IR 05000456/2006008

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May 25, 2006

EA-06-081Mr. Christopher M. CranePresident and Chief Nuclear OfficerExelon NuclearExelon Generation Company, LLC4300 Winfield RoadWarrenville, IL 60555

SUBJECT: BRAIDWOOD NUCLEAR POWER PLANT, UNITS 1 AND 2, BASELINEINSPECTION REPORT 05000456/2006008(DRS); 05000457/2006008(DRS);PRELIMINARY WHITE FINDING

Dear Mr. Crane:

On May 25, 2006, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection atyour Braidwood Nuclear Station Units 1 and 2. The preliminary results of this inspection werediscussed on May 25, 2006, with Mr. K. Polson and other members of your staff. The inspection examined activities conducted under your licenses as they relate to safety andto compliance with the Commission's rules and regulations and with the conditions of yourlicenses. Specifically, the inspection focused on the characterization and evaluation of onsiteand offsite tritium contamination that was reported to the NRC Region III staff onNovember 30, 2005. The inspectors reviewed selected procedures and records, observedactivities, collected independent and confirmatory samples for analysis by NRC's contractlaboratory, and interviewed station personnel.We recognize the extensive, recent monitoring performed by your staff to identify the extent ofthe contamination from historical leaks from the circulating water blowdown line vacuumbreakers. The NRC has also performed confirmatory measurements to provide an independentverification of your results. In this case, the contamination is limited to the radionuclide tritium. Tritium is a low energy beta emitter which represents a very low radiological risk as comparedto other radionuclides. Based upon the current radiological conditions and the concentrationsof tritium identified at the Braidwood site, the NRC estimated that the doses from thecontamination to be a very small fraction of the NRC's limit for doses to members of the publicand insignificant relative to normal background radiation dose. We have also received a morecomprehensive assessment from your staff that calculated bounding doses for the historical,unplanned radioactive releases. This assessment is more fully described in Section 2PS1.3 ofthe enclosed report. Although the details of your assessment remain under review by the NRCstaff, our inspection determined that public health and safety has not been, nor is likely to be,adversely affected by the historical circulating water blowdown line vacuum breaker leaks. Additional information relative to tritium, its properties, and its radiological characteristics maybe found at http://www.nrc.gov/reactors/operating/ops-experience/grndwtr-contam-tritium.html.

