ML20086B723
| ML20086B723 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 06/28/1995 |
| From: | Dennis Morey SOUTHERN NUCLEAR OPERATING CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9507060070 | |
| Download: ML20086B723 (3) | |
Text
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p Southern Nuclear Oper ting Company Post Office Box 1295 y
Birmingham. AL;bama 35201 Telephone (205) 868 5131 Southern Nudear Operating Company
- o. e umer v,ee ere.eent Farley Project the Southem electnC System June 28. 1995 Docket Nos. 50-348 50-364 l
U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 J
Joseph M. Farley Nuclear Plant Request for AdditionalInformation Regarding Southern Nuclear Operating Company Responses To The FNP Electrical Distribution System Functional Inspection Degraded Grid Voltage Unresolved Item Ladies and Gentlemen:
During the teleconference of June 15,1995 between Mssrs. Frank Ashe and Byron Siegel of the NRC and Brad Moore and Paul Hayes of SNC, the NRC requested additional information regarding Southern Nuclear Operating Company responses to issues related to the Farley Nuclear Plant (FNP) Electrical Distribution System Functional Inspection (EDSFI) Degraded Grid Voltage Unresolved Item. Attached is the information that SNC agreed to provide.
j If further clarification is necessary, please advise.
Respectfully submitted, Dave Morey RAH /maf:edsfitel. doc Attachment cc:
Mr. B. L. Siegel Mr. S. D. Ebneter Mr. T. M. Ross 9507060070 950628 PDR ADOCK 05000348 g
PDR l
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Attachment 1
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Request for Clarification of Additional Information Provided by the RAI Response Dated June 6,1995 Item 1:
Provide the approximate time for the degraded grid relay to actuate at 88.3% voltage based on Farley Nuclear Plant (FNP) experience from performing calibration using the Surveillance Test Procedure.
Response
Although the time is not required to be recorded, from interviews with personnel who i
perform the calibration, the time frame is estimated to be between 30 seconds and 2 minutes.
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Item 2:
I The degraded grid relay lower tolerance ( - 1%) allows for the actual dropout voltage to be as low as 87.45%. Are the components that are normally running and also a
needed during a LOCA capable of running at this lower tolerance?
Response
In the response to item 9 of the RAI response dated June 9,1995, SNC stated that, for sustained degraded grid conditions (no LOCA or plant trip), " Due to the time constraints of the abnormal operating procedure, these loads will be only temporarily exposed to lower than normal voltages, but would continue to run without damage at a 4160 volt bus voltage corresponding to the degraded grid relay setpoint."
These loads would also continue to run without damage at a 4160 volt bus voltage corresponding to the lower tolerance (87.45%) of the 4160 volt bus degraded grid relay setpoint.
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