ML17277B769

Application for Amend to License NPF-21,changing Tech Spec Surveillance Requirement to Demonstrate Operability of Suppression Chamber Drywell Vacuum Breaker Pairs from Once Per 31 Days to Once Per 92 Days.Fee Paid

ML17277B769
Person / Time
Site:	Columbia
Issue date:	05/30/1985
From:	Sorensen G WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	Butler W Office of Nuclear Reactor Regulation
Shared Package
ML17277B770	List: ML17277B769 ML17277B771
References
GO2-85-278, TAC-59793, NUDOCS 8506050421
Download: ML17277B769 (9)

Text

REGUI 0 INFORMATION DISTR IBUT TEM (RIDS)

ACCESSION NBR '506050421 DOC ~ DATE ! 85/05/3Q NOTARIZED YES 397 Nuclear oject~ Unit 2p k)ashington Public Powe 05000397 DOCKET'ACIL:50 1'(PPSS Pr AUTH'AME AUTHOR AFFILIATION SORENSEN~G.C, I'Sashington Pub)ic Power. Supply System RECIP,NAME RECIPIENT AFFILIATION BUTLERgH ~ RE Licensing Branch 2 SUBJECT! Application for amend to License NPF-21ichanging Tech Spec surveillance requirement to demonstrate operabili ty 'of, suppressjoq chamber drywell vacuum breaker pairs from once per 31 days to once per 92 days;Fee paid, D IS TRIBU TI ON CODE: A001D COP IES RECEI yED: L TR ENCL TITLE: OR Submittal: General Distribution 05000397 NOTES'L'12/20/83 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL>> ID CODE/NAME LTTR ENCL NRR LB2. BC 01 7 7 INTERNALS ACRS 09 6 6 ADM/LFHB 0 ELD/HDS2 1 0 NRR/DE/HTEB 1 1 NRR/DL DIR 1 1 NRR/DL/ORAB 1 0 NRR/DL/TSRG 1' N . I/METB 1 1 NRR/DS I/RAB 1 1 REG F I Q4 1 1 RGN5 1 1 EXTERNAl: 24X 1 1 EG8G- BRUSKEtS 1 1-LPDR 03 1 1 NRC" PDR 02 1 NSIC 05 1 1 TOTAL NUMBER OF COPIES REQUIRED: LTTR 28 ENCL 25

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Washington Public Power Supply System P.O. Box 968 3000 George Washington Way Richland, Washington 99352 (509) 372-5000 May 30, 1985 GOZ-85-278 Docket No. 50-397

'irector of Nuclear Reactor Regulation Attention: Mr. W. R. Butler, Chief Licensing Branch No. 2 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

NUCLEAR PLANT NO. 2 OPERATING LICENSE NPF-21, REQUEST FOR AMENDMENT TO TECHNICAL SPECIFICATIONS FOR SUPPRESSION CHAMBER-DRYWELL VACUUM BREAKERS (3/4.6.4 VACUUM RELIEF)

In accordance with the Code of Federal Regulations (CFR), Title 10, Parts 50.90 and 2. 101, the Supply System hereby requests an amendment to the WNP-2 Technical Specifications. Specifically, the Supply System is re-questing that the subject technical specification requirement (including the bases) to have all nine (9} Suppression Chamber-Drywell vacuum breaker pairs operable be revised so that seven (7) pairs are required to be operable with the further condition that all nine (9) pairs be verified closed on the same frequency as presently required in the technical specifications. 'Re-vised pages 3/4 6-.33, 6-34, and B 3/4 6-4 are attached. In addition, we are requesting a change in the surveillance requirement to demonstrate operability of the .vacuum breaker pairs as well as both position indicators from once per 31 days to once per 92 days (also on page 3/4 6-34).

This amendment will.reflect the analysis as previously reviewed and approved by the NRC in the Supply System FSAR, Chapter 6.2. 1.1.4, which normally re-quires only seven (7} operable vacuum breaker pairs. Nine (9) pairs of Suppression Chamber-'Drywell vacuum breakers have been provided which is two more than the seven (7) required for postulated post-accident conditions.

The additional vacuum breaker pairs are operational spares provided so that operation may continue indefinitely with as many as two (2) pairs inoperable in the closed position. Staff review of this analysis is documented in NUREG 0892, the WNP-2 Safety Evaluation, Report, Section 6.2.1.5.

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OO W. R. Butler Page Two May 30, 1985 REQUEST FOR AMENDMENT TO TECH. SPECS. FOR SUPPRESSION CHAMBER-DRYWELL VACUUM BREAKERS 6

The revision to surveillance requirements stated in 4.6.4.l.b.l and 2 is based on the WNP-2 dual disc vacuum breaker valve design versus a single disc design. The concern, as we understand i t, is that SRV actuation causes the air in, the tail pipe prior to actuation to be admitted into the suppression pool air space causing an increase in pressure. This increase in pressure is then postulated to have the potential for causing a slight opening of the vacuum breaker; i.e., not enough to provide a change in indication, but enough to provide for a'ypass leakage path.

