ULNRC-04898, Request for NRC Regional Enforcement Discretion

Request for NRC Regional Enforcement Discretion

ML032671224
Person / Time
Site:	Callaway
Issue date:	09/09/2003
From:	Witt W AmerenUE
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
ULNRC-04898
Download: ML032671224 (15)

Text

Union Electric PO Box 620 Callaway Plant Fulton, MO 65251 September 9,2003 U.

Nucea Regulatory COMMission DocumentContolDesk Mail Stop P1-137 Washington, DC 2055S40001 t

LAdiesand Gntemen:

UL1RC0898 wAmeren-UE DOR CALLAWAY PLANT UNION ELECTRIC COMPANY RE;QUEST.POR NRC REGIONAL This letr confirms the results ofa tleconferene tat was conducted.

between AmrefnUE (Union Electric) and NRC Staff represetives at 1900 hours0.022 days <br />0.528 hours <br />0.00314 weeks <br />7.2295e-4 months <br /> on September 6, 2003 in which AmeCUE requested the NRC to ercis enOement discretion for the Callaway Plot. regarding the qiem ofTechnical Specification (TS) Uming Condition fr Operation (LOG) 3A.14o Pressurze Power Operated Relief Valves (PORVs).* Wit the plant opeating In Mode I (at 100% Rated Thermal Power), the request was made in order to provide additional time to repar and test die pressurir PORV block. valve before a plant shutdown would have otherwise been required. Via a follow-up telephone call from NRC Region IV at 2100 hours0.0243 days <br />0.583 hours <br />0.00347 weeks <br />7.9905e-4 months <br /> on September 6, AmeresUEs request was appovad The events lading to AmerentU' request began when the OD" ftain pressurizer PORV block valve, SBHV8000B, was declared inoperable at 0601 hour0.00696 days <br />0.167 hours <br />9.937169e-4 weeks <br />2.286805e-4 months <br />.

Contra Daylight Time (CDI) on September4, 2003 to sppost a vave control switch modification With the plant in Mode I, Condition C of TS LCO 3A4.1I was entered at 0601 hou, thus plaing associated Rqird Actions C. I and C.2 into effect With one block valve nopeabLe, Required.Action C. 1 requires placing the associated PORV in manual control withIn 1 bour, and Required Action C.2 requires restoring the block valve to OPERABlE stus within a specified Completion Time of 72 houm Te 'B' train PORV (BBPCV0456A) was according placed in manual control at 0608 hour0.00704 days <br />0.169 hours <br />0.00101 weeks <br />2.31344e-4 months <br />.

a subsidiary of Amren Corporation

ULNRC-04898 Page 2 September 9, 2003 Following installation of the conthol switch modification, the Control Room Reactor Operator identifiedia loss of indication for thelvalve. During the process of troubleshooting the loss of indicationtation personnel reported an acrid odor in the electrical penetration room. Ibis odor proved to be indicative of an electrical failure that was subsequently confirmed in the block valve's actuator and associated control circuit.

Required Action C.2 was entered when the 'B' train PORV block valve was, declared inoperable at 0601 hours0.00696 days <br />0.167 hours <br />9.937169e-4 weeks <br />2.286805e-4 months <br /> on September 4. The 72.hour Completion Time for this Required Action requited theinoperabLe block valve to be restored by 0601 hours0.00696 days <br />0.167 hours <br />9.937169e-4 weeks <br />2.286805e-4 months <br /> CDT on Stember 7,2003 before entering ConditionD of LCO 3.4.11. This Condition requires a plant shutdown sutha t MODE 3 must be entered within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> (per Required Action D. Y and MODE 4 must be entered within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (per Required Ation D.2). Enforcmentdisdretion was sought to permit noncomplimace withLCO 3.4.11, Le., toptnibitadditiial time for testitfig troubleshooting and restadon ofthe block valvebeforaplantshutdown wu be requied. :

Specifically, an additional 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />swaslrequested to restore the "

train pressurizer PORV block valve to OPERABLE status such that entryinto Mode 3 would not be required until 1201 on September 9, 2003.

As noted previously, this request for enforcement discretion was verbally discussed with the NRC Region IV Office and Office of Nuclear Reactor Regulation on September 6,2003. It wasenoted t discussed in Regulatory Issue Summary 2001-20, this request requires a Regional Notice of Enforcement Discretion (NOED) since noncompliance with the Required Action Completion Time would be non-recurring and would not exceed 14 days in duration, and since a license amendment was unnecessay because the plant was expected to return to compliance in a short period of time. The requested additional time for restoring the block valve had been evaluated and was shown to involve no increase in net risk.

