAMPLE(as Zn) MEASUREMENT Effluent09 1Gross0

' i -,, -, r'":*". -;y. ; .010921 0 v ______T t~Oil and Grease SAMPLE .MEASUREMENT 03582 10 77p4"- '"-~"--~c2;~

~ t-~.~ P'~P -Effluent GrossFlow, in conduit or thin SAMPLEtreatment plant MEASUREMENT 5005010 ts > e qy 4 Jeq.o 4 Z--Effluent Gros tMEASUREMENT SAMPLEMEASUREMENT

_ _ _-__-- & ,.SAMPLEMEASUREMENT NIMce/TITLE I 8rdty unier penany Of law Mat Oif document and al a were prepared under y TELEPHONE DATEPRdICIPAL EXECUTIVE OFFIR diection or supeNvsim In accordnlce with a system desined to assure flnt qualdied persainei TELEHON DATEpropeuty gamer and evaitenme infomatinsubmittad.

Based on my inqiw of me persor pso .sti5 406-3700BenjarminwP.

Youman whomanage fu system, or fte pson=airecy responsl far gotering the informaioen.

u 061512infrmfamtion submnitteduis to the best of my ivoaedigea nd belief. trse, accutrate.

ean comrqtse Iam SIGAG R OFWCtNM__

____________

Plant Manager aware Man there are signicant penaftes tar subtmitg fare ionnatlim.

holding me poflay of EXECUTIVE OFFICER OR AREAMTweoo a l t and uipnaintat for bvwtng vomatione AUTHORIZED AGENT CODE NUMBER MM/OD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachmenta here)1. This discharge point was not used this month.2. Them was no discharge of processed steam generator chemical cleaning wastewater during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1//2012 PAGE 2 ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 May 2012Page 1 of 2MONITORING DATA:CWCWB D Flow Rock RiverDATE Temperature mgd Flowdeg F cfs05/01/2012 86.0 22.71 6,18005/02/2012 92.5 19.66 6,16005/03/2012 96.1 22.35 6,09005/04/2012 96.1 19.40 5,99005/05/2012 91.5 26.25 5,96005/06/2012 90.2 21.26 6,04005/07/2012 90.2 16.10 6,49005/08/2012 89.0 20.31 7,09005/09/2012 86.9 20.77 7,56005/10/2012 86.3 21.37 7,66005/11/2012 89.2 20.81 7,61005/12/2012 90.7 27.56 7,38005/13/2012 88.9 22.68 7,17005/14/2012 90.6 15.14 7,06005/15/2012 91.1 20.80 6,90005/16/2012 91.1 19.23 6,57005/17/2012 85.6 20.10 6,47005/18/2012 93.2 22.87 6,36005/19/2012 94.7 25.09 6,15005/20/2012 95.0 17.36 5,96005/21/2012 95.0 13.79 5,71005/22/2012 84.0 19.80 5,62005/23/2012 86.0 18.06 5,46005/24/2012 84.4 18.97 5,31005/25/2012 93.0 19.39 5,00005/26/2012 89.0 24.88 5,14005/27/2012 99.0 20.18 5,14005/28/2012 99.0 18.83 5,10005/29/2012 97.8 18.99 4,86005/30/2012 94.0 19.70 4,70005/31/2012 84.8 22.67 4,820K:\BYR_CH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\May\May 2012 ATTACHO L.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 May 2012Page 2 of 2HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (orassociated rinses) containing hydrazine discharged to the Cooling SystemBlowdown during the month of May 2012.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite was used this month. Bromine compounds were notused this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 31 of 31 days.4. Per Special Condition 24 the influent from the Rock River and effluentfrom Outfall 001-0 was monitored for Total Suspended Solids (TSS) thismonth. The Rock River TSS value was 25.3 mg/L on 05/07/2012, 31.3mg/L on 05/14/2012 and 22.8 mg/L on 05/29/2012.

The CWBD TSSvalue was 2.1 mg/L on 05/14/2012 and 1.1 mg/L on 05/29/2012.

5. Rock River flow for May 2012 was >2400 cfs therefore daily temperature calculations were not required this month. (Special Condition 12).6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in May 2012. (Special Condition 15).K:\BYR_C1{BYRON.DB\ClerkWMonthly Discharge Monitor Rpt\2012Reports\May\May 2012 ATTACHO1.doc ExekJn.Exelon Generation

Company, LLC www.exeloncorp.comN Byron Station Nuclear445o North German Church RoadByron, IL 61o10-9794 July 23, 2012LTR: BYRON 2012-0082 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyWater Pollution ControlCompliance Assurance Section #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276'

Subject:

Byron Station Monthly Discharge Monitoring ReportI In accordance with National Pollutant Discharge Elimination System (NPDES) Permit Number1L0048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report forByron Station, Units 1 and 2. This report covers the period of June 1, 2012 through June 30,2012.If there are any questions regarding this report, please contact Ms. Zoe Cox, Supervisor Environmental/Radwaste, at (815) 406-3035.

Respectfully, Benjami P. yourPlant ManagerByron Nuclear Generating StationBPY/ZC/eh Attachments EN-AA-105 Revision 4Page 14 of 14Attachment 2Example Verification Completion FormPage 1 of IVerification Documentation Correspondence/Letter number: 2012- ON 9- Origination Date: 7-19-12Agency/External Stakeholder:

IEPA Submittal Due Date: 7-23-12Recipient of Correspondence:

IEPA WPC CAS #19(name and title if known)Purpose of Submittal:

June 2012 DMROriginating Office: E] Cantera E- Kennett Square I] Site Byron(specify)

Preparer:

Zoe Cox 0 tw % /(print) (sign) (date)Peer Reviewer:

David Starke 4 9 (print) (sign) (date)Certified Mail Return Receipt Requested:

FI]Yes -INoApprovals (check box if applicable)

Attach additional page for comments.

NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERA01-0DISCHARGE NUMBERMONITORING PERIODMMIDDIMMDDYYYY I M1DYyDEMINERAUZER REGENERATE WASTE (001 A)External Outfall* -NO DISCHARGE FROMI06/01/2012 I TelI ........

IIUwir30/2 12IByron, IL 61010ATfN: Zoe Cox/ENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS E ANALYSISSAMPLE 9.7 10.1 19 0 01/30 08Solids. Total Suspended MEASUREMENT 0053010 PERMI -',--15 .30 flr , CMEffluent Gross REQUIREMENT

.._._._"- -_,__ _0D.A AVG DAILY MX f.... L Mon. .O.:.Chromium, hexavalent SAMPLE 500(as Cr) MEASUREMENT 5000103210 PERMIT ..-. .12EffluentGross REQUIREMENT 3_.,.___...

.0DA AVG DAILYVMX rW'- ,... .. ..Chromium, total SAMPLE ..................

5(as Cr) MEASUREMENT 0103410 PERMIT ..,..,, ... ' 2 mg/ " Da GRAB"Effluent Gross IREQUIREMENT.

30DA AVG ' ...... --Copper, total SAMPLE ...... ...... ...... 500(as Cu) MEASUREMENT 010421 0 PERMIT * ..5 .1Effluent Gross REQUIREMENT

_.__ .SDA AVG DAILY MX MOI *____ -Iron, total SAMPLE ..500......

(as Fe) MEASUREMENT

...... __5000104510 PERMIT -.- ,.,. 1 'E ff lu e n t G ro s s R E Q U IR E M E N T A," -, ."" , W,_ :_"_, D a il ,G"R".A..

..B- ,Lead, Total SAMPLE ............

...... ...... 500(as Pb) MEASUREMENT g'0105110 PERMIT .. " ..2 .4Effluent Gross REQUIREMENT 3_ _ __" _ SODAAv( OAII , -/ Di GRABNickel, total SAMPLE ...... 500(as Ni) MEASUREMENT 0106710 PERMIT -..-V2mIayREffluent Gross

"_, -, .-Daily -RABNEIr'LE cendy under penany of law that thi document and an artachmems were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER drectin or superir~n in accordance with a system designed to assure that quatified personnel prope rtygather an d eva knethe inform ation subm itt Wl. B a~se d an my inqu iry o te pe rson or pe rsos - : .t , --6 5 4 6 3 7 0 0Benjamin P. Youmnan who manage the system, or those persons directly responsible for gatheting the information, the I07/23=12 inlormation submitted is. to the best of my knowledge and balief. true. accurate, and cormplee.

I am SIGNATIE O RINCIPLEPlant Manager aware that thera are signiicant penalties for submnittg false iftormation.

irnduding the psibity 01 EXECUTIVE OFFICER OR AREAOR PR. me and imprisinmemnt for knowing violations.

AUTHORIZED AGENT ODE NUMBER MMDDYYYYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed 29 of 30 days during this month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 1/6/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoe Cox/ENV SPECDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERA01-0 -DISCHARGE NUMBERMONITORING PERIODMMIDD/YYYY MMIDD/YYYY DEMINERALIZER REGENERATE WASTE (O01A)External Outfall" NO DISCHARGE

[ "FROMI06/01/2012 TOI 0613012D12 Il IPUANRTITY OR LOADING QUANTITY OR CONCENTRATION No. FREQUENCY PARAMETER OF SMLVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPEZinc. Total SAMPLE ...... ...... ...... S00(as Zn) MEASUREMENT 0109210 PERdI- ,.-.. --Dl2 GRABEffluent Gross p2UIREMEN.

" _ "'___" 30DA AVG DAILY MXFlow. in conduit or thru SAMPLEtreatment plant MEASUREMENT 0.046 0.132 3 0 01/01 CN500501 0 PERMIT Req. Mon. Req. Mon. LEffluent Gross REQUIREMaENT 300A AVQ DAIJY..Ym 4tx Daily CON~hN.SAMPLEMEASUREMENT

'PERMIIT.-.

.REQUIREMENT

_ _., ;.. -,._"_'SAMPLEMEASUREMENT REQUIREMENT

, ......_,_....SAMPLEMEASUREMENT PERMIT-REQUIREMENT

.-.........

.-SAMPLEMEASUREMENT PERMITROQUIREMENT

,__r_ _ -SAMPLEMEASUREMENT,NAEmTITLE I certify under penalty ot law that this document and all attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIE OFFICER direction or supervision In accodance with a system designed to assure that qualified personnel properBym Pater and evalute the infomiation submitted.

Based an my inquiy of the person or persons .-) 815 406-3700Benjamin P. Youmnan who manage the system, or those persons directly responasise for gathering the infomtation, te 8,5....3.0 07/23t2012 information sumimned is, to the best ot my Inotiedge and bellet. true. accurate.

and comlete.

I am,,p E OI-RIN PLE .Plant Manager aware dhat there are significant penalties for submritting lalse information.

Including the EXECUTIVE OFFICER OR AREAT"WOD OR Pmm, Tr line and imprsionment Ifr knowing vielatons.

AUTHORIZED AGENT 4OD NUMBER MMIDD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 2 NATIONAL POLLUTANT DIS9ARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIT-rEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvitle, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010ATTN: Zoe Cox/ENV SPECDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERB01-0DISCHARGE NUMBERBIMONITORING PERIODSTP PLANT EFFLUENT (FORMER 001B)External OutfallI MM/DD/YYYY IIToIMM/DD/YYYY

-- IFROMI06/01/2012 06r3J/2012 I* **NO DISCHARGE

= ..I lOUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREOUENCY VALUE VALUE UNITS VALUE VALUE VALUE UNITS O ANALYSIS TYPEB/3D. 5-Day SAMPLE(20 Deg CASUEE 0.42 0.58 26 ...... 6.0 7.0 19 0 02/30 24(20 Deg. C) PMEASUREMENT 003101 0 PERMIT 5.3 VA10.5 Id "TcP30 60 X g/LoElfluent Gross REQUIREMENT 30DA AVG DAILY .... ,DAAVG D-LY X T PMont COMP24pH SAMPLE............

...... 7.54 ...... 7.58 12 0 02/30 GRMEASUREMENT 0040010 PERMIT 6 ., ... Tw,. .a MEffluent Gross 6RETUIREMENT MrohSAMPLESolids, total suspended MEASUREMENT 0.17 0.23 26 ...... 2.3 2.8 19 0 02/30 24005301 0 PERMIT 5.3 10.5 bld 30 ,60Effluent Gross REIGUIREMENT 300A AVG QAILY MX .30DA AVG DAILY fAX fL TWICe Per Month COMP.4Flow, in conduit or thru SAMPLEFo.IcodiorhrSAPE 0.006 0.013 3 ...... ...... ...... ...... 0 01/01 CNtreatment plant MEASUREMENT 500501 0 PERMIT Req. Man. Req. Mon. ... .... .y- a-"O" "Effluent Gross REQUIREMENT

.30DA AVG, DAILY MX M. .. .._qt .. :"-'--SAMPLEMEASUREMENT PERMITREQUIREMENT

..SAMPLEMEASUREMENT PERMIT,REOUIREMENT

....-.SAMPLEMEASUREMENT PERMITF______ BI=RO W _ _ _ _ _ __ __NAMEMITLE I certify under penalty of law that this document and alt attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFRCER direction or superaron in accordance with a system designed to assure that qualmed personnel propezy gather and evaluethe inmormation submitted.

Baseanminhulotheperonrpersons 815 406-3700Benjamin P. Youman who manage the system, or those persons directly respnsible for gathering the intormation,

-e 07/2o372012 information submitted is. to me best of my knowledge and belief, true. accurate.

and complete.

lam SIGNAIM OF INCIPLEPlant Manager aware that there are significant penalties for submitting false information.

including me EXECUTIVE OFFICER OR AREATIMED CA fITIE_ ine and hoprtsisrem tol Mnowing violatits.

AUTHORIZED AGENT CODE NUMBER- MMDD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Row existed through this outfall 25 of 30 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERI CO1-0II DISCHARGE NUMBERIMONITORING PERIODMMIDD/YYYY I MMIODIYYYY WWTP (FORMER 001C)External Outfall*NO DISCHARGE FROMI06/01/2012 TOI06030/2012 l l---- IByron. IL 61010ATTN: Zoe Cox/ENV SPEC ______ _______________

___________

__________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TPESAMPLE ............

...... ...... 4.1 4.2 19 0 02130 24Solids, total suspended MEASUREMENT 005301 0 15 30Effluent Gross REQUIREMENT

..-""._" -:__ -_.., 30DA AVG DAILY MX mng&L Twice Per Month COMP24Chromium, hexavalent SAMPLE ............

...... ...... Soo(as Cr) MEASUREMENT 0103210 .2 Daily GRABEffluent Gross REQUIREMENT

• _ _ .. 30,DA AVGi DAILY MX .Chromium, total SAMPLE ............

...... ...... 500(as Cr) MEASUREMENT 010341 0 PERMIT .. .2...* ,D... 1 2GAEffluent Gross REQUIREMENT

.. ...DA AVG DAILY M" ____ ...Copper. total SAMPLE ............

.....(as Cu) MEASUREMENT 0104210

• PERMIT ,,,.- ....'.5 1 .GRABEffluent Gross REQUIREMENT

" _ _ 301A AVG pALY Mx mg/LIron, total SAMPLE ............

............

500(as Fe) MEASUREMENT 0104 1 0 PERMIT .... ..... 1. DilyEffluent Gross REQUIREMENT

• - ,...*DAILY MXLead, total SAMPLE ...........

...... ......(as Pb) MEASUREMENT 0105110 PERMIT .2 .......Effluent Gross REQU__IREM__ENT

._._-._ 30DAAVq DAILY MX _ .P. al GRABNickel, total SAMPLE ............

...... 500(as Ni) MEASUREMENT, 0106710 PERMFIT ..1 2 ..Effluent Gross REQUIREMENT

.30DA AVG DAILY MX trtL. Daly GRAB.NAflTh. I certify under penalty of law that this document and all attachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUtiVE OFFICER direction or supervnisin in accordance with a system designed to assure that qualified personnel

_properly gather and evaute the Infonation subritted.

Based an my inquiry ol the person or persons 815 406-3700Benjamin P. Youman who manage the system, or those persons directly responsible lor gatheng the inlormation, the 07r2312012 information submitted is. to the best of my knowledge and belel, true, accurate.

and conplete.

I am SIGNARE OF NCIPLEPlant Manager aware that there are significant penalties lfo submitiing lalse including the possb4 of EXECUTIVE O CER OR AREAT'n O ine and imprisionment for knowing vioatons.

AUTHORIZED AGENT CODE NUMBER MMDD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed through this outfall 17 of 30 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (OMR)DMR Mailing ZIP CODE.MAJOR61010PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 Norlt German Church RoadByron. IL 61010ILMr13 IUMBC01-0 (SUCR 01)PERMIT NUMBER I I DISCHARGE NUMBER -CSMONITORING PERIODMM1DDIYYYY I I MMIDDJY~yyY WWTP (FORMER 001 C)External Outfall* I I NO DISCHARGE

"]FROMI 06/01/2012 1 TOl 06o132012 Il IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSISZinc, total SAMPLE ............

...... ...... 500(as Zn) MEASUREMENT 0109210 PERMIT ... ...... .....1.. 2Effluent Gross REQUIREMENT

.. .._._*_. 3I0IA AVG DAJLY MX it... patt -GRABFlow, in conduit or thiu SAMPLEtreatment plant MEASUREMENT 0.015 0.029 3 0 01/01 CN5005o 10 PERRMIT.

Rq. Mon. Req: Mon.Effluent Gross REQUIREMENT.

30DA AVG DAILY MX * .. ' D. l C...I.SAMPLEMEASUREMENT PERMITREQUIREMENT

"_____,__"_

SAMPLEMEASUREMENT PERMIT,REQUIREMENT

-...SAMPLEMEASUREMENT PERMITREQUIREMENT

_ _ _. -,-SAMPLEMEASUREMENT

.!,e rr.- ,REQUIREMENIF SAMPLEMEASUREMENT PEF.WIT

,I"NAMElhTrLE I cenrty under penalty of law that Otis document and alt attachmets were prepared under my TELEPHONE DATEPRINCIPAL EXECU~lVE OFFICER directlon or supervision in accordACe weth a system designed to assure that qualified pemronnel property gather and evaJute the1 nforniatior Based an my inqu of the perton or pemons 8 815 406-3700Benjamin P. Youman who manage dhe system. or those pesoons directly responsime for gathering the information, te -07/23e12infontation submitted is. to the best of my knowledge and belief. tre, accurate.

and complete.

I amn ___O__Plant Manager aware that there are significant penalties tor sumtitting false informiation.

including the possiblity of EXECUTIVE OFFICER OR AREAonPW OR ' io line and imupnssorment for knowing violations.

AUTHORIZED AGENT CODE NUMBER MMMD/YYYY COMIENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 2 PERMIT'EE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoe CoxIENV SPECNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)IL0048313 6o1-0PERMIT NUMBER DISCHARGE NUMBERFM 1 ONITORING PERIODMMIDOIVYYY MMIDD/YYYY FROM 0610112012 1TOI 06/3a(2012 DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010RADWASTE TREATMENT (FORMER 001 D)External OutiallI NO DISCHARGE

[ ...QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSISSAMPLE ............

...... ...... <0.5 <0.5 19 0 02/30 CPSolids, total suspended MEASUREMENT 005301 0 PERMIT ,.- .-. 3wEffluent Gross ,REQUIREMENT

_ -:_r_" _ 30DAAVG DAILY MX. m_,, Per ...,_ :Iflow, in conduit or thru SAMPLE i,Fo.icodiortrSAPE 0.022 0.023 3 ...... ...... ...... ...... 0 01/01 CNtreatment plant MEASUREMENT 500501 0 PERMIT Req. Mon. Req. Mon. dEffluent Gross REQUIREMENT 30DA AVG DAILY MX ...-SAMPLEMEASUREMENT PER~dltTREQUIREMENT

_SAMPLEMEASUREMENT

-PERMITREQUIREMENT SAMPLEMEASUREMENT PERMITREQu~Mi3ENT-SAMPLEMEASUREMENT PERMITREQUIREMENT

.._"_."_.-.._""

SAMPLEMEASUREMENT PERMIT* REQUIREMENT

.__ ..... ,INAMEnITTLE I ceritiy under penalty of law tha this document andal,, artaidirents were Prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER diection or supeism mn acance with a system designed to assure Ithat qualltled personnel L ODproperty gatner and evalute the informaon submeted.

Based an amy inqus of phe peron or personsBenjamin P. Youman whot manage the system. a those persons directy responsible for gatherng the inonmiaion.

te ,,...L 815 406-3700 07t23e2012 infomation submitted is. to the best of my knowledge and betel. true. accurate.

and conmlete.

I am SIGNA 6E OF P fCIPLEPlant Manager aware tha there are significant penalties for submitting false inlormaton including the posaiblity of EXECUTIVE OF ER OR AREA"MEDO TED fine andimonsionmen lot knowing violations.

AUTHORIZED AGENT CODE NUMBER MMDD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)1. Flow existed through this outtatl 4 of 30 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMfl-EE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenvire, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010OMR Malting ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERE01-0DISCHARGE NUMBERFMONITORING PERIODMM/IDD/YYYY I MM/DD/YYYY STORMWATER (FORMER 001LE)External Outfall* '

• NO DISCHARGE FROMI06/01/2012 I TOI06/30/2012 A'I-N: Zoo Cox/ENV SPECFRE_________UENC___Y_____

ATTN: QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEOF TPPARAMETER OVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESAMPLE ............

...... ...... 50Solids, total suspended MEASUREMENT 0053010 PIERMIT .5 30 mg&. Weekly GRASEffluent Gross REQUIREMENT

__._._. ..30DA AVG DAILY MX ____eky GASolzds, total suspended SAMPLE ............

...... ...... 16.4 17.8 19 0 01/07 GRMEASUREMENT 0053 80 PERMIT ...30 100Other Treatment, Process REQUIREMBT 30PDA AVG PAILY MX rag/L. Weekly GRABC om plete ..._. .. ... ..._ *__"_. .._"_" -__..._._,_"_..___"_'_"

"_i_"Chromium.

hexavalent SAMPLE ...... 500(as Cr) MEASUREMENT 010321 0 PERMIT .D*a* ... .1 mEffluent Gross REQUIREMENT

_ _" _.... 3ODA AV/G. DAILY MX ..... .GRABChromium, total SAMPLE ............

....... 500(as Cr) MEASUREMENT 0103410 PERMIT ....'.... ... 1 2Effluent Gross REQUIREMENT_,,..PA AVG DAILY .,g.I -Dolly GRABCopper, total SAMPLE ......0...... ....... S0o(as Cu) MEASUREMENT 0104210 PERMIT ...m- -- .5 1Effluent Gross REQUIREMENT*_._..

_'_"__ 30DA AVG DAILY W m* Daply GRABIron, total SAMPLE ............

....... 500(as Fe) MEASUREMENT 010451 0 PERMIT..

..,,. .GEffluent Gross REQUIREMENT,

' ._ ____ .._ .DAILY MX mg/L " DtGRLead, total SAMPLE ............

....... 500(as Pb) MEASUREMENT-0105110 PERMIT 1 , " .2 .4Effluent Gross REQUIRENENT I. 30DAAVG DAILY MIX moJL Da, .GRASNAIIE/TITLE I

under penalty of law that this document and al) attadments were prepared undoe my TELEPHONE DATEPUNCWPAL EXECUTIVE OFFICER direti .sevsioi aicordance with a system designed to assure etat fuaiased personlet lATEproperty gather and evalte the information submtted.

Based on my tquuy at the persos or personsBenjamin P. Youman who manage the sysem, or those persons direcey responsbe for gateing the information, the 07/23/2012 infeoation submned is, to the best of my imowedge and b.eief tnue. acwrate.

and conipee.

I am SIGNA 6E OF PRIOPLEPlant Manager aware hat there are signifcant penatties fo. subtting false Information.

including the possalty ol EXECUVE OFFICER OR AREAWEDon iemMn life and ithl)preOnment lfo knowing Viations.

AUTHORIZED AGENT MMIDCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during the month.2. Flow existed through this outfall 1 of 30 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4460 North German Church RoadDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS610101L004"113 PERMIT NUMBERFE01-0DISCHARGE NUMBERMONITORING PERIODMM/DD/YYYY I I MMIDD/YYYY STORMWATER (FORMER 001 E)External Outfall.NODISCHARGE

-oFROMI06/0112012 I TOI06/30/2012 Il IByron, IL 61010QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPENiclel, total SAMPLE(as Ni) MEASUREMENT 5000106710 PERMIT ... .1 2 Dai" GRAMEffluent Gross REQUIREMENT

_ _ _ _, 300A AVG DAILY MWX- DayGRABZinc, total SAMPLE .........

......(as Zn) MEASUREMENT 50_0109210 PERMIT 2. " -3 2Daiy GRABEffluent Gross REQUIREMENT ITODA AVG PA1LY MXFlow, in conduit or thru SAMPLEFoicodiortrSAPE 0.262 *0.262 3 ...... ...... ...... ...... 0 02/30 CNtreatment plant MEASUREMENT 50050 1 0 PERMIT Req. Mon. Req. Mon. MEffluent Gross REQUIREMENT 30DA AVG. DALY M .ga-d ".Twice Per Month CONT-SAMPLEMEASUREMENT

• "PERMITREQUIREMENT SAMPLEMEASUREMENT PERMITREQUIREMENT.

-"'_ " -"SAMPLEMEASUREMENT PERMITREQUIREMENT

-SAMPLEMEASUREMENT PERMITNAMTITLE I cility under panally oa law that this document and all attachmennts were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction or m accordance with a system designed to assure that qualifed personnel property gather and Ovatute the infomtionnak sutMed. Based on my mnqwiy of the peison or peisons 815i1 401 30Benjamin P. Youman who manage the system, or those persons directly responsible for gatherng the iojmalon.

time 815 --- 07/23/2012 intormation submitled IS. to the best of my kunowiedge and belief, tue. accurate.

and complete I amn SIGNVURE OF7RINCIPLE Plant Manager aware that there are significant penaltis tot submitdng talse information, inricdng the possi"t o EXECUTIVE OFFICER OR AREA7tIPD OR PRSOir.a li'n and _ _n __s_ __nt _or Imowing votati__ns.

AUTHORIZED AGENT COD NUMBER MM/DDYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachmenls here)1. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Metal Cleaning wastewater was discharged this month.2. Fire Protection drain water was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/12 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITrEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010IL0048313 PERMIT NUMBER001-0DISCHARGE NUMBERDMR Mailing ZIP CODE: 61010MAJOR(SUBR 01) CSCOOLING SYSTEM BLOWDOWNExternal Ouffall.NO DISCHARGE

• MONITORING PERIODMMIDD/YYYY I I MMOD/YVYYY FROM I06/0112012 I Tot08/30/2012 IATTN: Zoe Cox/ENV SPEC ______________________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO FREQUENCY PARAMETER OF___SAMPO.LE VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPETemperature.

water deg. SAMPLE ............

101.0 15 0 01/01 CNFahrenheit MEASUREMENT 000111 0 ERMr .. ...., ,_ ._ RPq. Lion.Effluent Gross REQUIR EI"Odeg F Daily OONP"pH SAMPLE ............

...... 8.21 ...... 8.66 12 0 01/07 GRMEASUREMENT 0040010 PERMIT6Effluent Gross

." N "I -I ISolids, total suspended SAMPLE ...... ...... ....... 3.3 3.3 19 0 01/30 GRMEASUREMENT 005301 0 PERMIT ,..,, *, Req. Mort. Req. Mon.Effluent Gross R-QUIREMENT,

._.___*____.__

_ _ __.* .DAAV ODNLY MX mg/L GRABOil & Grease SAMPLE ...... ......4 .4 19 0 01/07 RMEASUREMENT

...... ..... <1.4 <14_9___/0_G 0055610 PERMIT ..0 ... .. ",Wey GE ff lu e n t G ro s s _ _ __U _E_ _ _-TD A A V G -"A. .y M X " "_" _' "Chromium, total (as Cr) SAMPLE .........

<0.0021 19 0 01/07 GRMEASUREMENT 01034 10 PERMIT 0.2 W"GAEffluent Gross REQUIREMENT.

--... ....__.-*, " -Copper, total (as Cu) SAMPLE ............

.............

0.011 19 0 01/07 GRMEASUREMENT 010421 0 PERMIT ., .-.. ....,. 0.071 mg/I " Weekly GRABEffluent Gross REQUIREIAENT

• " -"__""*.._ .... .--Zinc, total (as Zn) ..... ...... <0.002 0.0025 19 0 01107 GRMEASUREMENT 010921 0 PEftMrr ,;,** ,..,. ... :213 .433 GRABEffluent Gross REQUIREMENT 3,.......ODA AVG DAILY ingWNMErnTLE I certify under penalty of law that this document and aal ttachments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER drectim or supervision In accordance with a system designed to assure that qualified personnel property gather and evatute tre infomation submritted.

Based an my inquiry at the person or personsBenjamin P. Youman who manage the system, or those persns dvicey responrsbe for gathring the intomnamn.

the 02402312information submitted is. to tre best of my knowtedge and befef, true. accurate, and complete.

an SIGNA RE OF PRVCIPLEPlant Manager aware hat there are significant penalties for submitting lalse infonr.ation.

induding the possituty d EXEC UIVE OFFICER OR UMDYTP R fine and imorisionment for knowing vioations.

AUTHORIZED AGENT CODE NUMBER MM/DDYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Monitoring data for outfall 001-0 is included on attachmenL EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES).DISCHARGE MONITORING REPORT (DMR)PERMI'TEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010A'l-T, ----~t -D.L0OT NO13PERMIT NUMBER001-0DISCHARGE NUMBEROMR Mailing ZIP CODE:MAJOR(SUBR 01) CSCOOUNG SYSTEM BLOWDOWNExternal Ouffall61010MONITORING PERIODI MM/DWYYYY I IMM/DD/YYYY FROM I06/01/2012 I TOI06/3012012 I' *

• NO DISCHARGE

°P QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY RM1E N. OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYS TYPEOxidants, total residual SAMPL .... .... ...... ....MEASUREMENT 003 19 0 0107 GR340 -10 PERMIT ..... ...03404410..

' .PA'LVU mg/. Weekly GRABEffluent Gross RBOuIREMEIT

.___ w R A.SAMPLE ...... ...Pnority pollutants total effluent MEASUREMENT 500500081 0 PERMIT Req. Mon Req. Mon.Effluent Gross R9OUIREMENT

___"_ PDAILY xLmg/L W-,y GRAFlow. in conduit or thru SAMPLEtreatment plant MEASUREMENT 21.09 29.39 3 ............

.............

0 01/01 CN500501 0 PERMIT Req. Mon. Req. Mon *.. .Effluent Gross REQUIREMENT

.DA DAIY .-.-"...i"SAMPLE ...Chlorine, total residual

.AS E N ......500MEASUREMENT50 5006010 PERMIT .... ..,eREffluent Gross REQUIREMENT

._,. .. wee.,.k.X

.GRASHydrazine SAMPLE ............

...... ......MEASUREMENT

_ 5008131310 PERMIT Q27 m.,. ."..011.

