ML18153A670
| ML18153A670 | |
| Person / Time | |
|---|---|
| Site: | Surry, North Anna  |
| Issue date: | 11/15/1995 |
| From: | Ohanlon J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 95-566, GL-95-07, GL-95-7, NUDOCS 9511200116 | |
| Download: ML18153A670 (3) | |
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VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 November 15, 1995 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 NORTH ANNA POWER STATION UNITS 1 AND 2 Serial No.
NL&P/MAE:
Docket Nos.
License Nos.95-566 R5 50-280/-281 50-338/-339 DPR-32/-37 NPF-4/-7 GENERIC LETTER 95-07 PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES In response to your letter dated November 3, 1995, and the clarification provided by the October 24, 1995 Region II meeting on this subject, Virginia Electric and Power Company (Virginia Power) hereby amends our previous response and commits to complete the 90 day actions for Generic Letter 95-07. Specifically we have completed the initial evaluation regarding potential susceptibilities to pressure locking and thermal binding which fulfills our understanding of the intent of the 90 day actions of the generic letter.
On August 17, 1995, the NRG issued Generic Letter 95-07, entitled "Pressure Locking and Thermal Binding Of Safety-Related Power-Operated Gate Valves." The generic letter requested two actions. First, within 90 days, 1) perform a screening evaluation of the operational configurations of all safety related power operated gate valves to identify those valves that are potentially susceptible to pressure locking and thermal binding and 2) document a basis for their operability. Second, within 180 days, 1) evaluate the operational configurations of all safety related power operated gate valves susceptible to pressure locking and thermal binding and 2) perform further analyses and corrective actions with justification for longer implementation schedules as needed.
On October 24, 1995, a meeting was held with representatives from the Office of Nuclear Reactor Regulation and Region II and licensees in Atlanta to discuss the NRC's expectations for the 90 and 180 day requested actions. At that meeting, the NRG Staff stated that their intent for the 90 day required action was primarily to have licensees perform a susceptibility screening of all safety related power-operated gate valves, or review previous screenings with emphasis on recent industry communications which identified specific functional applications. This would ensure that potentially susceptible valves were not inadvertently missed in earlier evaluations.
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The concern was that there may be obvious or significant potential problems representing possible common mode failures that should be addressed immediately.
- -They indicated that the reference in the generic letter, requiring licensees to 11document a basis for operability 11 of potentially susceptible valves was not intended to require that licensees perform rigorous analyses, since* analytical methods are still being formulated and verification testing by a number of groups is in progress.
It should be noted that Virginia Power has previously completed evaluations of pressure locking and thermal binding for both our plants, with the most recent comprehensive reviews being completed for Surry in 1992 and for North Anna in 1991. These evaluations were reviewed by the NRC in Inspection Reports 94-18 at Surry and 94-04 at North Anna. As stated in these inspection reports, "a review of all safety related valves had been performed and concluded that none of the valves had a significant probability of thermal binding or pressure locking."
- As clarified at the aforementioned meeting by the NRC, we have completed our initial assessment which includes reassessment of the previous evaluations augmented by our current understanding of specific valve applications and susceptibilities identified in recent NRC communications. These actions satisfy the intent of the 90 day required actions of Generic Letter 95-07.
If you have any questions, please contact us.
Very truly yours,
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James P. O'Hanlon Senior Vice President - Nuclear cc:
Regional Administrator U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, N.W.
Suite 2900 Atlanta, Georgia 30323 Mr. M. W. Branch N RC Senior Resident Inspector Surry Power Station Mr. R. D. McWhorter NRC Senior Resident Inspector North Anna Power Station
e COMMONWEALTH OF VIRGINIA )
)
COUNTY OF HENRICO
)
The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by J. P. O'Hanlon, who is Senior Vice President -
Nuclear, of Virginia Electric and Power Company. He is duly authorized to execute and file the foregoing document in behalf of that Company, and the statements in the document are true to the best of his knowledge and belief.
Acknowledged before me this /5' day of ~lu;v', 19~.
My Commission Expires: ~
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, 192.
(SEAL)