ML17292B739

Submits Withdrawal of Request for Amend to Secondary Containment & Standby Gas Treatment Sys Ts.Util Currently Plan to re-submit Amend Request in Entirety by 991112

ML17292B739
Person / Time
Site:	Columbia
Issue date:	07/16/1999
From:	Webring R WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GO2-99-133, NUDOCS 9907220046
Download: ML17292B739 (5)

Text

CATEGORY 1 REGULATO Y INFORMATION DISTRIBUTIOh SYSTEM (RIDS)

ACCESSIOQ>NBR:9907220046 DOC.DATE: 99/07/16 NOTARIZE/: NO DOCKET ¹ FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION WEBRING,R.L. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION Records Management Branch (Document Control Desk)

SUBJECT:

Submits withdrawal of request for amend to secondary containment &. standby gas treatment sys TS.Util currently plan to re-submit amend request in entirety by 991112.

DISTRIBUTION CODE: A017D COPIES RECEIVED:LTR 1 ENCL TITLE: OR Submittal: Append, J Containment Leak Rate Q

Testing SIZE:

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL CUSHING,J INTERNAL: ACRS ~Ãl9XER NRR/DE/EMEB NRR/DSSA/SPLB OGC/RP RES/DET/ERAB EXTERNAL: NOAC NRC PDR D

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NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATIONS CONTACT LISTS THE DOCUMENT CONTROL DESK (DCD) ON EXTENSION 415-2083 TOTAL NUMBER OF COPIES REQUIRED: LTTR 9 ENCL 9

WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 ~ Richlahd, Washington 99352-0968 July 16, 1999 GO2-99-133 Docket No. 50-397 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Gentlemen:

Subject:

WNP-2, OPERATING LICE<NSE NPF-21 WITHDRAWAL OF REQUEST FOR AMENDMENT TO SECONDARY CONTAINMENT AND STANDBY GAS TREATMENT SYSTEM TECHNICALSPECIFICATIONS

References:

1) Letter GO2-96-199 dated October 15, 1996, PR Bemis (SS) to NRC, "Request for Amendment to Secondary Containment and Standby Gas Treatment System Technical Specifications"

2) Letter dated May 28, 1999, Jack Cushing (NRC) to JV Parrish (SS),

"Supplemental Request for Additional Information (RAI) for the Washington Public Power Supply System Nuclear Project No. 2 (WNP-2)

(TAC NO. M96928)"

In the first reference, we requested an amendment to the WNP-2 Technical Specifications for secondary containment and the standby gas treatment system to reflect revised secondary containment drawdown and post-accident analysis results. Included in our amendment request was an analytical design basis change to increase the allowable secondary containment bypass leakage from 0.74 scfh to 18 scfh.

In the second reference, the staff requested that additional information be provided to support its review of our pending amendment request. In part, we were asked to provide additional detail of the modeling of secondary containment bypass leakage in our radiological model for the loss-of-coolant accident and the associated relationship to 18 scfh. Specifically, the staff requested that we provide information on how the leakage rate was adjusted for post-accident pressure and temperature conditions inside the drywell and wetwell.

Based upon a follow-up assessment, we hereby withdraw the amendment request due to the discovery of a non-conservative error in the methodology for computing the volumetric expansion that was used to determine the containment release concentration.

990722004b 9907ib PDR'DQCK 05000397 P PDR

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WITHDRAWALOF REQUEST FOR AMENDMENTTO SECONDARY CONTAINMENTAND STANDBY GAS TREATMENT SYSTEM TECHNICAL SPECIFICATIONS Page2of 2 The error pertained to the methodology used for increasing the bypass leakage to 18 scfh. In order to compute the source term concentration (Cilfi') for release in the offsite dose calculation, the volume in containment has to be expanded to standard temperature and pressure. The bypass leakage value had been computed for a containment release condition of 5 cfh, and then converted to standard conditions with a resultant allowable bypass leakage limit of 18 scfh. However, the derivation of this conversion factor was non-conservative in that it did not account for the impact of temperature on the containment volume. The impact of the error associated with the proposed secondary containment bypass leakage value of 18 scfh is limited solely to the determination of off-site dose and has no affect on the drawdown analysis.

Withdrawal of the amendment request also has no impact on our existing Justification for Continued Operation. As stated in our original submittal (Reference 1), the increase in the allowable secondary containment bypass leakage from 0.74 scfh to 18 scfh was considered an analytical change to the design basis and did not affect the operability of secondary containment or the standby gas treatment system, Therefore, the analytical change was not incorporated into the Justification for Continued Operation (which includes the current design basis).

Efforts are in progress to correct the methodology error and recalculate the value for allowable secondary containment bypass leakage. We expect that the recalculated value will be less than 18 scfh, but greater than 0.74 scfh. We currently plan to re-submit the amendment request in its entirety by November 12, 1999.

Should you have any questions or desire additional information regarding this matter, please call me or PJ Inserra at (509) 377-4147.

Respectfully, RL Webring Vice President, Operations Support/PIO Mail Drop PE08 cc: EW Merschoff - NRC RIV DL Williams - BPA/1399 JS Cushing - NRC NRR PD Robinson - Winston & Strawn NRC Sr. Resident Inspector - 927N DJ Ross - EFSEC

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