During the time that the requested enforcement discretion would be in effect, AmerenUE noted that it would be wheeling power in the north-to-south direction.

Ptojected grid conditions were such that slightly higher-than-normal demand was expected for Monday (9/8) and Tuesday (9/9), but stable conditions were expected to prevail throughout this period. AmerenUE committed to maintaining required switchyard voltage for Callaway thrsghout this timeframe. In light of the stable grid conditions and the fact that mild weather was forecast for the next several days, this request was determined to not involve a 'weather-related" NOED.

ULNRC-04898 Page 3 September 9, 2003 The details and basis for AmerenUE's request (as discussed in the September 6 teleconference) are providediin the Attachment to this letter, which was prepared in accoidance with the guidance provided in RIS 2001-20. The attachment reflects the state df events as they existed during the telephone discussions with the NRC on September 6.

It may be noted that subsequent to the telephone call in which NRC granted verbal approval of AmeUenUE's request, work continued on restoring the block valve to OPERABLE status. Testing of the block valve was completed by approximately 0400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br /> on September 7. However, as noted in the attachment to this letter, work was also performed in parallel to resolve an annunciator problem that occurred during the restoration effort (This work had already begun at the time of the telephone discssions on September 6.) Although there was a high degree of assurance tat this problim did not affect operability of the block valve, the block valve was conseravely not declared' OPERABLE until the operability impact ofthe annunciator Otoblem was fidly evalted. Extensive testing of the annunciator circutt was performed to ensure there was no impact on valve operability. Upon completion of the evaluation, the block valve was declared OPERABLE at 1418 hours0.0164 days <br />0.394 hours <br />0.00234 weeks <br />5.39549e-4 months <br /> on Septeuixber 7.

AmerenUE appreciates the prompt attention given to this matter. For any questions or additional information regarding this request, please contact me at (576) 676-8763 or Dae Shafer at (314) SS4-3104.

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v E, Warren A. Witt Manager - Callaway Plant TBE~mo : REQUEST FOR REGIONAL ENFORCEMENT DISCRETION REGARDING COMPLIANCE WITH TECHNICAL SPECIFICA-TION 3.4.11, WPRESSURIZER PORVS"

ULNRC-04898 Page 4 September 9, 2003 cc: U..S. Nuclear Iatoryt slnfginal and i copy)

Attn: Document motrol, bsl MailStopPl-137

-ik Washington, DC 2055S-0001 MW Thomas P. wynn t

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Acting Regionla Admlni

,tr U.S. Nuclear Regulatory Coniision Region IV 611 Ryan Plaza Drive, Suit 400 Aritq!, rx 760114005 t I.

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Senior Resident inspector Calaway Resident Office NU..NceAC3 Raeulatory CO.,

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MW.JackN.Donohew(2clis}

Licensing Project Manager, Callaway Plant Office of Nuclr React Reula

U. S. Nuclear

&igatqy Cii Wii lStop 7EI Washington, DC 265%-2M3 ";'"' '

Manager, Electric Depairment' t Missouri Public Service Cimiiib& -

PO Box 360

'";'ferson City, MO 65102 1.t It: It I.

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-? I to ULNRC-04898 Page 1 of 11 REQUEST FOR REGIONAL ENFORCEMENT DISCRETION I

xl,>,REGARDINGCOMPLIANCE WITH TPCU-NIVA 1. APRVIVIVATInThl -%Al I - "PROMTRIMR PORVRO'

1.

Technical Specification

)orother Lledse Conditions that will be Violated:

Thenactor coolant system (RCS) at Callaway is provided with a pressurizer which provides a point in the RCS where liquid and vapor are maintained in equilibrium under saturated conditions for pressur control purposes to prevent bulk boiling in the remainder ofthe RCS.

Key functions include maintaining required primirytystem pressure during steady-stat operation, and limiting the pressure changes caused by coolant thermal expansion and :!

contraction during normal load transients.

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Tbe pressurizer is cqpped!with two ps of deviks for pressure ief: pressuizer safety' t vlves and pressure-operated relief valves (PORVs). Specifically, two PORV are provided: an "A" valve and a "B" valve. The PORVs are safety-related DC solenoid-operated valves that are rntrolled to open ati specific'set pressure *hetithe pressurizetaressure increases, and to close when the pressurizer pressuredecreases. -e PORVs may a be manually operatd fromthe conitrolrroom.

