ML20126G645
| ML20126G645 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 12/23/1992 |
| From: | Link B WISCONSIN ELECTRIC POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| CON-NRC-92-146 VPNPD-92-381, NUDOCS 9301040180 | |
| Download: ML20126G645 (3) | |
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' Bectnc POWER COMPANY m w M.cnson to u xm men want pu)22t 2M5 VPHPD 381 NRC-92-146 December 23, 1992 Document Control Desk S.S. NUCLEAR REGULATORY COMMISSION Mail Station Pl-137 Washington, DC 20555 Gentlemen:
D_OCKETS 50-266 AND 50-301 Q
PUMP AND VALVE INSERVICE TESTING PROGRAM COLD SHUTDOWN JUSTIFICATLQllE POINT BEACH NUCLEAR PLANT. UNITS 1 AND 2 Enclosed is an addition to the Pump and Valve Inservice Testing Program for our Point Beach Nuclear Plant, Units 1 and 2.
The addition, a cold shutdown justification (CSJ-36) for Valves 1&2 SI-00897 A&B, is based on our recent re-evaluation of the risks associated with the stroke testing of these valves while at power.
SI-00897 A&B (SI Test Line Return Valves) are series, air-operated valves which function to block recirculation flow from returning to the refueling water storage tank (RWST) during long-term, post-accident recirculation. -Under normal conditions, the valves are gagged open in order to protect the safety injection (SI) pumps-against being deadheaded should either be started without an available discharge path.
The gagging of these valves in the open position was part of our final corrective action'in response to IEB 86-03, " Potential Failure of Multiple ECCS Pumps Due to Single Failure of Air-Operated Valve in the Minimum Flow Recirculation Line."
However,-quarterly inservice stroke tests,.in'which the valves were ungagged for a short period of time and repositioned for testing, were deemed to be necessary and considered to pose no significant increase in risk to the SI pumps.
A re-evaluation of our quarterly inservice testing practices for these valves was prompted by recent industry operating experience reviewsuon this subject.
A probabilistic risk assessment (PRA) analysis performed.as part of-our re-evaluation confirms that ungagging these valves for a short time to permit testing does not significantly increase the probability of SI pump failure.
Even ASAAan 93010/.0180 921223
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Document Control Desk December 23,.1992 Page 2 though the PRA analysis demonstrates that there is no significant increase in risk to the SI pumps, we believe the most conservative course of action is to defer testing of SI-00897 A&B to periods when the respective unit is in cold shutdown and,both SI pumps may be rendered incapable of being started.
Deferral of testing is in accordance with ASME Section XI-1986, IWV-3412(a), " Exercising-Procedure."-
Should you have any questions or require any additional infor-mation, please do not hesitate to contact us.
Sincerely, l
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j Bob Link Vice President Nuclear Power DEK/jg Enclosure cc:
NRC Resident Inspector NRC Regional Administrator, Region III Adele DiBiasio, Brookhaven National Laboratory l
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f COLD SHUTDOWN JUSTIFICATION CSJ-36 Safety Injection Test Line Return Valves 1&2 SI-00897 A&B Drawings:
110E017,' Sheet 2 (Unit 1), 110E035, Sheet 2 (Unit 2) 1 l
1 These valves are normally gagged open to ensure the availability of the common minimum flow recirculation path for both safety injection (SI) pumps.
Stroke testing these valves during condi-tions other than cold shutdown makes it possible for one or both-l SI pumps to be damaged should either of these valves fail in the-l shut position coincident with SI pump start without any other flow
'l path being available.
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