ML20072B292
| ML20072B292 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 06/06/1983 |
| From: | Fiedler P GENERAL PUBLIC UTILITIES CORP. |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| TASK-03-03.C, TASK-3-3.C, TASK-RR NUDOCS 8306130384 | |
| Download: ML20072B292 (2) | |
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GPU Nuclear Corporation NUC Mr 100 Interpace Parkway Parsippany. New Jersey 07054 201 263-6500 TELEX 136-482 Writer's Direct Dial Nurnber:
June 6, 1983 Mr. Dennis M. Crutchfield, Chief Operating Reactors Branch #5 Division of Licensing U.S. Nuclear Regulatory Coninission Washington, D. C.
20555
Dear Mr. Crutchfield:
Subj ect : Oyster Creek Nuclear Generating Station Docket No. 50-219 SEP Topic No. 11-3-0 Flooding Potential and Protection Requirements During the integrated assessment of the Systemtatic Evaluation Program for Oyster Creek Generating Station for the subject topic, the NRC staff requested CPUN to verify that all entrance Icvels for important structures are above a flood level of 23.5 ft.
Mean Sea Level (MSL) for protection against internal flooding caused by local Probable Maximum Precipitation (PMP).
The following are our findings and proposed corrective actions:
Reactor Building, Turbine Building, Old Radwaste Building, New Radwaste Building All sill and entry floor elevations are at or above 23'-6" MSL and the structures are not susceptible to flooding during the PMP.
Therefore, no corrective action is required.
Diesel Generator Building Two entrances and main floor are at elevation 23'-0" MSL which is five inches below the level of the PMP.
A third entrance is at elevation 25 '-6" and would not be af fected.
The Diesel Generator Building is located adjacent to the discharge canal and natural surface drainage paths exist both to the north and to the south of the building, which would drain surface water into the canal.
It is doubtful, therefore, that surface water would accumulate to the full predicted depth.
However, flooding in this building would be detrimental to operation.
G'306130394 830606 PDR ADOCK 05000219 P
PDR GPU Nuclear Corporation is a subsidiary of the General Public Utilities Corporation s
. Our field examination has shown that the diesel generators are skid mounted and are over 12 inches off the floor.
The PMP flood would have no impact on them. The switchgear housed in the building, however, is floor mounted and would be exposed to five inches of water within the cabinets.
In addition, it was noted that the conduit connecting the diesel generators and the switchgear runs in an open trench and would be subj ect to full immersion.
The two af f ected entrances are protected by alcoves with a floor, roof and one wall parallel to the wall serviced by the door. The floor is'an extension of the structure's foundation mat and the wall is doweled and keyed into the mat to form a valid barrier against the limited head of water under consideration.
In order to complete the protective encasement, GPUN will add an asphalt dike (approximately six inches high) at the two alcove entrances to provide protection from surface water entry.
The engineering and construction for these dikes will be completed during the next operating cycle following the current Cycle 10 refueling outage.
Off Gas Building All sill and entry floor elevations are at or above 23'-6" MSL and the structure is not susceptible to flooding due to water elevation at 23'-5" MSL.
However, the NRC staff has indicated that due to local contour configurations, the door in the southwest corner of the building may be subj ect to higher water elevations which could cause water entry to the building.
Examination of the contour maps of the site shows that adjacent grade to the south and east of the building is higher than the 23'-5" PMP level.
The area west of the building rises slowly and drains a moderate size area towards the building. However, there is a drainage path to the west of the building and it will direct flow to the northeast away from the building.
There is no indication of contours which might impound water at the door and cause building flooding.
No remedial action is necessary.
Very truly yours, 1
J Pe ckl Vice President and Director Oyster Creek 1r