..027 aily When GRAEffluent Gross REQUIREMENT

-, ,A., .,, --. ,De_. ,SAMPLEMEASUREMENT PERMITREQUIREMENT .. .., ;, ..SAMPLEMEASUREMENT PERMITREQUIREMENT

'_. -___"._.._..

...__" ._NAMErTITLE I certiy under Il olaw that t ns 0 ;= i aMtademets ere preard un 'myPRINCIPAL EXECUTE OFRCER afrection or supennion in accordance with a system desig to assure that qualbied peisonnel TELEPHONE DATEppetygather and evalute the informaion subirrtted.

Based n my nquiry o0 the person or persons 815 406-3700Benjamin P. Youman who ranage tie system. or those persons directly responsibe fo0 gathenng me itfnmeat~t, e SIGN I.RE OF PINCIPLE 07/23/2012 Plant Manager information submitted is. to the bes of my knowieoge and beLief. iue. accurae, and complete.

I am EXECUTIVE OFACER ORthat there are signiftiant penalties for subinfittg lalse intonnatlon, including tie of NUMBER MMIDD/YYYY TYM m fine and imprisionment for knowing violations.

AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11612' PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITiEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010IL0048313 PERMIT NUMBERf -0 02 DISCHARGE NUMBEROMR Mailing ZIP CODE:MAJOR(SUBR 01) CSSTORMWATER RUNOFF BASINExternal OutfallI

• I NO DISCHARGE

] "61010MONITORING PERIODMM/DDIYYY I MM1DDIyYYYY FROM I06/01/2012 I To!06/30/2012 I* IATTN: Zoe Cox/ENV SPECFREQUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER

______N.

OF SAYPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALSS TYPESAMPLE ............

......Solids. Total Suspended MEASUREMENT 0530 10 PERMIT -,,. -15 39 r;Effluent Gross REQUIREMENT

,, 300A AVG DAILY M X g/I. W RSAMPLE ............

............

Solids. Total Suspended MEASUREMENT 0053080 PERMITOther Treatment, Process " PMI .Weekly 301Complete R.EQUIREMENT

-*. 0DA 4VG DAILY MX f.ttOL Weekly GRASChromium, hexavalent SAMPLE ..........

...... ......(as Cr) MEASUREMENT 010321 0 PERMIT AVG AILYM,..Da.lG.A..011

.016Effluent Gross R=IREMENT

• - 30_.AVG "ILyMX_ (11. DaRy_ GRABChromium, total SAMPLE ............

(as Co) MEASUREMENT 010341o0 PERMIT 2.., *.. ....D 1 2Effluent Gross RE.QUIREMENT.

3.)A. AVG DAILY GRABCopper, total SAMPLE ............

...... ......(as Cu) MEASUREMENT 010421 0 PERMIT " ..,..025 .041Effluent Gross REQUIREMENT "30_,,,__"____*OA AVG DALY MX. maj ., Daly GRABIron, total SAMPLE ...........................

(as Fe) MEASUREMENT 010410 PERMIT ...... mg/L Daily GRAB.Effluent Gross REQUIREMENT DAILY MXLead, total SAMPLE ............

...... ......(as Pb) MEASUREMENT 01051 1 0 PERMIT .........

.. .. ... .063 .298 '1iEffluent Gross REQUIREMENT

.__ _ _ _____ SODA AVG DALY MX n'Lai GRABNAME/TITLE I cartify under penalty df law thai this document and at artachmenms were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction or supervis in accedance wth a system designed to assure t110 qualified personnel property gather and evalue the iofnnason submitted.

Based on my inquiry of the person or persons 15 406-3700Benjamin P. Youman who manage the system, or those persons directy responsible for gathering the infonration, the 07/2312012 infoimaton submitted is. to tIne best of my knowledge and tore, accordle.

and compltea Iam SIGNAJRE OF ItINCIPLE Plant Manager aware that there are significant penalties for submitting false infoaiatian.

Including tie possbulty Cof EXECUTIVE OFFICER OR AREANTYPED O PFrED line and impiianment for knowing vitatains.

AUTHORIZED AGENT CODE NUMBER MM/OD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachmenta here)1. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Metal Cleaning Wastewater was discharged this month.2. No Fire Protection.

Service Water or Closed Cooling System Drain Water was discharged this month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 1/6/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, 1i 60555-5701 FACIULTY Byron Nuctear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATT'N: Zoo Cox/ENV SPECOMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBER002-0DISCHARGE NUMBERF MONITORING PERIODI MM/DD/YYYY I MMIDD/YYYY STORMWATER RUNOFF BASINExternal Outfall""' NO DISCHARGE

[j) ...FROM I06/01/2012 STOI 0602012 IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER VAUVLEX OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX IS TYPENickel, total SAMPLE ............

.........

(as Ni) MEASUREMENT 0106710 PERMIT --.011 .176Effluent Gross .REQUIREMENT

.300AAVG D.ALY MX ,Dai GRABZinc, total SAMPLE ............

......(as Zn) MEASUREMENT 0109210 PERMIT ..... -. .. 047 .21Effluent Gross REQUIREMENT

• _,_"_,,

_ .. .... 30DA AVG. DAILY MX rr19/L "- : .. GRABSAMPLEOil and Grease M ASU LE ...... ...... ...... ......MEASUREMENT 03582 1 0 PERMIT .... ..... ... .... 15 20 When GEffluent Gross REQUIREMENT G __*_ ._.,, 3ODA AVG DAILY MX GRA- DschamiFlow, in conduit or thru SAMPLE ..................

treatment plant MEASUREMENT 500501 0 PERMIT Req: Mon. Req. Monr. MVd -..,, .When EEffluent Gross REQUiREMENT 30A AVG D)AILY MX. ..-.M ._ ,.

• ischArgng SAMPLEMEASUREMENT PERMITREQUIREMENT

..___..__.

SAMPLEMEASUREMENT PERMITREQUIREMENT

__"_"SAMPLEMEASUREMENT PERMITREQUIREMENT

________________

____NAMtEtmrl I certify under penalty of law that this document and all attaolments were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFRCER direction or supervision in aocordance with a system designed to assure that quariied personnel property gater and evalute tie mitoniatim sub mitted. eased on my iquity ot the person or personsBenjamin P. Youman who manage the system. or those persons diractry responsible for gathering the Information.

the O 815 40&3700 0722012informaton submitted is. to the best of my Inoetedge arid betet. true, accurae.

and compite.

I m SIGNA RE OF P CIPLEPlant Manager aware that them are sgniticant penals for submitting latse intormation.

incuding the possibtty ol EXECUTIVE OFFICER OR AREA NUMBERTSPo R PIM line and imprisioniment Ior knowing violations.

AE MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)1. This discharge point was not used this month.2. There was no discharge of processed steam generator chemical cleaning wastewater during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/612012 PAGE 2 ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 June 2012Page 1 of 3MONITORING DATA:D CD Rock RiverDATE Temperature mgd Flowdeg F cfs06/01/2012 85.8 23.50 5,06006/02/2012 86.8 29.39 5,09006/03/2012 93.9 15.58 4,79006/04/2012 93.9 5.58 4,54006/05/2012 87.0 0 4,31006/06/2012 88.2 0.201 4,19006/07/2012 93.0 13.78 3,88006/08/2012 99.6 22.64 3,74006/09/2012 96.4 28.23 3,56006/10/2012 97.0 22.35 3,07006/11/2012 95.5 16.75 2,83006/12/2012 95.3 24.58 2,68006/13/2012 89.4 20.26 2,79006/14/2012 92.1 22.56 2,74006/15/2012 92.1 24.85 2,63006/16/2012 97.0 25.63 2,71006/17/2012 97.0 24.49 2,69006/18/2012 98.7 16.35 2,75006/19/2012 99.6 21.98 2,59006/20/2012 99.1 21.26 2,51006/21/2012 98.4 25.22 2,47006/22/2012 96.2 20.56 2,32006/23/2012 98.4 26.56 2,33006/24/2012 98.4 23.64 2,35006/25/2012 95.1 17.34 2,24006/26/2012 93.3 23.75 2,25006/27/2012 92.3 20.54 2,28006/28/2012 101.0 22.39 2,20006/29/2012 99.5 23.16 2,12006/30/2012 98.7 28.61 2,120K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\June'une 2012 ATTACHO1.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 June 2012Page 2 of 3HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (orassociated rinses) containing hydrazine discharged to the Cooling SystemBlowdown during the month of June 2012.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite and Bromine compounds were used this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 29 of 30 days.4. Per Special Condition 24 the influent from the Rock River and effluentfrom Outfall 001-0 was monitored for Total Suspended Solids (TSS) thismonth. The Rock River TSS value was 34.4 mg/L on 06/11/2012.

TheCWBD TSS value was 3.25 mg/L on 06/11/2012.

5. Rock River flow was <2400 cfs in June 2012 therefore daily temperature calculations were required during that time period. (Special Condition 12).6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in June 2012. (Special Condition 15).K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\June\June 2012 ATTACHI01.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 June 2012Page 3 of 3Per Special Condition 12, in the event the Rock River flow is <2,400 cfs, dailycalculations will be undertaken to demonstrate compliance with the water qualitystandard.

The calculations are based on hourly measurements, averaged over a24-hour calendar day for Rock River flow, main Rock River temperature, CWBlowdown flow, and CW Blowdown temperature values. Results of thecalculations shall be reported in the DMR on a monthly basis.Calculation results are in the following table:Date Average Average Average Average Calculated WaterRock CW M/U CW CW Temperature QualityRiver Temperature Blowdown Blowdown at edge of StandardFlow (F) Flow Temperature mixing zone Temperature (cfs) (gpm) (F) (F) (F)6/22/12 2286 75.6 16060 94.3 76.3 906/23/12 2325 75.2 16076 93.9 75.9 906/24/12 2353 75 16105 95 76 906/25/12 2248 75 15985 92 75.9 906/26/12 2250 73 15883 93 74 906/27/12 2290 74 15942 95 75.2 906/28/12 2210 77 16037 101 77.6 906/29/12 2112 77 16035 96 77.8 906/30/12 2119 76 16083 97 77.3 90K:\BYR_CH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\June\June 2012 ATTACH01.doc Exelkn.Exelon Generation Company.

LIC www.exeloncorp.com NuclearByron Station4450 North German Church RoadByron, IL 61010-9794 August 24, 2012LTR: BYRON 2012-0094 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyWater Pollution ControlCompliance Assurance Section #191021 North Grand Avenue EastP.O. Box 19276Spdngfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring ReportIn accordance with National Pollutant Discharge Elimination System (NPDES) Permit Number110048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report forByron Station, Units 1 and 2. This report covers the period of July 1, 2012 through July 31,2012.On 7/4/2012 and 7/8/2012 the U2 Natural Draft Cooling Tower (NDCT) basin overflowed as aresult of plugging of the outfall screens caused by cooling tower fill pack debris. Operations took immediate corrective actions to lower the level in the flume and basin to stop the overflowcondition.

Additionally maintenance personnel were called in the clean the debris from theoutfall screens.

The cooling tower basin overflow water flowed north in the storm water ditchand entered Woodland Creek via storm water Outfall 003, East Station Area Runoff. Theestimated duration of the first overflow event is 5.2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> at a flow rate of approximately 20gallons per minute resulting in an estimated 6,180 gallons of cooling tower water flowingthrough Outfall 003. Analysis results of a sample of the cooling tower water obtained prior toentrance into the storm water ditch are summarized in the following table:pH Copper (mg/L) Zinc (mg/L) Chromium(mg/L)8.69 0.010 0.016 <0.0021The estimated duration of the second event is 3.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> at a flow rate of approximately 50gallons per minute resulting in an estimated 9,000 gallons of cooling tower water flowingthrough Outfall 003. Analysis results of a sample of the cooling tower water obtained prior toentrance into the storm water ditch are summarized in the following table:pH Copper (mg/L) Zinc (mg/L) Chromium(m800.08.63 0.007 0.008 <0.0021 August 24, 2012Byron Letter 2012-0094 Page 2Byron Station continues to closely monitor NDCT debris fence delta levels and replacement ofcooling tower fill is being planned.

Unit 1 NDCT fill replacement is scheduled to beginSeptember 2012. It is expected that the changes to the tower fill should prevent future toweroverflow events.If there are any questions regarding this report, please contact Ms. Zoe Cox,Environmental/Radwaste Supervisor, at (815) 406-3035.

Respectfully, Ben PoumaPlant ManagerByron Nuclear Generating StationBPY/ZC/eh Attachments bcc: J. Gould -Environmental

-Cantera (electronic)

Z. Cox -Chemistry

-Byron NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERFldTEE NAMEIADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenvil,.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010IL0048313 PERMIT NUMBERIDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IA01-0II DISCHARGE NUMBER IMONITORING PERIODMMIDDJYYYY

_J I MMIDDJYYYY DEMINERALIZER REGENERATE WASTE (001A)External Outfall0." NO DISCHARGE FROMI07/01/2012 I Tol07/31/2012 Il lATTN: Zoe CoxIENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SMLVALUE VALUE UNITS VALUE VALUE VALUE UNS ANALYS TYPES ld .T tlS s e d dSAM PLE ............

..... -<1.1 -0.2 19 0 01/30 08Solids, Total Sseed MEASUREMENT 00530 10 oL. .Effluent Gross , ,

Chromium.

haxavalent SAMPLE Soo......

(as Cr) MEASUREMENT

• 500-' .-4..... 2' '.?<" .=: -" ;r ,=,=Chromium, total SAMPLE ...... 500(as Cr) MEASUREMENT 5000103410 -s'ehrt JttQ~W~t

.-(> H 2 -Effluent Gross x~~~tCopper, total SAMPLE ...... ......(as Cu) MEASUREMENT Soo6-1~ .. atE Gross j _PUM'It:,

-r"" . " v-} ..."".. .29 "'Iron, total MPLIE. ...... ...(as Fe) MEASUREMENT

.......__ "" " 600Effluent Gross , ,_ ;. ..-, ,,r: +i, 0 Lead. Total SAMPLE ..........

(as Pb) MEASUREMENT SIX 50105110 *V'iYflS 5!;5 .,"1"i : ; " -. 3/4, --" .Effluent Gross 1.- n;- 2 ;'%j s v:.Nickel. total SAMPLE .............

(as Ni) MEASUREMENT 50001067 1 0 : -l il ... --. ..... .... ... ....Effluent Gross n7i IJ,. .t- I.- ,. .NMIFTlLE I camfy undr penally of law tam tis document antd al atadmunents were prepared under my TELEPHONE DATEPvmIPAL .XECUiivE OFRCER aection or super4vson In accordance with a system designed to assure tum quaars personnel propeygahel and evalue da.tomation subsmed.

BSwat an my mquiy of te person or peisons-Benjamin P. Youman who manage the system. or tose perssns dracay fr gaftht the infonration.

the 0/24/2012 Infonration sutmitted is.o the best oa my knowledge and beief, true. accurate, and Complete.

laIm SIGNA10E iSPRINCIPLE Plant Manager aware that tmere ae significant penalties for -sumi naIse lsformation.

iondudg tpoe psilyd EXECUTIVE OFFICER OR AREAwq aoA lne arid impAsiemlont tar knowing violatios.

AUTHORIZED AGENT MMODDYYYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed 31 o1 31 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 16/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAMEJADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarnnville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR Mailign ZIP CODE.MAJOR(SUER 01) CS61010IL0048313 PERMIT NUMBERA01-0DISCHARGE NUMBERI MONITORING PERIODI MMJDDIYYYY I MM/DD/VYDEMINERALIZER REGENERATE WASTE (001A)External OutfallI.. .FROMII07101/1270lII ........07/3112012 i* * *NO DISCIIARGEEJ3..

IaI~I NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DUR)PERMIT'EE NAME/ADDRESS NAME ExeloW Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010L0048313PERMIT NUMBERB01-0DISCHARGE NUMBERDMR Mailing ZIP CODE-MAJOR(SUOR 01) CSSTP PLANT EFFLUENT (FORMER 001B)Exteral Outfall* * 'NO DISCHARGE 61010MONITORING PERIODMM/DWfYYY

-MM1DD/YYYY FROMI07/01/2012 I TOI07/31/2012 IPARAMETER I O- IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OF TYPEBO D , 5-Day SAM PLE 79090SI2(20 Deg. C) MEASUREMENT 0.38 0.45 26 .7. 9.0 19 0 W= 240031010 8. a q 4 p~pH SAMPLE .. .... .O...pEASU N7.50T 7.53 12 0 02130 GRMEASUREMENT_____

___________

______ _____00o4oo010 o ' : ; ... ... -..:4. '-:Effluent Gross B --Solids, total suspended SAMPLE0.8.1 MEASUREMENT 008 0.12 26 cl.3 2.4 19 0 02030 240053010 .. .iA -§* -Effluent Gross 'A.Flow, in conduit or thru SAMPLEtreatrent plant MEASUREMENT 0.005 0.009 3 ...... 0 01/01 CN5005010 --. -,,. ---- .... -._ --__ ._ _ __. ..." .Effluent Gross ..."' -'"SAMPLEMEASUREMENT... .. .. .. ., ... ... ,. ... , :. ...:- --... : .. .SAMPLEMEASUREMENT-... ... .......SAMPLEMEASUREMENT NAML Enm.E i ceR C-f under penalty of law t0at thas document and au attaInmeints vwre prepare undet my TELEPHONE DATEP iAL EXECUtiVE OFFICER direction Of suPeAisin in accordance with a system designed to assure tha fied pemonnel TELEPHONE DATEppewy gate and eve einlaittiabon suied. ased onmy Uquiry of the persmn or , 815 406-3700 02s0aBenjamin P. Youan "who manage th system, or those persons diety reansUbS for gathering tme iormati.

the c=-2112irdonation submited is. to the best di my knowiedge and bein,. true. accurate.

and c*mgtte.

eam SIGNATqEOF*INCIPLE 0&24/2012 Plant Manager aware at tere are sincant penaties t1 submitting t21se WConaM. ndudcng the powAi, y ci EXECUTIVE OFFICER OR AREA.m ,ie and bpisinnen for mowing vicilizons.

4________________

iwn out anfomu AUTHORIZED AGENT CODE_ NUMBER MI&DD/YY__

COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Refereme all attachments hem)1. Flow exdsted though this outfall29 of 31 days dunng ft month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/12 PAGE 1 SNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMI7TEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR Mailing ZIP CODE.MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERC01-0DISCHARGE NUMBERI MONITORING PERIODMMIDD/YYY i I UMD YYYYWWTP (FORMER 001C)External Outfall*.. NO DISCHARGE FROMI07/01/2012 I TOI107r31/2012 I-I .lATrN: zoe Cox/ENv SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY AMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESolids, total suspended EAUMLE ..... ...... 4.3 7.2 19 0 02/30 24Effluent GrossChromium.

hexavalent SAMPLE ........

..(as Cr) MEASUREMENT 0103210 *Effluent Gross XChromium, total SAMPLE ... ......(as Cr) MEASUREMENT

....... ..._5000103410Copper, total SAMPLE ..........

..(as Cu) MEASUREMENT EffluentGross

..Iron, total SAMPLE ....S(as Fe) MEASUREMENT Effluent GrossLead, total SAMPLE .. ...(as Pb) MEASUREMENT 01051 IE~I' W-; '" ..' "- -- ..." "* ' .." " ..;Effluent Gross -rf,, ..:;. Nickel. total SAMPLE ............

.(as Ni) MEASUREMENT

.... 500010671 0 AEjgTEffluent Gross W*O- __NAMEITLE I certiay under penalty of law that this document and all attachonmr were prepared under my TELEPHONE DATEPRIPAL EXECUTIVE OF1CiER direction or Supemlon in accordance with a system designed to assure dtoa quaified personnel a tpopedy gather and evyee the formaon submted.

Based on

-ateerson

,. 815 1s406-3700 0Benjamin P. Youman who manage me system, or those persons dircy responsible for gatlheing the infonmsaon.

me 40=4/2012 inaomaton is. to the best of my kroledge and be"et true, accurate, and complete.

I am __GNA___O___R_

_PLEPlant Manager awar t them are siWgma penalties for submittng false information, Inuding the posslift EXECUTIVE OFFICER OR AREA NUMBER MMfDD/YYYY 1nMMORPLOw ne and imprexnad ot ,knowing vicions.

AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed through this outfall 25 of 31 days durng the month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 116r2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMWTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvile.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadIDMR Mailing ZIP CODE.MAJOR(SUBR 01) CS61010S R NIL0048313 PERMIT NUMBERI IC01-0J DISCHARGE NUMBERI [D ISCHARGE NUMB3ER1MONITORING PERIODMMIDD/YYYY I 110YYYYWWTP (FORMER 001C)Extemal Outfall* NO DISCHARGE EJ'FROMI07/01/2012 ITOI07/31/2012 IByron, UL 61010AT TN : Zoe C ox/EN V S PEC FR EQ U EN C YQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPEZinc, total SAMPLE....

.....(as Zn) MEASUREMENT Effluent Gros .s;-GFlow, in conduit or thru SAMPLEtreatment plant MEASUREMENT s005010 '77-',, P .-..M, .. -_. .. ;-- * .Effluent GrossSAMlPLEMEASUREMENT

' A.SAMPLEMEASUREMENT jx.. ,v-1 SAMPLEMEASUREMENT SAPLESMEASUREMENT SAMPLE.MEASUREMENT KAME nlTM.E Icertify under penalty of law duda On documnent and aU s were'lX'eBmor under my TELEPHONE DATEPRINCPAL EXECUTIVE OFCF.R dimaiu or supeamso in accorden, weith a system designed to assure goi Wuaffied pg ofne-prope* gather and evakute th'le Information submitted.

eased an my inquir of the person or Persons ..-J, 85 0-70Benjamin P. Youmnan whto 11a998 the systun, or those persofsdnsif rme sponsiD for 9111116 the Woeat"t, uthe 41 6.L 0700612412012 information sub~mitte is, to the best of my knowledge and belief, true. accurate.

and *ompiete.

I am iGINIAVEIi OP1#RINCIPLE P la nt M ana g e r aw are ta m there a re significant Pe aJ ties for sub fla se in orai on, U ftud f t hle po l of E X E C U T IVE O F FIC E R O R A RE ...a POINTE Pine and imrsomn for knowing violatfions.

I AUTHORIZED AGENT [CODE NUMBER MM/DD/YYYY COMMENTS ANn EXPLANATION OF ANY VIOLATIONIS (Reference all attachments here)EPA Form 332D-1 (Rev 01/06) Previous editions may be used. 1 1/6=12 A%LW NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM {NPDES)DISCHARGE MONITORING REPORT (DUR)11L0048313 DO1-0PERMIT NUMB8ER ý DISCHARGE NUMEI MONITORING PERIODPERMIlrEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60655-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadODMR Mailing ZIP CODE: 61010MAJOR(SUBR 01) CSRADWASTE TREATMENT (FORMER 001 D)External Outfall* **NODISCHARGE l -.-- IFROMI0710112012 ITot0713112012 I------------Il eByron, IL 61010ATrN: Zoe CoxiENV SPEC ____ ________

_________

__________

AQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. SAMPLEPARAMETER EX OF TPVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSISSolids, total suspended MEAMPLENT

.... .4.5 4.5 19 0 02130 CPEffluent Gross "24., m ,,.-. ,z, .....Flow, in conduit or thru SAMPLE........

tre a lm e n t p la n t M E A S U R E M E N T 0 .0 2 3 0 .0 2 3 0Effluent Gross *WTW'r. ,;t. W%. j" ..,7SAMPLEMEASUREMENT SAMPLEMEASUREMENT SAMPLEMEASUREMENT

.77=" 1l81MM, A' M u&nSAMPLEMEASUREMENT 4;' %~ ~dv '?~W~ ~ u~!2A+ *Z-~..- ~3/4yA~~4,~.....

~ NAME/IITLE I ceanty uade pennyt l law that me domnent and at, alacmetmei were pared ucnde my TELEPHONE DATERNCIPAL E.XECUTIVE OFCER direcon r supeivse mn acwodance wdi a system des9ged to surm that qualfed personrnl properly gather and evatke We mfomiatim subnled.

Based an my hnQuiy of Ve person n pereataBenjamin P. Youman who mnage me sysmemy o those Persons ar,,ty rsporae fo gathen te Worman the 0824/2012 Wwito Is. to th be of mhy an 00. true. accrat. an ýý Iam SM=.N R 0 O CL"LEPlant Manager aware do there an sogratam penats fto subitbTag ae bainaatln,m bmdm L Wthe P S EXECUh1JEfqGCER OR AREA" nca. mn fs din and rapusonment tor lontoag violaaom AUTHORIZED AGENT CODE NUMBER MMIDDJYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (RAefOerce all attachments here)1. Flow exdsted through this outfall 10 of 31 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11W2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvile.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010IL0048313 PERMIT NUMBERE01-0DISCHARGE NUMBERDMR Maeling ZIP CODE:MAJOR(SUBR 01) CSSTORUWATER (FORMER 001E)External Outfall***NODISCHARGE j *61010MONITORING PERIODf MWDDIYYY I 11MJDDI113YYYY FROMII07/01I2012 IToI07/31/2D12 I-I !RE Itd £J Or-'1.. _____FRE_______UENCY______

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. F SAMPLEPARAMETER EX TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSISSolids, total suspended SAUMPE ..... 8.1 8.2 19 0 01/07 GRSoids, total suspended MEASUREMENT 0053010 zi"&Other Taatment, Process .A"" ""CompleteChromium, hexavalent SAMPLE ....... ...(as Cr) MEASUREMENT 0103210,'..<..

! .' Chromium, total SAMPLE ...... ......(as Cr) MEASUREMENT 0103410 I' t.1 .-' .. -.,-,- ... ..'"' : ',. :P, "' ,Copper. total SAMPLE ................

(as Cu) MEASUREMENT Effluent Gross F. ..at..... "* : .Iron, total SAMPLE .............

(as Fe) MEASUREMENT_________________

_______ _______________

____Lead. total SAMPE ....... 500(as P1) MEASUREMENTr________"

__________

__-________

......._.___ -________'_______j -Effluent GrossNMEITTE I catr*y under penaty of law that this document and aln attachmanes were prepared under my TELEPHONE DATEPRIACIPAL JECUTMVE OFFICER d&ection or supernstion In accordance with a sytam dasrgned to assure that qutfifd personnel prory gather and evalsa moemon saurmitaed Based on my nquy the Perso or pemns 815 406-370Benjain P. Youman who miu, a te system. or thse piusan diectly r t gathe" me htonnado, te 08/24/2012 Intomation subrmittd

i. to the best ol my imowledg and baele. true. accurate.

aWd complete.

am SIGNAIsuRE OuVtuRCIPLE Plant Manager aware that them are sinifcan penaltes lor tsubtn lawe IWouion.

Incudking Me possily of EXECUTIVE OFFICER OR AREAowan oPn -I rum ad nctlsionmemn lot violaft.

AUTHORIZED AGENT CODE NUMBER___________

COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during the month.2. Flow e)dsted through this outlall 4 of 31 days during the month.EPA a 1 (Rev 01106) Previous editions may be used. A 1/6/2012 ElL -WW NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DUR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenviWle, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010OUR Mailing ZIP CODEOMAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERE01-0DISCHARGE NUMBERIMONITORING PERIODUMIDDIYYYY MMI/YYYSTORMWATER (FORMER 001E)External Outfall***NODISCHARGE FROMI07101=212

-_ITOI07/31/2012 IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER EX OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSISNickel. total SAMPLE ...... ...500(as Nil MEASUREMENT Zinc. total SAMPLE ......S..o.."(as Zn) MEASUREMENT_____

_______________

01092 1 0 A-. , .-* , .. ....--.., -" "Effluent Gross C -.1s --Pft .-gFlow, in conduiLt or thru SAMPLE 0 0 020 CNtreatment plant MEASUREMENT 5005010 V'Pt...~~o.~.

Effluent Gross , .:SAMPLEnMEASUREMENT

• °~ ~ ... .. .. ....A

• c... .........,41( 1L Ak _SAMPLEMEASUREMENT SAMPLEMEASUREMENT

/SAMPLEMEASUREMENT I"n M ngr wr tha there are :.* "infcn pe ..t.e ta ..ub-mitti-g ta ,e ,itor '.ion .trukgte eatt EXEC""UTI'-

-':-.. OR.. A"" R NUMBER .... ... .NAMENTSLANE I CeETy under penaNty VI O aw aO NS (Rfumemrnd ld attachments here p)a InWormy TELEPHONE DATEP iNoIPAL EXECUTWE OFFCER dinctian o

in acroance with a system dwas to dsshre aged quhim personhlpmpely gter andevaue meatw~ nsubmtt.

Be a n y m par o te pemn opesmms , =[ _ 815 4o 700Benjamin P. Yournan who manage me system, or amoe peman dhcty nesparw for gavedo die kdormu. Me 08/24A2012 Vdannto submitte is., to di be d myknwlde an be, tru., ac.,m , an cwnpl. Iam NJ R% 0F P CIP LEPlant Manager aware ghatthere am sodfic= pen,"fmsubmttin tabsn Womeatio.

ftd to posrsyf cl EXECUTIVLOQPCER OR AREAl UBRM/DYYTymopm -I fine and kmrisamnmt tar Wxming vk~ladn.

I AUTHORIZED AGENT CODENUBRM/OYY COMMENTS; AND E:XPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. No Generic Non-Chemical Metal Cleaning wastewater was discharged this month.2. No Frue Protection drain water was discharged this month.3. Turbine Building Fire and Oil Sump wastewater was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/212 PAGE 21121 PG NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAMEIADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWanenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadIOUR Mailing ZIP CODE*MAJOR(SUDR 01) CS61010IIL0048313 I I001-0I PERMIT NUMBERDISCHARGE NUMBERIl ![ MONITORING PERIOD&MM/DD/YYYY

-j I MMIDW/YVYY COOLING SYSTEM BLOWDOWNExtemai Outfafl* NO DISCHARGE FROM I 07/01/2012 07/31/2012 IByron, IL 61010ATTlN: Zoe Cox/ENV SPEC ______________

___________________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OF TYPETemperature, waterdg SAMPLE ...... 103.0 0 01/01 CNFahrenheit MEASUREMENT 0001110-

&c -.<% t,-s* *W4l-Effluent Gross pHAMPLE ...... 828 8.73 12 0 01/07 GRpH ~ MEASUREMENT Effluent Gross -~ 9 * .' tSAMPLE ..... 3.0 3.0 19 0 01/30 GRSolids. total suspede MEASUREMENT 0053810 Prj1j11 LA, -.~6"4~ 4PQWflz i .~'Effluent Gross A MgaafiSOil & Grease cAA -..4 19 0 01107 GR00&GaeMEASUREMENT 0*1 -10Chromium, Gtaro (as Cr) MEASUREMENT

-'tV.-ry,,'-:, '"° .-, " *,', ". ';Capper, total (as Cu) A E0021 19 0 0107 OREffluent Gross MIn: 1r i iL U h h:iCope, total (as Cu) SAMPLE ...... .......002 9 a 0WGZinc.Mtotal (as.Zn)SA

<0.0027 0.0042 19 0 01/07 GREffluent Gross 0 4t1! tNME/llTLE I cerly under enafty al law Wm it document and all atachMars were PreParea under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER dfrec or supenuswn in accordance wuh a System designed to assure da quarlied personnel papofny agerand evatue ve Innmmam ubite. B ae onmyinquiryof te pason Wpersons T" bk 815 4:0r-3700 N 21Benjamin P. Youman who manage de system, or mose persmn dlmc responaAe (or gadin eng die hdml. die2201Infomnatin

&e&nMed is. to the bess of my WicAesege an be[, inue, accura andi complee.