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s Block valves, which are normally open, arelocated between-the ptessurizer and the PORVs; The block valves are used to isolate the PORVs in case df Excessive leakake ora stuck open PORV.

Block valve clo Is normlyaccomplished manually using contro in the control oom. As discussed fiuther in Section 3, the PORVs and their associated block valves may be used by plant opratorsa to depressurize t-RCS to recover from certain transients if normal pressurizer spray is totavailable. Operability and test rquirementsfor t the PORVs and block valvesI are set forth in Callaway Technical Specification ()

3.4Ct1, "Pressurizer Power Operated Relief Valves (PORWs)."

On September 4, 2003 the "B" train pressurizer PORV block valve (BBHV8000B) was delared hioperable at 0601 hours0.00696 days <br />0.167 hours <br />9.937169e-4 weeks <br />2.286805e-4 months <br /> Central Daylight Time (CDT) to support modification of an associated valvebontrol switch. Condition C of the Limiting Condition;for Operation (LCO) section of TS 3A. 1 was entered at 0601 hours0.00696 days <br />0.167 hours <br />9.937169e-4 weeks <br />2.286805e-4 months <br />, thus requiring associated Required Actions C. and C.2 to be mdt With'one block valve inopetable, Required MAton C.1 requires placing the assobiated PORV in manual control within I hour, and RequireddAction C2 'requires restoring the block valve to OPERABLE stits vithin a specified Cmpledon ime of 72 hous. The B jain PORV (BBPCV04S6A) was accordingly placed im manual control at 0608 hours0.00704 days <br />0.169 hours <br />0.00101 weeks <br />2.31344e-4 months <br />. -

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With Required Actidn C.2 currently in effect, the inoperable "B" train pressurizer PORV block valve must be restored no later than 0601 hours0.00696 days <br />0.167 hours <br />9.937169e-4 weeks <br />2.286805e-4 months <br /> CDT on September 7, 2003. If the PORV block valve cannot be restored to OPERABLE status in that timefiane, Condition D must be entered, which requiresa plant shutdown. Specifically, Required Action D.l requires entry into MODE 3 (Hot Standby) within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and Required Action D.2 requires entry into MODE 4 (Hot Shutdown) within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. Enforcement discretion is being sought such that it would allow up

Attachment I to ULNRC-04898 Page 2 of II to an additional 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> for restoring the B train pressuizer PORV block valve to OPEWBLE status. In effect, it would allow delayed entry into Mode 3 per Required Action D. I such that enty into Mode 3 would not be required until 1201 on September 9, 2003.

2.

Circumstances Requiring the Request for Enforcement Discretion Background on Control Switch Modification As part of a design change implemented with Ucense Amendment 137 dated September 25,,

2000, the pressurizer PORV block valve hand-indicating switches (BBHIS8000A and B. as shown on FSAR Figure 7.6-4) were replaced per a new switch design. That switch design required the operating staff to manipulate two switches when operating in the cold oveapressure protection mode with the Cold Overpressure Mitigation System (COMS) manually armed. The block pushbutton on the COMS arming switch would have to be depressed before the pressurizer PORV block vaIv hand-indicating swt ca.iaA work.,

5-The opeating staffsubsequontly muestedht tthe prsuimr PORV.block hand!indicating -

switches be replaed with a design at Iock*4owailthe CLOSED position. ITe new hand-indiating switch design that was sclot tqob ibsuled and retested woudamvea maintained-CnSED position, and the OPEN posidon wpuld be noenta a springretur to the AUTO position. :Iis design would allaw the oprating staff to release the OPEN pushbutton after the demand is m

., Nonally, dwt Ivwold be eectedto be open with h hand-ind ig switchin the AUTO posiion. '!wI 0.:-3.;.