WNP-2 has a dual disc vacuum breaker'valve design with actuators that provide for remote cycling. This testabili ty design prohibits the simul-taneous opening of both discs using the remote operators. This then would preclude the WNP-2 design from venting a differential pressure less than the .5 psid necessary for valve operation. The Supply System believes the test requirements pertain to containment designs that employ single disc vacuum breaker design and is, therefore, not applicable to WNP-2. The surveillance format adopted is based on an accepted industry standard (ASME Section XI) for ensuring valve operability with the emphasis placed on the valve being in the closed position. This is consistent with the original intent of the surveillance requirement which is concerned with the potential introduction of bypass leakage path.

No relief is being sought with respect to the three (3) pairs of Suppression Chamber-Reactor Building vacuum breakers, as all three (3) of these are required for postulated post-accident conditions.

The Supply System has reviewed this change per 10 CFR 50.59 and determined that no unreviewed safety questions will result from this amendment.

In the case of the reduction from nine (9) to seven (7) vacuum breaker pairs, the Supply System has reviewed this change per 10 CFR 50.92 and determined that it does not:

1) Involve a significant increase in the probability or consequences of an accident previously analyzed because the Supply System had previously analyzed this specific condition and included a discussion in Volume 12, Chapter 6.2. 1.1.4 of the FSAR. This analysis supports safe plant operation with as few as six (6) pairs of Suppression Chamber-Drywell vacuum breakers (WNP-2 has nine (9) pairs for redundancy}; or 2} Create the possibility of a new or different kind of accident than previously, evaluated because our analysis, as discussed in FSAR Chapter 6.2.1.1.4 confirms adequate conservatism such that the original accident assumptions are still valid with only, seven (7) vacuum breaker pairs operable; or

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W. R. Butler Page Three May 30, 1985 REQUEST FOR AMENDMENT TO TECH. SPECS. FOR SUPPRESSION CHAMBER-DRYWELL VACUUM BREAKERS

3) Involve a significant reduction in a margin of safety because our analysis confirms the assessment that the technical speci-fications are overly conservative. The real underlying safety concern is that the vacuum breakers not be inoperable in the open posi tion, or fail such that a path for Suppression Chamber to Drywell bypass leakage is provided. This has not been changed.

In the case of the reduction in surveillance testing from once per 31 days to once per 92 days, the NRC published guidance in the Federal Register (48 FR 14870 dated April 6, 1983) concerning examples of amendments that are not likely to involve significant hazards consideration. One such example, (vi),

involves a change "... which either may result in -some increase to the prob-ability or consequences of a previously analyzed accident or may reduce in some way a safety margin, but where the results of the change are clearly within all acceptable criteria with respect to the system or component specified in the Standard Review Plan: ...". Accordingly, the proposed change to the technical specifications involves no significant hazards consideration.

The Supply System has evaluated this request in accordance with the criteria contained in 10 CFR 170.21 and has included a warrant for One hundred fifty dollars ($ 150.00) as initial payment for this application for amendment under Facility Category A (Power Reactors).

In accordance with 10 CFR 50.91, th'e State of Washington has been provided a copy of this letter.

J This Technical Specification change has been reviewed and approved by the WNP-2 Plant. Operations Committee (POC) and the Supply System Corporate Nuclear Safety

,Review Bo'ard (CNSRB). Should you have any questions, please contact Mr. P. L.

Powell, Manager, WNP-2 Licensing.

Very truly yours, G. C. Sorensen, Manager Regulatory Programs PLP/tmh Attachments cc: JO Bradfute - NRC WS Chin - BPA C Eschels - EFSEC JB Martin - NRC RV E Revell - BPA NS Reynolds - BLCP8R AD Toth NRC Site

IINP-K 0) NP)-fl, Request Specs. For Suppression Chamber - Drywell Vacuum Breakers (3/4.6.4 Vacuum STATE OF WASHINGTON

Subject:

Relief)

County of Benton )

I, G. C. SORENSEN, being duly sworn, subscribe to and say that I am the Manager, Regulatory Programs, for the WASHINGTON PUBLIC POWER SUPPLY SYSTEM, the applicant herein; that I have full authority to execute this oath; that I have reviewed the foregoing; and that to the best of my knowledge, information and belief the statements made in it are true.

DATE 3O . 1985 G. C. Sor sen, Manager Regulatory Programs On this day personally appeared before me G. C. SORENSEN to me known to be the individual who executed the foregoing instrument and acknowledge that he signed the same as his free act and deed for the uses and purposes therein mentioned.

GIYEN under my hand and seal this ~BI day of 1985.

ary P lic in and for he State of Washin on Residing at

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