Im en GNAt-J RINCIPLEPlant Manager aware di tdniem am sivfca penales for summlig lalse binttlii hcktt idu ft e pstity 0 EXECUTIVE OFFICER OR NUMBER MM3DD/YYYY WDn 9 f bn and hntfme fr OMn v AUTHORIZED AGENT CooDCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Monitoring data for outfall 001-0 is Included on attachment EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1"/201= 1PAE 1SS 0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)IL0048313 001-0PERMIT NUMBER DISCHARGE NUMBERMONITORING PERIODMWIDIYYY I I MWIDIYVYYY PERMITrEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winetld RoadWarrenville.

IL 60555-5701 FACIUTY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010ATTN: Cnx/FMU RPI=rWMR Mailing ZIP CODE. 61010MAJOR(SuIBR 01) CSCOOLING SYSTEM SLOWDOWNExtaenal Outllt***NO DISCHARGE FROM L07101/2012 I TOI07/31/2012 IQUANTITY OR LOADING QUANTITY OR CONCENTRATION No. OF AMLPARAMEER OF SAMPLERMETER VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPEOxidants.

total residual SAMPLE0.04 19 0 07 GRMEASUREMENT Effluent Gross ,. .- lPdouity pollutants total effluent SAMPLEMENT...

MEASUREMENT

""SIX0Effluent Gross a. m -.. .. ._ _ "ltl :!Flow, in conduit or thMm SAMPLEtreatment plant MEASUREMENT 20.99 2827 3 0 01101 CNE ffluent G ross & 4e.--.'T-Chiaorti.

total residual SAMPLE ...........

MEASUREMENT SIX81 1 1 --, * ....-.. .. .. ... ..... ..Effluent Gross 9 .... a U .'Hydrazine SAMPLE .........

MEASUREMENT 500SAMPLMEASUREMENT SAMPLEMEASUREMENT PR"CUAL E.MC OFRCER rifectmin or superein i accordance wfm a systemn desow to assure oiawaec pann TELEPHONE DATEBenjain P yo gan 91018 and evafija the Womntciazg subaienld.

Based an mvy mcpfty ofte person at peansa, ~Ck 815 406-3700Benjamin P. Youman wo manage me system, or mose perons directly responsaft for gawtlg me "iatlm me S AA0&24/M012 Plonmt Min g s1 i la t Wl is. to he best do c oy kno wad e and b "e .m.. acon t , and co roete. Ia m EXEA I! , E O FaICmEPlant Manager ausare that th are sinkn penatbe for absbglahz aa ifmtumao Incmeg me pcaauizy o EXJECUTVE OFFICER OR AFao mnr , .AUThO:RIE AGENT Cfet NUMBER MMIDD/YYYY TWO UM fine and

• anan tafr knwyviolations.

________________

AGENT_____CODE__

COMMENTS AND EXPLAATION OF ANY VIOLATIONS (Reference a attachments hem)EPA F6oM 3320-1 (Rev 01106) Previous editions may be used. 1111=12 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvilie, L 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadI I L0048313PERMIT NUMBER002-0DISCHARGE NUMBERDMR Mailing ZIP CODE:MAJOR(SUlR 01) CSSTORMWATER RUNOFF BASINExternal Outtell"NO DISCHARGEE J61010MONITORING PERIODMM/DD/YYYY I I MMIDDWYYYY

! II Il .....FROM I07/0112012 IToI07/31/2012 Ij IByron. IL 61010ATTN: Zoo Cox]ENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SAMPLE,, VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANA TYPESAMPLE .........

... .......Solds ToaiS~sened MEASUREMENT____

_______ __________

Effluent Gross ASolids. Total Suspended MSASUEMPLEN 003Other Treatment8 Process :.!III :" ...... ... .,, ..:" .. ..Comolete it AM~ k '.<:~ 'i-Chromium, hexavalent SAMPLE ......(as Cr) MEASUREMENT Effluent Gross

" ... .Chromium, total SAMPLE ................

(as Cr) MEASUREMENT 0103410 :' W _ ..2 ;::Effluent Gross RIM ..________.,_

--_ "Copper. total SAMPLE ............

...(as Cu) MEASUREMENT Iron. total SAMPLE ..... ......(as Fe) MEASUREMENT 010 51"0Effluent Gross L .,. -.:. ,_._....

,7.5. .-Lad., total SAMPLE ...... ...(as Pb) MEASUREMENT

"________

" __"""_*_

.r_*_._.

_ _ ..... -.__--.._,_..

..__I M.LE .E OFU I cany Uinder penalty of law that tah document and ao attachuents were prepared under my DATEPdiNCtPAL EUTIVE OFFIC tiR on or supe-rsi in accordance with a system desiogad to assure that qualifind persinnet TELEPHONE DATEBenjain P.Yournn wprpely gather anld evelute the intomnatio submte. Sasen my incluiry of the person or persons_0

_4V30Benjamiwn P. Youman etto manage systenm.

or thae Persons directv reapolse for gathenng the Inomionme..

the 0824/2012 m oam atim sutbn ited Is. to the best d my nW oote dge a r , i glae. .sc u m s. and compete.

IJam SIG XA .LR F LE 'FPlant Manager awanrieat nther are signiricant penaties for suMittng labse bonnaon, bicuding te possaiby of EXE~CJTIVE OFI OR AR MYandD anmonet 1wOM NUMBERg violatins

__sw roe and! buusnunt for blow ng AUTHORIZED AGENT CODo NUMBERM _ ____ ____COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)1. No Turbine Building Fire and Oil Sump or Genetic Non-Chemical Metal Cleaning Wastewater was discharged this month.2. No Fire Protection, Service Water or Closed Cooling System Drain Water was discharged this month.EPA Form201 (Rev 01/06) Previous editions may be used. 11612012WiL -

00NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)OUR Mailing ZIP CODEtMAJOR61010PEMITT`EE NAMEADDRESS NAME Eaton Generation Co., LLCADDRESS 4300 Winfield RoadWarenvi,,

06055-5701 FACUIY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, L 610101Ar=Ka* 7,.P eCUccr-IL0048313 PERMIT NUMBER002-0DISCHARGE NUMBER(SUBR 01)CSMONITORING PERIODMM/D"/YYYY I MMIDYYYYSTORMWATER RUNOFF BASINtal Outfall* *NO DISCHARGE MFROM I07/01/2012 I TOl07/31/2012 Il lQUANTrIY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARMETER

..OF TPVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPENickel, total SAMPLE ............

(as N) MEASUREMENT Effluent Gross Sig = 4--ý. ..Zinc, total SAMPLE , .,(as Zn) MEASUREMENT 0109210 ,. -jr ... -.Effluent Gross , .; , , ,. ..,. .-Oil aGeasSAMPLE Oil andGreaseMEASUREMENT

____ ____ ____ ____035 2 1 ........ ..Flow, in conduit or thru SAPL ...... --tetetpatMEASUREMENT

____________________________

____ ___Effluent GrossRowm cndui

.........

MEASUREMENT SAMPLEMEASUREMENT SAMPLEMEASUREMENTNMEM I caddy under penalty ol law at thUs documen and al atucnants were prepared undeo my TELEPHONE DATEPRWNAM EXECTNE or supenhi I with a system designed assure dMt quafied!

personnel preped gather and evabia tea bdnfonatimgsubmitted Basd an my bquury ofMe person or persons ~ ja gy ,062/2Benjamin P. Youman wo maonage th system or those pemons dncoy respwisae for gamefg the Itmnatan.

the 0W24/2P12

mfonato submittd is. to the best of rny kiowleOe and betel. hue, &=crfand omplete.

Iar SIGN= OFZ CIPzz=Plant Manager aware gs tere ar sipfcant penaltes fo SLt'rmo false Ifonaran.

Induftg te M W Y EXECYEO YYORnoRM pns and Ca b AUThORIZED AGENT COO NUMBE MMIDD/VYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hav)1. This discharge point was not used this month.2. There was no discharge o processed steam generator chemical cleaning wastewater during the month.EPA Form 3320-1 (Rev 011M) Previous editions may be used. 116012 PAGE 2 ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 July 2012Page 1 of 3MONITORING DATA:CWBD Rock RIverDATE Temperature CW gd Flowdeg F cfs07/01/2012 99.0 22.04 2,13007/02/2012 101.0 18.63 2,12007/03/2012 101.0 24.02 2,08007/04/2012 102.0 17.52 2,04007/05/2012 102.0 20.72 1,99007/06/2012 102.0 19.99 1,88007/07/2012 102.0 24.39 2,01007/08/2012 101.0 14.60 1,92007/09/2012 96.0 12.80 1,79007/10/2012 95.8 18.91 1,77007/11/2012 97.0 18.21 1,80007/12/2012 96.4 17.75 1,78007/13/2012 98.0 23.14 1,77007/14/2012 97.7 25.89 1,76007/15/2012 99.4 22.63 1,85007/16/2012 101.0 15.86 1,75007/17/2012 102.0 25.27 1,78007/18/2012 102.0 19_.07 1,73007/19/2012 100.0 22.15 1,98007/20/2012 100.0 21.85 2,01007/21/2012 95.0 27.78 1,99007/2212012 99.6 25.38 1,92007/23/2012 101.0 15.15 1,84007/24/2012 103.0 21.70 2,06007/25/2012 102.0 22.94 2,07007/26/2012 102.0 21.17 2,00007/27/2012 97.6 20.88 1,93007/28/2012 96.3 29.27 1,94007/29/2012 98.0 21.98 1,95007/30/2012 98.0 15.87 1,94007/31/2012 101.0 23.01 1,9500K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012 Reports\July\July 2012 ATTACHO1.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 July 2012Page 2 of 3HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (or associated rinses) containing hydrazine discharged to the Cooling System Blowdownduring the month of July 2012.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite and Bromine compounds were used this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 31 of 31 days.4. Per Special Condition 24 the influent from the Rock River and effluent fromOutfall 001-0 was monitored for Total Suspended Solids (TSS) this month.The Rock River TSS value was 29.2 mg/L on 07/09/2012.

The CWBD TSSvalue was 3.00 mg/L on 07/09/2012.

5. Rock River flow was <2400 cfs in July 2012 therefore daily temperature calculations were required during this time period. (Special Condition 12).Per Special Condition 12, in the event the Rock River flow is <2,400 cfs,daily calculations will be undertaken to demonstrate compliance with thewater quality standard.

The calculations are based on hourlymeasurements, averaged over a 24-hour calendar day for Rock River flow,main Rock River temperature, CW Blowdown flow, and CW Blowdowntemperature values. Results of the calculations shall be reported in theDMR on a monthly basis. Calculation results are in the table on thefollowing page.6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in July 2012. (Special Condition 15).K:\BYR_CH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012 Reports\July\July 2012 ATTACHO1.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 July 2012Page 3 of 3Date Average Average Average Average Calculated Water Quality-Rock CW M/U CW CW Temperature StandardRiver Temperature Blowdown Blowdown at edge of Temperature Flow (F) Flow Temperature mixing zone (F)WcS) (gpm) (F) (F)7/01/12 2,123 78 15,830 98 79 907/02/12 2,124 80 16,221 100 80 907/03/12 2,088 81 16,208 99 82 907/04/12 2,040 81 14,777 101 82 907/05/12 1,999 82 12,686 102 83 907/06/12 1,875 84 13,113 102 85 907/07/12 1,987 84 12,675 102 85 907/08/12 1,938 83 12,059 96 83 907/09/12 1,807 81 12,293 97 82 907/10/12 1,770 78 13,375 96 79 907/11/12 1,802 77 13,411 97 78 907/12/12 1,781 78 14,590 98 79 907/13/12 1,775 78 15,685 99 80 907/14/12 1,752 77 15,525 99 79 907/15/12 1,850 80 15,433 101 81 907/16/12 1 758 83 15,565 101 84 907/17/12 1,774 84 15,449 102 85 907/18/12 1,731 85 15,736 101 86 907/19/12 1,964 83 15,658 97 84 907/20/12 2,010 80 15,688 95 81 907/21/12 1,995 81 15,828 96 82 907/22/12 1,927 80 15,778 98 80 907/23/12 1,835 79 15,749 100 80 907/24/12 2,050 79 15,805 100 80 907/25/12 2,082 79 15,676 99 79 907/26/12 2,003 78 15,550 98 79 907/27/12 1,940 78 15,500 96 78 907/28/12 1 941 77 15,390 95 77 907/29/12 1,998 76 15,493 95 77 907/30/12 1,945 76 15,386 98 77 907/31/12 1,952 78 15,499 99 79 900K:\BYR_CHXBYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012 ReportsJulyUuly 2012 ATTACHO1.doc Exelkn,.Exelon Generation

Company, LLC www.exeloncorp.co0,,.

NuclearByron Station4450 North German Church Road.Byron, IL 61010-9794 September 25, 2012LTR: BYRON 2012-0106 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyWater Pollution ControlCompliance Assurance Section #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring ReportIn accordance with National Pollutant Discharge Elimination System (NPDES) Permit Number1L0048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report forByron Station, Units 1 and 2. This report covers the period of August 1, 2012 through August31,2012.On 8/9/2012 the U2 Natural Draft Cooling Tower (NDCT) basin overflowed as a result ofplugging of the outfall screens caused by cooling tower fill pack debris. Operations took* immediate corrective actions to lower the level in the flume and basin to stop the overflowcondition.

Additionally maintenance personnel were called in to the clean the debris from theoutfall screens.

The cooling tower basin overflow water flowed north in the storm water ditchand entered Woodland Creek via storm water Outfall 003, East Station Area Runoff. Theestimated duration of the overflow event is 63 minutes at a flow rate of approximately 0.13gallons per minute resulting in an estimated 8.3 gallons of cooling tower water flowing throughOutfall 003. Analysis results of a sample of the cooling tower water obtained prior to entranceinto the storm water ditch are summarized in the following table:pH Copper (mg/L) Zinc (mg/L) Chromium(mg/L)8.39 0.014 0.044 0.004On 8/30/2012, cooling tower water was seen coming out of the storm drain pipe located next tothe U2 NDCT. The water had pooled on the ground and run underneath the barrier erectedaround the storm drain pipe to prevent this from happening.

Maintenance personnel adjustedthe catch containment devices for the temporary Mechanical Draft Cooling Towers which werethe source of the pooling water. This stopped the flow of water entering the storm drain pipe.After walking down the area it was determined the water had pooled at the storm drain pipe exitand had not entered the drainage ditch nor exited via Outfall 003. The estimated duration of thisevent is approximately 2.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> at a flow rate of approximately 0.5 to 1.0 gallons per hourresulting in an estimated 2 gallons of cooling tower water entering the storm drain pipe.Analysis results of a sample of the cooling tower water obtained prior to entrance into the stormdrain pipe are summarized in the following table:Copper (mg/L) Zinc (mg/L) Chromium0 (mg/L)0.029 <0.0020 <0.0021 September 25, 2012Byron Letter 2012-0106 Page 2Byron Station continues to closely monitor NDCT debris fence delta levels and replacement ofcooling tower fill is being planned.

Unit I NDCT fill replacement has started as of September 2012. It is expected that the changes to the tower fill should prevent future tower overflowevents.If there are any questions regarding this report, please contact Ms. Zoe Cox,Environmental/Radwaste Supervisor, at (815) 406-3035.

Respectfully, Benjamin P. YoumanPlant ManagerByron Nuclear Generating StationBPY/ZC/eh Attachments bcc: J. Gould -Environmental

-Cantera (electronic)

Z. Cox -Chemistry

-Byron NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMrl-EE NAMFIADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010ATTN: Zoe Cox/ENV SPECDMR MaIlIng ZIP CODE.MAJOR(SUBR 01) CS61010I IL0048313 It A01-0DISCHARGE NUMBERI PERMIT NUMBERqi BDEMINERALIZER REGENERATE WASTE (001A)I External OutfallIMONITORING PERIODi MOIDDJVYY I TOMMIDD/YYYY 1FROMI08101/2012 08/31/2012

• *

• NO DISCHARGE E ...PARAMETER QUANTITY OR LOADINGVALUEVALUEUNITSVALUESolids, Total Suspended MEAMUREENT

..0053010 PERMIT-Effluent Gross REQUIREMENT.

_ _, "_.* ..Chromium, hexavalent SAMPLE ...(as Cr) MEASUREMENT 010321 0 PERMIT ..,.Effluent Gross REQUIREMENT

, .Chromium.

total SAMPLE ... ...(as Cr) MEASUREMENT 0103410 -PERMIT-Effluent Gross RIEQIWREMENT

_ ... .. --Copper, total SAMPLE ...... ......(as Cu) MEASUREMENT 0104210 .. PERMIT .-.**.. ..,Effluent Gross REQUIREMENT I_..... ..-Iron. total(as Fe)010451 0Effluent GrossSAMPLEMEASUREMENT

.-PERMIT,REQUIREMENT

• ": :....., ...Lead. Total SAMPLE ...... ......- ..(as Pb) MEASUREMENT 5000105110 PERMIT " -..2 .4Effluent Gross REQUIREMENT 3AVG DALY"MX* _ *4, *3D AG D L M ..1NICkel, total(as Ni)0106710Emfuent GnrosOAMPLEMEASUREMENT

,e-. -. -_ ... --.,.. ... ... ...... .. -.-.I ... ,r~ain -*."i ."eeeemm.........

....... .... ... _ _ _ _ _ "" " ." "1" ....... ... ...iW ARIEn T TLE I certify un de pena lt dl law duda h is docum e nt an d al attac h mn t we rem p repare un de m y T E L E P H O N E D A TEP__ _ ___AL EXECUTIVE OFRCER diretio of supervio in a=oft= wit a system designed to assure that quakted personnel properly gather and evalute site ubmittted.

Balsed at my inquiry of the persa or persons 815 406-3700Benjamin P. Youmnan who manage the system. o those persons directly respaltbla for gathering the bttomatxe.

the 09/25/2012 Infomation submed is. to the best d1 my knowledge and befef. true. acjrate, and contelete.

,am, SIGNAV E OF PR IPLEPlant Manager aware hat here are significant pensitles fo submitting tslse kitnfoaI, inducing the of EXECUTIVE OFFICR OR AREA NUMBER MM/DDIYYYY o_ N b n Ie and impilsionmner for knowing violations.

AUTHORIZED AGENT CODE N B__COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments heme)1. There was no discharge of processed steam generator chemical cleaning wastewater during fths month.2. Row existed 31 of 31 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116,2012 PAGE 1S NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010DMR Mailing ZIP CODE:MAJOR(SUOR 01) CS61010IL0048313 PERMIT NUMBERA01-0DISCHARGE NUMBERMONITORING PERIODMMJDDJYYYY MM(DDIYYYY DEMINERALZER REGENERATE WASTE (001A)External Outfall"**NO DISCHARGE

[ ...FROMI08/01/2012 TOIl08/31/2012 II IIl IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREOUENCY SAMPLEPARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSISZinc. Total SAMPLE .. 500(as Zn) MEASUREMENT I____0109210 puur -12. 'Effluent Gross REQUIREMENT

.00 V DAILY LIX GFlow, in conduit or thru SAMPLEtreatment plant MEASUREMENT 500501 0 PERMIT'.-'

Req. Mon., *" -. -Effluent Gross REQUIREMENT 30DA AVG DAILY MX * -D* ; ...tTSAMPLEMEASUREMENT PIBRMW .............

..-.... I" ". "...-"...:.:

.".** ., ..'.-....-

'." .." .,-.',./':,-..1.-.....-"

REQUIREMENT

._ __"__'_ _"_....SAMPLEMEASUREMENT PERMIREQUIREMENT

... ." --SAMPLEMEASUREMENT PERMIT -... .: ...,7' .-, .". .. ., ii ...-.-- .^ ,. .. ..,- -* i .. °': .: ...* ..... ...REQUIREMENT

......._._"_* _ ' .I'"___..

.SAMPLEMEASUREMENT PERMTREQUIREMENT

___SAMPLEMEASUREMENT REQUIREMENT

_ _ _ _"_- " -" --NAMF..TLE I certify inder penafty d taw thal fts docmment and all attadnients wmer prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER

• aon W SupemWM In ac=orance with a syWtm designed to mWuM that quafifed per-onnsprapert gather and evakie the inonii sutieni Based an my inqufy of Me peisan or persons 854-30Benjamin P. Younan who manage the system. or thw persora dcrectly responsilits for gathering the Ifonnatcn, the /212infonnarm rnsutirnied is. to the best df my Imowledge and belef, trie. acc,-ate.

and cornpelte.

i en OF PR CIPLEPlant Manager aware that here are sencant penalties ublnit, fablseowmalnm bmcbng te posshfy EXECUTIVE OFFICER OR ARUATY*PE OR rH E 0nd P D iolatonsw AUTHORIZED AGENT COD MM/DD/YYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reftrence all attachments here)1. Flows for August 2012 are estimated based on July 2012 values due to totalizers being Out of Service in August The totalizers are an obsolete model and work orders are in place to findreplacement totalizers and get them installed in the system.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 11A12012 PAGE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Wintfild RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERB01-0I DISCHARGE NUMBERI MONITORING PERIODI MMIDDIYYYY I I MMIDDJYYYY STP PLANT EFFLUENT (FORMER 001B)External Outfall-"" NO DISCHARGE C]"I _ .I! ._FROMIl08/01/2012 ITOI08/3112012 II I!Byron, IL 61010ATTN: Zoo Cox/ENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX A Y TYPE>< ANALYSISBOD, 5-Day SAMPLE(20 Deg CAME 0.38 0.40 26 6.5 7.0 19 0 02/30 24(20 Deg. C) MEASUREMENT E l n G N .O A.. f,: > .-DA AV G.- flAY X l. , -e ..... C.t .P24.:' ....-. --0 'pHSAMPLE 7.41 7.61 12 0 02/30 GRMEASUREMENT 0040010 -PERMIT' 7 ~ 7~- rrV -SEffluent Gross REQUIREMEN

...- ~ ~ MINIMI.M4' ---.MA______

-. _____Solids. total suspended MEASUREMENT 0.063 0.080 26 <0.78 1.2 19 0 02130 240053010 ~ PERMIT:.

soT 77ki~ ..~ -.'.-. IEffluent Gross REQUIREMENT

-"DA AVG. ,'"' AVG 301/2LY:MX C -Flow, in conduit or thru SAMPLEtreatment plant MEASUREMENT 5005010 .... " p , .' e- o.n.' " Req..Mo.rr.,

7. , ' " " '. .. .. -' -..--:Effluent Gross REQUIREM.T

.301A AVG -DAILY MXM.:g-/..

." '. -- .. -+ .. .. .t ° .,CSAMPLEMEASUREMENT PERMITSAMPLE- --,SAMPLEMEASUREMENT

• PER1M1NT 777... -" '77 7'-'SAMPLEMEASUREMENT NAMElTTLE I ceitly under penalty of law that tsie document and all atlacdunants were prepared under my TELEPHONE DATE EXECUTIVE OFFCER diectin or supesviei in acomdance with a system designed to assure pemownnproperly gather and evadute the Wlnonnaion submitted. Qulymo the per= or pereons , U(:,,,, 815 406-3700Benjamin P. Youmnan wrto manage the system, or amse pesais diec* responsUbe lot gathietig Ste ndonmatia.

tMe 0925012bnomain suteittd I. to the best of my knowledge and beliel. true. accurate, and complete.

I am SIGNATURE OF IICUPLEPlant Manager aware that them am signfcard penallie for subimittIng labsa infonnation, ft of EXECUTIVE OFFICER OR AREATWINEnPe raeand biroeiment norn knoi ong violatlWI AUTHORIZED AGENT CODE NUMBER MM/DD/_YY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hers)1. Flow existed through thi outtai 29 of 31 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. I1A/2012 PAGE 10 SPERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 610100NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)IL0048313 I PERMIT NUMBERC011-0DISCHARGE NUMBERMONITORING PERIODMM/DDIYYYY I I MM/DWIYYYY DMR Mailing ZIP CODE:MAJOR(SUBR 01) CSWWTP (FORMER W1iC)External Outfall* *

• NO DISCHARGE j *J61010-- ---- 4I IFROMI06/01/2012 I TOI08/31/2012 IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESoids.totalsuspended SAMPLE 5.5 7.1 19 0 02/30 24MEASUREMENT Effluent Gross REQUIREMENT

-0DA AVG DAILY MX.Twice1,er.Month.C-IX#A

Chromium, hexavalent SAMPLE 500(as Cr) MEASUREMENT So-0103210 PR -*... .,,..'Effluent Gross REQUIREMENT DDALY MX mgI -,--DaAly:..;.

RChromium.

total SAMPLE A AV....(as Cr) MEASUREMENT

...... 5000103410 PERMIT" -." -1 2 -.Effluent Gross REQUIREMENT:-_._:.__.

30DAAVG DAILY MXCopper, total SAMPLE ......(as Cu) MEASUREMENT Soo0104210 .-PERMIT' 1 -.Effluent Gross REQUIREMENT G -..- "OD A.:AL ."Da, ,RABIron, total SAMPLE 5(as Fe) MEASUREMENT So-0104510 PERMIT , --'Effluent Gross REQUIREMENT

-__ _ _ _ " .." _. " _"'__ .._ ._."_:_OD LY MX "m11. Daily. GRABLead, total SAMPLE(as Pb) MEASUREMENT 5000105110 PERMIT A.. --.2 AEffluent Gross REQUIREMENT 3"DA .-.SOA AVG DAILY MX mgDL .* GRAB "Nickel. total SAMPLE ...... ..........

..500(as Ni) MEASUREMENT 5000106710 PE.' .... 1 2Effluent Gross REQUIREMENT

-_"_ " "_ 3DA AVG DAILY MX mG.ABNAMEITTLE I ceu* under penany d taw that this documen and ,an attachments were pepard undw my TELEPHONE DATEPRNPAL M CUV OFFICER o :luimcn or supemin In accmdance with a system designed to assure tiat claffied pemTnENdProperty gathe and evalue the aocn subirrtted Baised on my hlquu of the persa or joeirons 1 40 -70= 5 2Benjamin P. Youman who 8ma1ge te syste5rs 09/25/2012 bntonnation submitted Is. to the best at my Wwolidge and belfel, tree. accurate.

and -plete. lam SIGNAYURE O1RINCIPLE Plant Manager aware that tere are significant penas for submitting false iomuatlon, twe posstiy of EXECUTIVE OFFICER OR N EMATV LM OR nEn Ie and IMonmen lor knowing violins.

AUTHORIZED AGENT COD N MMDDYYYYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hers)1. Them was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow exdsted through this outfall 15 of 31 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvile, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010iL0048313 PERMIT NUMBERC01-0DISCHARGE NUMBERDMR Mailing ZIP CODE:MAJOR(SUER 01) CSWWTP (FORMER 001C)External Outfall* NO DISCHARGE M "61010MONITORING PERIODMMIDDIYYYY MM IDDYYYYFROMI08/01/2012 iTo08/31/2012 AI-rN: Zoe CoxIENV SPEC ____________________

___________________

A QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEAPAAMETER OF SMLVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OF TYPEZinc, total SAMPLE ........

........

500(as Zn) MEASUREMENT 0109210 % PERM1IT 7 1 .2 " G.Effluent Gross REQUIREMENT

".. ... .30tA AVG DAILYMX ._ ..___Flow, in conduit or thru SAMPLEFo.IcodiortuSAPE 0.0,18 0.025 3 ...........

0 01/01 CNtreatment plant MEASUREMENT 0.018 02 0 01C500501 0 -ERMAIT .- Req. M0.1 -.T."7 ?T ., " -" *?'0 ." --Elfluent Gross REQUIREMENT

-:30AAVG

.. DALY MX ,.. ... ... ." ". -SAMPLEMEASUREMENT

• PIERMIT-

.,_.,,._.

.,,"_',.._.

.,.REQUIREMENT_

_ __ _ _-_"SAMPLEMEASUREMENT

• PERMIT -77 77 777 .7ý. .-- .7`7 ---I- -7.TREQUIREMEI, T .... f. .-* , -., "..SAMPLEMEASUREMENT

-PERMIT-.

77- ---s72-~~-~-

,9-REQUIREMENT

.. .-SAMPLEMEASUREMENT_______________________

PERMIT________________REQUIREMENT_____

________________________

SAMPLEMEASUREMENT

_ 7*PERMIT':

77__ _ _ _ _ _ _ _ REQUIREMENT"ER T ..'- .. : " ,." .. *-.,...-

.-, .. .. ........ " ." ...._ _ .__ ___..___"1"__

__-__ _z _____1____:.,:

' " .. " __"_. ___... ...'1. .... ":. f.. '/ 7 T 7 .. ... ..NAMEjnTLE I cetilly under penalty of law thai toe document and at attachment were prepard under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direction o supaeWs in accordance with a system designed to assure tat quaifiod personnel NIppety gather and evate the Information submitted Basd an y Inquiry of the person or persons 15 406-3700Benjamin P. Youman who manage the system. or those persons directly, responsih for galierog the Information.

ths, 09/25/2012 ibormation suWnittod Is. to the beat of my knowledge and baitl. true, accJrate, and compiete.

Iam SIGNAj*E OF P",NCIPELE Plant Manager aware that there are ndicare penalties for submittng tabs Information.

bibding the possibl of EXECUTIVE OFFICER OR AREATYPED ORt P101CFo annd imprsionment for knowing violations.

AUTHORIZED AGENT ]COD NUMBERI MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1112012 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMrTTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvite, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoe Cox/ENV SPECDMR Mailing 23P CODE:MAJOR(SUOR 01) CS61010IL0048313 PERMIT NUMBERDI01-0DISCHARGE NUMBERMONITORING PERIODI MMIDDIYYYY I I MMIDOIYYYYY RADWASTE TREATMENT (FORMER 0010)External OutfallI * *NO DISCHARGE ED ...FROMI08101/2012 08&31/2012 Il ll lQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEQUATIYARMONCNTATONOF VALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPESolids, total suspended

............