C. Crane-2-Despite your recent monitoring activities to address the groundwater issue, we concluded thatyour staff did not perform adequate, timely radiological evaluations following the historical leaks,which impacted your ability to assess the environmental impact from the releases and tomitigate the releases; did not account for the potential public impact; and did not adequatelycontrol licensed material. The multiple failures of your staff to adequately evaluate theradiological hazards associated with the leaks from the circulating water blowdown line vacuumbreakers and to assess the resultant environmental impact were determined to be a finding,which was assessed applying the public radiation safety significance determination process(NRC Manual Chapter 0609, Appendix D). The NRC's public radiation safety significance determination process was developed to assessthe risk of licensee non-compliance with regulatory requirements and licensee programs andprocedures. The preliminary significance of the NRC's finding was not based on the risk fromoffsite dose. The public radiation safety significance determination process also considers thepotential impact of program breakdowns. In developing the reactor oversight program, theNRC recognized that a licensee's control of radioactive material is of interest to members of thepublic, even when, as in this case, very low levels of radioactive materials are involved. Consequently, the NRC integrated a deterministic factor into the public radiation safetysignificance determination process, which provides for a higher level of significance than wouldbe warranted based solely on the risk from exposure to the radioactive material. In this case,the preliminary significance of the NRC's finding is based on the adequacy of the licensee'scontrols and assessments of environmental impact. In our preliminary determination, we assessed the finding utilizing the environmental monitoringprogram pathway within the significance determination process, as described in Section 2PS1of this report. We determined that your long-term lack of timely radiological monitoring andassessments following the leaks from the circulating water blowdown line vacuum breakers andfailure to revise your environmental monitoring program concurrently to evaluate the impacts tothe groundwater pathway resulted in an impaired ability to assess the environmental impact. Furthermore, we concluded that the absence of any environmental monitoring data prior to2005 for that leakage pathway and the impact from the leaks also resulted in no assessment ofthe environmental impact between 1996 and 2005. Although your staff was knowledgeable ofthese leaks when they occurred, they did not fully recognize the potential radioactivecomponent of the leaks and did not respond properly. Based on this assessment, we havepreliminarily determined that the finding is White. This finding applies to both units. The finding also involved five apparent violations of NRC requirements (effective at the time ofthe leaks): (1) the failure to perform adequate radiological surveys, as required by10 CFR 20.1501; (2) the failure to adequately implement a program to assess the cumulativedose contributions, as required by Technical Specification 6.8.4.e.5; (3) the failure to conductan adequate environmental monitoring program to provide data on measurable levels ofradiation and radioactivity in the environment resulting from the releases, as required byTechnical Specification 6.9.1.6; (4) the failure to report the unplanned releases in annualreports, as required by Technical Specification 6.9.1.7; and (5) the failure to maintain records of C. Crane-3-the spills that resulted in the spread of contamination in and around the facility, as required by10 CFR 50.75(g) and which are being considered for enforcement action in accordance with theNRC's Enforcement Policy. The current Enforcement Policy is included on the NRC's Web siteat http://www.nrc.gov/reading-rm/adams.html. The significance determination process encourages an open dialogue between the staff and thelicensee; however, the dialogue should not impact the timeliness of the staff's finaldetermination. Before we make a final decision on this matter, we are providing you anopportunity: (1) to present to the NRC your perspectives on the facts and assumptions, usedby the NRC to arrive at the finding, at a Regulatory Conference; or (2) submit your position onthe finding to the NRC in writing. If you request a Regulatory Conference, it should be heldwithin 30 days of the receipt of this letter and we encourage you to submit supportingdocumentation on the docket at least 1 week prior to the conference in an effort to make theconference more efficient and effective. If a Regulatory Conference is held, it will be open forpublic observation. If you decide to submit only a written response, such submittal should besent to the NRC within 30 days of the receipt of this letter.Please contact Steven Orth at (630) 829-9827 within 10 business days of the date of receipt ofthis letter to notify the NRC of your intentions. If we have not heard from you within 10 days, wewill continue with our determination and enforcement decision and you will be advised viaseparate correspondence of the results of our deliberations on this matter.Since the NRC has not made a final determination in this matter, no Notice of Violation is beingissued for the inspection finding at this time. In addition, please be advised that thecharacterization of the apparent violations described in this letter may change as a result offurther NRC review.In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter and itsenclosure will be available electronically for public inspection in the NRC Public DocumentRoom or from the Publicly Available Records (PARS) component of NRC's document system(ADAMS), accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (thePublic Electronic Reading Room).

Sincerely,/RA by A. Boland acting for/Cynthia D. Pederson, DirectorDivision of Reactor SafetyDocket Nos. 50-456; 50-457License Nos. NPF-72; NPF-77

Enclosure:

Inspection Report 05000456/2006008; 05000457/2006008

w/Attachment:

Supplemental InformationSee Attached Distribution

SUMMARY OF FINDINGS

IR 05000456/2006008; IR 05000457/2006008(DRS); 02/13/06 - 05/25/2006; Exelon GenerationCompany, Braidwood Nuclear Power Station, Units 1 and 2; Event Follow-up and PublicRadiation Safety.The report covered the inspection activities for an unresolved item regarding the migration oftritium to the unrestricted areas and to the environment. The inspection was conducted by tworegional inspectors with resident inspector support. The inspection identified one preliminaryWhite finding and five associated apparent violations (AVs). The NRC's program foroverseeing the safe operation of commercial nuclear power reactors is described inNUREG-1649, "Reactor Oversight Process," Revision 3, dated July 2000.A.Inspector-Identified and Self-Revealed Findings

Cornerstone: Public Radiation SafetyPreliminary

White.