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1 The switch replacements were scheduled to be performed on-line by modifying one PORV block valve control circuitat a ime ad toring them to service upon completion oftheimodification and assoated gcsting The 'B' blo vatve was selected to be modified firs.; ip The switch modification on the 'B' train pressurizer PORV block valve (BBHV8000B) including retqing.was completed on September4,2003 at 1817 hourm Atapproximately 1830

bo4, the on-coming Balanceof Plant (BOP) operatorzoted the open indication for flBHVW00QB ws.pt illuminated during his contrl bord walk-down. The on-shift BOP operator attepied to aplace the indicating light bulbs. At 1840 hours0.0213 days <br />0.511 hours <br />0.00304 weeks <br />7.0012e-4 months <br />, following the BOP oparator shift turnover, the ff-going BOP Operator told the Control Room Supervisor (CRS) that he ttmpted to replase thebulbs twice but the lights would not wo&,. The CRS informed the hift Sippviso (SS) and the Field Supervisor (FS) that a problem may exist with the new switch and/or the valve. The on-shift crew strted an investigation into the scope of work that had cheeinperfocnvxL i ' "

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s.t Atapproxinately. 1850 hours0.0214 days <br />0.514 hours <br />0.00306 weeks <br />7.03925e-4 months <br />, security psonel reported an acrid odor in the south electrical peJetration roqm, id dthe primary Equipment Operator (EO) was dispatched to that location.

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to ULNRC-04898 Page 3 of 11 The FS was sent to help investigate, and at 1920 hours0.0222 days <br />0.533 hours <br />0.00317 weeks <br />7.3056e-4 months <br /> he reported that the breaker was found to be tripped.

Apparent Csse=

It has been determined that during rewiring of the control circuit in the MCC cubicle, a vendor wire that was In a previously inactive part of the circuit should have been reoved but was not The drawings included in the work package did not reflect this vendor wire. This vendor wire was in effect a jumper around the MOV "open" limit switch and the open"W torque switch. This allowed the "open" contactor coil to remain energized with the "open" limit and "openW torque switches open. This caused the valve actuator to continue to drive the valve open until motor damage occurred and the b r trip;_

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Extentof Damage Elctricians tested the motor and found that it had shorted widinsgs Upon coweing the MOV acatordarae to the motor and limit switch assembly was found. The power cables for the motor were tested and were found undamaged. Evaluation has determined that the Locked Rotor Current is well below the Penetration Thermal Damage Curve and no damage would have occurred at the penetrtion. The successfid megger testing of the power cables supports this determination. Visual inspection of the visible portions of the threads, vae stem, and bonnet indicated that these items are undamaged. A GL 91-18 operability determination documents that valve, stem and bonnet operability is assured until Refuel 13 (April 2004). In addition, the MCC cubicle (NG02BDFI) was inspected and the overload relays were found damaged. No other components in the MOC cubicle were damaged.

Westinghouse has evaluated the extent of damage to the valve, and concluded that stem integrity was the limiting fictor for the condition of over4hrust on opening into the backseat It was determined that the valve stem is acceptable for use until Refuel 13 at a minimum.

Restoration Work Activities Work performed for the inoperable block valve thus far includes several acities. The Limitorque motor and actuator have been replaced. The power cables to the motor have been tested to verify required insulation resistance, and the associatedd overlod heaters and relays have been replaced. The MCC bucket and new hand-indicating switch were scheme-checked to confirm the as-installed wiring configuration. Further, the MCC bucket and the hand-indicating switch have been rewired to the pre-modification configuration. MOVATS testing will be performed an the new actuat and motor prior to declaring the valve OPERABLE an.

At presawttroubleshooting is in progress to address an unanticipated annunciator associated with the COMS system, which was received during restoration of limit switch settings. Specifically, Annunciator 64A, COP. BLOCK VALVE NOT OPEN toggled iu several times while performing initial limit switch ajustmenten BBHV8000BE

-The ennunciatorcircuit is such that the annunciator-should be lit when valve BBHV8000B is not open and when handswitch to ULNRC.04898 Page 4 of 11 BBHS8000B is in ARM. A work history review indicated that a previous occurrence of this problem happened in May, 2001.

Troubleshooting has indicated that the handswitch contacts are currently open, which is consistent with the current state of the handswitch. The handswitch is being replaced with a new handswitch that has been verified to operate propedy, It is believed that this problem does not affect operability of the block valve or its associated PORV, this is being confinned.