...... 0.9 1.3 19 0 02130 CPMEASUREMENT 0053010 PERMIT I' .-T.viePerMort COMPO1Effluent Gross REQUIREMENT

" , " ' 300AAVG DAILY MX" .T c P M C..P. SFlow, in conduit or thru SAMPLEtreatment plant MEASUREMENT 5005010 .P.UW Req. Mon.' .... -7ReMo "7 " -.- ..Effluent Gross REQUIREMENT 30DA AVG DALY MX Daid "y "a CONTINSAMPLEMEASUREMENT_____

PERMIT 7 --7. ". .7_______ ~REQUIREMENT

_ _ _ _SAMPLEMEASUREMENT PERMIT! 7 -. 7-7. ",.. ....._______________REQUIREMENT_____

_______________

MEASUREMENT_____

REQUIRMlENT

_ _ _ _ _ _ _ _SAMPLEMEASUREMENT Pl- -- '-"- -.' -:-.. -,..-*.. -.:: .: .*" .-..-..i__._-..__.__i._i REQUIREMEN."

""" ____SAMPLEM EASU REM ENT -7 7 -_ _7 7PERMITREQUIREMENT INAMERIN nLE Icertify under pealty of law that the douMe and al attahmants were prepard under my TELEPHONE DATEPFOOMPAL EXCTV OFI=ICER dretin -,tk supervision in accondance with a system designed to assure that waffed persannei propeuly gather and evaluta the Informatlon subinett Based m my Inquiry of the persn or pesmons J\ 7d 815 406-3700Benjamin P. Youman who manage the systen or those persons directly responsble for the Infomaitlon.

the .1..- 09125/2012 informatio submitted Is. to the best d6 my kovtedge and beflef. true. accumrae.

and ccmpiete.

I am SIGNATiE OF _ _ __ChPLEPlant Manager aware that there are signcant penalties Ifr submitivg lalse informion.

ncuding the possbfty at EXECUTIVE OFFICER OR AREAporrm lm mid it men for knowing vidanno.

AUTHORIZED AGENT CODE NUMBER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hers)1. Flow existed through this outfall 9 of 31 days durng the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116912 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAMEIAODRESS NAME Exelon Generation Co., LLCADDRESS 4300 winfietd RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR Mailing ZIP CODE.MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERE01-0DISCHARGE NUMBERI MONITORING PERIODI MMIDDIYYYY I MM/DDIYYYY STORMWATER (FORMER 001E)External OutfallI I I NO DISCHARGE

-JFROMI08/01/2012 I oI08/31=2012 II IATTN: Zoo Cox/ENV SPECFREUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESolids. total suspended SAMPLE ....MEASUREMENT 50053010 PERMIT 7. .. 30 -'We"" GRASEffluent Gross RE0UIRBAIT

___...:__

___AAV___-

-M-Solids, total suspended SAME 7.9 8.0 19 0 01/07 GRMEASUREMENT_____-

0053080 3 0Other Treatment, Process .. ..,..,. A ., ,ee "' , ...Complete

_ -,__. .... ....__-__. __.._"_"_.

.Chromium, hexavalent SAMPLE 500(as Cr) MEASUREMENT 5000103210 7p~j~ W w 77 D:ny 2:7,Effluent Gross REQUIREMENT

" "_"__'_.--:

.30ODAAVG DAILY MX GRABChromium, total SAMPLE ...500(as Cr) MEASUREMENT 50001034 1 0 7- PERMlr ,,, :1 -7 2 ". GEffluent Gross REQUIREMENT

.._*.._". O3DA AVG DAILY MX -Copper, total SAMPLE ...0...... ...(as Cu) MEASUREMENT 50-0104210 PERMIT ,..,, ; "... ' .5 -.. '. G.ABEffluent Gross REQUIRBIENT

• _ " _,,__....

"30DAAVG bAiLY MX -_"Iron, total SAMPLE ...... ..... So5(as Fe) MEASUREMENT 0104510 PERMIT ..... .... -" -cc- ---- ""Effluent Gross REQUIREMENT

"__ _ ...__ DAILY MX .GRASLead, total SAMPLE o..... ....... 500(as Pb) MEASUREMENT-010511 0 PERMIT -..,... -,... ..., .2 .4 *Effluent Gross REOU .* EMENT. 300A AVG DAILY MX GRASKAM E/nnE I celt./under penalty ol law awi this domimemt and an attaorhmens were prepared under my TELEPHONE DATEPRNCIPAL EXI.CUTIVE OFFICER oreton or supenisiTLn accordance wEh a sDTtem designed to assure ow TEaPiOd pNE DATpropety gather and evatute the Infmmatin submied.

Based on my bIqutry of the pemmr or persons 5 43Benjamin P. Yournan who manage the system, or 0Ue persons drecty responsUe for gatetrng me the 4_0 09/25/12Wonnatlon submfted Is. to the best of my knowledge and beliet, ue. eccurate, and comrplete.

Iam SIGNAinEOFII PLEPlant Manager aware that them arm sigcant pentites for submftnig fals inlomratton.

kitng the posay ol EXECUTIVE OFFICER OR AREA NUMBER MM/DD/YYYY owR Poi is and ouisonment for niowkii viltions.

AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during the month.2. Flow existed through this outag I of 31 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11112012 PAGE 110 0 49 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAMEJADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010DMR Mailing ZIP CODE.MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERE01-0DISCHARGE NUMBERI MONITORING PERIODUM/DOVYVYY MMIDMNYYYY STORMWATER (FORMER 001E)External Outfall** NO DISCHARGE F- ...FROMI -08/01/2012 I TOI08/3112012 IFREQUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPENickel. total SAMPLE ...... 500(as Ni) MEASUREMENT 5020106710 ..-:AVl RM .- ." ." .+" ."- -' " "a ""Effluent Gross REQUIREMENT 5-" , YMX*Zinc, total SAMPLE 50..0o(as Zn) MEASUREMENT

• ru" rr .*.AAV -. .A..,,101092 1 0 *PERM IT ' 2 .m.& *a .RA1 ..... ' :. .. -. ...Effluent Gross REQUIRE1M"NT 6 30DA AVG ""LYMX .L.Flow, in conduit or thru SAMPLEtreatment plant MEASUREMENT 5005010 PERMIT Req. Mon. Relq. Mft.-Effluent Gross REQUIREMENT 30DA AVG -Rg-.DAILyM.MX" Per Mnt CT .SAMPLEMEASUREMENT PERMIT ---_______________REQUIREMENT'__________

__________

SAMPLEMEASUREMENT

-PERMIT_______________REQUIREMENT,_____

________

____SAMPLEMEASUREMENT

__________

________

___REQUIREMENT

__________

________

__________

SAMPLEMEASUREMENT PER~~rr : -.-. .................

"-.;,".+"

.. ......- ....'..-- .............................

'.1 " -.i.' -" .,:+.;.- REOItRqEMBII

"___________

-. ____ ___"__ __REASUIREMENT NAMEnTTLE I cattily under penalty of law i0at t~s document and al attadcments were prepared under my TELEPHONE DATEPFNC4PAL EXECUTiVE OFRCER directin or supenidslon In accordance with a system desined to -ssure toa qualified personnel properly gathe and evahtVithe Informain smtllted.

Based on my InCqury of the personr pesona PaBenjamin P. Youman whto manage the system or thse persons directly responsible lot gatheuing the inlion.iF, 815 406-3700 09/25/2012 minoration submitted is. to fte best of my iknoeedge and balef, tuse. atmuret and complee lamn Im NATU OF PPlant Manager aware that them amr sniFfcant pen for submnt false Infonrttion, thnft the possblt of EXECUTIVE OFFICER OR ZAR NUMBER Ily PsoR pe d e and b tsnent for iprowng vicationm AUTHORIZED AGENT CODE _MM/DOYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. No Service Water or Closed Cooling System Drain Water was discharged this month.2. Fire Protection drain water was discharged this month.3. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Cleaning wastewaiter was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/2012 PAGE?

NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITrEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS' 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010IL0048313 PERMIT NUMBER001-0DISCHARGE NUMBEROMR Mailing ZIP CODE:MAJOR(SUBR 01) CSCOOLING SYSTEM SLOWDOWNExternal Outfall61010MONITORING PERIODMMIDD/YYYY I MUMID1Y YYYFROM I08/01/2012 IToI08/31/2012 l* NODISCHARGE

...! IATTN: Zoo Cox1ENV SPEC____

__________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SA.MPLVALUE VALUE UNITS VALUE VALUE VALUE UNITS E ANALYSIS ETYPETemperature, water deg. SAMPLE ...... .........

0 01/01 CNFahrenheit MEASUREMENT

.00011 10 ... PEM....7'~

~Effluent Gross REQUIREME)N MO

..pH SAMPLE 7.81 8.31 12 0 01/07 ORMEASUREMENT Effluent Gross REQUIREMENT..

N..U- ....... .-L I __.MNIU _ : " -." MAXIMUM'.

..-S total suspended SAMPLE ........

12.0 12.0 19 0 01/30 ORMEASUREMENT

_ _ _ _ _ _ _ _ _ __ _005301 0 .M -" ' '. ,;, -. Req,Moret-:

' .Mon .....' * ..Effluent GrossR -I, M E ... , I "" :' '6 "". " :DAAVG/.

.. DALY.IMX

-.. -" BOil & Grease SASRMPLENT

<11.4 <1.4 19 0 01/07 GRMEASUREMENT

_____0055610 PERMIT 7. 2 'D -" " ...15 --20G R.:Effluent Gross REQUIREME9T

.". '30DAAVG DAILY .. -W.ey.. GRABChromium, total (as Cr) SAMPLE ..............

" ... ... ... <cO.0021 19 0 01/07 ORMEASUREMENT 010341.0..

..........

" oL -: .Effluent Gross REQUIREMENT DAILY_" .., .....-,. ... ....Copper, total (as Cu) SAMPLE ...... 0.015 19 0 01/07 ORMEASUREMENT 0104210 -PERMOT!-

777 .017Effluent Gross REQUIFIEMENT

... -..DA5LY 0M07 '.. .-Zinc, total (asZn) SAMPLE .<0.003 0.006 19 0 01/07 GRMEASUREMENT 1.01092 10 -.PEROIT -.X -.1 -?:;-; 7YEffluent Gross RiMUIREMEkT

--- 300A AVG DALY MX..-NAcE/tITLE Icaly unWer penaflyal law wat ts doument and all atachments were prepared wnder my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER dbectia or supervision I acoidanre with a system designed to assure Mat qiaped p rope rty aU wrand e au e f r ame atnmo su bm itt , eaed.S on my mquiy a M pe rm o rpe 815 406-3700Benjamin P. Youman who manage the ssM7M o 00se persom diecty IsonA for pathe the ,omatim.

te 09/25/2012 kdarmntion suttmided Is. to the REst d my Q and Iel, true. II, and , e.laIa OI= CiPLEPlant Manager aware Mal Nude are signiicant penalties tor suvmft lalse mtiarnon.

bIdnurd the possaty dl EXECUTIVE OFFICER OR N EY1W0on Ra f and EWUsiomem W owf vattis. AUTHORIZED AGENT COaE NUMBER MM/DDYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachmenta helr)1. Monitoring data for outfall 001-0 is Included on attachment.

EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11u2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60655-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010IL0048313 PERMIT NUMBER001-0DISCHARGE NUMBERDMR Mailing ZIP CODE: 61010MAJOR(SUER 01) CSCOOLING SYSTEM BLOWDOWNExternal Outfall* *INODISCHARGE EJi MONITORING PERIODII .MMIDDJyYYYY I IMMIDD/YYYY I---------

4FROMt__ -108/01/2012 l1 1UýýglcvicQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OFANLYE_________________

ANALYSIS TPSAMPLE ........

.n.t ....... .519 0 0/7GOxidants, total residual MEASUREMENT 0.0 19 0 01107 R3404410 "PEuMr. , ..r.. GRASEffluent Gross REQUIREMENT "I MX "_T- yPriority pollutants total effluent SAMPLE 500MEASUREMENT

__________

__________

________5000810 PERMIT-mm Fq.Mn.... .. " * *. DAILYM X 'Effluent Gross REQUIRSEIM ENT DALY MX- ..W__... .DAILY....

.AFlow. in conduit or thru SAMPLE ....treatment plant MEASUREMENT 5005010 PRMIT .Req. Mwn Req. Moný. 'i~ S 8~CONTINEffluent Gross REQUIREMENT 30ODAAVG' DALY MX. jly:__ _. __: _.__ ,_"_...._

.__",,, -. .Chlorine, total residual

.....S .ME .. 500MEASUREMENT 500601 0 PERMIT II- ~ ~ ~. 0Effluent Gross REQUIREMENT

_-_*_": ._., .." .- ,. ,AILY( Weekl. GRASHydrazine SAMPLE ...... ... .-..."500MEASUREMENT 81313 10 PERMI.:0 2-...*- .Ol07 clawil Ihe GRABEffluent Gross REQUIREMEIT

" _.. ... __ .__, _ ._ -SODA AVG -DAILY MX .-.SAMPLEMEASUREMENT PERMIT"REQUIREMENrT

.._... .__"_/______

SAMPLEMEASUREMENT S*li T ..* : .: .- .- , ..: ..- .-... .-, .... -.... ..... ...-REQUIREMENT

-.NAUEnrrrLE cernny unlder Penl aft Il truef MM;;; and JTEaLEP ONE DATEMPRINCIPAL EXECUTIVE OFFCER directlmn or supeviaslm bI accodance with a system desgned to assure that Wafi Persnel TELEPHONE DATEpperty gaMtariand evakfte I memation Based on my tlquiy d Me pesant or 'Il 81 406-3700 09/25/2012 Benjamin P. Youman who manage the system, o Mome persons dsvecttm respanslet for gathering the Infonatim.

Me SIGNA IRE OF iINClPLE 0_r_5/2012 Plant Manager kommaa submitted Is. to Mte best ai my knowledge and belIef. that. acmirate, and eomplete.

I am UTOIVED AGEN CMawarehgo tere a re signifcant penaltes fo r su bmittig fa bse info rnatim. In kd ing the ssitf ofX C T V F I ER O R A N M E M M /DO/YYYYfnOn pME fe and hToelsbrntment for knowbnW violations.

AUTHORIZED AGENTECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 111/2012 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Wintield RoadWarrenviUe, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadOMR Malting ZIP CODE*MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBER002-0DISCHARGE NUMBERMONITORING PERIODMMnDDvYYYY I I MMIDDIYYYY STORMWATER RUNOFF BASINExtemal Outfall* -NO DISCHARGE 1 ...I II IFROM I08/01/2012 I TOI08/31/2012 IByron, IL 61010ATTN: Zoo CoxJENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER

_____ON.SML VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALO TYPESAMPLE t*.nneee e oeoSolids, Total Suspended MEASUREMENT______________

0031 rITll~-

-.., ... .,,.,30OAAVG1 "n ,...n."We

'"GA'Eiffuent Gross EURIT ....SDAV DAYM'Wel.

GASAMPLE ..... .............

Solids. Total Suspended MEASUREMENT 0053080 -'.. ......./. --. VR. ..; .... I GRADOffluenth Troa-ss REORUEET-

-:'!.i:, !'. 300DA AVG -DAILYMX" ng/L *, Weely.,$

ACom olete _.. _.- ___..- _- *__ __ _ _ ,, .-' .* .-. -- -*... "-. ...Chromium, hexavalant SAMPLE ........

.....(as Cr) MEASUREMENT 01032 10 *-. PERMIT"+"-":'

,,. ..-, :- te.,.," -'+" " : -. " .0o1 ~6 .i " ': " .+"; -:+ ..".... ... .. hV LW" , :; I .* .Etuert Groatent RErUceMss

______ 3 AVG DILM -3GAChromium, total SAMPLE(as Cr) MEASUREMENT 01310PAERMIT-

.01' al -RB'1EIff t Gs- " O "DA AG" DAILY MX" .. "Choim toa SAMPLE ICopper, total SAMPLE ... .., ... ...(as Cu) MEASUREMENT 01034210

, 7...... .. 7 .7 .... -t -3Effluent Gross

.SDA AVG ,DAILYMX

..GRA.Iron, total SAMPLE n.... ......(as Fe) MEASUREMENT 0104510 " PERM ...- j.77 7 7 V "

• 71". .Emuent Gross RE.UI El ... -DAILYMX mgIL Daiy GRAWLead, total SAMPLE ..........

(as Pb) MEASUREMENT 01051410 PERMIT" -... " ". "GR.S .63 298.Effluent Gross -REQUIREMENT

, .,. ... ..SODAAVG DAILYMX.

D.. .... GR ..NAMITInTLE Icerwy unmut ienasy tw mat ets doonent and sit etadeirent~s were prupaed under myTEPONDA--

PRINCIPAL EXECUTiVE OFFICER dfrctia ot supensmon In accordance wttt a este designed to msure.-a qiagte TELEPnNEeDAT whoen am anag te sstm o toe pe iscom dresuy m.pBasbed fon gatqwing the peomatmt Vt.nm 154630Benjamin P, Youman wh anagdessn ovaji de Inom istio msonse my QaU'yn de PcmtSon W 815, 406-3700PL 092501____ fits a~nd mieomn o mwzgvoain.nomtalio subinlied ts. to mhe herl si my fooleg and bethe, true. somurat and om~plete.

Irant IN R NIL _ _ _ _ _ _ _ _ _ _ _ _ _ _Plant Manager sware tttt there ame signifian pensates hrosubitting be Iroisi btdudng mhe poessey c EXECUTiVE OFFICER OR AR UMEEMAWYY "nmm ____ ___ ___ __PERMIT___________

AUTHORIZED AGENT COD7 NUMBER M7-DD/_ __YCOMMENTS AND EXPLANAtION OF ANY VIOLATIONS (Reference all attachments he)re1. No Tutbine Bwidtng FIre and Oil Sump or Genetic Non-Chemical Metal Cleaning Wastewater was discharged this month.2. No re Protection, Service Water or Closed Cooling System Drain Water was discharged this month.EPAForm 3320-1 (Rev 01/06) Previous editions may be used. 1/r/2012 PAGE 1EPAalnsb~c s otebe fIn nweg mble.tuamae adcnf .1a INTR tRNIL 0PERMrITEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvitle.

1 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 610107nar twIF=NV SPI=CONATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)DMR Mailing 23P CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBER002-0DISCHARGE NUMBERMONITORING PERIODMMIDDJYYYY I MMID/YYYY STORMWATER RUNOFF BASINExternal Outfall... NO DISCHARGE jjJI .... .. .II IFROM I 0810112012 ITO08131/2012 I IQUANITTY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMErIER OF TPVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPENickel, total SAMPLE ..........

..(as Ni) MEASUREMENT 0106710 .GRPERMBIT'

---'ee em.' .011+ " " .' '+* .-- ..- 30DAr AVG DAILYMX,.

Effluent Gross REQUIREMENT

__ .-"____ -_,_- _AMX *GRASZinc, total SAMPLE .. ...(as Zn) MEASUREMENT 0109210 P1011117

.,, ---, .... 047 .26Effluent Gross REQUIRENT ADAIY"MX t' DallyOil and Grease SAMPLE....

MEASUREMENT_

03582 1 0 PERM IT 7 7"7"-"-7e'!

" .15 " * "Effluent Gross REQUIREMENT

...._.__*.__300AAVO DALY MX .I.I.._c

..,, -Flow, In conduit or thru SAMPLE .... ... ......treatment plant MEASUREMENT 5005010 PERUT -RKq'Mon.

-- Req. Mon. ..... .hn,Effluent Gross 3DREQUIR "V" 300A AVG DAILY K .. .. Discha. ging-SAMPLEMEASUREMENT REQUIREMENT

"~~~~~~~~~~..

.. .. ....--." .. ....-'-.,-.......

• , -... ...,' .....______________REQUIREMENT

,_________

---SAMPLEMEASUREMENT PERMITREQUIREMENT

'_" _,__SAMPLEMEASUREMENT

________________REQUIREMEN1

___________

________

______ ___NAME/1T1.E I certily under penalty of law that this docurnen and all atachmens were prepared undr my TELEPHONE DATEPRIMCPAL EXECUTIVE OFFICER O superisio In accordance wbi a system designed to assure ta quaeued pesonnelB .roperty ga-the and evate fte Informatio submitted.

Based an my mlquwy o the person or persons 815 406-3700Benjamin P. Youman who manage the system, of tose peemons directly responsible for gathering the mforimatin, the 0942512012 mtfor.ation suftned Is, to the best of my linoledge and belJ, bee accurate.

and conplvete, am SIGNAa EOFP CIPLE__Plant Manager aware a Owere am saqicant peraiafttsor aisuMinaO raise Imtonna.on Inctuding the Possibityd EXECUTIVE OFFICER OR UBM.ATVMm OR PRO'ED fine and irnipdionmenl for woxmg viclatmons.

AUTHORIZED AGENT OD NUMBER MM/DDYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. This discharge point was not used this month.2. There was no discharge of processed steam generator chemical cleaning wastewater during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 2 ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 August 2012Page 1 of 3MONITORING DATA:CWBD CWBD Flow Rock RiverDATE Temperature d Flowde F mg cf08/01/2012 100.0 19.82 1,90008/02/2012 100.0 21.62 1,89008/03/2012 101.0 20.67 1,84008/04/2012 101.0 28.92 1,89008/05/2012 100.0 21.11 1,89008/06/2012 98.3 13.43 1,82008/07/2012 100.0 22.51 1,84008/08/2012 100.0 9.30 1,83008/09/2012 98.5 17.04 1,86008/10/2012 95.6 16.07 1,90008/11/2012 97.3 17.09 1,82008/12/2012 97.3 15.25 1,84008/13/2012 95.5 14.28 1,86008/14/2012 96.3 22.12 1,83008/15/2012 100.0 19.58 1,85008/16/2012 100.0 24.91 1,89008/17/2012 98.9 18.27 1,91008/18/2012 98.1 27.19 ,81008/19/2012 95.2 22.86 1,83008/20/2012 94.4 16.50 1,82008/21/2012 95.5 19.79 1,79008/22/2012 97.1 16.71 1,80008/23/2012 97.1 17.08 1,76008/24/2012 96.6 17.76 1,76008/25/2012 99.8 15.95 1,68008/26/2012 97.8 18.62 1,66008/27/2012 97.1 13.46 1,69008/28/2012 99.5 22.30 1,59008/29/2012 98.5 17.98 1,60008/30/2012 101.0 17.03 1,63008/31/2012 102.0 18.14 1,550K:\BYR_CH-BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\August\August 2012 ATTACHOI.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 August 2012Page 2 of 3HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (or associated rinses) containing hydrazine discharged to the Cooling System Blowdownduring the month of August 2012.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite and Bromine compounds were used this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 31 of 31 days.4. Per Special Condition 24 the influent from the Rock River and effluent fromOutfall 001-0 was monitored for Total Suspended Solids (TSS) this month.The Rock River TSS value was 37.0 mg/L on 08/06/2012.

The CWBD TSSvalue was 12.0 mg/L on 08/06/2012.

5. Rock River flow was <2400 cfs in August 2012 therefore daily temperature calculations were required during this time period. (Special Condition 12).Per Special Condition 12, in the event the Rock River flow is <2,400 cfs,daily calculations will be undertaken to demonstrate compliance with thewater quality standard.

The calculations are based on hourlymeasurements, averaged over a 24-hour calendar day for Rock River flow,main Rock River temperature, CW Blowdown flow, and CW Blowdowntemperature values. Results of the calculations shall be reported in theDMR on a monthly basis. Calculation results are in the table on thefollowing page.6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in August 2012. (Special Condition 15).K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\August\August 2012 ATTACHO1.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 August 2012Page 3 of 3Date Average Average Average Average Calculated Water QualityRock CW M/U CW CW Temperature StandardRiver Temperature Blowdown Blowdown at edge of Temperature Flow (F) Flow Temperature mixing zone (F)I_(cfs) (gpm) (F) (F)8/01/12 1910 78 15492 97 79.0 908/02/12 1892 79 15386 99 80.0 908/03/12 1848 80 15255 100 80.4 908/04/12 1867 80 15531 100 81.2 908/05/12 1939 79 14197 97 79.3 908/06/12 1820 77 10402 96 77.4 908/07/12 1840 77 11936 98 77.5 908/08/12 1818 76 12105 97 76.9 908/09/12 1863 73 12130 95 73.9 908/10/12 1889 71 12022 92 71.7 908/11/12 1828 71 7827 91 71.4 908/12/12 1845 70 12257 93 70.8 908/13/12 1850 69 14858 94 70.3 908/14/12 1828 69 14927 97 70.6 908/15/12 1849 73 14998 99 73.7 908/16/12 1881 73 15125 98 73.6 908/17/12 1914 69 15320 93 70.2 908/18/12 1800 71 15278 94 71.8 908/19/12 1831 70 15283 94 70.9 908/20/12 1821 69 13557 94 70.3 908/21/12 1790 71 14433 93 71.7 908/22/12 1799 71 12377 94 71.6 908/23/12 1768 72 12491 96 73.1 908/24/12 1765 74 8394 97 74.5 908/25/12 1691 74 12515 98 75.2 908/26/12 1654 74 12906 97 74.9 908/27/12 1695 73 13512 97 74.1 908/28/12 1590 74 14901 97 75.5 908/29/12 1603 75 12747 96 75.5 908/30/12 1628 75 12720 97 75.9 908/31/12 1555 75 11960 100 76.4 90K:\BYRCI-I\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\August\August 2012 ATTACHO0.doc Exelon.Exelon Generation

Company, LLC www.exeloncorp.com NEuxeaTByron Station44,o North German Church Road.Byron, IL 61010-9794 October 16, 2012LTR: BYRON 2012-0112 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyWater Pollution ControlCompliance Assurance Section #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring ReportIn accordance with National Pollutant Discharge Elimination System (NPDES) Permit Number1L0048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report forByron Station, Units 1 and 2. This report covers the period of September 1, 2012 throughSeptember 30, 2012.If there are any questions regarding this report, please contact Ms. Zoe Cox,Environmental/Radwaste Supervisor, at (815) 406-3035.

.Respectfully, Bena ýYoumaePlant ManagerByron Nuclear Generating StationBPY/ZC/eh Attachments bcc: J. Gould -Environmental

-Cantera (electronic)

Z. Cox -Chemistry

-Byron0 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadIL0048313 PERMIT NUMBERIDMR Mailing ZIP CODE:MAJOR(SUDR 01) CS61010IA01-0t .......[ DISCHARGE NUMBERDEMINERALIZER REGENERATE WASTE (001A)External OutfallIMONITORING PERIODI MMID01YYVY I TO[MMIOD/YYYY IFROMI09/01/2012 09/30/2012 I* ** NO DISCHARGE M ...l gByron, IL 61010ATTN: Zoo CoxIENV SPEC _____________________

______________________________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAME'TEFR OF,,, VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESolids. Total Suspended

............

CO.71 40.71 19 0 01130 08Solds ToalSusened MEASUREMENT 0053010 EMT --Effluent Gross PO. MP .,-..- _-.... .COW-aChromium.

hexavalent SAMPLE ...... ....(as Cr) MEASUREMENT1 0103210 ... .2Effluent Grosse' ,.: .. 4 p A A -"ALY Mx-" " -Chromium, total SAMPLE ........

SI(as Cr) MEASUREMENT,-

-0103410 .- MIT ~ ,... .-.. .GEffluent Gross 2.!- 1 .., -., , ..-Copper, total SAMPLE ....... ..(as Cu) MEASUREMENT 0 10 42 1 0 Soo.. .. ....:, : .-" -' , ..-. .y G.A_Effluent Gross r: ...... -.- W.D- I .." ...... .-,.. -Iron, total SAMPLE .........

(as Fe) MEASUREMENT 0104510 SMT- ,, ~ .~ ' ml___ _ _ _ _ _ _ _ _ _ _ _ IX

• REffluent Gross .: .... ;" : ' .., ' ; " ." '. " .-.Lead, Total SAMPLE .., 5Effluet)

MrssEASUREMENT~~-'

~a~ QDAVG~~Eflu ntGos s .1 1 --.": .;./ --. ;- .: ..Nickel. total SAMPLE ....... .(as N i) M EASU R EM EN T ...... ...... _ _ _ _ _ _ _ _.._01067.10 500 , .- -_ ., ..<:, .2Effluent Gross *UA-UIR..IBN

' .S ..._ -:.O;. , ,. , .X .: _ .._ .. ...2.--NAL EX TTI I. E I ceairy under penally al lw thWat fts documnTu and all auduna rAlm wer pWepared under ny TELEPHONE DA TEPfiINCIPAL IXECUIlVE OFFICER decton or Bupenivwm i aI n darnc wih a systen designed to assure tha qualfied personnel TELEHON DATEproperty gather and evalute the ettarrnamat submtimed Based On my hoqiity d the person or pawsna 1 6701~~1Benjamin P. Youman who manae the syateM or =me persons directly resplble f1w gaherng the Infofmnatft the6101Pna onnatton W uOrti n ted is. to the best of my W ledg and be e, Ine , eca rrea .and con e .Iaia SemN RE 0 INCtPLEPlant Manager aware at there aM sedmiPeant ies for sulnftaveingoIdeaisn, nalia 9 thngposl EXECUTVE OFFICER OR NURE ER MMIDDIYTVPED OR Pmur It'- end unprdeiounent fmr knowing viadow XCTVEOFCR R AEiwaoon pur ean ctssm m fc voa~ AUTHO RIZED AG ENT CODE NUM BER _ _ _ _ _ D_ _ /_ _ _ _ _ _COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachmente here) ...1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed 30 ot 30 days duing this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11/62012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exalon Generation Go., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR Mailing ZIP CODE.MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERA01-ODISCHARGE NUMBERMONITORING PERIODMMDDYYYY I MMIDDTYYYY DEMINERALIZER REGENERATE WASTE (001A)External Outtail* NO DISCHARGE FROMi09/01/2012 1 TOE000/2012Il ii IATTN: Zoe Cox/ENV SPEC ____________________________________

_____QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF AMLVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPEZInc, Total SAMPLE ......is.

• ee

• otQ = m500(as Zn) MEASUREMENT

__0109210 2." ~ _ .-'. .oi s.o .- .*

• 2ri. .-.ail: G -Elffluent Gross ." BAB-4~?-.

~____Flow, in conduit or thru SAMPLEtreatment plant MEASUREMENT 0.057 0.243 3 0 01/01 ES5=00510 9WQ MWLI RMVW*Effluent Gross -- -.--NTINMEASUREMENT

__________

• . ..--- .* -____lO__

_-_ -, RA-UI-. R"M.----

..... ._ CSAMPLEMEASUREMENT

.*... ., ___.,_-._._.._

.,- -. * ..- .*. .-'-SAMPLEMEASUREMENT__

_ _ _ _.,_" -. '<.. .. ; ' ..... _ _ _ ". _ _ _SAMPLEMEASUREMENT SAMPLEMEASUREMENT

.WWW 7. t -NAM, lurpEPAINCIPA EXECI~fVE OF &G- Or at osupervisio In accodance widi a system designed to a=sure diat qtiatle personnel

_ _ _ ____________

NAME~~fl1L PM I cetd h Uif plaftY Ci aw dae Me docmeihnt subid tted Bsd anmy vptS a5Illd ft~d perso TELEHONEDAT BejmnP omn who manage die system. orthos person diudly resporisidl totgatheringdie informalke~t, di a7(informataio submitted IS, to Ite best of my knowledge and balet. true. accurate.

and complate.