A finding and five AVs of NRC requirements were identifiedassociated with unplanned radioactive leaks from vacuum breakers along the circulatingwater blowdown line that occurred in 1996 through 2005 and that resulted in the spreadof radioactive contamination in groundwater beyond the site boundary. Based on theseevents, apparent violations of 10 CFR 20.1501; Technical Specifications 6.8.4.e.5,6.9.1.6, and 6.9.1.7; and 10 CFR 50.75(g) were identified. Following each leak, thelicensee failed to perform adequate radiological surveys to characterize the hazard andto assess the dose to the public and, for certain releases, to report the unplannedoccurrences in required annual reports and to maintain records of the contamination fordecommissioning purposes. In addition, the licensee failed to revise its radiologicalenvironmental monitoring program in a timely manner to ensure that the impact to thegroundwater effluent pathway resulting from the unplanned radioactive releases wasadequately monitored.The finding was determined to be more than minor because the finding was associatedwith the Program & Process attribute of the Public Radiation Safety Cornerstone andpotentially affected the cornerstone objective to ensure adequate protection of the publicfrom exposure to radioactive materials from the release of liquid effluents. Although thefinding has been determined to not result in any public health risk, the finding waspreliminarily determined to be a White finding following the significance determinationprocess (SDP) evaluation because of the licensee's failure to assess the impact on theenvironment from the leakage pathway. Corrective actions taken by the licenseeincluded the cessation of all liquid radioactive releases through the circulating waterblowdown line, performing a plume characterization study, and performing a boundingdose analysis.

Enclosure2Based on current environmental measurements, the calculated doses to members of thepublic from the contamination represent a very small fraction of the NRC's limit fordoses to members of the public and insignificant relative to normal background radiationdose. Our inspection determined that public health and safety has not been, nor is likelyto be adversely affected by the historical circulating water blowdown vacuum breakerleaks. (Sections 2PS1)

B.Licensee-Identified Violations

No violations of significance were identified.

Enclosure3

REPORT DETAILS

2.RADIATION SAFETYCornerstone: Public Radiation Safety2PS1Radioactive Gaseous and Liquid Effluent Treatment and Monitoring Systems (71122.01).1Radiological assessment of unplanned radioactive releases from the circulating waterblowdown line

a. Inspection Scope

The inspectors reviewed the licensee's radiological assessment of leaks from thecirculating water (CW) blowdown line that occurred from November 1996 throughNovember 2005, which resulted in the spread of contamination (tritium) in thegroundwater both onsite and beyond the site boundary. The inspectors reviewedhistorical records to evaluate the licensee's response to the leaks, including radiologicalsurveys, dose assessments, and mitigative actions. The inspectors' evaluation wasperformed to determine if the licensee adequately implemented the requirementscontained in 10 CFR Part 20 and the licensee's Technical Specifications. Specifically,the inspectors discussed aspects of the 1996, 1998, and 2000 leaks from VacuumBreakers No. 1, No. 3, and No. 2, respectively, as well as other leaks from the vacuumbreakers with licensee staff. The inspectors also reviewed:*radiation protection surveys for affected areas; *maintenance work orders for selected vacuum breakers associated with thereleases; *identification of potential pathways based upon release location;*reports contained in the licensee's corrective action program for these events;*parameters and results of licensee's groundwater characterization study;*files that contain environmental contamination events;*select annual effluent release reports; and*select liquid effluent release permits.

b. Findings

Introduction:

A self-revealed preliminary White finding and five apparent violations(AVs) were identified following the review of the events that resulted in the identificationof tritium in onsite and offsite groundwater monitoring wells. The inspectors identified afailure to perform adequate radiological evaluations of the leaks that occurred on theblowdown line necessary to properly quantify and assess the radiological impact of theleaks and to report and document the associated releases.

Description:

On November 30, 2005, the NRC Region III office was notified that thelicensee had measured tritium levels as high as 58,000 picocuries per liter (pCi/L) inshallow, groundwater monitoring wells located at the northern edge of the ownercontrolled area. The licensee attributed the contamination to historical leakage ofvacuum breakers along the circulating water blowdown line that is routinely used for Enclosure4radioactive liquid releases to the Kankakee River. As an immediate corrective action,the licensee suspended all further releases of liquid radioactive material, while thelicensee performed a more comprehensive evaluation of the incidents. During March 2005, the licensee was notified by the Illinois Environmental ProtectionAgency of reports of tritium in wells in a nearby community. Following that notification,the licensee began monitoring groundwater between the community and the Braidwoodstation and obtained samples from a drainage ditch that was near the community. While no contaminated groundwater was identified, the licensee did measure levels oftritium in the drainage ditch near the Braidwood access road. The licensee performedadditional monitoring to identify the source of that tritium contamination.Between March 2005 and March 2006, the licensee sampled the wells of severalhomeowners with drinking water wells and installed groundwater monitoring wells todetermine the extent of the tritium contamination. Beginning in December 2005, theNRC performed an independent analysis of split samples taken from some of thelicensee's monitoring wells and collected independent samples from some residentsnearest to the site boundary. The NRC sample results were consistent with thelicensee's results. The licensee identified tritium levels between 1400 and 1600 pCi/L in one residentialdrinking water well. The tritium levels detected in that well were below theEnvironmental Protection Agency (EPA) drinking water standard of 20,000 pCi/L. Thetritium levels also corresponded to calculated doses which are well below thecorresponding NRC dose limits. The remaining residential well samples had nomeasurable tritium above normal background levels. However, the licensee'smonitoring identified an area of contaminated groundwater that extended about 2000 to2500 feet north of the site boundary. Initial measurements by the licensee andindependent measurements by the NRC confirmed that gamma emitting radionuclidesand strontium-90 were not detected in the contaminated groundwater. The inspectors reviewed the origin of the tritium contamination with the licensee's staff. Based on the information presented and the licensee's measurements, the inspectorsconfirmed that the measured levels of tritium in the environment were consistent withpast leakage of the vacuum breakers on the circulating water blowdown line. That linenormally carried non-radioactive CW discharge back to the Kankakee River but alsoserved as a dilution pathway for planned liquid radioactive releases. The line was about5 miles long and contained 11 vacuum breakers that compensated for pressuretransients within the line from liquid surges. The licensee's recent investigationidentified that significant unplanned radioactive releases from three of these vacuumbreakers during 1996, 1998, and 2000 and other minor releases between 1996 and2005 entered the groundwater system. The 1996 event resulted in the leakage of anestimated 250,000 gallons of water. The 1998 and 2000 events each resulted in aleakage of an estimated 3,000,000 gallons of water. Each leak from a vacuum breakeroccurred over a period coincident with ongoing, liquid radioactive releases through theblowdown line. The inspectors reviewed the licensee's effluent release documents forthe time periods described above and confirmed the that intended releases would havemet NRC requirements if the releases had been made to the Kankakee River.

Enclosure5Following the 1996 and 1998 vacuum breaker leaks, the licensee failed to recognize thepotential radiological component of the leaks and, consequently, failed to perform anyradiological measurements to evaluate the quantity of radioactive material that wasreleased from the line through the vacuum breakers and to evaluate its impact to thepublic and the environment. Following the 2000 vacuum breaker leakage incident, thelicensee sampled, collected, and returned the available surface water to the blowdownline. Although the licensee's corporate staff developed a plan to evaluate the potentialfor groundwater contamination, the plan was not implemented due to a lack of continuityduring personnel changes. Consequently, the licensee failed to account for and toevaluate the potential impact to the groundwater pathway. The licensee also identifiedseveral (approximately 14) smaller leaks from other vacuum breakers leaks during itsroot cause evaluation, which also were not adequately evaluated. Based on a review oflicensee records and discussion with licensee staff, the inspectors concluded that thelicensee failed to perform adequate radiological evaluations following each of the leaksfrom the blowdown line vacuum breakers. Although the licensee had recognized eachleak and appeared to correct the applicable mechanical issues related to individualvacuum breakers, the licensee failed to adequately evaluate the radiological hazardsassociated with the leakage, to calculate a dose to a member of the public, to revise itsenvironmental monitoring program to adequately measure the impact to theenvironment, to report aspects of the leakage in its annual report, and to record theresidual contamination in files for decommissioning purposes.

Analysis:

The inspectors identified a performance deficiency in that the licensee failedto perform adequate radiological evaluations of the leaks from the blowdown linevacuum breakers necessary to properly quantify, assess, and report the radiologicalimpact of these associated releases. In accordance with Inspection Manual Chapter(IMC) 0612, "Power Reactor Inspection Reports," Appendix B, "Issue Screening," issuedon May 19, 2005, the inspectors determined that the issue was associated with theProgram & Process attribute of the Public Radiation Safety Cornerstone and potentiallyaffected the cornerstone objective to ensure adequate protection of the public fromexposure to radioactive materials from the release of liquid effluents. Therefore, theissue was more than minor and represented a finding which was evaluated using theSignificance Determination Process (SDP). Since the finding involved a problem with the licensee's radiological effluent andenvironmental assessment program, the inspectors utilized IMC 0609, Appendix D,"Public Radiation Safety SDP," to assess its significance. This failure was evaluatedwith the Environmental Monitoring Program branch of the SDP:Impaired Ability to Assess Environmental Impact: The failure to perform timelyradiological assessments and monitoring following the leaks and to revise itsenvironmental monitoring program concurrently to provide data on measurablelevels of radioactivity in the environment to evaluate the impacts to thegroundwater pathway impaired the licensee's ability to assess the environmentalimpact of the releases. At the time of the releases, the licensee's groundwatersampling was performed near the Kankakee River and at the Braidwood CityWell (deep well), which would not have been affected by the leaks from thevacuum breakers.

