ML20116K786
| ML20116K786 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 11/12/1992 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.D.1, TASK-TM 92-557, IEIN-89-090, IEIN-89-90, NUDOCS 9211180006 | |
| Download: ML20116K786 (2) | |
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VIROINIA ELECTRIC AND POWER COMPANY RicuMOND, VIRGINIA 23201 November 12, 1992 U.S. Nuclear Regulatory Commission Serial No.92-557 Attention: Document Control Desk NL&P/MAE:
R7 Washington, D.C. 20555 Dockot Nos.
50-338 50 339 License Nos. NPF-4 NPF-7 Gentlemen:
VIRGINit.ILECTRIC AND POWER COMPANY t
NORTH ANNA POWER STATION UNITS _1_AND 2 MODinCATION OF RESPONSE TO NUREG 0737. ITEM-II.D.1.
AND NRC IrlFORMATION NOT!CE 89-90 in our letter dated October 31,1991 (Serial No.91-604), we committed to install continuous drain lines, drain line supports on the pressurizer safety valve (PSV) loop seal piping and revised PSV discharge piping supports on both North Anna units. The modifications were intended to address NRC Information Notice 89 90 conceming the PSV lift setpoint shift issue for both units, and NUREG 0737, Item II.D.1, which involved water hammer effects ano extended blowdown times, for Unit 1. (The NUREG 0737, item II. D.1 modifications on Unit 2 have already been completed.) The modificaticns were to be accomplished during the 1994 and 1993 refueling outages for North Anna Units 1 and 2, respcctively.
The October 31,1991 commitment was based on our preliminary review of the Report on Pressurizer Safety Valve Setpoint Shift (WCAP 12910) prepared by the j
Westinghouse Owners Groep (WOG). This report identified that the time iequired to bleed off the water 4pstiearr Of the PSV is the primary contributor to what was:
previously identified as the setpoint shift issue and provides guidance for determining acceptable bleed rates. Westinghouse, on behalf of the WOG submitted this report to 1
tbn NRC for approval on March 25,1991. Since the NRC is currently reviewing the
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WOG report, we have concluded that we were premature in committing to ths.
g modifications discussed in our October 31,1991 letter because the NRC's disposition of the report cout. have an impact on the actions necessary to resolve the PSV setpoint shift issue and hence, the final configuraticn of the Unit 1 PSV discharge piping supportt. Therefore, we now intend to defer our commitment for complying with NUREG 0737, item II.D.1 for Unit 1 and NRC Information Notice 89-90 for Units 1 and 2 until the NRC has approved the WOG report. This will ensure that any NRC concerns 9211180006$1112 DR ADOCK 0500 6
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c idtdtified during the. review could be addressed prior to implemet dng the modifications.
If you have any questions or require additionalinformation, please contact us.
Very truly yours, lQ'-lJ%l/
i rq W. L. Stewart Senior Vice President - Nuclear oc U.S. Nuclear Regulatory Commission Region ll 101 Mariotta Street, N.W.
Suite 2900 Atlanta, Georgia 30323 Mr. M. S. Lessor NRC Senior Resident inspector North Anna Power Station
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