I SIGNATWRE OF P~jWCIPLE

____ W ____0__1__2012

_Plant Manager aware diet diers are sign~llcaml penalties tor aubnudg 1MM kinlommtlo.

hi~dkig die possaif of EXECUTIVE OFFICER ORNMERMDDYY pWED OR__________________________________________lations AUTHORIZED AGENT CO4 NUMBER ______________

COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)CO _1. Flows for September 2012 are estimated based on July 2012 values due to totalizers being Out of Service.

The totalizers are an obsolete model and work orders are in place to findreplacement totalizers and get them installed In thes system.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/212 PAGE 210ESRMN PERMITTEE NAMEJADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010NATIONAL P&LLUTANT

1. ARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)IDMR Mailing ZIP CODE:MAJOR(SUDR 01) CS61010II.0046313 I IB01-0-4PERMIT NUMBERI I DISCHARGE NUMBER1MONITORING PERIODMMJDDIYYYY i MM1DWfYYYY STP PLANT EFFLUENT (FORMER 0015)Extemal Outfall* NO DISCHARGE FROMI09/01/2012 I TOI09/30/2012 I! lM41IIfl.

£. 't.AJflO*Y Or--1 _,, _FRE______SAMPL QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAME'TER OF YPVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPEBOD, S-Day SAMPLE 21 .62BO 5- 2C14 3.76 26 .... 29.0 50.0 19 0 02/30 24E~ffluent Gross _011-~ ____ _____ ,ALW wPMr~MEASUREMENT

_yat0040010 .Q.. "-a.. t..Effluent Gross TIM ~~ ~ ~ -SJ ~GA-m illn e ',. ýý i pa. --.. ,.1 ,,1111 I- .o .I- .-- ....."o--~Soital sSUdMPLE 121 2.22 26 15.7 29.5 19 0 02130 24Solds toalsusened MEASUREMENdT 0053010 5.)u 1015' 30 60._~~ ~ ~ ., -,,.. .-. w_ý " IaIYX 'A*m .I! .......w.Effluent Gross PY&L ~I4NFlow, in conduit or thru SAMPLEtreatment plant MEASUREMENT 0.008 0.014 3 0 01/01 CN5005010 ~. e.Mn eJ4n'-v-'pM OJIEffluent Gross ,.emu W 9&2mA ' -_____ -SAMPLEMEASUREMENT aco .n.*. ..REQUIREMENT.,,

SAMPLEMEASUREMENT_____Iil r,___. .._ _ _ .t. ; 1" , .: ... .... .;. .... ..."__.. .._ _ " "SAMPLEMEASUREMENT NAME/rrTLE comfy under pealty of law owUist1t document and anf attachments were prepared wnder myPMMciPAa.m or -,

.... in ....anc wi- , a syster- das..d .s .r. M,.........

TELEPHONE DATEwhOSI mOandg the kf fyte. 9orun.emnal dibrrtetl BO r anrnyl lo" gted go therslmaton thepBenjamin P. Youman propeif ngatheresyseemkor thew Persons iatam rsubituted.

for gatheingub flte peaT=o esn ________

815 140&3700 10/l1612012 W'Om'Vallm eubnto IS. to the bea of MY kz(IONISC and bmele, tre actae and cornpals.

I am SIGNA SRE OF IRINCIPLE

-Plant Manager aware that atere ame elgnant penaltes tar subiitltki false bInornnedel.

Incben die possbdty d EXECUTIVE OFFICER OR EAl UMERMID1YY iwwn OR IRMUTan r- and brfbufn fo bmwb v~a AUJTHORIZED AGENT IcoDEj U1E MIDYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attarhment heme)1. FRow existed through fthi outfall 28 of 30 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116120112 PG NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITI"EE NAMEJADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenvlle, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church Road.... IIDMR Mailing ZIP CODE.MAJOR(SUBR 01) CS61010IPERMITNUMBE II-C01o0........

II PERMIT NUMBERI I DISCHARGE NUMBER1MONITORING PERIODMMIDDIYYYY I MNIJDDrYYYY WWTP (FORMER 001C)External Ouffall.. NO DISCHARGE EJFROMI09101/2012 I Tot0930=12III Il iByron. IL 61010ATT'N: Zoe Cox/ENV SPEC ________________________________________

_____QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY IPLEPARAMETER OF TPVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESAMPLE ....... ..... 2.4 2.9 19 0 02.30 24SolidS, total suspended MEASUREMENT 00M3010 v.. PERM , ....1_ ., .._. .' ..,.: w._,Effluent Gross : .... ... , _, _.".... .,-Chromium.

hexavalent SAMPLE .........

(as Cr) MEASUREMENT 0103210 -iI..e I .," ". .: .1 " 12Effluent Gross _,__T .. ._ "__._ _ _..._.. .... DAILY MX -9111 .GRAChromium, total SAMPLE ...... 500(as Cr) MEASUREMENT 0103410 .EI.h...1..

2...Effluent Gross " ____-__:.

.. __._'" "0. " -ACopper. total SAMPLE ..............

..(as Cu) MEASUREMENT 0104210 Fir R3IMTvi-*'.

Eff luent Gross BEQUIRWENT 0 flIron, total SAMPLE ....0......0(as Fe) MEASUREMENT 0104510 P.gRTW ,,m-' .Effluent Gross ____........

DAILY m-Lead, total SAMPLE ....500(as Pb) MEASUREMENT 0105110 RMT -., 2Effluent Gross REURM~ ____ ' ~ ~ AAV.G Q'AIIY.MX

-. RANickel, total SAMPLE ........

S(as Ni) MEASUREMENT 0106710)

PAMIT ..* ', 2 .p ~ ___Effluent Gross go%. .I "-. ____ ,_ ---DA AVG O.iV , ..... _.. _-NAMMEfIII I tans under penagy oflaw that this and aD aftadunent were prepared undeer ff TELEPHONE DATEPRIM.AL E OICER wemor auennsion in aOFRanEe wR a spter desqned to assure TE quaEied PHONEATpmpefty garer and evahita Me

,umtied.

Based on my muwr a me pemro or pemrsos 815 406-3700Benjamin P. Youman who nanage mte SySM6 OF me" peOsM imty respasAe for 9afuig the imomaun.

me 4 406-3700 10/162012 inonn ubim te is. to fe beat l my knowedge and true. acuuae. and cdnplete.

Iam SjGN4VURE OF PI__INCIPLE Plant Manager awa"M trmUe we sindifcant

,enwoes for wutAnlifng false Wmain.m bxidng fte posaslif of EXECUTIVE OFFICER OR AREAwela l xtta _ _e __and ________n_

for _mo _ _ _ _ vi__al_ _ __. AUTHORIZED AGENT 1coD NUMBER MMDD__ _ _ _ _COMMENTS AND EXPLANATION OF ANY VIOLAT1ONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed through this outall 19 of 30 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 10 0 0 0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMI1TrEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenvifle.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010AT-N: Zoe Cox/ENV SPECOUR Mailing ZIP CODE.MAJOR(SUBR o) CS61010IL0048313 PERMIT NUMBERC01-0DISCHARGE NUMBERMONITORING PERIODMMIDO/YYYY

_ I MMJDOIYYYY WWTP (FORMER 001C)External OutfallI* NODISCHARGE-l FROM[09101/2012 I Tol09/30r2012 Il Jl IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER

-.OF TPVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPEZinc, total SAMPLE ..... ..S,(as Zn) MEASUREMENT 010921 0 ..........

.". .A...__-

GRA-Effuent Gross rE~I~IU 6y:. RaAy iLDFlow. in conduit or Uiru SAMPLEtreatnment plant MEASUREMENT 0.024 0048 3.0 01101 CN5005 10 w'"FR-..

Mon. R- MMn. .i * ,"Effluent Gross l -..-- ",SAMPLEMEASUREMENT

-.- -: : .. ... ...' :: : ..,,*. .. .....SAMPLEMEASUREMENT

________________

EQUIREMEMT.

.' ,SAMPLEMEASUREMENT_______________________________________

, .PaRM.T .7 .. ,-.-

-., I -' -, .....SAMPLEMEASUREMENT SAMPLEMEASUREMENT UREMENTI criyudr eal flw d ot ocm nt n talntwerepeprd nerm TELEPHONE DATEPRINCIPAL EXECUIWE OFFICER urection ar superision In accorance with a system designed to assure thai quaffied personnel prepetgater and evalute the Inforaton asad on my Inquiry ot the person or persons 815 406-3700Benjamin P. Youman omanage te system. or thse persons diectly responsIft for geaming de Irloimatim te 10/16/2012 nformatlon submited

i. to th be my k e a b, t, accrat. a c .I am -SIGUATUREfOF PRINCIPLE MOM and ipithiwefornt IknO io .AUTHORIZED AGENT c2o NUMBER M__ OD__ _ _ _COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference ali atlachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/2012 PAGE2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60655-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010IL0048313 PERMIT NUMBERIDMR Mating ZIP CODE:MAJOR(SUBR 01) CS61010D01-0DISCHARGE NUMBER]MONITORING PERIOD.MODDIVYI I MMIDO/YYv RADWASTE TREATMENT (FORMER 0010)External OutfallNO DISCiARGE

-- "*FROMI09101/2012 09/30=2012 IlATTN: Zoe Cox/ENV SPEC______________

__________

__________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER____"

_OF__ AMPLIEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX A S TYPE>< ANALYSISSolids, total suspended

"" 1.2 1.4 19 0 02030 CPMEASUREMENT 30501 .1 i-3Eflun Grs z #-.6 yWFlow, in conduit or thru SAMPLE ... ..0.. 30....teallment plant MEASUREMENT 00600530 011C5005010 V.w*. 3fy CN1gEffluent Gross "Ohl A.m. -ONTINRaw %,( -:...SAMPLEMEASUREMENT SAMPLEMEASUREMENT_____

&AMPLEMEASUREMENT______________________

______MEAUREMENT-

'InTE I car*y under Penalty af law that Oft document and all attadrnenta were prepared unlder my TLPOEDTPrPNopel athe and evalute fth adnloraton submitted.

Based on mInquk hM the person at Persons 81 406-3700Benjamnw P. Vouman wit manage the WaUnt. of those Persona dirfdi resp fonsber gmalhang fth Ileomiation.

the W22=2IT.L 10/16/2012 minormation submitted,,.

to the beat of my knowledge and belief, m^. accurate.

and copt I a SIGNA14pRE OF y1INCIPLE Plant Manager aware that fthm are SgnFican Penalties tor submitting false Wionnatlon.

includng the possiblll of EYCUTIVE OFFICER OR ARENMEAMIDYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Refernene all attachmenta here)1. Flow existed through this outfall 14 of 30 days during the month.rEPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1I61212 PAGE 1 NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAMEADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Wnfleld RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, L 61010DMR Malling ZIP CODE:MAJOR(SUOR 01) CS61010IL0048313 PERMIT NUMBEREO1-0DISCHARGE NUMBERMONITORING PERIODMMIDOYYYY I I MMIDDYYYY STORUWATER (FORMER 00lE)External OuthallNODISCHARGE I ...! .... IFROMiI09101/2012 I Tel0309012I-L--I !ATTN: Zoe Cox/ENV SPECFREUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TPVALUE VALUE UNITS VALUE VALUE VALUE UNITS E ANALYS ESolids, total suspended SAMPLU E 5000053010 H5lIT..i

..t m4. -Wpy IRASolids, total suspended SAMP 28.0 50.0 19 0 01/07 GRMEASUREMENT 0053080 -30 ~ 0Other Treatment Process Q..-(RASComplete

____ ____ ____ ____ __ ____Chromium, hexavalent SAMPLE ...........

5(as Cr) MEASUREMENT Soo0103210.

._.. ...... _ _Effluent Gross _________

~i- DAPMXChromium, total SAMPLE ...... --.......

(as Cr) MEASUREMENT Soo __"_50103410rr- Effluent Gross , EMM __________A

-"Copper, total SAMPLE ... .....5......"500 (as Cu) MEASUREMENT 010 21 .7"." r i'. A....-:;: :.i Effluent Gross -..Iron, total SAMPLE ....... .....(as Fe) MEASUREMENT 5000104510 -., ., .. .... .., ... [ ..A,- AEffluent Gross _____ a .-7Lead, total SAMPLE ...... t(as Pb) MEASUREMENT Soo0105110 .. R ..2 .4 f....... ~ ~..-. '" " : 2: " ..!:Effluent Gross -. -AAV~AIL-Y__

-NAMEMfTLE I certy tnder penalty of law thai th0 domonmud and all ataclhrie wvere prepared under my TELEPHONE DATEP " r OFFRCER drecl or supernimen h accordance wdh a system designed to assu that quaMd personnel preperty gather end evalut the InlormalW suW~osid.

Based an my knquty of fth person or personsa1 0530Benjamin P. Youman who manage sys=t or thse persons drctly rNsponae for gaMhen the Wntmeon.

the 10/1612012 Boitonion Is, to the boe of my Wedpe and befid, true. ecunjp and cogro. Ie am SIGNAWRE OF P CIPLEPlant Manager aware ta there are a6i0cM penalties for submittirt Wee bnomiart.

ftbidin Me ponsitit of EXECUTIVE OFFICER OR AREA NUMBERo PImms e end alnmn r owng AUTHORIZED AGENT CODENU ED.COMMENIS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachmenta here)1. There was no discharge ot processed steam generator chemical cleaning wastewater during the month.2. Flow eidsted through this outfall 16 of 30 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1162012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMrIrEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvitle.

IL 60655-5701 FACILITY Byron Nuclear Power StationLOCATION 4460 North German Church RoadByron. IL 61010IL0048313 PERMIT NUMBERE01-0DISCHARGE NUMBER [DMR Mailing ZIP CODE:MAJOR(SUBR 01) CSSTORMWATER (FORMER 001E)External Outfall** NODISCHARGE F-1 ..61010MONITORING PERIOD"MIDO Y I I MMIDOIYYYY FROMI09/01/2012 I TOII ....... IIUW09ruA12 IAlIuI: 40 ___________rm QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPENickel, total SAMPLE ...... 50(as Ni) MEASUREMENT 0106710 "'2," " -2 A. Dal. GR.ABEffluent Gross '. * < __"__-__

-D,. " *,Y "___"_-__

Zinc, total SAMPLE ..... ... 5W(as Zn) MEASUREMENT E.ffluent Gross 1AW ARatmen clnt 0.530 0.967 3 0. o 02/30 , CNtreatment plant MEASUREMENT 5005010 Ra______

IG( Peýr~JMO.5

ýCONTWEffluent Gross __________WT

... DALSAPL:-' -i.-:

" .. ..... ... ..... .7 .Efi, uo t _oss _;_ES I .-.._"* .-.._. ., "..._, ' ...._,"_.....

,SAMPLEMEASUREMENT SAMPLEMEASUREMENT SAMdlPLEMEASUREMENT NASAMPLE_._*_ _._ _._*_ _. ..., .._ " -.PRINAL EXECUTIVE OFICRIy unde Py of law Val Mb ocumeaa a unalaaeu were pelaeiin my V TELEPHONE DATEPRINCOAL OF~tER nction or suparnMsIon a mccoiincl WWI a system desigikld asure that quafe pemannelpopey gaMer and evalut dhe kdrmnaton Oased on my kquiry ol die persmn or perg s 1Benjamin P. Youman tno MPna me "Mm of de petm s drecUy rO s les b tar gamreng die norna. to, 815 1431602012 Untom twi Is. to the besg d my true. accwahe.

and comlete.

I am SIGN6 JRE ON CIPLE_10/62012 Plant Manager saws dia dtm e aw sigWn am n pA l te 10 rig tai99a ia3ma. bUWAlirg the psaifty of EXECUTIVE OFFICER OR AREANInne and lrprionmenm fa knowig vlorla. AUTHORIZED AGENT COD] NUMBE M_/DD/____

COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attashments here)1. No Closed Cooling System Drain Water was discharged tis month.2. Fire Protection and Service Water System drain water was discharged this month.3. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Cleaning wastewater was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 111/2012 PAGE 2p 0 4 0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationIL0048313 PERMIT NUMBER001-0DISCHARGE NUMBERDMR MalHng ZIP CODE: 61010MAJOR(SUBR 01) CSCOOLING SYSTEM BLOWDOWNExternal Outfall" NO DISCHARGE MONITORING PERIODMM/DD/YYYY j MM/DD/YYYY LOCATION 4450 North GermByron, IL 61010an Church RoadFROM 10910112012 I TO!09/30/2012 Il; 2r QUANT11TY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIPTemperature, water deg. SAMPLE ....102.0 0 01/01 CNFahrenheit MEASUREMENT 0001110 .11 oI ...;W .-'-g.C"" .q, MOn...,.E ff lu e n t G ro ss -." .* .F .-" , ",. ,pH SAMPLE .. 8.15 8.60 12 0 01/07 GRMEASUREMENT_____

_________

______ _____004001 0 I5lMI6T-: :" ... .-.- ': "* * .Wehld " GP,,BEffluent Gross -_ *_:_-. , __... " ___ ...- ...___ .-. -Solids, total suspended S .2.0 2.0 19 0 01/30 GRMEASUREMENT 00501 0 -EITP, * ., teq. Mon. Req. Mmnoo0o1 .....Mnt*. GEffluent Gross -E... " ____': ..: .,. ". "0IAAV(.

"DAlLYI4X L ___il & Grease SAMPLE ...... ...... .. ..... <3.1 7.0 19 0 01/07 GRMEASUREMENT 0055610 RM..... ....o. o .15.20Fn GRABEffluent Gross REQIREEN AV fUY AChromium, total (as Cr) SAMPLE ....... <0.0021 19 0 01/07 GRMEASUREMENT_____________

_____ _____ ____ _____SA P E..........

..Copper, total (as Cu) MESURMPEN 0.028 19 0 01/07 GR0104210 .PM07 'It " ,.....',.;RAB.

Effluent Gross * -, " ' i"--i"_ _:"' ....... _Zn.oa(s8)AMPLE

............

<0.0020 19 0 01/07 GRncpe, total (as Zn) MEASUREMENT 01092 1 0 ,.' W I ..,-Ir... " ..13 .433, ..Effluent Gross .. ..-; .... I.Y MX __I " "Ii, ttl(a .)MAURMNNAMErTITLE I cew*l under ietnall d law Mlat dus docund and al antadwwtns were prpae uncder my TELEPHONE DATEPRIN4CIPAL EXECUTIVE OFFICER d or supennsion iaccrdance with a system designed to assure tht quafifed personneT

,arpedy gather and evatue the information submitted.

Based on my lnquuy of the pemon or perains 1'5 406-3700Benjamin P. Yournan who manage Me, system, or Vicse pesmn directly rep4 for gathering the Waratonn, the 10116='12 nformat.mn subatmtd Is. to me bes d my knovwedge and betef. true. aimunate, and impmete.

Iai SIGaTUR___

PRINCIPLE

sPlant Manager aware that ter are sqgiVficant penanies lot sutenit=tg talse lnlumnmatin.

ncltudig Ma f EXECUTIVE OFFICER ORan 61o1 rine and inpuimmern tor nowing vwrialns.

AUHRZDAET POENUMBER MMIDDIYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Monitoring data for outfall 001-0 is included on attachment EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116A2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMiT"EE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACIIlY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010OMR Mailing ZIP CODE*MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBER001-0DISCHARGE NUMBER IMONITORING PERIODMM/DD1YYYY I MMIDD/YYYY COOLING SYSTEM BLOWDOWNExternal Outfall' *" NO DISCHARGE FROM I09/01/2012 I TOI09/30/2012 I.QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER VALUE VALUE UNITS VALUE VALUE VALUE UNIT EX ALOF TYPE____________

> <_ VALUE____

VALUE___

UNITS____

UNITS__ _______ _____ ANALYSIS

_____Oxidants, total residual

...........

.. ..........

0.04 19 0 01/07 GRMEASUREMENT 3404410 o ERI4-+- ..,., .. .: -10. "IWY "Effluent Gross .REO IREMI .---" " .. _ ...._._ ..+ ILyMx. ._' _ .--Priority pollutants total effluent SAMPLE500 50008 10 uiqrr Mon. .... Rqq. Mon.Effluent Gross M9 '"_______

'Mon D GRASFlow. in conduit or thru SAMPLE 1.249 01577 242 3"" "..... 0 01/01 CNtreatment plant MEASUREMENT 50050.10 o T Req. on. Re% Wm,-... .. C4 :r .:n: -CNT-INEffluent Gross .F-MB qE V g. ._A .,.+ ._..-._-_.

-. --.... ,, -Chlonne.

total residual SAMPLE .........

.... .... S0MEASUREMENT 50068 1 0 1 0 , ." .... .- .02- "ai W-, .."Effluent Gross Jy -.._ _ _ _- .: .l Y .n -.,SAMPLE ..... .5OMEASUREMENT

__ _ _ ___ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ __ _ _ _ _813131 0 ..... Dail " .1..SAMPLEMEASUREMENT

.. -..... ..PRINCIPAL EECME OFFICER rirection or sujpervaiso in accodance ofth a system desiged to assure mhat quablfed pomesanl TEEHONE IDATEproperty gatner and evalfta Me inforiation sijmItted.

eased on my lnqzM d th pe~on or peisons 8120-70Benjamin P. VoIuifan who mange mhe systeM. or ftsoe persons directly mspoatt for gathering mhe avltormbn.tht~fe SG RE RNCPE10/1 6/2012Pat aelo n vutin "ed i. to=the best 01:- ... .. ole. and be.- .true. accrate, and Com .plete. I am .SI .-.. E OFF.ICE OR APat mare are s fficaa penalties tor sut ..t..ng I.as itonatinidig the p..si.. d ,,FFICE OR ARA

• B .OTMOR PRIPMES Irme and ownJonment for knowina vigiation.

AUTHORIZED AGENT CODENME MIDYVCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem.)-EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6A212 PAGE...:f Tep (' : "," ..,` .. ., .:, " : " 1 "E'R A: %

0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 winfmld RoadWarrenville.

L 60555-5701 FACILUTY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010Ajj"lN- 7rn ".,.,Ivb=NV

.PFtDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBER002-0DISCHARGE NUMBERMONITORING PERIODMMIDD/YYYY I I MMIDDJYYYY STORMWATER RUNOFF BASINExternal Outtall***NODISCHARGE J ...I II _ !FROM I09/01=2012 J TOI 09/30/2012 Iq WATTN:UNC ZooAMPLE PEQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER EOF TYPEVALUE VALUE -UNITS VALUE VALUE VALUE UNITS ANALYSISSAMPLE m. ,.Solids, Total Suspended MEASUREMENT

...... .Effluent Gross ,..,'.'>

1 D .. --SAMPLE .. .......Solids, Total Suspended MEASUREMENT 0053080-3010 Other Treatment.

Process w .*..:, , GRA13., '10Complete

,"________

7Chromium, hexavalent SAMPLE(as Cr) MEASUREMENT 01032 1 0 -.. .. ..., .....011 .016 ." -iy ..:.-Effluent Gross or, I -;m an'I;, .p.a V. .......-

.Chromium, total SAMPLE ........(as Cr) MEASUREMENT 0103410 RERMT PR.A,Effluent Gross ___________

___________x__________

Copper. total SAMPLE ..........

(as Cu) MEASUREMENT

.-0104210 -pwE:fIT'f-

...... .-ly GAEffluent Gross AW~ "~- ~ ~ ~ --Iren, total SAMPLE ..........

(as Fe) MEASUREMENT 0 0 1.0 -... ... --'. , --1 1 -4G0104510 Dal " .-.,.:. ;'".m,: t. ..... .-.-."- .f: ? ,.Effluent G ross .-_. .' "..__"

-7.Lead. total SAMPLE ........(as Pb) MEASUREMENT 01051 10 .-003MI.-,':.. ..NAIJTTLE i car*ty und! pnfty di law OW ums domwd and aul anahnnerds were prepared under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFRCER or suparbon in attedance with a Sysem daslgned to assure atd qualfied personnel I XVe0M and evalte fthdiniorm etl rsusbnd e Based en my ro e InW rOr MeM I,.___,..._

815 40&-3700Benjamin P. Youran who manage Lp e syss. or ase amm- direV:t/

Uio fortgtflithe itn. faste at gO OP n I015 101162012 Infonnafen submitted Is. to mOtes 13651 nowfeMge and bere. tn', acmruate.

and c-Wnete.

lai 8IGNA-RE IaimRINCIPLE__

Plant Manager aware m atmere are slgi pkaftt for tOrnnig false IOnnwmau.

induding me p-bbly of EXECUTIVE OFFICER OR NUMBER MMIDDIYYYY TM OR pmn flne and kldptos e for Wwwin AUTHORIZED AGENT COD NUMBERMM/DD/YY

__COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hers)1. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Metal Cleaning Wastewater was discharged this month.2. No Fire Protection, Service Water or Closed Cooling System Drain Water was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1162012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIIrEE NAMEIADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

U 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010DMR Mailing ZIP CODE:MAJOR(SUOR 01) CS61010IL0048313 PERMIT NUMBER002-0DISCHARGE NUMBERMONITORING PERIODM/DYYvI MMIDDJYYYYY STORMWATER RUNOFF BASINExternal Outfall* **NODISCHARGE EDJFROM I09/01/2012 I TOI09K30/2012 I! Il IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF TYPEVALUE VALUE UNITS VALUE VALUE VALUE UNITS E ANALYSIS TYPENickel. total SAMPLE ...... ......(as Ni) MEASUREMENT 0106710 I0.1-ERMr"

.,. .. " ... .-..":1 ,. .176 .."Effluent Gross ....IRLY: 1 0 'Zinc, total SAMPLE ......,,*(as Zn) MEASUREMENT 0109210 PERMIT ,.... .n.q..m .047 .26Effluent Gross _r___RE_

_ __._,__.

,. ,_", .." 3OPA AVG DAILYNMX GRABOil and Grease SAMPLE ....MEASUREMENT EffluentGross B.EQUIRElE

". .l,. 15 MxFlow. in conduit or thru SAMPLE ......treatment plant MEASUREMENT

......5005010 .ERI Req m.on .Req..Mon..-.

,..., ., -Whefn AEffluent Gross 7 WhenAAV -" ;.... " " .ischagig

.-SAMPLEMEASUREMENT SAMPLEMEASUREMENT

l-rEo u rrlma "--, ., .. ...".- .:;: -"-,

-::... ..3UN .... ...... ... ..: :...SAMPLEMEASUREMENT PERMIT .. -.." ..NCALECIE ify under penalty o law tus edocumen and aft attnaunems were prepared uner my TELEPHONE DATEPRINCIPAL EXcuTVE OER di suPe in aoance with a system design to assure y quaffTed peTonnelproper gather and evakfle the Informiationi submitted.

Bsed an my Inquiry at the perewor persosaftJ~L

~ .15~ii~iBenjaminP.Youan who manage the system, orhose prsms dlcby rsnssbel orjgathae Uin the nm, _ 406-370011at1onth infoImation submitted is. to fte beef o my Ietaatedge and betef. true. accurate.

and corr ef I am SIGNA OF e RINCIPLE 101/2Plant Manager aware at there awe s91flcer pnaloties or Subtl9iftg false infomation.

indudin ae possibliy of EXECUTIVE OFFICER OR U EMAIYMw 1 e and Imptsnaunn (O u vwotatn.

AUTHORIZED AGENT coDNUMBER MM__D_/Y__

Y_COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)1. This discharge point was not used this month.2. There was no discharge of processed steam generator chemical cleaning wastewater during the month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 1/6=2012 PAGE 20 0 4 ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit Mtf0048313 September 2012Page 1 of 3MONITORING DATA:WBD C WBD Flow Rock RiverDATE Temperature mgd Flowdeg F cfs09/01/2012 102.0 21.42 1,44009/02/2012 99.0 16.63 1,45009/03/2012 101.0 10.50 1,52009/04/2012 101.0 19.32 1,57009/05/2012 101.0 11.26 1,62009/06/2012 93.5 0.010 1,55009/07/2012 n/a 0 1,57009/08/2012 91.6 12.62 1,53009/09/2012 91.6 19.17 1,58009/10/2012 94.0 24.29 1,59009/11/2012 96.1 17.98 1,58009/12/2012 99.1 13.72 1,58009/13/2012 99.1 13.23 1,48009/14/2012 92.1 18.01 1,50009/15/2012 92.1 16.78 1,50009/16/2012 93.7 15.95 1,52009/17/2012 93.7 14.51 1,54009/18/2012 91.5 16.85 1,51009/19/2012 86.5 14.65 1,56009/20/2012 92.7 15.91 1,62009/21/2012 88.5 16.02 1,41009/22/2012 87.8 17.11 1,55009/23/2012 85.2 18.36 1,64009/24/2012 85.4 14.37 1,60009/25/2012 91.6 18.47 1,51009/26/2012 91.6 15.92 1,47009/27/2012 89.6 15.97 1,59009/28/2012 90.3 15.46 1,58009/29/2012 91.0 18.10 1,48009/30/2012 91.0 14.65 1,440K:\BYR_CH\BYRON.DB\CIerk\Monthly Discharge Monitor Rpt\2012Reports\September\September 2012 ATTACHOI

.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 September 2012Page 2 of 3HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (or associated rinses) containing hydrazine discharged to the Cooling System Blowdownduring the month of September 2012.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite and Bromine compounds were used this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 29 of 30 days.4. Per Special Condition 24 the influent from the Rock River and effluent fromOutfall 001-0 was monitored for Total Suspended Solids (TSS) this month.The Rock River TSS value was 28.0 mg/L on 09/10/2012.

The CWBD TSSvalue was 2.0 mg/L on 09/10/2012.

5. Rock River flow was <2400 cfs in September 2012 therefore dailytemperature calculations were required during this time period. (SpecialCondition 12). Per Special Condition 12, in the event the Rock River flow is<2,400 cfs, daily calculations will be undertaken to demonstrate compliance with the water quality standard.

