ML20088A454

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Discusses Evaluation of NUREG-0737,Item II.B.1 Re Design & Operational Anomaly of Target Rock Solenoid Valves,Per 830825 Request for Schedular Exemption from 10CFR50.44. Anomaly Acceptable
ML20088A454
Person / Time
Site: Beaver Valley
Issue date: 03/29/1984
From: Carey J
DUQUESNE LIGHT CO.
To: Varga S
Office of Nuclear Reactor Regulation
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.B.1, TASK-TM TAC-52184, NUDOCS 8404120057
Download: ML20088A454 (2)


Text

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'Af Telephone (412) 393-6000 Nuclear Division P.O. Box 4 Shippingport, PA 15077-0004 March 29, 1984 irector of Nuclear Reactor Regulation United States Nuclear Regulatory Camtission Attn: Mr. Steven A. Varga, Chief Operating Rcactors Branch No. 1 Division of Licensing Washington, DC 20555

Reference:

Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 NUREG-0737, Its II.B.1 Reactor Coolant System Vents Beaver Valley 1 Gentlemen:

In our letters dated July 1, 1981 and May 11, 1982, we provided you information and details related to the design of the head vent system. By letter dated August 25, 1983 and in accordance with 10CFR50,12, we requested a schedular exemption to 10CFR50.44 (c) (3) (iii) (48FR58484) which was subse-quently granted by your letter of January 12, 1984. During this period, we have continued to evaluate the design and the operational ananly associated with the Target Rock Solenoid Valves.

We have concluded that the anmaly associated with these hydraulically assisted valves is acceptable since our review of the phenmenon has not identified any case whereby two series valves would misoperate for a sustained period simultaneously, and further that revised procedures can largely eliminate the probim. Because the misoperation of the valves is short in duration, contains an orifice (7/32") to preclude a significant IOCA and is understood at this time, we have taken steps to make the system available such that our schedular exemption to the fourth refueling outage is no longer required.

Our procedures have been revised such that the downstream valve will be opened first and closed last to avoid pressure impulses on the downstream side of the valve which is the primary cause of the misoperation, or burping.

We have compared the system design to the criteria of the Standard Review Plan 5.2.3 and incorporated the valves into our Seismic and Environ-mental Qualification Program as requested in your SER dated September 8, 1983. The valves have also been tested and incorporated into the Inservice Testing Program and the safety analyses for the design change has been revised to reflect our review.

8404120057 840329 PDR ADOCK 05000334 p PDR gd I

r Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 NUREG-0737, Item II.B.1 Reactor Coolant System Vents Beaver Valley 1 Page 2 Based on the considerations expressed above, we have a* ermined that the modificaticn can be made available under the provisions of 10 T R50.59 and are proceeding on this basis. At the present tire, the valve alignment is empleted and electrically available. 'Ihe systat could be utilized if required and is under the control of the shift supervisor.

Nb have aggressively pursued those actions necessary to make this system available for service so as to provide its associated safety benefit at the earliest possible time.

Very y s,

. J. Carey Vice President, Nuclear cc: Mr. W. M. Troskoski, Pesident Inspector U. S. Nuclear Regulatory Camission Beaver Valley Power Station Shippingport, PA 15077 U. S. Nuclear Regulatory Ca mission c/o Document Management Branch Washington, DC 20555 Director, Safety Evaluation & Control Virginia Electric & Power Cm pany P.O. Box 26666 One James River Plaza Richmond, VA 23261