ML20095C098
| ML20095C098 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 08/15/1984 |
| From: | Fiedler P GENERAL PUBLIC UTILITIES CORP. |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0661, RTR-NUREG-661 NUDOCS 8408220375 | |
| Download: ML20095C098 (2) | |
Text
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b GPU Nuclear Corporation s
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Route 9 South Forked River.New Jersey 08731-0388 609 971-4000 Writer's Direct Dial Number:
Mr. Dennis M. Crutchfield, Chief Operating Reactors Branch No. 5 Division of Licensing U.S. Nuclear Regulatory Commission Washington, DC 20555
Dear Mr. Crutchfield:
Subject:
Oyster Creek Nuclear Generating Station Docket No. 50-219 Plant Specific Analysis to Determine Gas and Water Clearing Thrust Loads Asso:iated with Second SRV Actuations in Relief Valve Discharge Lines Your letter dated June 15, 1984, inquired if any analyses were performed utilizing methodology not previously approved in NUREG 0661 in determining if setpoint logic changes were needed to reduce water clearing thrust loads associated with second SRV actuations. Additionally, we were requested to identify if any credit for operator action is required to prevent or reduce the thrust loads associated with second actuations of SRVs.
For the Oyster Creek plant, only loading and structural response methods contained in NUREG 0661 were used when evaluating the Mark I containment.
By analysis, the Oyster Creek Mark I containment has been demonstrated to be structurally adequate for a five (5) valve actuation followed by an additional five (5) valve actuation.
ADS logic changes were incorporated in 1977 to assure that if an EMRV were to lift under hign pressure during ADS time-out, the valve would remain open. This strategy rules out the possibility of a valve closing just before ADS time-out.
If this were to happen, vacuum relief would not occur in the downcomer whereby an ADS actuation would have propelled a long slug of water into the torus.
ADS logic requires that one valve in each header be set lower than the other(s).
Oyster Creek takes no credit for operator action. Operator action is not required for ADS operation. Manually lifting all EMRVs, given a valid ADS signal, would not defeat the ADS modifications, but would instead effectively create a new timer limit. Manual opening of the low setpoint valve has the same effect as opening on high pressure. Manual opening of any other valve may cause operation beyond analyzed limits.
8408220375 840815 PDR ADOCK 05000219
$00l GPU Nuclear Corporation is a subsidiary of the General Public Utilities Corporation
- Dennis M. Crutchfiold, Chief U.S. Nucl:ar R:gulat:ry Commission Page 2 Should you have any questions regarding this information, please contact Mr. Drew Holland, Oyster Creek Licensing Manager at (609)971-4643.
Very truly yours,
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. Fied1'er Vice President and Director Oyster Creek P8F/BH/ dam cc: Dr. Thomas E. Murley, Administrator Region I U.S. Nuclear Regulatory Commission 637 Park Avenue King of Prussia, PA 19406 NRC Resident Inspector Oyster Creek Nuclear Generating Station Forked River, NJ 08731 I
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