The calculations are based on hourlymeasurements, averaged over a 24-hour calendar day for Rock River flow,main Rock River temperature, CW Blowdown flow, and CW Blowdowntemperature values. Results of the calculations shall be reported in theDMR on a monthly basis. Calculation results are in the table on thefollowing page.6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in September 2012. (Special Condition 15).K:\BYR_CH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\September\September 2012 ATTACHO1.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit 1L0048313 September 2012Page 3 of 3Date Average Average Average Average Calculated Water QualityRock CW M/U CW CW Temperature StandardRiver Temperature Blowdown Blowdown at edge of Temperature Flow (F) Flow Temperature mixing zone (F)(cfs) (gpm) (F) (F)9/01/12 1440 74 11971 97 75.2 909/02/12 1456 72 11983 99 73.4 909/03/12 1513 75 11971 100 75.6 909/04/12 1577 77 12038 101 77.9 909/05/12 1615 77 1658 96 77.5 909106/12 1544 81 0 N/A N/A 909/07/12 1570 80 1175 89 79.8 909/08/12 1531 75 14546 92 75.9 909/09/12 1571 73 14904 91 74.2 909/10/12 1593 74 15200 89 74.4 909/11/12 1577 73 11321 95 74.2 909/12/12 1578 75 10421 97 75.4 909/13/12 1487 73 10421 91 73.2 909/14/12 1508 69 11258 91 69.5 909/15/12 1498 71 11229 93 71.6 909/16/12 1521 71 11213 93 71.7 909/17/12 1538 70 11188 93 70.8 909/18/12 1518 68 11204 88 68.5 909/19/12 1557 65 11221 89 66.2 909/20/12 1621 66 11208 90 66.4 909/21/12 1417 64 11225 88 65.4 909/22/12 1537 61 11233 86 61.7 909/23/12 1633 60 11925 85 61.0 909/24/12 1609 58 11563 88 59.3 909/25/12 1516 60 11583 92 61.0 909/26/12 1472 62 11629 91 63.6 909/27/12 1574 61 11642 88 62.2 909/28/12 1586 60 11650 89 61.0 909/29/12 1487 61 10342 91 62.3 909/30/12 1450 62 12171 90 63.3 90K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\September\September 2012 ATTACHO1.doc Exeikn.Exelon Generation

Company, LLC www.exeloncorp.com Byron Station Nuclear445o North German Church RoadByron, IL 61olo-9794 November 26, 2012LTR: BYRON 2012-0123 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyWater Pollution ControlCompliance Assurance Section #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring ReportIn accordance with National Pollutant Discharge Elimination System (NPDES) Permit Number 1L0048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report for Byron Station, Units 1and 2. This report covers the period of October 1, 2012 through October 31, 2012.On 10/06/2012 at 11:20 hours a leak was discovered on the piping for the temporary mechanical draftcooling tower equipment.

The plastic pipe fractured and water flowed from the crack at an estimated 5,000 gallons per minute. The majority of the water was retained by sandbags and the leak was isolatedat 11:27. Approximately 30,000 gallons overflowed the sandbags and entered Woodland Creek via stormwater Outfall 003, East Station Area Runoff. Analysis results of a sample of the cooling tower waterobtained prior to entering the storm water ditch are summarized in the following table:pH I Copper (mg/l.) I Zinc (mg/.) I Chromium (mg/L)8.68 1 0.033 0.0181 <0.0021The remainder of the leaked water was pumped back into the Unit 2 Natural Draft Cooling Tower basin.If there are any questions regarding this report, please contact Ms. Zoe Cox, Environmental/Radwaste Supervisor, at (815) 406-3035.

Respectfully, Benj oumanPlant ManagerByron Nuclear Generating StationBPY/DS/eh Attachments bcc: Jennifer Gould -Environmental

-Cantera (electronic)

Zoe Cox -Environmental

-ByronI-00LILtaccwzr zIwcc0I09iwzwaINILU010-io -d~wU~d~j'gliiihIZRIto-.

NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555.5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. L 61010DMR Maeing ZIP CODE:MAJOR(SUHR 01) CS61010I 1-L0048313 PERMIT NUMBERA01-0DISCHARGE NUMBERMONITORING PERIODI MMIDDJYYY I MMIDO(YYY DEMINERALIZER REGENERATE WASTE (0011A)External Outfall***NO DISCHARGE

[ **! _ _FROMI10101/2012 ITOlII _ _ I10/31/2012 Il lI NATIONAL POLLUTANT

[ GE ELIMINATION SYSTEM (NPDES)

REPORT (DMR)61010PERMITTEE NAMEJADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010ATTN: Zoe Cox/ENV SPECDMR Mailing ZIP CODE:MAJOR(SUER 01) CSI L0048313PERMIT NUMBERB01-0DISCHARGE NUMBERMONITORING PERIODMMIDDIIYYYY

_j I MM1DDfYYYY SP PLANT EFFLUENT (FORMER 001B)Extamal OutUl-" NO DISCHARGE F-1FROMl10/01/2012 I Tot1013112012 Il III IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TPVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS EBOD, 5-.Day SML(200.74 0.96 26 16.0 23.0 19 0 02r30 24(20 Deg. C:) MEASUREMENT 0031010 sný 10.5 ,.2 TWI~9tR Mnt -vQqMMEffluent Gross ~~B A. 2~LZ~aL*

.~PH .... .-7.51.. 7.61 12 0 02/30 GRMEASUREMENT 00400 1 0 ,.-_ .' "" ' : -i-. ..., ... ...Effluent Gross ALL UMM -, *!,.' -SAMPLESolids, total suspended MEASUREMENT 021 0.32 26 4.3 7. 0 0230 2400530.10

.-, -,. -. , ....,, ' :. ....Effluent Gross oEWIIW -. 1-,w Mm ~t~ ____Fow in conduit or th....A..E.......

0 01/01 CNtreatment plant MEASUREMENT 0.0 _ _ 0_00_ 3_001_1__

5005010 o W4 '-: ' 4.eq, o

-..--* "

-.,,,-A._~ Ft. ... ...Effluent Gross I". ... N .-- ...-;- " -* "' ".SAMPLEMEASUREMENT SAMPLEMEASUREMENT SAMPLEMEASUREMENT IRU ___ __ __ --* , -. " .,.NAMEI'lTLE I ceGOy under penalty d law 0a 016 doslme and a11 were prepared un R TELEPHONE DATEPIRINCIPAL EXECI~LVE OFFICER Aontn or supenion c ac arnce with a syame designed to assure da quated persnnelPreer gather and evakta die Irdonmatim submmlat.

Based on my quWt at the poeran o persons 815 406-3700Benjamin P. Yournan who mamae the aYStemo thda. permons directly respaosle for gathenl t Infomalna.

the 11/19/2D12 iroimation

a. tothe best almy owxle and bele. true. a=zu- and ompieta ,am g aE 4NA PRINCIPLE Plant Manager aware tha Viere m s1nWCant ar odmtbM. dg the poLnstd EXECUTIVE OFFICER OR N EM Yow ,Jead Io nwn voan.AUTHORIZED AGENT CODE NUMBER M__ D______COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Flow ekisted through this oulfall 31 of 31 days dunng this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11612012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIlTEE NAME/ADDRESS NAME Exalon Generation Co., LLCADDRESS 4300 Winfifld RoadWarrenvilie, IL 60655-5701 FACIITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 610101L0048313 PERMIT NUMBERC01-0DISCHARGE NUMBEROMR Mailing ZIP CODE:MAJOR(SUBR 01) CSWWTP (FORMER 001C)External Outfall"* NODISCHARGE 61010MONITORING PERIODMMIDD/YYYY I I MM/DDJYYYY I I4FROMI10/01/2012 I Tol10/31=12IATTN: Zoe Cox/ENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SMLVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESolids, total suendedS..

.... 9.4 9.7 19 0 02130 24So~ls toalsusened MEASUREMENT 0053010 t.1*5R~4 4pen4' j m t' Tw'~r~fiCM2 Effluent Gross ft_-.?. .. " -. ......Chromium, hexavalent SAMPLE(as Cr) MEASUREMENT 5000103210 " .eg." " ".. "Effluent GrossChromium, total SAMPLE .. .....(as Cr) MEASUREMENT Soo0103410 ":'" .flt:;" " :l G"Effluent Gross RA.

t3j a.r ! 4 .' :" -Copper, total SAMPLE .....5(as Cu) MEASUREMENT Soo0104210 ". -". .1, ! 4-'. .n" r.$ '1"- -.Effluent Gross -SWJRMEr 2pi ;wAAva.-

tAY~~.'e' Iron, total SAMPLE ...... .-me.......

(as Fe) MEASUREMENT SIX0Effluent Gros .____ -P' ';x UfS. .Lead, total mS.AMPLEese

• ~n 0(as Pb) MEASUREMENT s____ ______________

____ ___0105110 M'I1/2T-,..:

s "a". M. A $ REffluent Gross A.M -IM bM4..

..

L2 __.,-- 9. , .aE e , ' : -Nickel, total SAMPLE ........

.(as Ni) MEASUREMENT SIX001067 1 0 :"< -.-

" ;- -tý- -" "1 -.i .4 -. ...vng- .. .-0 .i,,,'"Effluent Gross I- -.*... .

, ,'- .:...Ni kel, TT toa.APE ... .......NAMVFlITE I cedy w1der pnally of law mat dcment and an anacdnwn

-09 prepared undjr myPRINCIPAL EXEOnVE E dream w sjpeu sin f accriene ui asyem essns tor a ist quae- e i TELEPHONE DATEPfOyV aue am evah"ftrdmkvfon asubadeal.

eas an x %my at the epersons lxmm---81 063Benjamin P. Yournan who anac the sysMO P 0e r Msy Maspe trg Owm1nfuri me a m" ) 615 406-370011/19/2012 Mlonmat sumitted is. to the best o my mo ,edge and beoS. tnsee and compe. I am SIGNATIRE OF I/C9IPL2E Plant Manager aware ha Stre am significarn peae Im subm ase innatim, kb te s E T OFFICER OR AREAibispfnw r and bpnpibhwnien for knonbi sianw EXCTVJFIE R UBRMIOYiwm rums nmvI AUTHORIZED AGENT CODENMR//_

COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Roference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed through this outlali 14 of 31 days during the month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 1/6/2012 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIT'EE NAME/ADDRESS NAME Exelon Generalton Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadIL0048313 PERMIT NUMBERI C01-0DISCHARGE NUMBERMONITORING PERIODM"OrYYY I I MMIDD1YYYY DMR Mailing ZIP CODE:MAJOR(SUBR 01) CSWWTP (FORMER ODIC)External Outall**NO DISCHARGE 3.61010FROMI10101/2012 TOI10/31/2012 III III IByron, IL 61010ATTN: Zoe Cox1ENV SPECFREUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TPVALUE VALUE UNITS VALUE VALUE VALUE UNITS O F TYPEZinc, total .. ....500(as Zn) MEASUREMENT Soo0109210 1._Wa.. aiEffuent Gross J __,___. _.. -__ .- .. .. .--...;..Row, in conduit or thru SAMPLEtreatment plant MEASUREMENT 5005010 PERIyIT.-

Rgq.Mqn .Req. ...-.-. .... ........ --E~ffluent Gross , --SAMPLEMEASUREMENT

, * .R5'IIM W ... -,.___.. ....___ ____! / ......~ ..S _____.____..

_ __...______-"

... SAMPLEMEASUREMENT

____________

• MEASUREMENT

.__,___"______

' .'" .: ..-. ...,.L.- ..-. ; .. ...SAMPLEMEASUREMENT

_ _ _ _ _.__.__ _ ..E, ..EW. -i .

_. _ __.._

' _ ..... ._.-__ _ _ __ _ _ __ _ __ _ _ __ _ _ _ _-______.-

.q ....SAMPLEMEASUREMENT--

-_: ...-- --. ' , ; .... .__.....

...A........_

_ __ _ _NAMEI1TLE cerUy unde penarly d of taw Me do doument and an atactunants wwe preared under liy TELEPHONE DATEPRINCXPAL EXECU1hVE OFFRCER or upervisi in accdance with a system designed to assure tda quafied personnel

,rlegatherand evalue te inknnatin submittd.

Based an my hquiry of the person or penisons81 0630Benjamnn P. Youman m manage the syste or those persns diecty respsbe for game"i the iymbon. the N E , 815 1i406-3700 11/1912P12 Informan submitted is. to te best of mi Ismatedge and Inbef , acurate.

and conpIbea SIGNARE OF MNCIPLE_Plant Manager aware o taere a sigricant penalis for submitting talse ifomati inclutin pOssiity d EXECUTIE OFCER OR AREAam a and pun t bwag w AUTHORIZED AGENT CODE NUMBER _ MDD/YYYYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1162012 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIrIEE NAMEIADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarenvie,'lL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010OMR Mailing ZIP CODEtMAJOR(SUBR 01) CS61010"- 1.0048313 PERMIT NUMBERD01-0ý DISCHARGE NUMBERMONITORING PERIODMMWDDIYV I MMIDD/YYYV RADWASTE TREATMENT (FORMER 001D)Extenal Outfail"**NO DISCHARGE "JFROMI10101/2012 TIT10/31/2012 II lIt II 0NATIONAL POLLUTANT DISCHARGE EUMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITrEE NAME/ADDRESS NAME Exeton Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010I lL0048313 PERMIT NUMBERE01-0DISCHARGE NUMBER[ MONITORING PERIODMMIDDIYYYY I MMIDDJYYYY STORMWATER (FORMER 001E)External Outfall*" I NO DISCHARGEr FROMI10/01/2012 1 TOI10/31/2012 Il I! IByron. IL 61010ATTN: Zoe Cox1ENV SPEC ____________________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX FrTYPE>< ANALYSISSolids. total suspended SAMPLE 500MEASUREMENT_____

_____ _________

_______________

_____005310 4q~T- n1 GRAPEffluent Gross RE M .'E * ... .M r D, 4' , .- A ": 4 ."SAMPLE ...... 29.4 48.1 19 0 01/07 GRSolids. total sused MEASUREMENT 0053080-

., ...Other Treatment, Process RNT.*.- 3 1complete

.-;z~".,Chromium.

hexavalent SAMPLE ...... 500(as Cr) MEASUREMENT oim io -,,:",.:-

!. -*. **.. ...' ..*-,.Effluent Gross

• __________

.* ____Chromium, total SAMPLE ...... 500(as Cr) MEASUREMENT Copper, total SAMPLE S.I... ...,5(as Cu) MEASREMENT 0104210 e'lM" .." .-_ .. ..GR..Effluent GrossIron. total SAMPLE Soo.. ...... ..(as Fe) MEASUREMENT 0104510 "RE DEffluent Gross REQ JIREME .. ., .., .". ..:,._, ..--', -.;D m .Lead, total SAMPLE ................

500(as Pb) MEASUREMENT Effluent Gross firEQUIREMT-

-NAMEittLE I ceitly under penalty of law gho ft domumner snd ag anadrmnlits were prepated under mi J TELEPHONE DATEPRWWCAL EXECUTrIVE OFFICER dwmcmo W suers ,n =0,d,=c w a system "eO~ed to assthe Wellafied Muneloupropedy gether and evablte fthinformation sutimld.

Based an my inquiry of the person or per8sonBejmin P. Youan who manage the sm or those persons dWcly responsrbe for gathering the infonathon, the 11/191M12 kdonnadon sul~ b e s, to Me besg o my bnw belie, nMo. aca nte, and *onmel e I am SlGNAO E C F INCP LPlant Manager aware tat me are s9inicant penahes tar submalung ese bdonnadon, bidug the pobrdy of EXECUTIVE OFICEOR N EEA.. ON line and bpsnsusf ohtq violatns.

AUTHORIZED AGENT CODE NUMBER MMDD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachmenta here)1. There was no discharge of processed steam generator chemical cleaning wastewater during the month.2. Flow existed through this outfall 4 of 31 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6I2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010DMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERE01-ODISCHARGE NUMBERMONITORING PERIODMMIDDIYYYY IMMIDDIYYY STORMWATER (FORMER 001E)External Outfall***NODISCHARGE EJFROMI10/01/2012 I TOI10131/2012 II IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF ApVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPENickel. total SAMPLE ....(as NI MEASUREMENT 0106710 11u -'. ...1 2 " .D GRABEff luent Gross ~~'.~-~ .i-& -Z-~~ ~~' ___Zinc. total SAMPLE ............

....(as Zn) MEASUREMENT 0109210 , ;".-. ,.. V .Effluent Gross ,JqEEI- .-, _"_..._"

_'""-*Flow, in conduit or thru SAMPLESpalM A U E E T 0.219 0.356 3 ..-.......

• "**~ 0 02/30 CNtreallment plant MEASUREMENT Effluent Gross 7*_____M

~::>er*

...SAMPLEMEASUREMENT

-_, .-. ., -, .-- .. -.;--: .:.; ......i.- -._ _-SAMPLEMEASUREMENT

________

____ ______ _ _ _ _ __ _ _ _ EQUIREBBEI

.. ;-. .I.. .-. .:-. -.-,,.,... :..-.. ;.... ., ....... -.,.SAMPLEMEASUREMENT SAMPLEMEASUREMENTq le .

,. ., .,.. ::,/., ,. ,.,-:....

..... .. ...... ....... .... ........-.

...... a.".-.. .__.,__.._..___..

...:. .._ __.._.__....*

.: .-. " ., ,,. .' ,.. .~ d ..:... £. .: ..- .,. ....-.. ..: .., .,.PRINCIPAL EXECUTIVE OFFCER :irectim a s in accorance wah a system dTELEPd to aNsure VW Oaied pDmAelpmpeuy gather and evjt the Wdmmabi snrumbmd.

Basedn my kquIYal iPetib l m , ,,- 815 me6-37 1s orBenjamin P. Youran who manage tha syston or ume persons directy responsbe tar gathaertng the inkiomal, ir 11/11212information t is. to Male best d my awdege and beielf. true. accursM and complete, SI GNA aE OF P %jLEPlant Manager aware thatl ere are significar pona for submittig talse nfomatim.

bkiin Me posstily l EXECUITIVE OFFICE R N BMDAREATVM0"FF~rW pn and inprmmimman for knowing vidaions.

AUTHORIZED AGENT COD NUMBER MMIDDIYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. No Closed Cooling System Drain Water was discharged this month.2. Fire Protection and Service Water System drain water was discharged this month.3. No Turbine Buildina Fire and Oil Sump or Generic Non-Chemical Cleanina wastewater was discharged this month.EPA Form 3320-I (Rev 01106) Previous editions may be used. 1/6/2012 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010DMR Maeling ZIP CODE:MAJOR(SUBR ol) cS61010I IL0048313 PERMIT NUMBERF- 001-0DISCHARGE NUMBERMONITORING PERIODMMJDDJYYYY

_ MMIDDIYYYY COOLING SYSTEM BLOWDOWNExternal Outfall* " NO DISCHARGE J *I .......FROMI1010112012 ITOI10/31/2012 II Ii T--! !ATTN: Zoe CoxIENV SPECFREQUEN_

_QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. SAMPLEPARAMETER OF TYPE" VALUE VALUE. UNITS VALUE VALUE VALUE UNITS EX ANALYSISTemperature.

water c1eg. SAMPLE ...CN..........92.1 Fahrenheit MEASUREMENT 0s q .M * .Effluent Gross : :; .......C.. .-TI .SAMPLE 829 8.58 12 0 01/07 GRMEASUREMENT 0040010 .EljMIT ' .... -..,.6. .. .9Effluent Gross " .Tjj " ". _ ,,,_. "U .Sos, total suspended PLE ..... 5.6 5.6 19 0 01/30 GRMEASUREMENT 0053010 4'-!,T ,., .. .. 1 i.-" -q.4'. e Effluent Gross 11 In___________________

Oil& Grease SAMPLE <1.4 <1.4 19 0 01/07 GRMEASUREMENT 00556110W"T Effluent Gross _________

M. -,

M, i* .. .______."_

Chromium, total (as Cr) SAMPLE .... ... ... ..... .<0.0021 19 0 01/07 GRMEASUREMENT 0103410 .-'.:., -* ...".. ..6.Effluent Gross BEQUIREIEMT-.

.-

'..- 31 ....._, -Copper, total (as Cu) SAMPLE ...... 0.030 19 0 01/07 GRMEASUREMENT 0104210 P 0.071R.iEffluent Gross REQUIREMENT

" , " " " .' I ". ':,'". " " ..... ".....Zinc, total ( Zn) SAMPLE ....... 4.002 0.004 19 0 01/07 ORMEASUREMENT 0109210 ,REW -, , .., ..*.*.. " '.., .214. .. 3 --Effluent Gross .RE IREME .,- .. ., .

.... -.NAMEnTLE I cW* under peakMy 0 law go this doOument and au atachments worw prpamd under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFRCER or surs in accodance with a system designed to assure dud qualifed pensornel propetly gather and evahne the Inaimafdwtm su s'my bqxy d do peso1815n or6perso1 406-3700Benjamin P. Youman who manage we system. r m.of diecey rspmsbe for gathering me -f1m-a -11/19/2012 information aftnated is. to go beat di my bwmtledge and b"ie, tre. accurate.

and co;p'-s.

lamn SIGN OURE 0 CIPLEPlant Manager awam that mtm am significan penaes for submitgin abe IkdonmaT.

Including th possiblily d EXECUTIVE OFFICER OR AREjI nR ome and nprisuiamen for itrar, ong VIOIamenL AUTHORIZED AGENT CODE NUMBER MMDD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. Monitoring data for outfall 001-0 is included on attachment EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6=2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAMIJADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, L 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010DMR Mailing ZIP CODE:MAJOR(SUOR 01) CS61010I IL004831 3PERMIT NUMBER001-0DISCHARGE NUMBERMONITORING PERIODCOOUNG SYSTEM BLOWDOWNExternal Outfall* " NO DISCHARGE FROM I100112012 ITOI10/31/2012

! Ii IQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY

• OF SAMPLEPARAMETER VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX NO TYPESAMPLE ANALYSISOxidants.

total residual MASURE 0.04 19 0 01/07 GR3404410o

" ...10 _ _ _Effluent Gross RE ..-'P wPriority pollutants total effluent MEASUREMENT

.5005000810 MT.- Req Mon. -_.... ., P, Re.7711-Effluent Gros x e m B .-; .2.,L 1. W.o.y i ( ,:5Flow. in conduit or thru SAMPLEtreatment plant MEASUREMENT 5005010 1 .. -..;..'.,. -., ,n.- .Effluent Gross AW irM 4 .CONTIChlorine.

total residual SAMPLEMEASUREMENT Soo50060 10 '.'t~r p ~ ~> ~%...-. -ec1 ___Effluent Gross .N-. ,__ , .:, .- .,: .-...[ J-y MX. ". L,:. : ,_.. .".SAMPLE ......t-ydn MEASUREMENT 5008131310 4 M._ .-,,- ... .. ._ " .- .0. .o ..027 -Da""y- WhnEffluent Gross .U. ...' .* .-.. , ..,V " , .RAGSAMPLE -MEASUREMENT

_____"__"___R__IT'___',,_ :" :: "m.~..L ... " ;'~ " ~ ~ .SAMPLEMEASUREMENT

___ _. ......_ E UIAY -'..... t --,- .... ....'NAME/IAMPLE PRINCIPAL EXECUTInVE OFFCR directimo or sipemin acmoance wit a systwni iesied to do quaffed pam -d TELEPHONE DATEBenjamin P. Youmnan Prcpaltr oatim amd evalita the bionnabat slaultad.

EBaed an frev inquiry d die peis or perms 81 40ii-3700 who manage Ow systemn or Sose permns directly MepwUD lot gadfltng the tntonmaton.

f IG E OF 1119/212Plant Manager inml onaion subrnabd is. to Me best ol my nowaledge and oewl. e and cmpete, lam E V C_ OR_6111110M=__

Owlhatm ___a_ ____P_ for suIT_____

fa___ __ WMn the _ al EXECUTIVE OFaICER OR AREA NUMBER MMD_IIt penafan ad bwftsionl lor knowing vPS. AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)EPA Form 3320-1 (Rev 01/06) Previous editmis may be used. 11612012 PAGE 2 0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDESDISCHARGE MONITORING REPORT (DMR)PERMrrTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010IL0048313 PERMIT NUMBER002-0DISCHARGE NUMBER;)DMR Mailing ZIP CODE-MAJOR(SUBR 01) CSSTORMWATER RUNOFF BASINExternal Outfan61010IMONITORING PERIODI MMI/DWYYYY ITO FMM/DD/YYYY IFROM II10/01/2012 10/31/2012 I~NO DISCHARGE

=wj -QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS SIS TYPES o i s o a d dS A M P L E. ..,. .,, .. .Solids. Total Ssend MEASUREMENT 0053010 ..-...' -. GRASEffluent Gross w,4+ !l, ; -, ,.,Solids. Total Suspended EAUMLE00530 8 0 .' , ,, .*.*,,'.,. ..-." ... ..q *..

.-. ..-..., .Other Treatment Process V',Chromium, hexavalent SAMPLE .......(as Cr) MEASUREMENT 0103210 ....... -..* : " pEffluent Gross I's .j"41 akka-- t e' _____Chromium, total SAMPLE .......(as Cr) MEASUREMENT

__0103410 * ,.Effluent Gross JWQ______U

-*1'IICopper, total SAMPLE....

(as Cu) MEASUREMENT 01042 10 "U+ ..

..0 ..'.2M .:: ..041 *:: .+ +.. :l ,Effluent GrossO "Iron. total SAMPLE .........

(as Fe) MEASUREMENT 0 1 0 4 5 1 0 , .' -.."' ..., -.l .-Effluent Gross GRAUIRE],

T _____. ___ ....Ct2.... ._. .. ....'-Lead, total SAMPLE ....(as Pb) MEASUREMENT 01051 10 `-PARRMIToly

.RAEffluent Gross -V." Q6~ .AIY4NAMEITILE I certify under penaly of law dd fts documern and ag aeanacmes were piepared under my TELEPHONE DATEPRNCIPAL EXECUTIVE OFRCER irectin or supeemion In accordance with a system designed to assure that quad Persnneproperty gathe and evalute fth infrmatian submintted.

Based an my mwqus d the person or pesrtsona40-70 1/91Benjamin P. Youman who manage the system. or thse persons durctly responsmft for gatherngM Me infarmation, theasulnmned is. to the best of my knoedge and beief, true. scrals. and complete.

Iani SIGNAU RE OF NCIPLE 1Plant Manager aware that tere are sGnificant penahes for submitling labse Inimatio.

Mckn fte poasibrily al EXECUTIVE OFFICER OR AREAr OR pHRIM i and k~iSnnMlfll for knowing violation.

AUTHORIZED AGENT CODE NUMBER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)1. No Turbine Building Fire and 00 Sump or Generic Non-Chemical Metal Cleaning Wastewater was discharged this month.2. No Fire Protection, Service Water or Closed Cooling System Drain Water was discharged this month.EPA Form 3320-1 (Rev 01106) Previous editions may be used. 1/6/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvile.

! 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010A"rTJ. -1%" ML CQDar"I L0048313I PERMIT NUMBERFR N002-01 DISCHARGE NUMBERIMONITORING PERIODMMIDDIYYYY MMIDDIYYYY DUR Mailing ZIP CODE:MAJOR(SUBR 01) CSSTORMWATER RUNOFF BASINExternal Outtanl***NO DISCHARGE

[J61010I._FROMI10/01/2012 IITot10/31/2012 IlQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OF TYPE__________

_____ __________

_____ _____ ANALYSIS TPNickel. total SAMPLE ..........

...(as Ni) MEASUREMENT 0106710 "P .... '" .011 -.176 .... .Effluent Gross .. .Ai-.- ' -.-'- .., -. 77RA8Zinc, total SAMPLE ...(as Zn) MEASUREMENT 0109210 0~~T.047Effluent Gross DeEwIJIID " " .: .-0i and Grease SAMPLE ......MEASUREMENT 0358210 "*- .. .: w ."N' pis ...--.Effluent Gross IM Mg~WhnFlow, in conduit or thru SAMPLE -- ...- ..........

treatment plant MEASUREMENT 5005010 R rg8 -T , .--,.'*:.' .: , ; ".q,#M.^.

WhqpEffluent Gross -IBEQUIREMEN7

.,W :P. , ..' ....sc1rgl ..SAMPLEMEASUREMENT SAMPLEMEASUREMENT REUIR .* ....t,, .... *SAMPLEMEASUREMENT NAmErmnn.E I cenily under penatty d law that thits dcwime and ag atadiments were ppatled under my TELEPHONE DATEPRINCIPAL EXECUtlVE OFFICER ecwion o, suMW macadence with a system designed to assure that qualfied personnel Poperty gather and evaa the domnman submitted.

Based an my InqWry d the person or personsBenjamin P. Youman who manage the system those pers drectly resmnpae for gatherg the lnImaonell.

the m OF CIPLE 11112012Information sub is. to te best cd mi kwledg eand b"e. uie. accurale.

and completI.

1Plant Manager aware at there are slWgn, caM penafts for suhnitting false indomam wkdg the pasasbsi EXECUTIVE OFFICER OR N EM Y, oR !.. lnprabdtmkent for knowIng vkLatains.

AUTHORIZED AGENT CODE NUMBER MM__ /DD_ _COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)1. This discharge point was not used this month.2. There was no discharge of processed steam generator chemical cleaning wastewater during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 11582012 PAGE 2SL ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 October 2012Page 1 of 3MONITORING DATA:CWBD Rock RiverDATE Temperature mgd Flowdeg F cfs10/01/2012 89.7 16.53 1,52010/02/2012 89.2 17.71 1,53010/03/2012 89.9 16.99 1,45010/04/2012 91.8 17.62 1,55010/05/2012 91.8 18.17 1,55010/06/2012 83.4 18.70 1,45010/07/2012 81.2 17.50 1,42010/08/2012 82.3 18.01 1,58010/09/2012 81.9 13.78 1,55010/10/2012 78.8 15.67 1,45010/11/2012 78.9 18.82 1,60010/12/2012 78.9 17.59 1,45010/13/2012 78.9 21.09 1,50010/14/2012 90.8 21.01 1,79010/15/2012 89.1 13.78 1,82010/16/2012 82.1 17.26 1,82010/17/2012 84.6 17.34 1,93010/18/2012 82.2 18.0 2,22010/19/2012 80.1 16.21 2,05010/20/2012 79.7 23.59 2,20010/21/2012 77.5 17.88 2,16010/22/2012 90.3 13.60 2,13010/23/2012 90.3 16.17 2,43010/24/2012 91.8 16.73 2,82010/25/2012 92.1 19.90 2,86010/26/2012 79.4 19.11 2,75010/27/2012 77.9 23.52 2,71010/28/2012 76.1 19.37 2,59010/29/2012 73.7 15.88 2,50010/30/2012 72.8 18.13 2,46010/31/2012 74.9 21.30 2,440K:\BYR_CH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\October\October 2012 ATTACH01.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 October 2012Page 2 of 3HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (or associated rinses) containing hydrazine discharged to the Cooling System Blowdownduring the month of October 2012.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite and Bromine compounds were used this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 31 of 31 days.4. Per Special Condition 24 the influent from the Rock River and effluent fromOutfall 001-0 was monitored for Total Suspended Solids (TSS) this month.The Rock River TSS value was 13.6 mg/L on 10/08/2012.

The CWBD TSSvalue was 5.6 mg/L on 10/08/2012.

5. Rock River flow was <2400 cfs in October 2012 until October 24th therefore daily temperature calculations were required during this time period.(Special Condition 12). Per Special Condition 12, in the event the RockRiver flow is <2,400 cfs, daily calculations will be undertaken todemonstrate compliance with the water quality standard.