Enclosure6Failed to Assess Environmental Impact: Although the licensee had undertakenrecent, significant efforts to monitor the current environmental impact, thelicensee did not monitor the groundwater pathway near the site at the time of thereleases nor in the short term afterwards. As such, the licensee did not haveany environmental monitoring data prior to 2005 for that pathway and the impactof the vacuum breaker leaks. Consequently, the licensee failed to assess theenvironmental impact of these leaks between 1996 and 2005 in a timely manner,which could have afforded the opportunity for earlier mitigative measures.Based on the Public Radiation Safety SDP, the inspectors preliminarily determined thatthe finding is White.Enforcement: The licensee's actions following the leaks from the circulating water linerepresent multiple examples of five apparent violations.1. 10 CFR 20.1501 requires that each licensee make or cause to be made surveysthat may be necessary for the licensee to comply with the regulations in Part 20and that are reasonable under the circumstances to evaluate the extent ofradiation levels, concentrations or quantities of radioactive materials, and thepotential radiological hazards that could be present. Pursuant to10 CFR 20.1003, survey means an evaluation of the radiological conditions andpotential hazards incident to the production, use, transfer, release, disposal, orpresence of radioactive material or other sources of radiation. 10 CFR 20.1301 requires the licensee to conduct operations so that the totaleffective dose equivalent to individual members of the public from the licensedoperation does not exceed 0.1 rem (1 mSv) in a year.Between November 1996 and March 2005, the licensee did not make surveys toevaluate the potential hazards and to assure compliance with 10 CFR 20.1301,which limits radiation exposure to members of the public from licensedoperations to 0.1 rem. Specifically, in November 1996, December 1998, andNovember 2000, failed vacuum breakers in the licensee's radioactive wasteblowdown line resulted in large volumes of liquid contaminated with licensedmaterial to leak in an uncontrolled manner to the unrestricted areas. Followingthe identified releases of radioactive material, the licensee failed to perform anadequate radiological survey to identify the extent of radiation levels, to evaluatethe potential hazards associated with the radioactive material, and to ensure thatthe dose to the public did not exceed the levels specified in 10 CFR 20.1301. (AV 05000456, 457/2006008-01)2. Technical Specification 6.8.4.e.5 requires that the licensee maintain andimplement a program to determine the cumulative dose contributions from liquideffluents for the current calendar quarter and the current calendar year inaccordance with the methodology and parameters in the Offsite DoseCalculation Manual (ODCM) at least once per 31 days.