Need for Prompt Action IIis

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Without enforcementdiscretion, the 72.hour Completion Time imposed by the LCO 3A.4.1 Required Action C.2 will expire at 0601 hours0.00696 days <br />0.167 hours <br />9.937169e-4 weeks <br />2.286805e-4 months <br /> COT on September 7j 2003. 'Tereafter, in accordance with RequiredActions D. 1 and D.2,espectively, Callaway Plant will be required to shut down to MODE 3 within 6 hburs (i.e.jbya 120l1urs on September 7) and to MODE 4 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (i.e., by 1801 hours0.0208 days <br />0.5 hours <br />0.00298 weeks <br />6.852805e-4 months <br /> on September 7). Enforcement discretion is being sought to allow additional time for the IVI pressutizer PORV block valveto be restored to OPERABLE statussuchthatentryintoMode3ewodnotbeequieduntil 1201 onSeptember9,2003. Out

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Safety Bals Including'Evaluatlon of Safety Sgufilcance and Qualitative Risk ssm*

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. i pesi~t lisFunction of PssurizaPORV:BlockValv s-.- -L.1.1i 8 1 j z x 1 ts t 6 \\) }1.

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! S'.. r Motor-opertdblck vprovided-foriefoollowing finctions:z

'i;t The valves may be remote-manually stroked to the open position upon demand (using controls in themain control kiom)t6enable thepressurizer PORVtbprovide pressure re;if in the 6eet of aimlndvertent EmergencyCore Cooling System (ICCS) Actuation

f '!\\ (adiscussed in VSARSection 15.S;1),SteamGenrator TubeRuptr '(SOlas discutkd in FSAR Section 1S.63);wm Antdcipated Mankiedt Without Scram (ATWS,

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asdiscssedinthebodyof rferencesist6dltSAR!Sectinl~15.8);

I Thevalves atmatilly stroke to the antosition upon aming of COMS (i.., th pre-nmodificatioblifigurafon) to enable the pressuriet PORVs to provide cold

- -ov pirsAte protection; and

• i The val*siniad be aftnt&emanual1y Acdkd to the closed position upii demand (tsing

• conitrolsti thd~d~in cointrol room) td Ibsob a PORV(s) VkesiV6 seat leakage deveopg cn'if the PORV tils to close eizlldting mn effect, a unall break iko of oolait

ccident (SBLOCA).

The caeabifty'to remote.nianually stroke the blockvalves fiom the main control room was includedin ficensingbakisc6imltmnents made in nse to NUREG.0737 and NRC Generic Letter90-06(5O!54(f) tettir).' '

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Attachment I to ULNRC-04898 Page 5 of II The PORVs, with the block valves open, may also be used for. feed-and-bleed core cooling in the case of multiple equipment failure events that are not within the design basis, such as a total loss of feedwater. These events ar "plzed in the Callaway PRA.

jfety Assessment and Probabilistic Rislc Assessment MWlAEvaluation Regarding the current impact of the request on sfety, it should be noted that the W train pressurizer PORV block valve is fully OPERAHLet this time. Both the 'A" and "B' train PORVs are fully OPERABLE at this time. The '8' train pressurizer PORV block valve is inoperable in the fully open position and will have power removed, except when closed for short durations for testing or maintenance activities during valve restoration. With the block valve in the open position, however, the functions dicusse4 AbqW are t1 capable pfbeing fuIly atisfied except for the function to stroke closed to iskolk g

r Vst '-open POVi For the closing function, it may be noteddd-ith ith oyvnt ofa dmand, with the valve "declutched"' from its motor-operator, local closure of the valve may be effected for events that would not immediately render the containment iacpsible, Moryaer,houghut most of~the latter stages of yalve rstoraion, during MOV4TS ting fq Qxle, fw4ctionalityof the valve will exist to the poit that it will be capable of being closed fiom the control room in the event of ademandL Fmally. At should be noted that from an acdent anaysis point of vi, if the WB" train PORV were to o andastick in thposition (with the block valve open), the associatd, ensuing transient t mat y be assumed is uoinded by analyses carrently contined within FSAR Section 15.6.1 (equivalent of a stuck-open safety valve) and FSAR Section 15.6.5 (SBLOCA).

Therefore, granting this, est for enforcement discretion will have a minimal impact on nuclear safety during tIhe short time frame it will be in force.

W~th rspect to risk assessment, and as noted previously, the pressurizer PORVs, i.e.,

B.PCV 4f5Apnd BBPCVO456A, and their associated block valves (BBHV8000A and BBfIV8O@, qspectively) are credited to mitigate core damage events in the Callaway PRA.

SjXcifilyt.the valves are credited to mitigate the effects of an A1WS evt, and are credited (along with operatoractions) for RCS feed-and-bleed cooling to mitigate the effects of various ti"ensients given the loss of secondary cooling. ITe PORs and PORV block valves are thus red to qti to provide these mitigative functions. As also noted previously, the PORV blfck valves ae credited to mitigate the effects of a stuck open PORV, and are thus required to close to provide this finction.