The calculations are based on hourly measurements, averaged over a 24-hour calendar dayfor Rock River flow, main Rock River temperature, CW Blowdown flow, andCW Blowdown temperature values. Results of the calculations shall bereported in the DMR on a monthly basis. Calculation results are in the tableon the following page.6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in October 2012. (Special Condition 15).K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\October\October 2012 ATTACHO I.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 October 2012Page 3 of 3Date Average Average Average Average Calculated Water QualityRock CW M/U CW CW Temperature StandardRiver Temperature Blowdown Blowdown at edge of Temperature Flow (F) Flow Temperature mixing zone (F)(cfs) (gpm) (F) (F)10/01/12 1,520 62 12246 89 63.1 9010/02/12 1,530 61 12304 90 62.2 9010/03/12 1,450 62 12283 90 63.4 9010/04/12 1,550 61 12254 90 62.2 9010/05/12 1,550 57 12321 83 58.0 9010/06112 1,450 53 12225 81 54.4 9010/07/12 1 420 52 12167 82 53.5 9010/08/12 1,580 52 11838 79 53.1 9010/09/12 1,550 52 9750 79 52.9 9010/10/12 1,450 52 12750 75 53.2 9010/11/12 1,600 51 12713 77 52.0 9010/1212 1450 52 12754 76 53.2 9010/13/12 1,500 .54 12883 81 55.1 9010/14/12 1,790 57 13142 86 58.2 9010/15/12 1 820 55 12229 79 55.8 9010/16/12 1,820 55 12408 83 56.0 9010/17/12 1,930 57 12204 84 57.9 9010/18/12 2,220 54 12217 78 54.7 9010/19/12 2,050 54 13013 77 54.7 9010/20/12 2,200 54 13046 78 54.7 9010/21/12 2,160 54 12229 81 54.8 9010/22/12 2,130 57 10513 88 57.7 9010/23/12 2,430 58 13242 89 58.8 90NK:\BYR._CH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\October\October 2012 ATTACH01.doc Exelon.Exelon Generation

Company, LLC www.exeloncorp.com Byron Station445o North German Church RoadByron, IL 61010-9794 December 17, 2012LTR: BYRON 2012-0133 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyWater Pollution ControlCompliance Assurance Section #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring ReportIn accordance with National Pollutant Discharge Elimination System (NPDES) Permit Number1L0048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report forByron Station, Units 1 and 2. This report covers the period of November 1, 2012 throughNovember 30, 2012.If there are any questions regarding this report, please contact Ms. Zoe Cox,Environmental/Radwaste Supervisor, at (815) 406-3035.

Respectfully, Benjai oumanPlant ManagerByron Nuclear Generating StationBPY/ZC/eh Attachments K~rVt,-bcc: Jennifer Gould -Environmental

-Cantera (electronic)

Zoo Cox -Environmental

-Byron0 0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIF-rEE NAME/ADDRESS NAME Exblon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010DMR Mailing ZIP CODE.MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERA01-0DISCHARGE NUMBERMONIrORING PERIOD-D/YYYY j I DEMINERALIZER REGENERATE WASTE (001A)External Outfall**INODISCHARGE EJFROMI11101012TOI11/30/2012 II IATTN: Zoo COXIENV SPEC _________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER EXOF TPVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX AAL TYPESolids, Total Suspended MEASUREMENT

-r..3.6 <.7 19 0 01/30,_ 08Effluent Gross -A POW. -Chromium.

hexavalent SAMPLE 5....(as Cr) MEASUREMENT 01032 1 0 "J ..Effluent GrossChromium, total SAMPLE Soo(as Cr) MEASUREMENT 0103410 ... ..- 7 7- a, .... ,. .,Effluent Gross -T.;--.f-Copper, total SAMPLE 50(as Cu) MEASUREMENT 0104210;VPFrt.

.t -"~ 1 N, -E~ffluent Gross A3K$S .__Iron, total

.......oo.. .f.(as Fe) MEASUREMENT Effluent Gross

..Lead. Total SAMPLE .50(as Pb) MEAS5REMENT

"'A4 .. --, ,..". -. AoA"".. Y_'f:a -,v " ..NickSl. total SAMPLE ........

......500(as Ni) MEASUREMENT50 NAMEIfll.E J cendy wider penany of law mat mt document and at anenta were prepared wder rmy TELEPHONE DATEPRICIJ.AL EXECUTWE OFRCER d*ecbwl or i accrdance wdh a system designd to assure mat qualified pnpeuly ga2mer and evalute me Inmmaibi aubmitted eased an my inquiry o me pem o enom )rperBenjamin P. Youman who manage me systemn or mine pessa diirecly mapisbe for goameang me information.

me 815 406-3700 12J17/2012 infomonn subitted Is, to me beat of my knowledge and belief. tbue. a5 e, and onpiS. amn SIGNA rE 0 CIPLEPlant Manager aware Mot mere are signtant penalis fo ru Mlg Lawe Infomaon, ldig me posaiy ol EXECUTIE OFFICER OR AREATPDONfiW= and for knowng vilak AUTHORIZED AGENT _,CODE NUMBER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewatar during this month.2. Row existed 30 of 30 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/682012 PAGE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIlTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winlield RoadWarrenville.

IL 60%55-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010IL0048313 PERMIT NUMBERI A01-0IDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010I DISCHARGE NUMBERIMONITORING PERIODMMIDWYYYI MMIDDJYYYY DEMINERALIZER REGENERATE WASTE (001A)External Outfall* **NODISCHARGE E]"FROM'I11/01/2012 TOI11/30/2012 II gI NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMrTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winlield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadIL0048313 PERMIT NUMBERB01-0DISCHARGE NUMBERDMR Mailing ZIP CODE*MAJOR(SUBR 01) CSSTP PLANT EFFLUENT (FORMER 0013)External OutfallM *' NO DISCHARGE r]61010I MONITORING PERIODMMIDDYYYY I I MMDD/YYYY I ..FROM-!11=01/2012 t Tol11/3012012 ILIByron. IL 61010ATTN: Zoe Cox/ENV SPECFREQUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEP VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OF TYPE_______ ANALYSIS

___SOD.027 0.35 2' 5.0 7.0 19 0 02/30 24(20 Deg. C) MEASUREMENT 003io1o 194 30 ~ ' ot)>9J2Effluent Gross "it- ... I *.pHSAMPLE

..... 7.13 ...7.61 12 0 02W3 GRpHMEASUREMENT 0040010 Cri"w .u-~~r rGAEffluent Gross 3 M ý :.ý,- -Sol.ttlsseddSAMPLE

-c0.11 0.12 26 ...0<.8 2.4 19 0 02030 24Solids, total suspended MEASUREMENT 0053010 .* h-Effluent Gross

'A .").'..- .-, ...'"Z.,:'"

.,2.".Flow, in conduit or thru SAMPLE 0006 0007 3 0 01/01 CNtreatment plant MEASUREMENT 5005010 .0- ..- r --.. 't...Effluent Gross- -_ _ .it aSAMPLEMEASUREMENT MEASUREMENT

__________

___SAMPLEMEASUREMENT

.____._._,__

_.-___..--..

,r ;s. .M.4Z. ",:. "" gg,, .-~, -rt c: " .. ... .... ' Ns' .' a-. .n- .' .. ."- .'- .-... .. -.- _ .A-. ..It..--A....-.

NAMEnITLE I corfy under penalty of law maimt domimn and al atacumms w-re prepared under my TELEPHONE DATEPRINOPAL.

EXECUTIVE OFFICER irectio or supervison in acomdance with a system desgned to assure tht coalifidE perNoEnel properly gather and evake the Wnoation asubmitted.

Base an my inquuy at lte pemrso or pe'sons 815 406-3700Benjamin P. Yournan who manage me system those persons directly responshe for gathering the inforation, he i 12/17/2012 information submitted s, to the best o my nowledge and true. accurf. and complete.

I am SlGNADIRE OFrORINCIPLE Plant Manager tware M there ae sianificant penes for suitiftngV fale Including the possiblity o EXECUTIVE OFFICER OR N EDAiwma .TEo fne and PUsNmneE for NTEnD AUTHORIZED AGENT CODE NUMBER MM/DDYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachmente here)1. Row existed through this outfall 28 of 30 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/A 12 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenviue, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010ATTN: ZOA CxIFNV SPFtCIL0048313 PERMIT NUMBERC01-0DISCHARGE NUMBERMONITORING PERIODMMIDDWYYYY I I MMIDDWYYYY OUR Mailing ZIP CODE:MAJOR(SUOR 01) CSWWTP (FORMER ODIC)External Outfall***NO DISCHARGE EF ...61010IFROMI11/01/2012 JTOI! I!1 130/2012IQUANTITY OR LOADING QUANTITY OR CONCENTRAllON NO. FREQUENCY SAMPLEPARAMETER EXOF TMPLE* VALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPESolids, total suspendedAME 1A4 2.5 19 0 02030 240053010 10 1.. " C. ,.Effluent Gross Ax. .....Chromium, hexavalent SAMPLE ... ..... ........(as Cr) MEASUREMENT 5000103210 ToX .:..'Effluent Gross.Chromium, total 0M0PLE Soo(as Cr) ME ASREMENT_500

'Effluent Gross 42 AH,Copper. total 5AMPLE S(as Cu) MEASU RE__MENT_

0104210 ,.. + ....- " Iron. tolal SAMPLE ,., Soo......

(as Fe) MEASUREMENT 5_001045 10 ~-. '~1 ~ -~Effluent Gross Litz! _____~*,Lead, total S.A L So..... .... .,......5.0 (as Pb) MEASUREMENT

________

____ __0105110 RO W .. j .* -., .,.Effluent Gross ,;,E A _____ -f -. ___Nickel, total SAMPLE ........(as NI)) MEASUREMENT, 5J0106710 F. '""" ....'-' ""Effluent Gross MxNAME/IL.E I candy under penarly d law dial ths document and al atladmvents ware prepared under my TELEPHONE DATEPIRIVNCIPAL EXECUTIVE OFICER a rctim at wuwwmi in acodarwe wit a system desoe to ssre thaT quaATd peEsD,1 3properly gathe and evabite inse utformaa subMItted.

Based on rry kiquu d the persmn or persona 1 0-7011721 Benjamin P. Yournan w'ho mfsan fte s or fthse n diely respyonsbe Ior gatherinfa me inhanl ,,tel me12117/2012 inf suberitted Is. to the boest my knowledge and befiel, true. accurate.

and Coplt I am SIGNATURE OF PWCIPLE_Plant Manager aware it ame are aslpicart penaies for subtm0 false kiformitim k ft possiby of EXECU1IVE OFFICER OR AREAiwmoee lum and Hermem tIor WoY#g vicians.

AUTHORIZED AGENT CODE NUMBER _MDDYYYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow existed through this outfal 111 of 30 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 16/2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (OMR)PERMITrEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010IL0048313 PERMIT NUMBERC01-0DISCHARGE NUMBERDUR Mailing ZIP CODE:MAJOR(SUBR 01) CSWWTP (FORMER ODIC)External Outfali61010MONITORING PERIODMMIDWYYYY MMIDOIYYY I ..... IFROMI11101r2012 IITOIA'L I1 1iO12012I* NO DISCHARGE F1 .---I lTOwII lPflul IayI -- -NAMEnITLE PAINCIAL EXECUTMVE OFRCERBenjamin P. YoumianI ceiliy under penalty d ltw thal te dos men and all aatmntv s were prepared Under mydirectimor w petvim m accodance with a sysem desgned to assure tt quiatted pemainelproperly gather and evalut me ftonnan submite.

Baseed a my di te pesmn o persswho manage the system, atr tme persons ditly rsponsae far gatdwin Me Itwaf m i. the sumitted is. to te beso of my knowtedge and beief. true. accurate and compete I amnaware that them are mt penatst fr sutexdttg taine kitmiatm.

bedudf the possiaby al.te and bnpWrsnmef for aWmi valions.Plant Manager.. sm RUN=1 AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)

NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITrEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarranville.

IL 60555-5701 FACILITY Byron Nuclear Power SlationLOCATION 4450 North German Church RoadByron, IL 61010OMR Mailing ZIP CODE:MAJOR(SUER 01) CS61010IL0048313 PERMIT NUMBERF01-0DISCHARGE NUMBERMONITORING PERIODMMIDO/yyyy I MMIDDIVMY RADWASTE TREATMENT (FORMER 001D)External Outfal"* ' NO DISCHARGE-

"FROUI11/01/2012 ITOt11/30/2012 Il ll lIiIII NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 WinFreld RoadWarrenville, IL 60655-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010]DUR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010I IL0048313 IFE81-0I PERMIT NUMBERDISCHARGE NUMBER1IgI .MONITORING PERIODSTORMWATER (FORMER 001LE)External Outfall*

• NO DISCHARGE FROMI11/01/2012 TOI11/30/2012 II lATTN: Zoo CoxIENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPESolids, total suspended SAMENT005301 0U0ý --. 0Effluent Gross, .-: .' , ..-__, '__. ' " ..Solids. total suspended SAMEOther Treatment.

Process !3 .... "n"" iYComplete

.........

....V......Chromium, hexavalent SAMPLE ..........

.(as Cr) MEASUREMENT

""" '

.1,.-' :7 -2 * " + ..' "0103210 .2I" ""...Effluent Gross. " 7-'.. 4 ...., ...LChromium, total SAMPLE ........

....(as Cr) MEASUREMENT

_ __iii__010341 0 A-, L m ..-...'*.. .: Effluent Gross 1 1t !ý?Copper, total SAMPLE.........

(as Cu) MEASUREMENT 0104210.

..-.. .... .Effluent Gross -W ,i , IIron, total SAMP.....L

....(as Fe) MEASUREMENT

_ _ _ _*__ _ __ ___ __01045.10

-,.:r.. ... ... .._..Effluent Gross ,Lead, total SAMPLE(as Pb) MEASUREMENT II______

___0105110Effluent Gross i w m lNAMEfTILE I ceriiy under penalty of law that ths document and ao aadiments were prepared uwider my TELEPHONE DATEPNCIPAL EXECUTIVE OFFICER dectn or supervsmn i accoMdance with a system designed to assure that qualifed personnel ipmperty gater and evalute Me sutnitteod Based on my kility of the po o person s Of ,.1, -1 7oBenjamin P. Youman who manage the system, or Utse pemms diectly spnsla for gatht ted i815I. 46e =370 12/17/2012 Inormation

.to the best o my Wowedge and belief, Int. acutate.

and cWVotete.

Iam SIGNAPPE Dir RINCIPLE rPlant Manager aware tt Mrese are signifcant penaJtes to n fals itnnation, ioiflg the ps of EXECW'nVE OFFICER OR AREANUMBER MMDDYYYYT04E OR P Ime and nprseaonnnt for knowing U *vions. AUTHORIZED AGENT COD NUMBER _ _ /D____YYCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. There was no discharge of processed steam generator chemical cleaning wastewater dudng the month.2. This discharge point was not used this month.EPA Form 3320-1 (Roe 01106) Previous editions may be used. 1/612012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAMEIADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 44,50 North German Church RoadByron. IL 61010IL0048313 PERMIT NUMBERIE01-0IS DISCHARGE NUMBERDMR Mailing ZIP CODE:MAJOR(SUBR 01) CSSTORM WATER (FORMER 01 E)External Outfall61010MONITORING PERIODMMIDO/YYYY I MMIDDIyyyy FROMI11/01/2012 I TOI11/30/2012 I*** NO DISCHARGE MX ...1 III lI1I.

NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIT'EE NAME/ADDRESS NAME Exalon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadDMR Mailing ZIP CODE:MAJOR(SUOR 01) CS61010I IL0048313 PERMIT NUMBERF -00 1-0DISCHARGE NUMBER[ MONITORING PERIODMMJD/YYI MMJD1YyYYY COOLING SYSTEM BLOWOOWNExtrnal OufallFROM I 11/01/2012 ToI11/30/2012

"'. NO DISCHARGE

[ ...m AByron, IL 61010ATTN: Zoe Coz/ENV SPEC _____ ____ ________

___________________

____QUAN'TIrY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER EX OF TPVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPETemperature, water dog. AMPLE 84.6 15 0 01.01 CNFahrenheit MEASUREMENT 000t110 yen," -*. ~ ~ -RqEffluent Gross : 'j L 'PH SAMPLE 8.44 8.69 12 0 01/07 GRMEASUREMENT 00400A10

.. 5. .9/Efluhent Gross ____ ____ ____ m r .i ý-Solids, total s- MEndedASEE 5.0 5.0 19 0 01/3E GR00530 10 o .. ..., : .,..n...

-, .. -. seq)M¥rL-Req Mar L .' .-Effluent Gross V_______

'z" -" : .." ,_n..0i & Grease SAMPLE ........

<.....14

<1.4 19 0 "01/07 GRMEASUREMENT 0055610 ."Effluent Grass __________~h5

Chromium, total (as Ci) SAPL 0.0021 19 0 01/07 GR0103410 ...............

...... .... ........Effluent Gross _., .,Copper, total (as Cu) SAMPLE ....... ...... .0.0040 19 0 01/07 GRChrmim, otl (s r) MEASUREMENT

_-" ,*."'2 L ,. "- .Z " ' -.....* ' ______:ZincLtoal.........

.....00" " 0.010 19 0 01/07 GRCopertoal as u) MEASUREMENT, Effluent Grs ,w. .. -,. .. ...NPmE/TITLE I ceruty under pentaly o law a Ots documnt and al an w pr under ly TELEPHONE DATEPRINCIPAL E)ECUTIVE OFFICER dumreon or supen~on in acýoac wih a s~ey desý to assure to quafi"ed pereor, "Drprmperly gade and evauz the informador autmiled.

Based an my ahelUse pesm or perSo n14-7Benjamin P. Youman who manage the syatam, or rmee persons diecly esponsbe for the itfonmalion.

the- 815 406-3700 12J17/2012 nloimaon suwmitd is, to the beat oo my " wde and bet.ie tru. accurate.

and canpietI am SIGNA R F 0 ____Plant Manager aware Met ther are sinc pen1a es tor R v iabn intorrnaon.

ixuding the posamiuy d EQ OCER OR AREANUMBER MDYYYYoRMNI Ifire knpnandb isme2 l Whknowaig AUTHORIZED AGENT cODE NUMBER _ _ _ _ _ _ _ _ _ _COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Referemnce all attachmenta here)1. Monitoring data for outtall 001-0 is included on attachment EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/8=2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMrrrEE NAMEIADDRESS NAME Exeton Generation Co., LLCADDRESS 4300 Winfield RoadWarrenvile.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, L 61010IDUR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IIL004N313 I I001-0I PERMIT' NUMBERI I DISCHARGE NUMBEA 1....... .... ... DI C A G NU BE .. .... .... .MONrIORING PERIODUM/IDIYVYYI MMIDD/Yyyy COOLING SYSTEM SLOWDOWNExternal Outaidl** NO DISCHARGE r-- "*"FROM I11101/2012

! TOI11/30/2012 IQUANTITY OR LOADING QUANTITY OR CONCENTRATION

__ .FREQUENCY ARAMETERO OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX AOSF TYPEOxidants, total residual SAME .... ..0.05 19 0 01/07 GRtotl rs~dal MEASUREMENT___________

____________

3404410 ... '"-- ,. ..- "- -.,Effluent Gross -1. ._' .: ..., ---L , .: :.. ,, -,RPriority pollutants total effluent SAMPLE .........

MEASUREMENT Soo.505000810 'aww*.Effluent Gross Y. M ..Flow, in conduit or thru SAMPLE ......treatment plant MEASUREMENT 1874 2928 3 0 01101 CN500501 in 4.,.Chlorine.

total residual SAMPL.E .....MEASUREMENT SIX05006010 1 u' n ,-. -.. .- .... .." -........Effluent Gross -Z -.,,_ ,_-_" -r-;Hydrazine SAMPLE........

......MEASUREMENT 5008131310 :.. ..-.. * " .7..911- -.,,.,.- "'Effluent Gross "'A- P___ _ ._ , "SAMPLEMEASUREMENT 7_ ..... ... ! ."NAMIfTL ~~Wwm~wtegm,.'AMPL____E I[AUiF./1111 I under Parkell 01 law 80 domainen and all atlamnmets wev repirepad wunixPRINCIPAL EXECUrTIVE OFFICER dacaion or supervi In with a system designed to assure dim quatfied personnel TELEONE DATEBenjaminrP.

Youman erlygather and OvakMa the Inoimnian subhl1tLd.

BasOed aniny equnyat dethpeserinm peos'- 37Y n o manage de system, tose persns dirocty respons r to gat-emnn te lonnan. the 4 12/17/2012 PlantaManager WOtatian Subansled IS, to eua banad rmy knowledgeand bel'. ue. arai'e and congple.

lamPlan Maager war thimter are signitiant Penalte lot submiting taise bidannation, intdiidg the possibulyt NUBE MMDVYT f1ne and intrnsionment for knowing vioatatas AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1162012 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIlTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadIL0048313 I PERMIT NUMBER002-0DISCHARGE NUMBERMONITORING PERIODS MMIDD/YYY I I MMIDnIYVYY OMR Mailing ZIP CODE*MAJOR(SUBR 01) CSSTORMWATER RUNOFF BASINExternal Outfall*' NO DISCHARGE r61010I II ....FROM i11/01/2012 I T"o11/301,012 IByron. IL 61010ATTN: Zoe Cox/ENV SPECFREQUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF TPVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSISSolids, Total Suspended SAMLEM00530 10 ..... " "i'Effluent Gross .110__ , .0_-

Solids, Total Suspended SAMPLE0053080 pjJg ; " nOther Treatment, Process ."- ::' " -A : ." '. .,....Chromium, hexavalent SAMPLE(as Cr) MEASUREMENT 01032 1 0 A,. .... -.. .Q .-,Effluent Gross 12SChromium, total SAMPLE(as Cr) MEASUREMENT 0103410 777" y ...- '" .U " : -O.p...

.. .ft"QEffluent Gross vt~lj _____.- ___Copper, total AMPLE.(as Cu) MEASUREMENT 0104210 ...R IR'lT ,.* :. *"- .-Aj -.,04- x: ..."Effluent Gross C___ .j ~ aIron, total SAMPLE .....(as Fe) ME.ASUJREMENT 0104510 -u *RWv -Effluent Gross I _

Pi-, ,, ,._, ,A.Lead, total SAMPLE ......(as Pb) MEASUREMENT 0105110 ~GAEffluent Gross _"______,__

'NAMETITmLE I certify under penalty d law tat Ud s do=wet and at alladunemnta we prepad under my TELEPHONE DATEPRINCIPAL EXECUTIVE OFFICER direl0w or supenisolin arcordance with a system designed to assure qualified personnel TLPOEDEprpet Gather and evalute Me infomaon asubretted.

Based a my inquiry of the peaon or persons 815 406-3700Benjamin P. Youman who lmanage the systern.

or Vos persons resp fo gaterng the lnloma12/17t2012 Information subTWitte s to the best al my bmwledgle and balie. true, accrate, and cowtpiete l am SIGNA=TIJ F CPLE 121-21Plant Manager aware that there we wignc penalties tor aoranling fale intfomation, chding the posabily a EXEU OR A NEATVo OR PRM_ ..ne and kpr__nMent far Mowing vW131ons.

AUThORIZED AGENT CODE NUMBER MM1DDr/YYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Referance all attachments hee)1. No Turbine Buiding rm and Oil Sump or Generic Non-Chemical Metal Cleaning Wastewater was discharged this month.2. No Fire Protection.

Service Water or Closed Cooling System Drain Water was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous edilions may be used. 1/612 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWaenviTle, IIN 60555-5701 FACILUTY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010OUR Mailing ZIP CODE.MAJOR(SUBR 01) CS61010I IL0048313 I PERMIT NUMBER002-0DISCHARGE NUMBERMONITORING PERIODMM/DYYYY I I MMIOOYNYSTORMWATER RUNOFF BASINExternal Outfall* *NO DISCHARGE M- ...I.I TOII ... ..IFROMI11/01/2012 ITOt11/30/2012 II li -v-l IIj.IIIII.iI ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 November 2012Page 1 of 3MONITORING DATA:WBD C WBD Flow Rock RiverDATE Temperature mgd Flowdeg F cfs11/01/2012 78.6 18.85 228011/02/2012 78.6 17.29 226011/03/2012 78.0 21.35 227011/04/2012 78.0 13.75 231011/05/2012 75.2 21.48 220011/06/2012 75.3 18.99 219011/07/2012 75.3 16.59 217011/08/2012 78.0 19.01 222011/09/2012 76.1 16.86 217011/10/2012 82.8 21.39 219011/11/2012 83.1 17.06 229011/12/2012 83.1 13.66 244011/13/2012 74.0 18.21 227011/14/2012 74.0 17.48 227011/15/2012 78.8 20.53 231011/16/2012 78.8 17.97 230011/17/2012 75.4 25.52 225011/18/2012 78.5 19.54 224011/19/2012 76.0 13.52 221011/20/2012 82.8 21.90 222011/21/2012 77.8 16.88 221011/22/2012 84.6 18.34 231011/23/2012 83.9 19.55 224011/24/2012 72.2 29.28 210011/25/2012 73.8 16.12 208011/26/2012 75.8 14.28 209011/27/2012 72.3 19.84 208011/28/2012 74.4 18.57 210011/29/2012 74.2 19.11 206011/30/2012 78.4 19.36 2070K:\BYR_CH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012ReportsNovember\November 2012 ATTACHO1.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 November 2012Page 2 of 3HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (or associated rinses) containing hydrazine discharged to the Cooling System Blowdownduring the month of November 2012.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite and Bromine compounds were used this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 30 of 30 days.4. Per Special Condition 24 the influent from the Rock River and effluent fromOutfall 001-0 was monitored for Total Suspended Solids (TSS) this month.The Rock River TSS value was 5.5 mg/L on 11/12/2012.

The CWBD TSSvalue was 5.0 mg/L on 11/12/2012.

5. Rock River flow was <2400 cfs starting on November 5, 2012 therefore daily temperature calculations were required during this time period.(Special Condition 12). Per Special Condition 12, in the event the RockRiver flow is <2,400 cfs, daily calculations will be undertaken todemonstrate compliance with the water quality standard.

The calculations are based on hourly measurements, averaged over a 24-hour calendar dayfor Rock River flow, main Rock River temperature, CW Blowdown flow, andCW Blowdown temperature values. Results of the calculations shall bereported in the DMR on a monthly basis. Calculation results are in the tableon the following page.6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in November 2012. (Special Condition 15).K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\November\November 2012 ATTACHO1.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit 1L0048313 November 2012Page 3 of 3Date Average Average Average Average Calculated Water QualityRock CW M/U CW CW Temperature StandardRiver Temperature Blowdown Blowdown at edge of Temperature Flow (F) Flow Temperature mixing zone (F)(cfs) (gpm) (F) (F)11/05/12 2330 45 13239 71 45.6 9011/06/12 2328 44 13075 72 44.9 9011/07/12 2300 45 13129 74 45.6 9011/08/12 2250 46 12379 75 47.0 9011/09/12 2044 46 12133 78 47.3 9011/10/12 2055 50 12171 84 50.9 9011/11/12 2153 52 12158 82 53.1 9011/12/12 2300 47 12246 70 48.1 9011/13/12 2138 44 12738 69 44.8 9011/14/12 2205 44 13600 73 45.3 9011/15/12 2294 44 13475 74 45.1 9011/16/12 2285 44 13613 75 44.9 9011/17/12 2240 43 13692 76 43.8 9011/18/12 2219 43 13713 78 43.8 9011/19/12 2190 45 13688 78 45.9 9011/20/12 2205 47 13663 80 48.2 9011/21/12 2205 48 13600 78 48.6 9011/22/12 2318 48 13417 83 48.8 9011/23/12 2243 45 13538 69 45.4 9011/24/12 2101 41 13638 71 42.4 9011/25/12 2076 41 13646 74 42.8 9011/26/12 2093 40 13721 72 41.4 9011/27/12 2030 38 13592 69 39.1 9011/28/12 1973 38 13683 73 39.1 9011/29/12 1963 38 13571 74 39.9 9011/30/12 2060 41 13596 75 42.2 90K:\BYR_CH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\November\November 2012 ATTACHO1.doc Exelon.Exelon Generation

Company, LLC www.exeloncoTp.com NudeaTByron Station445o North German Church RoadByron, iL 61010-9794 January 17, 2013LTR: BYRON 2013-0010 File: 2.09.0411 1.10.0101 Illinois Environmental Protection AgencyWater Pollution ControlCompliance Assurance Section #191021 North Grand Avenue EastP.O. Box 19276Springfield, IL 62794-9276

Subject:

Byron Station Monthly Discharge Monitoring ReportIn accordance with National Pollutant Discharge Elimination System (NPDES) Permit Number1L0048313, issued January 24, 2011, we are submitting the Discharge Monitoring Report forByron Station, Units 1 and 2. This report covers the period of December 1, 2012 throughDecember 31, 2012.If there are any questions regarding this report, please contact Ms. Zoe Cox,Environmental/Radwaste Supervisor, at (815) 406-3035.

Respectfully, Benjamin P. VoumaY 7Plant ManagerByron Nuclear Generating StationBPY/ZC/eh Attachments bcc: 4-Geutd -Environmental

-Cantera (electronic)

Z. Cox -Chemistry

-Byron RM-AA-101-1008-F-03

-Revision 0-Exelon Generation,,

Page 1 of ISPECIAL HANDLING TARGETBEST AVAILABLE COPY ............................................

(Next j2 pages)CHART/PHOTO(S)/TRACES REMOVED .............

(Next pages)OVERSIZED PAGE/DRAWINGREMOVED

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(Next pages)EXPLANATION:

To Be Completed By Preparer:

Document Number:List of pages, documents or drawings removed:** SEE SITE RECORDS MANAGEMENT FOR HARDCOPY LOCATION

NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (OUR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadOMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010EI D101IN13

__A01-0DISCHARGE NUMBERMONITORING PERIODMMIDDIYYYY

[_ MMDDJYYYDEMINERALIZER REGENERATE WASTE (O01A)Extenmal Outfall* *NO DISCHARGE

...FROMI12101/2012 iTOI12131/2012 Ii IByron. IL 61010ATTN: Zoe Cox/ENV SPEC ______________

___________________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF 8MLVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESolids. Total Suspended SMPLE 1.1 1.2 19 0 01M30 08(as Cr)MEASUREMENT Effluent Gross..........

Chromium, total SAMPLE .. .. .. ... -.(as Cr) MEASUREMENT So'Effuent Gross2Copper, total SAMPLE ...0104210 ".' 'A'.Iron, total SAMPLE(as Fe) MEASUREMENT SooEffluent G

PLELead. Totl. SAMPLE t........

...n. t....(as Pb) MEASUREMENT 50001051 1 0 777 =,'."" '; ."... -" --"Nickel, total SAMPLE ..... ...., .,.,00(as Ni) MEASUREMENT Soo!Effluent06 1Gross0

mw -=02="

.-A ,:. ...4':Nicite.......

toalSAPE

...NkAETnTTLE I coesiy under penaly of law dMi dms dcummet and an attactmms ware ptepamd n TELEPHONE DATEPR"INPAL EXECUTIVE OFFICER imect or saupemismon In accoudance wair a system designed to assure md quaaed peabronel BnanPty games and evakte Me subitted.