Enclosure7Between November 1996 and March 2006, the licensee failed to determine thecumulative dose contributions from liquid effluents that inadvertently leaked intoonsite and offsite groundwater (resulting from failed vacuum breakers along thecirculating water blowdown line in 1996, 1998, and 2000) in accordance with themethodology and parameters in the ODCM within 31 days. Specifically, anestimated 250,000 gallon leak from Vacuum Breaker No.1 in November 1996released water with radioactive material to the groundwater pathway; however,the licensee did not determine the dose from the release. In December 1998, anestimated 3 million gallon leak from Vacuum Breaker No. 3 released water withradioactive material to the groundwater pathway; however, the licensee did notdetermine the dose from the release. In November 2000, an estimated 3 milliongallon leak from Vacuum Breaker No. 2 released water with radioactive materialto the groundwater pathway; however, the licensee did not determine the dosefrom the release. (AV 05000456, 457/2006008-02) 3. Technical Specification 6.9.1.6 requires that the Annual RadiologicalEnvironmental Operating Report include summaries, interpretations, andanalyses of trends of the results of the radiological environmental monitoringprogram for the reporting period and that the material shall be consistent with theobjectives outlined in the Offsite Dose Calculation Manual (ODCM) and in 10 CFR Part 50, Appendix I, Sections IV.B.2, IV.B.3, and IV.C. 10 CFR Part 50, Appendix I, Section IV.B.2 states the licensee shall establish anappropriate surveillance and monitoring program to provide data on measurablelevels of radiation and radioactive materials in the environment to evaluate therelationship between quantities of radioactive material released in effluents andresultant doses to individuals from principal pathways of exposure.Between November 1996 and March 2006, the licensee did not establish anappropriate surveillance and monitoring program to evaluate the relationshipbetween quantities of radioactive material released in effluents and resultantdoses to individuals from principal pathways of exposure. Specifically, theunplanned radioactive material released in 1996, 1998, and 2000 from thecirculating water blowdown line vacuum breakers constituted new principalpathways of exposure (i.e., the groundwater pathway) which the licensee had notadequately evaluated with the existing Radiological Effluent Monitoring Program(REMP). (AV 05000456, 457/2006008-03)4. 10 CFR 50.75(g) requires each licensee to keep records of information importantto the safe and effective decommissioning of the facility in an identified locationuntil the license is terminated by the Commission. The Commission considersinformation important to the decommissioning to include records of spills or otherunusual occurrences involving the spread of contamination in and around thefacility, equipment, or site. These records may be limited to instances whensignificant contamination remains after any cleanup procedures or when there isreasonable likelihood that contaminants may have spread to inaccessible areasas in the case of possible seepage into porous materials such as concrete. These records must include any known information on identification of involvednuclides, quantities, forms, and concentrations.

Enclosure8As of March 6, 2006, the licensee did not keep records of spills or other unusualoccurrences involving the spread of contamination in and around the facility forthe 1996 or 1998 unplanned radioactive releases from the circulating waterblowdown line vacuum breakers. Specifically, in November 1996, an estimated250,000 gallon leak from Vacuum Breaker No. 1 released water with unknownquantities of radioactive material to the groundwater pathway that was notrecorded. In December 1998, an estimated 3 million gallon leak from VacuumBreaker No. 3 released water with unknown quantities of radioactive material tothe groundwater pathway that was not recorded. (AV 05000456, 457/2006008-04) 5. Technical Specification 6.9.1.7 requires that the Radioactive Effluent ReleaseReport include a summary of the quantities of radioactive liquid and gaseouseffluent and solid waste released from the facility during the prior year and thatthe material shall be consistent with the objectives outlined in the ODCM and in10 CFR Part 50, Appendix I,Section IV.B.1. The ODCM Section 12.6.2 requires, in part, that the Annual Radioactive EffluentRelease Report include a list and description of unplanned releases from the siteto areas beyond the site boundary of radioactive materials in gaseous and liquideffluents made during the reporting period.As of March 6, 2006, the licensee failed to identify the occurrence of unplannedreleases of radioactive liquid effluent that correspond to the vacuum breakerleaks to areas beyond the site boundary in the 1996 and 1998 AnnualRadiological Environmental Operating Reports. Specifically, in November 1996,an estimated 250,000 gallon leak from Vacuum Breaker No. 1 released waterwith unknown quantities of radioactive material to the groundwater pathway thatwas not reported in the 1996 annual report. In December 1998, an estimated3 million gallon leak from Vacuum Breaker No. 3 released water with unknownquantities of radioactive material to the groundwater pathway that was notreported in the 1998 annual report. (AV 05000456, 457/2006008-05).2Characterization of the extent of tritium groundwater contamination from the unplannedradioactive releases from the circulating water blowdown line vacuum breakers

a. Inspection Scope

The inspectors reviewed the licensee's radiological monitoring and assessmentsperformed during March 2005 through March 2006, to characterize the extent ofgroundwater contamination from blowdown line vacuum breaker leakage. Specifically,the inspectors reviewed:*the licensee's characterization report, which documented the local hydrogeologyaround the facility through the installation of groundwater monitoring wells onlicensee owned property around the blowdown line;*the licensee's sampling and analysis program, which included groundwater anddrinking water samples from private wells near the blowdown line; and Enclosure9*the licensee's evaluation of blowdown line integrity, which included acousticalmonitoring of the line.The inspectors compared the licensee's results to the independent analysis performedby the NRC's contract laboratory to evaluate the accuracy of the licensee'smeasurements. The tritium results from the NRC's independent analysis of split sampleand samples that were independently obtained by the NRC are included in Appendix Ato this report.