To provide assurance that the requested NOED is risk-neutral, the following risk-offsetting Compensatory Actions will be taken during the time period the NOED is in force. Based upon risk insights fiom the Callaway PRA, these actions will serve to reduce core damage and large early release risk.

BBHV8000B will be kept in the open position during the NOED period, except for valve stroking required for maintenace or testing. This serves to maintain the availability of the associated PORV and its pressure relief finctions as described above. This reduces

z to ULNRC-04898 Page 6 of 11 the risk impactof the most risk-significant block valve fiilure mode (i.e., failure of the block valve to open is more risk-significant than failure of the valve to close.)

As a contingency action, Operators and work crewswill be directed, via briefs, to shut the block valve if a demand for closure should arise. This supports the above-noted PORV isolation function of the block valve and would help to reduce risk.

Access will be restricted to the swtchyard to6reduce the likelihood of a lots of offiite power (L.OOP). In addition, no work will be performed in the switchyard. Reducing the LOOP frequency reduces Callaway's overall risk, and reduces the risk of a PORV open demand.

No work or surveillances will be performed on the Reactor Trip System (RTS) or a

Engindered Safety Feature Actuation System (ESFAS) that could initiate a reactor trip or lan ESFAS actuation in order to reduce the likelihood of a plant asient Reducing plant transient frequency reduces Caaways risk of a PORV open demand.

No iotiki be perf aid obA" ttinponents to prote(

hfhe OPERABLE train.

This heljms to ensuwe'il presrd-reieffiWoti-sna has a risk-itducing effect.

N No work will be performed on the Aukiliary Feedwater Systm, steam generator atmospheric steam dump valves (ASDs), or the main steam dump control valves, in order to reduce thwe SeliSood of a PORV demnaifaplant trient were to occur. This compensatory meUre also reduces the risk Wfosing secondary cooling during an event, which reduce the risk of needing the PORV block valves to support feed-and-bleed cooling. ';

t These Compensatory Actions will be delineated and discussed in Plan of the Day Meetings and during shift turiboveri. In iddition, thrdlhgh(0&"y's Maintenance Rule 10 CFR S0.65(aX4) program, plant risk will bd assessed antd maaged th ghoui'tie NO)ED period, including any risk ass6biaWei&t unaidcpated eiergeniblant

&oniditions.

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• ctions, this request for cdortient discretion'to allow aidditional outa4 thie'tor tfb ii n6erble block valve was'quitabvel )

determined to invlvei do ncreae in ret

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Attachment I to ULNRC-04898 Page 7 of 11

4.

Justifickdon for Duration of Non-Compliance Due to the damaged valve actuator, the work activities to be performed for restoring the block valve to operable status, as described in Section 2,'may require riore time to complete than what the Completiontmune of Required Action C.2 of IS LCO 3A..1 I permits. This effort also involves resolving the annunciator problem that has been ideitified. (It is believed that this problem ddes not affect operability of the block valve or its associated PORV, this is being confirmed.) It should be noted that from a hdman fctors perspective, a very deliberate and careful approach to restoration of the block valve is requiftd in tight ofthe fact th the work must be performed in the containment where highpoisetevels-and elevated tmper which limit worker stay timeexist Although adiation levels in the work rea are modemate, cae must be taken wheneverntly into the containment istequird.

The safety/risk assessment suimarized in Section 3' upports the, imefiame required to tomplete repairs and post-nisintensaictesting t;'

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Basis for Coridusion ThatNon-C6Wpllsn6 is not a tential Detriment to the Public Healtb and Safety add that;No:8gfecant Hazard Couidertion s Involved No Significynt Hazards Con~sidertin 1vih41on

.i, In accordance with 1O0FR 50.92(c), AmenU sevaluatiot of the proposed enforcement discretion for significant hazards concludedtbhe request would uob.*

(1)

Involve a significant increase intheftrability or consequences of an accident previously evaluated.