Based on fm mqway d de perrsso 406-370Benjamin P. Youman who manage me systman or ies pemis drecay responsiue for gafthenng ume 01112013idonfan sutnfte is. to me best o my tu,,edge and bene, tie, and a coW0in. am 8GITU RE(OF PRINCIPLE Plant Manager swam Owat the1e are penaltres fo subln bonnal. bicutth de possb* of EXECUTIVE OFFICER OR NMfAiv mo o an a and krofb nai fo k viakna AUTHORIZED AGENT CODE NUMBER __IDDI__

_ _COMMENITS AND EXPLANATION OF ANY VIOLATIONS (ReFenmce al attachments hem)1. There was no discharge of processed steam generator chemical cleaning wastewater during this month.2. Flow edsted 31 of 31 days during this monh.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/62012 PAGE1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAMEJADDRESS NAME Exalon Generation Co.. ILLCADDRESS 4300 Winfield RoadWarrenville.

L 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010OMR Mailing ZIP CODE.MAJOR(SUBR 01) CS61010iL0048313 PERMIT NUMBERA01-0DISCHARGE NUMBERMONITORING PERIODMMIDD/YYYY

__ I MMIDDI"YYY DEMINERAUZER REGENERATE WASTE (O01A)External Outfall* *

• NO DISCHARGE FROMII1201/2012 To[12/3112012 Il II NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAMEIADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarranvifle, L 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByronm IL 61010A fýf.=Klk c-7r ' IL0048313 PERMIT NUMBERiB01-DISCHARGE NUMBERDMR Mailing ZIP CODE:MAJOR(SUBR 01) CSSTP PLANT EFFLUENT (FORMER 0015)External Outfall' NO DISCHARGE 61010I ~ MONITORING PERIODI MM1Daq-fYY I TO[MM/DDIYYYY IFROMI12/01/2012 12/31/2012 Il iQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPEBOD, 5-Day SAMPLE0.2 4.0 40 19 0 02/30 24(20 Deg. C) MEASUREMENT 0024.12_Effuen Gros E1UM M1II ýý7 an' -ýe 'pHAMPLE 724 7.46 12 0 02/30 GRpH MEASUREMENT Solids, total suspended SAMPLE 010 02_12922MEASUREMENT 0.00126--19201 0 00 4Flow. in conduit or tiru SAMPLE lag .treatment plant MEASUREMENT 0_004 0.00__ 3 0 _010___5005010 ý' Ma~v 'PiG~~..

fjqIoRMin.

~-~rEffluent Gross .:x -. .SAMPLEMEASUREMENT SAMPL.EMEASUREMENT

.__.._____._"_____._-,_

....-,.

...... ;.7 .*SAMPLEMEASUREMENT NAMEITlTLE I cei* urtnd penafy ,U tof taw QW documn Sfl am attadhnta e iaeda, 'erV TELEPHONE DATEPRINCIPAL EXECU11VE OFIFICER dmj w supenan in a :gance with a syton deswgn to assure toas quaffia penamTPel PmPtwoandevatme clyl. Based aon Iy gahurod me pedm or per"* ,Benjamin P. Youman wto "aa Of s te sPOM &'O' for galhef ' w iCdmokw%

the -01/17/2013 Wfnabmn sWjflf i to d to beso f my Wodep and bWe .tue,. a, aopir, la SIGNAadnE OFr IICIPLE .I_____Plant Manager aware mad mare am sl*gfncam penawds t0f suba&fg faWs W=ta .bkWdAtg ma P9ua9t of EXECUTIVE OFFICER OR AsFJWa OR ,mPOW= foe and k inpsnnnt for knawin0 vailatmins.

AUTHORIZED AGENT CODE NUMBER MM/DD/YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)1. Flow eidstad through this outfall 28 of 31 days during this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012 PAGE 1*0 0 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60655-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadDMR Mailing ZIP CODE.MAJOR(SUOR 01) CS61010IL0048313 PERMIT NUMBERC01-8DISCHARGE NUMBERMONITORING PERIODMM-/DYYY I MM.OYYYYExenal Ouftfl* N ISHRE E .l IFROMI12101/2012 IITO12031/2012 I! iByron, IL 61010ATTN4: Zoe Cox1ENV SPEC_____

_________

_____________________________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER E____OFPARAMETER

_ _ _ VALUE VALUE UNITS VALUE VALUE VALUE UNITS 0X 24 TYPESld.ttlsseddSAMPLE

.........

5.8 6.2 19 0 02r'J0 24So~s, ota supened MEASUREMENT 0053010Al Effluent Gross an.- _ --Chromium hexavalent SAMPLE Soo(as Cr) MEASUREMENTEfmflunt Gross -,Chromnu.

total SAMPLE ....(as cr) MEASUREMENT 010341 ýF-4 --copper. towa SAMPLE .... 0(as Cu) MEASUREMENT 50104510Effluent Gross ail&010 51 ... ..~ A ... ...total APi. ..(as Pe) MEASUREMENT Effluent.

GrossLNckAel total SAoMiPLEc......

"W'""'DATE (as Nb) MEASUREMENT Pln aae wr itmr resgismpni o umn lae kulmuta.

uma th 5iEEUTV CRO(a apin MEASUAREOMEDNAENT CO010671 .'. .-,,-- ...- ...........Effhluent Grs ...... ..a-n .sL:ltm ..."m ".; ' -NAMEF.E ACeNDyuPLNpeAIyO law AV aO (Rectecumaene all attachmntos werepd ) udet a TELEPHONE DATEP1U.Tmwa ExndcuhE OFaRCER orcesnsed stam genea assureng thi maodnt2.pFly ease tevhrughe m s. ed ti outfallhe1person or 21, 815 du4ine7oBenPamin P. You(Ran 011o ma8Pae te systeMt on mae peMuns dreCtd .spna* ko 0aet te infonnam fe 01/17/2013 Inorrnadon subnmtted IL. to the besooJ dy rri mftd and befiel, true. &=Mne. and *ompleteI arn 81GNA'IRJRE OF FMCIPLEPlant Manager aware doa there are sJ~mman perwatis for subyqMmiss Waratsikomdn, Wb th #w poL~ d XCUIEr OFACER OR AREANUERMfDYY UoR51M m -mu f re and hofteonmet for bmin Adta AUTHORIZED AGENT ICOIDE NME MDNCOMMENTS AND EXPLANTION OF ANY VIOLATIONS (Raefenrce all attacheunnts here)1. There was no discharge of processe steam geneaetor chemical cleaning wastewater dufiN this month.2. Rlow through this outfall 12 of 31 days during the month,EPA Form 3320-1 (Rev 01M0) Previous editions may be used. 1/6/212 PAGE 11 PERMITTEE NAME/ADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenvllle, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadNATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)1L0048313

-C01-0OPERMIT NUMBER DISCHARGE NUMBERMONITORING PERIODMMIDD/YYYY M umiDWYYDMR Mailing ZIP CODE.MAJOR(SUDR 01) CSWWTP (FORMER 001C)External Outfall... NO DISCHARGE 61010FROMI12f01/2012 TOE12/31/2012

-l .11l !Byron. L 61010ATTN: Zoe Cox/1ENV SPEC _ _FREQUENCY QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OF AMLVALUE VALUE UNITS VALUE VALUE VALUE UNIT EX ANALYOS TYPEZinc. total SAMPLE ........

.... ..... 500(as Zn) MEASUREMENT Flow. in conduit or thin SAMPLE 00500730 0/1Ctreatment plant MEASUREMENT 50050 10 ,N&4 .AEffluent Gro.ss i .....SAMPLEMEASUREMENT A:r, Ir L... ....-r --SAMPLEMEASUREMENT SAMPLEMEASUREMENT SAMPLEMEASUREMENT MAM~nLt.E I comy I w ier penally a law that ON documen and afl aulltac ens were prpared wnder my TELEPHONE DATEPRNcIPaAL ENECUE OFRCER a.econ oa supesiwon In with a sstem designd to assure Ins quamuied pemonnelpmpeily gather and evaelut e Ibomaan ationsubated.

Based on my fiqubV ol the peson or pers" 815 406-37WBenjamin P. Youman who manags me system or Wans persons direcly responsie ko gad.ie0g Ue InlonWal the 01117/2013 nfmoamtion subnitted Is to the best o my Ikowledge and beaef, trnue accurate, and complete.

sin a 1GNA1 REOFOFAC ICPLE L EPlant Manager aware that there are signifirant pties for subn Wlee innnatlm.

idug the d EXECUTIVE OFFICER OR ARE.DTVM ON pRV'W fine and kpembonient for knowwn g AUTHORitED AGENT CODE N RCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hame)EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/612012 PAGE 2 0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAMEIADDRESS NAME Exelon Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadDMR Mail'ng ZIP CODE.MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERD01-0DISCHARGE NUMBERMONITORING PERIODMmDOJYtY I MUJDW/YYYY RADWASTE TREATMENT (FORMER 001D)Externl Outfall*'*NODISCHARGE I .. .. .IFROM!I12101/2012 I7ot1"2F31/2012 IFROMI-I IByron, IL 61010ATTN: Zoo Cox/ENV SPEC _ _ _ _ _ _ __ _ _ _QUANTITY OR LOADING QUANTITY OR CONCENTRATION

.FREQUENCY SAPLEPARAMETER OXFYPVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSISSolids. total suspended EAURMLEN3 5 19 0 0230 C00530 10 V- *Effluent GrossFlow. in conduit or thru SAMPLE 0-=2 0.022* 0 01/01 CNtreatment plant MEASUREMENT 5005010Effluent Gross-iv -.*... ..7'.. ~ ~ ~ ~ *~~SAMPLEMEASUREMENT SAMPLEMEASUREMENT SAMPLEMEASUREMENT SAMPLENAMERM I cewy wvdar ipanay of law 00 dils domman an a. anadners wae paae wia ,nri TELEPHONE DATEEXECUlME OFfRr= dmcum or &Wve#M= Mn wfire a dfsi~nd to assure 0a0 %WaNW perm40nngame and mavaile die Warriai uteid. Based an mry quizy of the paisan s 7815 7Benjamin P. Youman who manag de swatm. o mdie persons directly responsUae lr gadw0g me kdamma. the 0 01/17/2013 mfonmatn sutimted Is. to me best of my Irmwledge and betel. true. maarate.

and cMMMa. I am SI RE OF __N-'_PLE Plant Manager aware dial dmer are sil0aicar penates for wAumta falsse tdoarnani.

icdig fe ol EXECUTIVE OFCER OR NUMBER MWDD/YYYY oa and Impds~ne f AUTHORIZED AGENT CODECOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)1. Flow existed through this outfall 4 of 31 days during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. I/6012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMIITEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWarwville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 NoMtt German Church RoadByron, IL 61010AI'rlM. 7nn DMR Maling ZIP CODE'MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBERE01-0DISCHARGE NUMBERE MONITORING PERIODMMIDD/YYYY j I MMIDDJYYYY STORMWATER (FORMER 001E)External Outfall* 6 NO DISCHARGE M ...FROMI12101/2012 12/31/'2012 QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFVALVAL UALUE UNITS VALUE VALUE VALUE UNITS E ANALYSIS TPESolids .-tota SupndMAURMLEN 500Solids. total suspended APLE..161 182 19 0 01/07 GRChrmium hexavalent SAMPLE ..*.. ... .. 00103410 MEASUREMENT Copide, total SAMPLE ..... ....... 0107(as Cu) MEASUREMENT 01034210

."'. ..'.'"" -' 4:. ,.,Efflu~enlmt ProeosIts Crome, total SAMPLE ...........

O(as CF) MEASUREMENT Soo0 1 0 3 2 1 0 .., .! <. .... .....'- ..' .; , -.- "..,- 4 4 -* -.... ." --..'- '.E fflu e n t G ro s s .- ; -.. .. ._ .i ---------- -Chromiu, total SAMPLE.............

(9s CF) MEASUREMENT 500Lead, total SAMPLE...........

......(as Pb) MEASUREMENT_500 NAE1nE i cartIIy wtde penaity ,d lw Sta ti nw and aD Itchmest were iragard under inTEEPON DATE____________________ aupendeamin in accordance wair a syte designed to assure that quashed pericnna

___ _____________

proeitygathr aneviahue te horniasubei aotad. 8ased onmy Inquhy te person orm pera-- 1540-30Benami P.Youan who manage the system. or these pei~sat dlrec~ reposlema for piherbg the inonabon.

the017/03 Belma MOnlabOI sum~ s .. me bes ,, myI ~ddg tast in, anti oonme.m em SIGNA RE OF/

0/721Plant..M~anager aware tha there are slgritean penslas for auailn false bionmtaio, bldud~ng the poassbuty d EXECUTIVE O1ICER OR NUBERMIDIYY-.m , e and mrnpiismarei ho kncow~ng sioIORZD GEa OE UMERM/DsY.

COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments hem)1. There was no discharge os processed steam generator chemical cleaning wstewater during the month.2. Ftow etialed through this oull 0of 31 days dunng the month.3. There was no flow from this outlall this month however FRe Protection drain waler was discharged to this outfall this month which rsauires TSS samplinaj.

EPA Faont 3320-1 (Rev 01/06) Previous editions may be used. 1/6/2012

_PAGE 1I NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITTEE NAME/ADDRESS NAME Exalon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010A1TT'-

Acc:r'1DMR Mailing ZIP CODEtMAJOR(SUBR 01) CS61010RIN0048313 PERMIT NUMBERIfE01-0DISCHARGE NUMBER1MONITORING PERIODMM/DW1YYYY j I MMIDDIYYYY STORMWATER (FORMER 001 E)External Ouffall* "*NODISCHARGE J 7 ..FROMI12/01/2012 TOI12/31/2012 il *QUANTITY OR LOADING' QUANTITY OR CONCENTRATION NO. F SAMPLEPARAMETER EX OF TPVALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSIS TYPENickel, total SAMPLE .500(as Ni) MEASUREMENT" Effluent-GrossAic, total SAMPLE ...... ...... SI-as Zn) M EAS U R EM ENT _ _ _ ...--, -F1ow, in conduit or thi SAMPLE Sootreatmn plant MEASUREMENTI SAMdPLEME.ASUREMENT" SAMIIPLEMEASUREMENT SAMPLEMEASUREMENT SAMPLEMEASUREMENT iMEirn.uE I cead under penalty al tar thas thaus dfcument an alt taces wem prepared tinderY TELEPHONE DATEEE WE dormn or i awdin ance with a system desrgned to assum dos cpqauhed pereonetpropeity gaowe and eva~lue the mfomatuon sassaa Based an my tupy of fth pe=o or perona 1 4630Benjamin P. Youmnan vanage the system a tfse msona y esptmsWae for gamem the adon. the --01117/2013 intoustiom subn*,M i. to the best d my ,uzusedge and nue. acuse, and cmpe. I am flNATUR#

nCIPLEPlant Manager awam dal there are s0ficant penaltIes fortalg lalse nldoma.b kcduding fth Pefity Of EXECUTIVE OFFICER OR AREA NUMBER MMIDDJYYYY Au.OR AWFlD The and porsblnmme for lonM,,g violatwns.

AUTHORIZED AGENT CODE NUMBE M_/DD/_YY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Refererne all etachments hea)1. No Closed Cooling System Drain Water was discharged this month.2. No Service Water System drain water was discharged fths month.3. No Turbine Building Fire and Oil Sump or Generic Non-Chemical Cleaning wastewater was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 16/2012 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)PERMITrEE NAME/ADDRESS NAME Exalon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron, IL 61010[ IL0048313 II PERMIT NUMBERao-1cDISCHARGE NUMBERMONITORING PERIODMMIDD1YYYY I I MMIDD/YVDMR Mailing ZIP CODE:- 61010MAJOR(SUBR 01) CSCOOLING SYSTEM SLOWDOWNExternal Outfall***NODISCHARGE E *iI I1FROM I12/01/2012 I TOI12J3112012 l lATTN: Zoe CoxffENV SPEC ____________________________________

_____QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OF SAMPLEVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX A F TYPEANALYSISTemperature, water dog. SAMPLE .90.5 15 0 01101 CNFahrenheit MEASUREMENT Effluent Gross 61,'D = = " IýPH 8AMPLE -- 8.53 8.71 12 0 01/07 GRpH MEASUREMENT 0040 10 ~ ~ ~ 'Effluent Gross I' 90 i-06ý M AN RAj

..... ...- SAMPLE 4.2 4.2 19 0 01/30 GRSolds toalsusened MEASUREMENT 00530 10L"Effluent Gross ___OiASURESAMPLE

... ...1.4 <1.4 19 0 01/07 GROil & ~~ MEASUREMENT

__________

Effluent Gross .Chromium.

total (as Cr) SAMPLE -<..0021 19 0 0107 ORM E A S UR EM E N T. .. ..0 21 001 / 7R01034106Effluent GrossCo~pper.

total (as Cu) SAMPLE ...........

........07 OMEASUREMNT0.038 19 0 01/07 GR0104210 :"!.. ..

-" -D- .Effluent GrossZinc. total (as Zn) SAMPE 4.005 0.014 19 0 01/07 GR!Zin. ttal(asZn)MEASUREMENT, Effluent Gross r. -...ANAKEInTLE I ceitiy under penalty l law tht Os document and alt atachrnents were prepared under nm TELEPiONE DATEPfUML EXECUeVE OFRCER drecon or mkoemisin acwdance with a system designod to assure tha quaited personnel prpiygather and evalulo the intomtnaton sutnaltad.

Based an mry kqutLy at the person of Persons854630 Benjamin P. Youman mho Manage the system. or thoee pewsons directly mpWse tor gath the uifonnaMn the 01/17/2013 fornma=in submined Is. to the best .d m knonedge end ballet. tue. amurate.

and omite. I aam SI REOFiiNCIPLE Plant Manager aware that Mere am swripcaN penaltmies forubAing false Ieonnaimn, incdting te fpass" of EXECUTIVE OCFICER OR AREATWEmappamiml fine and nprsbnenfng viecatlow AUTHORIZED AGENT nnNUMBER MMaDDaYYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Rahefmnce all attachments hem)1. Monitoring data for outfall 001-0 is included on attachmenL EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 1/8/2012 PAGE 1 0NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DMR)IL0048313 001-0PERMIT NUMB3ER DISCHARGE NUMBER0PERM7TrEE NAMEJADDRESS NAME Exaton Generation Co.. LLCADDRESS 4300 Winfield RoadWarrenville, IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadByron. IL 61010AT"rNI 7n MONITORING PERIODMMUIDIYYVY I UMADOIYYYY DMR Mailing ZIP CODE: 6101(MAJOR(SUBR 01) CSCOOLING SYSTEM BLOWDOWNExtenal Outall**INO DISCHARGE EJ"'0FROMFROM I100112012 I TOI IPi 1A)- -QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER VALUE VALUE UNITS VALUE VALUE VALUE UNITS EX OF TYPE>< ANALYSISOxidants.

total residual SAMPLE ...... 0.04 19 0 01107 GRMEASUREMENT 34044 10 ..'- ...Effluent Gross Fl fPnority pollutants total effluent SAMPLE SooMEASUREMENT 060006810 V.., ~Effluent GrossFlow, in conduit or thru SAMPLE ""treatment plant MEASUREMENT 1965 25.55 3 .0 01/01 CN5005010Effluent GrossChlorie.

ta residual MEASUREMENT50 6006010

"" ":-"' , ."; ,, ....Effluent GrossHydrazine PLE 500MEASUREMENT 508131310 7.... .... Qs -Z " .."Effluent GrossSAMPLE-'MEASREMENT SAMPLEMEASUREMENT PRINCIPAL EXECUT1VE OFRCOM Ifb or suoesmtn In accmance wb a syster deineo to asure am qga~llw IPOEDT-W ypeaglh nd evalum the klm,.mmurus-clL Baudanaqmqlft oft M- r, mper-m I-M 815 406-37001 Benjamin P. Youmnan Ww manap the system, of mos persons &acty mspw-,ft for 9whef fte um .meNPE0)YRNIL 01/17/2013 Plant Managler Mxmnadm umteo Is to the best of mvy bwwmcp anda bdef trim. acaraWe and emO GU1 lIn 81- R ,=RICsao~g ware 20a "Mo are sofficant mowns for Wubv false wnmoabm hdlut the pos of EXCTIE FICER OR AREA NUBRMM/DD/YYYY 7,. fins and ImDW-M=O fOr M..M AUTHORIZE AGENT COMMENTrS AND EXLANAT1ON OF ANY VIOLATIONS (Reftmice al attedmnems h"r)IEPA Form 3320-1 (Rev 01106) Previous editions may be used. 116=212 PAGE 2 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DUR)*1PERMITTEE NAME/ADDRESS NAME Exelon Generation Co., LLCADDRESS 4300 Winfield RoadWanenville.

IL 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadOUR Mieling ZIP CODE:MAJOR(SUDR 01) CS61010IL0048313 PERMIT NUMBER002-0I DISCHARGE NUMBERI MONITORING PERIODMMDD'IYYYY I I MMIDDYYYYI STORMWATER RUNOFF BASINExern Outfai~NO DISCHARGE I IIFROM I1201/2012 I TOI12031/2012 IByron. L 61010ATTN: Zoe Cox/ENV SPEC______________

__________

__________

QUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY PARAMETER OFVALUE VALUE UNITS VALUE VALUE VALUE UNITS EX ANALYSIS TYPESolids. Total Suspended SASMPEN .....00A3010 E.... ...Effluent Gross b Z N a ;Solids, Total Suspended MEASUREMENT 00538Tr0ie Pwo.Compirlete Chromium.

hexavalent SAMPLE(as Cr) MEASUREMENT 0103210 %,l ' "Chromium, total SAMPLE(as Cr) MEASUREMENT 010341 0 .....' : ..., -' ' .. ... .. ..'- .' W-. ". "....Effluent GrossCopper. total SAMPLE *. ,*(as Cu) MEASUREMENT 0104210 " ' 1Effluent Gross(as Fe) MEASUREMENT Effluent GrossLead, total SAMPLE ....... ...(as Pb) MEASUREMENT 01051 10

-' ':i]: " ' '".. .....Effluent Gross ;..

' ....'NAMEII1TLE I certiy under penafty o law that thi docmemu and aff aachimems were prepared under my TELEPHONE DATEPRINCPAL EXECUTIVE OFI=CER irection or supenmsln in accrdance with a aysen to assure hat mared pesonnelpropeu gather and evalute the information submitted Based an my trly of the person or perons .815 406-3700Benjamin P. Youman who manage the system or those persons drdW respae sbe for gathering the Weomatin, the 01/17/2013 Infomation submitted Is to te best of My WONeg and bettef. rue,.

and ciplete.

Iam 9LEPlant Manager aware at them are significant penalts for submittling lalsme inforama, Icluding the possbrty ol EXECUTIVE'OFFICER OR AREAssW O am Oni and imprislantmenl for Incetng vxiatlanMERa.OIYY

________

1e and_________________________

AUTHORIZED AGENT CODE NUMBER _MDDY __YCOMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. No Turbine Building Fire and Ol Sump or Generic Non-Chemical Metal Cleaning Wastewater was discharged this month.2. No Fire Protection, Service Water or Closed Cooling System Drain Water was discharged this month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 16/'2012 PAGE 1 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)DISCHARGE MONITORING REPORT (DUR)PERMrTTEE NAME/ADDRESS NAME Exalon Generation Co., LLCADDRESS 4300 Winfield RoadWarrenville, U 60555-5701 FACILITY Byron Nuclear Power StationLOCATION 4450 North German Church RoadDMR Mailing ZIP CODE:MAJOR(SUBR 01) CS61010IL0048313 PERMIT NUMBER002-0I -DISCHARGE NUMBERMONITORING PERIODI Muuwvvw I I MMIDnnnnr STORMWATER RUNOFF BASINExteral Outfall* * *NO DISCHARGE ...I -~I- -. ...FROMI12)01)2012 I TO012311/2012 l--lByron, IL 61010ATITN: Zoe Cox/ENV SPECQUANTITY OR LOADING QUANTITY OR CONCENTRATION NO. FREQUENCY SAMPLEPARAMETER OFTYPE: VALUE VALUE UNITS VALUE VALUE VALUE UNITS ANALYSISNickel, total SAMPLE ......(as Ni) MEASUREMENT 40106710 *~,.>. ' ~Effluent Gross WZinc, total SAMPLE(as Zn) MEASUREMENT Effluent Gross A, ..- -,- 7.".'.- M -v-" , , ... >s, .. Ji.qOil and Grease SAMPLE....

MEASUREMENT Effluent Gross;

"';' ' 201W ..........

Flow. in conduit or thru SAMPLE ...... ......treatment plant MEASUREMENT

-0. 1 0-. ." .- ... ...SAMPLEMEASUREMENT SAMPLEMEASUREMENT SAMPLEMEASUREMENT NABEnTIllE I ceaity under penalty d Sw thadw s docunent and aS attadnen were prpared under my TELEPHONE DATEPRnmPAI.

uEXEcTmv ORnO dection or supemso in accidance mwih a aes desgned to swsue Ut quaited peisatvnt_____---____-_

Ippe y gather and evaelte theinlonnawlin sutnited.

Based an my nquiry oS te person o pmona J 815 403700Benjamin P. Yournan who manage the epsten, or thse persona directly respnarte for ge9Mg the fte 0117/2013 an W is. to ft begd my loterge and debt. trute, iuralt and oip-ete.

I am SIWWUREVPRINCtPLE Plant Manager aware cth there am sag:cant penaitt for subnftlg false Inductng the pawtity d EXdtUMIEtFFICER OR AREAOR PA e and brionnant for owmeing udakm AUTHORIZED AGENT CODE NUMBER MM/DD'YYYY COMMENTS AND EXPLANATION OF ANY VIOLATIONS (Reference all attachments here)1. This discharge point was not used this month.2. Them was no discharge of processed steam generator chemical cleaning wastewater during the month.EPA Form 3320-1 (Rev 01/06) Previous editions may be used. 116/2012 PAGE 2 ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 December 2012Page 1 of 3MONITORING DATA:WBD CRock RiverDATE Temperature mgd Flowdeg F cfs12/01/2012 80.4 25.55 2,18012/02/2012 84.9 17.62 2,13012/03/2012 90.5 18.12 2,18012/04/2012 90.5 18.25 2,25012/05/2012 77.1 19.23 2,12012/06/2012 75.1 17.99 2,11012/07/2012 74.0 19.58 2,11012/08/2012 75.7 24.21 2,08012/09/2012 70.9 19.38 2,12012/10/2012 74.0 15.54 2,20012/11/2012 72.8 21.14 2,21012/12/2012 78.5 16.87 2,10012/13/2012 78.5 19.45 2,15012/14/2012 78.0 21.80 2,13012/15/2012 75.6 22.13 2,21012/16/2012 82.8 17.93 2,37012/17/2012 71.3 13.12 2,31012/18/2012 73.1 16.72 2,30012/19/2012 74.6 17.83 2,30012/20/2012 74.6 20.85 2,65012/21/2012 70.3 21.32 3,13012122/2012 70.6 24.02 2,72012/23/2012 73.0 20.59 2,52012/24/2012 74.8 18.76 2,42012/25/2012 73.9 16.27 2,67012/26/2012 73.0 24.56 3,12012/27/2012 71.8 16.42 3,08012/28/2012 73.5 22.18 2,78012/29/2012 73.5 23.37 2,58012/30/2012 68.8 20.56 3,96012/31/2012 72.8 17.91 3,94000K:\BYR_CH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\December\December 2012 ATTACHO L.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 December 2012Page 2 of 3HYDRAZINE MONITORING:

There were no steam generator chemical cleaning solutions (or associated rinses) containing hydrazine discharged to the Cooling System Blowdownduring the month of December 2012.TOTAL QUANTITY DISCHARGED:

N/ATOTAL DURATION OF DISCHARGE:

N/ACOMMENTS:

1. Sodium Hypochlorite and Bromine compounds were used this month.2. There was no discharge of steam generator chemical cleaning wastewater containing hydrazine in this month.3. Flow existed through this outfall 31 of 31 days.4. Per Special Condition 24 the influent from the Rock River and effluent fromOutfall 001-0 was monitored for Total Suspended Solids (TSS) this month.The Rock River TSS value was 12.0 mg/L on 12/03/2012.

The CWBD TSSvalue was 4.2 mg/L on 12/05/2012.

5. Rock River flow was <2400 cfs starting on December 1, 2012 therefore daily temperature calculations were required during this time period. TheRock River flow was >2400 cfs from 12/20/2012 through 12/31/2012.

(Special Condition 12). Per Special Condition 12, in the event the RockRiver flow is <2,400 cfs, daily calculations will be undertaken todemonstrate compliance with the water quality standard.

The calculations are based on hourly measurements, averaged over a 24-hour calendar dayfor Rock River flow, main Rock River temperature, CW Blowdown flow, andCW Blowdown temperature values. Results of the calculations shall bereported in the DMR on a monthly basis. Calculation results are in the tableon the following page.6. There was no discharge of the 126 Priority Pollutants from cooling towermaintenance chemicals in December 2012. (Special Condition 15).K:\BYRCH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012ReportsDecember\December 2012 ATTACHO1.doc ATTACHMENT TOCOOLING SYSTEM BLOWDOWN (Outfall 001-0)DISCHARGE MONITORING REPORTFor Exelon Byron StationPermit IL0048313 December 2012Page 3 of 3Date Average Average Average Average Calculated Water QualityRock CW M/U CW CW Temperature StandardRiver Temperature Blowdown Blowdown at edge of Temperature Flow (F) Flow Temperature mixing zone (F)WS) (gLm) (F) (F)12/01/12 2,150 42 13,642 79 42.8 6012/02/12 2,097 45 13,650 82 46.6 6012/03/12 2,147 48 13,879 87 49.4 6012/04/12 2,223 50 13,692 79 50.6 6012/05/12 2,091 45 13,517 70 46.1 6012/06/12 2,076 44 13,554 75 45.2 6012/07/12 2,080 44 13,667 74 45.6 6012/08/12 2,048 43 13,679 73 44.6 6012/09/12 2,075 43 13,683 73 44.1 6012/10/12 2,169 41 13,679 70 42.0 6012/11/12 2,208 39 13,633 67 40.1 6012/12/12 2,110 39 13,821 74 39.8 6012/13/12 2,141 39 13,742 75 40.0 6012/14/12 2,132 39 13,738 75 40.0 6012/15/12 2,196 41 13,271 77 41.7 6012/16/12 2,363 42 12,667 75 43.0 6012/17/12 2,315 42 12,371 70 42.4 6012/18/12 2,301 41 12,079 72 41.6 6012/19/12 2,307 40 13,879 71 41.1 60K:\BYR_CH\BYRON.DB\Clerk\Monthly Discharge Monitor Rpt\2012Reports\DecemberADecember 2012 ATTACHO1.doc