b. Findings

No findings of significance were identified. The inspectors independently estimated the extent and magnitude of the groundwatertritium contamination through NRC's contract analysis of water samples collected fromresidential drinking wells near the facility and from shallow monitoring wells installed bythe licensee. The NRC's contract laboratory analyzed the samples for tritiumcontamination. In addition, the NRC's contract laboratory analyzed selected samples forother radionuclides using gamma spectroscopy, and analyses have also beenperformed for Strontium-90 (Sr-90) and Technetium-99 (Tc-99). The contract laboratoryalso utilized special techniques to identify "difficult to detect" radionuclides, such asIron-55 (Fe-55), Nickel-63 (Ni-63), and transuranic elements.The NRC's results confirmed that tritium was present in one offsite residential well atlevels of about 1300 to 1500 picocuries per liter, which is a small fraction of the EPAdrinking water standard of 20,000 picocuries per liter. In all other residential wells, nomeasurable levels of tritium or other licensed radioactive material above normalbackground have been detected. In a deeper onsite groundwater well, the NRCmeasured tritium as high as 282,000 picocuries per liter. Measurable levels of tritiumhave been found offsite in shallow monitoring wells and in a pond located near plantboundary. Appendix B contains a map of the area near the plant and the correspondingtritium results from various locations. The colored dose gradients represent licenseemonitoring results while the specific values annotated indicate selected NRC monitoringresults.3 Assessment of offsite doses from the leaks releases from the circulating waterblowdown line

a. Inspection Scope

The inspectors reviewed the licensee's assessment of the bounding dose from historicalreleases from the circulating water blowdown line vacuum breakers, which wascompleted by the licensee near the end of the NRC's inspection. The inspectorsreviewed the assessment to ensure that the licensee provided a technically sound basisfor its underlying assumptions (historical, current, and projected radiological sourceterms), included the most probable exposure pathways, and calculated the doses usingtechnically sound health physics principles. The inspectors also compared thelicensee's dose estimates to the NRC dose limits contained in 10 CFR 20 and thelicensee's Technical Specifications.

Enclosure10

b. Findings

The licensee calculated an estimated bounding dose of about 0.16 millirem per yearfrom the ingestion of drinking water from the contaminated residential drinking waterwell that contained about 1500 pCi/l of tritium from the vacuum breaker releases. Thatcalculation was based on a hypothetical child consuming the tritiated water and wasperformed using the methods of Regulatory Guide 1.109, "Calculation of Annual Dose toMan from Routine Releases of Reactor Effluents for the Purpose of EvaluatingCompliance with 10 CFR Part 50, Appendix I." The licensee also performed anadditional calculation that considered the actual residents. Based on that mostreasonable scenario defined by the licensee, the licensee calculated a maximum doseof about 0.072 millirem per year to a member of the public. That scenario was based onadults consuming the tritiated water and used the updated NRC guidance contained inNUREG/CR 4013, "LADTAP II - Technical Reference and User Guide." The NRCinspectors also calculated a dose of about 0.07 millirem to an adult using applicableNRC methods. Although the estimated dose was well below NRC requirements, theNRC will continue to evaluate the details of the licensee's dose assessment with respectto historical and future dose estimates during subsequent inspections..4Evaluation of potential sources of underground leakage

a. Inspection Scope

The inspectors reviewed the analysis of groundwater monitoring wells installed onsite todetermine the hydrogeology characteristics of the site. Based on these measurements,the inspectors evaluated the licensee's characterization of the groundwatercontamination both onsite and offsite and the origin of that contamination. Theinspectors verified that identified areas of underground contamination within theprotected area of the facility near the turbine building were adequately incorporated intothe licensee's fleet wide initiative to "evaluation of systems that handle radioactivelycontaminated water."

b. Findings

No findings of significance were identified. 2PS3Radiological Environmental Monitoring Program (REMP) And Radioactive Material Control Program.1Evaluation of preliminary results from routine environmental water sample locations

a. Inspection Scope

The inspectors reviewed the concentrations of liquid radioactive material that weremeasured in the environment from January 2005 through December 2005. Theinspectors reviewed the results of the composite samples collected at the circulatingwater blowdown discharge point, just before the water enters the Kankakee River.Based on these measurements, the inspectors evaluated the results of the compositesamples collected at the input to the Wilmington municipal water system, which collects Enclosure11water from the Kankakee River downstream of the plant. The inspectors also reviewedthe results of ground water samples near the Kankakee River and surface watersamples collected from the Kankakee River downstream of the plant. The inspectorsreviewed this data to ensure that any environmental impact from plant operations wasadequately evaluated by the licensee as required by its Offsite Dose Calculation Manualand Technical Specifications.

b. Findings

No findings of significance were identified.

