ML17284A686

Provides Addl Info Concerning 9.5 Plate Section W/Regards to Current WNP-2 P/T Limit Curves

ML17284A686
Person / Time
Site:	Columbia
Issue date:	07/14/1998
From:	Coleman D WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GO2-98-121, NUDOCS 9807210164
Download: ML17284A686 (4)

Text

CATEGORY 1 REGULA Y INFORMATION DISTRIBUTI 4 SYSTEM (RIDS)

ACCESSION NBR:9807210164 DOC.DATE: 98/07/14 NOTARIZED: NO DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTP.NAYS p, AUTHOR AFFILIATION COLEMAN,O.W. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION Records Management Branch (Document Control Desk)

SUBJECT:

Provides addi info concerning 9.5" plate section w/regards to current WNP-2 P/T limit curves.

DISTRIBUTION CODE: A001D COPIES RECEIVED:LTR ENCL SIZE:

TITLE: OR Submittal: General Distribution NOTES:

E c RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD4-2 LA PD4-2 PD POSLUSNY,C INTERNAL: ACRS 1 NRR/DE/ECGB/A 1 NRR/DE/EMCB NRR/DRCH/HICB 1 NRR/DSSA/SPLB NRR/DSSA/SRXB 1 NUDOCS-ABSTRACT OGC/HDS3 1 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 LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD) ON EXTENSION 415-2083 TOTAL NUMBER OF COPIES REQUIRED: LTTR 14 ENCL

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WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 ~ Richland, Washington 99352-0968 July 14, 1998 G02-98-121 Docket No, 50-397 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Gentlemen:

Subject:

WNP-2, OPERATING LICENSE NPF-21 ADDITIONAL INFORMATION ON RPV PRESSURE TFMPERATUM>>

LIMITCURVES

References:

1) Letter G02-97-077, dated April 24, 1997, JV Parrish (SS) to NRC, "WNP-2, Operating License NPF-21, Submittal of WNP-2 RPV Surveillance Materials Testing and Analysis Report"

2) Letter GO2-97-144, dated July 16, 1997, PR Bemis (SS) to NRC, "WNP-2, Operating License NFP-21, Request for Amendment to Technical Specifications to Support Vessel Leak Testing"

3) Letter GO2-98-092, dated June 2, 1998, D.W. Coleman (SS) to NRC, "WNP-2, Operating License NPF-21, Withdrawal of Request for Amendment to Technical Specifications to Support Vessel Leak Testing" Reference 2 submitted, for review and approval, new minimum reactor pressure versus reactor +0 (

metal temperature (P/T) curves applicable for up to 12 Effective Full Power Years (EFPY). While~

the data contained in Reference 2, the NRC reviewer questioned how consideration of a 'ssessing 9.5" thick plate section in the lower core region would influence the submittal results. The NRC reviewer further questioned whether the current 32 EFPY P/T curves in the WNP-2 Technical Specifications bounded the reference nil-ductility temperature (RTDT) associated with the 9,5" thick section in view of the fact that the current P/T curves were developed using a thickness of 7.5". This letter provides additional information concerning the 9.5ss plate section with regards to the current WNP-2 P/T limit curves.

i 98072i0164 9807i4 05000397 PDR ADGCK P PDR

-* 'EQUEST FOR ADDITIONALINFORMATION PRESSURE TEMPERATURE LIMITCURVES Page 2

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To answer the NRC reviewer's question, new reference temperatures were calculated for the 9.5" plate section using the existing computer code which was updated to include the 1989 version of ASME Code Section XI Appendix G. An estimate of 80% peak fluence at the 9.5" plate section was used in calculating the new reference temperatures. The 80% value is conservative because peak fluence occurs at approximately 100" above the bottom of active fuel (BAF) whereas the 9.5" plate section extends approximately 14" above BAF and fast neutron flux levels drop off significantly near both ends of the active fuel.

After reviewing the computer generated results obtained using the above described input, the Supply System has determined that the current 32 EFPY P/T curves bound the RT~ for the 9.5" section.

The Technical Specification amendment requested by Reference 2 has been withdrawn by Reference 3. However, based upon a commitment contained in Reference 1, the Supply System will submit new P/T limit curves by April 24, 1999.

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

Respectfully, D.W. Coleman (Mail Drop PE20)

Manager, Regulatory Affairs cc: EW Merschoff - NRC RIV DL Williams - BPA/399 KE Perkins, Jr. - NRC RIV, WCFO PD Robinson - Winston 8c Strawn C Poslusny, Jr. - NRR NRC Sr. Resident Inspector - 927N