The increased allowed outage time for thePORV block valve has ho impact on the firquencyr of occurrence for those events for which PORV or PORV block valve protection is credited or assumed. The valve itself is not part of the initiating mechanisms or failure mnodes for tuch vtsnts (such as inadvertent SI actuation or S/G tube nipture). Therefore acchange in the allbwed outage time for the PORV block valve has no impact on fthe probability of ocdrrende of such events.. With regard to a closed block wlve serving to isolate leakage through a PORV that is not lecak-tight, extension of the.AOTfor aninopemble block valve has no impact on the PORV itself and thus has no impact on the probability of PORV leakage. (Block valves are normally open and are typicall only closed for any length of time when needed to isolate a POR that has begun to leak exbessively.) i Similarly, with regard to an event involving a stuck open PORV, although the block valve may be credited to provide isolation of the stuck-open PORV, etension of tie block valve AOT itself has no impact on the probability of occurrence of a stuck open PORV. Therefore, based on all of the above considerations, extension ofthe AOT for a block valve does not involve a significant increase in the probability of an accident prviously evaluated.

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to ULNRC-04898 Page 8 of 11 During the requested additional time trestore operability of the block valve, the valve will be maintained in the open position (except when closed on a shbort-term basis for valve stoking or testing as needed). 'Further, the "A" train (PORV and block valve) is OPERABLE and will be maintained ad such'throughout the subjebt period. Under these conditions, with the PORV themselves fiuly OPERABLE, pressure reliefeapability will continue to fully exist for the mitigation of all events that may require such capability.

With the block valve in the open position and not capable of being remotely closed from the control room, the capability of isolating a stuck-open or excessively leaking PORV under worst-cse conditions is temporarily reduced, notwithstanding the low probability of an event that would require this capability, and the fICt that the associated PORV is acurrently leaklight; However, in the eventof a demandwiththe Valve "declutched' from its motor-operator, local closure of the valve may be effected fdr events That would not immediately render the containment inaccessible. Further, for a significant part of the restoration time it is anticipated that sufficient functionality will exist to enable the block

.. valve to be closed from the control room.), Notwithstanding this closure capability, if the

!B'train PORVwere to open and stilc in tht position, the ensuing transient would be bounded by analyses currently contained *ithin PSAR Section 15.6.1 (equivalent ofs. -

... ituck-open safety valve) and FSAR Secdb 15.6.5 (ma break LOCA). From these conoiderations it-may be concluded thathe proposed change (to temporarily extend the

-block valve restoration period) does not involve a significant increase in the consequences of any accident previously evaluated.

IO toal, therefore, the proposed change does not involve a significant increase in the probability or consequences ofan accident previously evaluated.

(2)1 Create the possibility of a new or different kind of accident firm any accident previously evaluatea The Completion Time extension involves no hardware or design changes (except as needed for repair of the single, affected block valve to preserve its current design fumction), nor any changes in the methods by which safety-related plant systems perform their safety function. (With regard to the block valve being open, an unisolated, stuck-open PORV is an event or condition that is already evaluated and is therefore not a new or different accident from any previously evaluatedL) No new accident scenarios, transient precursors, failure mechanisms, or limiting single failures are introduced as a result of this request.

Therefore, the requested Completion Time extension does not create the possibility of a new or different kind of accident from any accident previously evaluated.

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(3)

Involve a significant reduction ina margin of safety.

TherequestedCompleton Tuneextnsion (withtheblock valve open) doesnotaffect any total system response time or acceptance criterion assuned in the safety analyses, nor does it involve any change to a safety analysis limit, limiting safety system setting, or

Attachment I to ULNRC-04898 Page 9 of 11 safety system performance criterion. No mar-gin of safety assumed or required in the deterministic accident analyses is thus affecte& The only intent and effect of the change is to temporarily extend the Completion Time for redoring the inoperable block valve to OPERABLE status, given tat the Technical Specifications permit an allowed outage time for an inoperable block valve. If risk margin is considered in this regard, the increased Completion Time has been evaluated, and it has been detenmined that the requested change involves no increase in net risk, given the risk-offsetting compensatory actions in place. Based on the above, the proposed Completion Time extension does not involve a significant reduction in any margin of safety.

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Conclusion:==

,Based on the above information, it has been determined that the #roposedtrquest for enforcementdiscretion meets the requirements of 10 CFR 50.92(c) and does not involve a significant hazards consideration.

Consistent with the above conclusion regarding no significant hazards consideration, and as supported by the qualitative risk evaluation that has been performed, the compensatory measures thatare in place (as described in Section 7), and the determination that there is no adverse impact to radiological effluents or reactor operation (as discussed in Section 6 below), it is concluded that the requested Completion Time extension does not constitute a potential detriment to public health and safety.