4OA3 Event Follow-Up

.1Events that resulted in tritium contamination in unrestricted areas

a. Inspection Scope

The inspectors reviewed the licensee's historical records of circulating water blowdownline vacuum breaker leakage, including the licensee's root cause evaluation report andapplicable condition reports. The inspectors also conducted staff interviews andphysical walkdown of the facility. Based on that review, the inspectors developed atimeline of events (Appendix C) associated with the tritium contamination to fullyunderstand the events and the licensee's response to those events.

b. Findings

Findings are documented in Section 2PS1.1..2 Radiological steam release from relief valve

a. Inspection Scope

The inspectors reviewed the licensee's initial radiological assessment and actionsconcerning a release of steam that was discharged from a failed relief valve in thefeedwater system on April 6, 2006. The relief valve provides over pressure protectionfor the feedwater heater drain cooler and contains low levels of tritium. The inspectorsevaluated the licensee's preliminary results of air and water samples taken in theimmediate area of the release and the actions taken to mitigate the spread of potentiallycontaminated steam/water. In addition, the inspectors reviewed the licensee'spreliminary radiological assessment for a group of workers who were in the area nearbythe steam release. The inspectors assessed the licensee's actions to ensure that NRCrequirements (e.g., 10 CFR 20, Technical Specifications, and licensee procedures) wereadequately implemented.

Enclosure12

b. Findings

On Thursday, April 6, 2006, a relief valve failed open on the shell side of the drain coolerin the feedwater system. The relief lifted at 1:25 p.m. (Central time), and the licenseewas successful in isolating the drain cooler and the release at about 5:47 p.m. (Centraltime). Based on water usage from the condensate storage tank, the licensee estimatedthat about 114,000 gallons of steam/water was released from the Turbine Buildingthrough the relief valve. A group of workers (approximately 10 persons) was working on the primary waterstorage tanks, which were in the vicinity of the steam release. The licensee discussedwith the inspectors its evaluation of the potential exposure of the persons to the steamand its application of procedure RP-AA-220, Revision 03, "Bioassay Program." Sincethe airborne levels of tritium were less than the licensee's detection limits, the licensee'sprogram and procedures did not require specific bioassay monitoring, which wasconsistent with the NRC requirements for monitoring contained in 10 CFR Part 20. The licensee collected samples of condensed steam that accumulated as surface wateron areas of the site. The licensee detected tritium at levels of about 41,000 to 46,000pCi/l in samples near the release point. The licensee also obtained samples from adrainage ditch that was located near the licensee's property line and measured tritiumlevels of about 400 - 600 pCi/l. Immediately following the release, the licensee installeddams to prevent the contaminated water from migrating across the site boundary. Thelicensee also collected the surface water and was storing the water in temporary onsitetanks. The licensee indicated that it was planning to conduct additional soil andgroundwater samples to ensure the full extent of the contamination was determined andto assess how potential offsite dose from the release and any previous steam releasesfrom the secondary system which will be reviewed in future NRC inspections.4OA5Other Activities.1(Closed) Unresolved Item (URI) 05000456, 457/2005010-02: Tritium contaminationfrom past vacuum breaker leaks on circulating water blowdown lineThe inspectors reviewed the licensee's actions to determine whether the licensee hadfully characterized the extent of the tritium contamination, whether the source of thecontamination was properly identified, whether the licensee had correctly evaluated theintegrity of the blowdown line, whether corrective actions were appropriately developedto prevent future releases from the blowdown line, and whether the licensee adequatelyevaluated potential mitigative actions for the tritium already released. The results of thatreview are described in Section 2PS1. The licensee's corrective actions and potentialmitigative actions will be reviewed by NRC during future inspections. This URI is closed.

Enclosure134OA6Meetings.1Exit MeetingThe inspectors presented the inspection results to Mr. K. Polson and other members oflicensee management at the conclusion of the inspection on May 25, 2006. Theinspectors asked the licensee whether any materials examined during the inspectionshould be considered proprietary. No proprietary information was identified.

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