ML20070M285
| ML20070M285 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 04/20/1994 |
| From: | J. J. Barton GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| C321-94-2035, GL-89-10, NUDOCS 9404250286 | |
| Download: ML20070M285 (2) | |
Text
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GPU Nuclear Corporation E U. Nuclear
=fn:r388 Forked River. New Jersey 08731-0388 609 971-4000 Writer's Direct Dial Number:
April 20,1994 C321-94-2035 U. S. Nuclear Regulatory Commission Att: Document Control Desk Washington, DC 20555 Gentlemen:
Subject:
Oyster Creek Nuclear Generating Station (OCNGS)
Operating License No. DPR-16 Docket No. 50-219 Generic Letter 89-10 Motor-Operated Valves NRC letter to GPU Nuclear dated January 27,' 1994, conditionally accepted our design basis assumption of proper operator action after the 35-second time delay for closing the isolation condenser system (ICS) condensate return line motor-operated valves (MOV). This letter further stated that these MOVs must be modified to be capable of closing against a system differential pressure wed on no delay in the closing of these valves.
GPU Nuclear disagrees with the position that the established design basis scenario for these valves is an interim design basis acceptable only for satisfying the intent of Generic Letter (GL) 89-10, Supplement 3. The high flow trip signal time delay is provided specifically to prevent spurious system isolation due to operating transients. The design basis scenario developed for the ICS condensate return line MOVs postulates a transient which initiates the ICS as well as a full guillotine high energy line break (HELB) in the ICS at the same time. In addition, a single failure of the redundant valve occurs and the remaining valve has degraded grid voltage available. GPU Nuclear considers this group of assumptions to be very.
conservative and does not need to also include an assumption of full reactor pressure as part of.
the evaluation.
Therefore, on. Itent is that the dynamic conditions resulting from this postulated HELB scenario constitutes the design basis condition for which then valves are to be designed and maintained under the ongoing GL 89-10 Motor-Operated Valve Program as documented in the OCNGS MOV Program Description. Additionally, we re ognize that the OCNGS MOV Program will continue to evaluate the affects of new plant and industry test information on all applicable safety-related MOVs within the scope of the GL 89-10 Program.
9404250286 940420
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GPU Nuclear Corporabon is a subsidiary of General Public Utihties Corporabon
Y C321-94-2035 Page 2 As clarified above, GPU Nuclear is not planning to modify the ICS condensate return line valves to accommodate dynamic conditions associated with an event that is beyond the current design basis.
If additional information is needed, please contact Mr. David Distel, of the Corporate Licensing staff, at 201.316.7955.
Sincerely J 4hn J. Barto ice President and Director Oyster Creek Nuclear Generating Station DJD/ pip cc:
Administrator, Region 1 Oyster Creek NRC Project Manager Senior Resident inspector 1