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6.

EnQVlronmentljEva*uatiop,.

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With rega to anvimeta assessment, has detennined that this request for enforcement discretion meets the categorical exclusion eligibility criteria set forth in 10 CFR 1.22(cX9) as specibfi~4 i

w, (I)

Itinvolves no igpificanthazardsconsiderati.n.

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(2)

Thpres no 4ignificant change in the types or significant increase in the amounts of any effluents that may be released offsite.

X eguss i -notiiRVQqlv ad getothe ~~oroperati w Ibi ~

.p~oertn ptoce~, Jhaut would Terqum aachnge oo

.X; puse an,creasf in em ts of effluents or create new types of effluents.

(3)

There is no significant increase in individual or cumulative occupational radiation C

TI The requested noucgmpince would not adversely affect the operation of the reactor, nor does it create 04ddtiona e3ospre to lity personnel or affect radiation levels that are present.

to ULNRC-04898 Page 10 of 11 Based on the above, it may be concluded that there would be no impact on the environment resulting fnom the request, and that the requestrneets the criteria specified in 10 CFR 5 1.22 for a categorical exclusion from die requirements of 10 CFR 51.21 relative to requiring a specific environmental assessment by the Commission.

7.

Compensatory Actions C

To provide auwace that the requested NOED involve no increase in net risk, the following risk-offsetting Compensatory Actions (which were discussed fiuther in Section 3) will be taken during the time period the NOED is in force. Based upon risk insights from the Callaway PRA, these actionsisvIl serve to reduce core damage end large early release risk.

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BBHV8000B will be kept in the open;fwdition during the NOED period, except for valve stroking required for tenance or testing.,

• Operators and work crews will be directed, via briefs, to shut the block valve if a demand k

for closure should arise.

441 d.r Acce will be restricted to the switchyard to reduce the likelihood of a loss of offsite p6wet (LOOP). In addition, no work will be performed in the switchyard.

No work or surveillances wiU be performed on the Reactor Trip System (RTS) or Engineered Safety Feature Actuation System (ESFAS) that could initiate a reactor trip or an ESFAS actuation to reduce the likelihood of a plant transient

• No work will be performed on "A" train components to protect the OPERABLE train.

• No work will be performed on the Auxiliary Feedwater System, steam generao atmospheric steam dump valves (ASDs), or the main stean dump control valves, in order to reduce the likelihood of requiring the PORV block valve fiunctions.

These Compensatory Actions will be delineated and discussed in Plan of the Day Meetings and during shift turnovers.

In addition, through the plant's Maintenance Rule 10 CFR 50.65(aX4) program, plant risk will be assessed and managed throughout the NOED period, including any risk associated with unanticipted emergent plant conditions.

Approval by the Onsite Review Committee This request for enforcement discretion was reviewed and approved by the Callaway Plant Onsite Review Committee on September 6,2003.

Attachment I to ULNRC-04898 Page 11 of 11

9.

Basis for Type of NOED Required (Per Criteria Specilfied in Section B of Part 990o, "Technical Guidance: Operations - Notice of Enforcement Discretion" The type of NOED required per this request was identified to be a "regular NOED, i.e., one that does not involve severe weather or other natural phenomena. It involves a nonrecurring noncompliance as it only involves a single request for extending the period of time that an inoperable plant component must be restored to OPERABLE status as specified per the plant Technical Specifications. As such, it involves a plant condition whereby the plant would be returned to compliance with the plant operating license within a short period of time. The request was therefore determined to require an NRC Region-issued NOED (if approved).

With regard to "regular" NOEDS, Section 2.1 ofthe NRC's Part 9900 guidance identifies NOED criteria applicable to various plant conditions, which the NRC takes into consideration when considering the issuance of an NOED. Specifically, this guidance refers to "operating plants,"

"plants in a shutdown condition," and "plants attempting to dart up." It notes that for an operating planit, the NOED is intended to (a) avoid unnecessary transients as a result of compliance with the license condition and, thus, minimize potential safety consequences and operational risks, or (b) avoid testing, inspection, or system realignment that is appropriate for the particular plant conditions.

With the Callaway Plant currently in Mode Iet tlO % power, this request is foran operating plant The intent is to avoid an unnecessary plant shutdown, thereby avoiding the increased potential for a transient associated with plot shutdown, consistent with criterion 2.1.1 (a) above.