ML20116A045
| ML20116A045 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 10/22/1992 |
| From: | J. J. Barton GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| C321-92-2280, NUDOCS 9210290164 | |
| Download: ML20116A045 (2) | |
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=.n:r 88 GPU Nuclear Corporation Forked River, New Jersey 087310388 609 971-4000 Writer's Direct D.a! Numbor:
, October 22, 1992 C321-92-2280 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555
Dear Sir:
Subject:
Oyster Creek Nuclear Generating Station Docket No. 50-219 Station Blackout
Reference:
GPU Nuclear Letter C321-92-2192, dated July 14, 1992 Response to Supplemental Safety Evaluation Repnrt - Station Blackout In the above reference, GPU Nuclear committed to revise the control room heat-up analysis for a loss of ventilaticn condition during a station blackout (SB0) event. The purpose was to demonstrate, under certain assumed initial conditions, that the control room 4emperature would be 120 F or less at the end of the first hour into the SB0 event.
This, together with the availability of AAC within I hour, would obviate the need to open control room cabinet doors during the first 30 minutes of the event, or to proced'Jrally monitor the control room temperature during normal operation to ensure it does not c-ed 75 F.
The uised control room beat-up analysir used five different initial control room temperatures.
These varied between 75*F and 95 F, at 5'F intervals, ror each of these, the outdoor temperature was assumed to be 89 F (plant design basis) and 106 F (maximum recorded temperature). The surrounding room temperatures for all cases varied between 104 F and 120 F.
The. analysis also assumed narmal control room heat loads during plant operation, which is canservative during an SBO, and one-half the control room lights.off.
The results of the revised analysis indicate that at the end cf the first hour, with an initial control room temperature of 95 F and an outdoor temperature of 106 F, the temperature in the control room is 112 F.
This calculated 112*F is considered conservative for the following reasons:
1.
The control room temperature is normally maintained at 75 5 F.
P.
The 106 F assumed outdoor temperature rarely occurs.
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The control room heat loads would be significantly reduced during an SB0 event.
Since-the control room temperature at the.end of the first hour into the SB0 event has been conservatively established to be below 120*F, there is no need for GPU Nuclear to open control room cabinet doors during the $B0 event or to procedurally ensure that the control room temperature does not exceed 75'F during normal operation.
It is our understanding that this letter serves to close out the NRC'open-issue related to the control room lors of ventilation.
Sincerely,
(
J. J. Barton Director, Oyster Creek JJB/EP:1ga cc:
Administrator, Region I Senior Resident Inspector Oyster Creek NRC Project Manager
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