ML13322A597
| ML13322A597 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 09/25/1979 |
| From: | Ziemann D Office of Nuclear Reactor Regulation |
| To: | James Drake SOUTHERN CALIFORNIA EDISON CO. |
| References | |
| NUDOCS 7910220394 | |
| Download: ML13322A597 (3) | |
Text
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50-206 HSmith ABurger TCarter Mr. James H. Drake OELD Vice President OI&E(3)
Southern California Edison Company DGEisenhut 2244 Wal nut Grove Avenue JRBuchanan Post Office-Box 800 TERA Rosemead, California 91770 ACRS(16)
Dear Mr. Drake:
RE:
SAN ONOFRE MUCLEAR CENERATING STATION, UPIT PO.
1 We are currently reviewing the adequacy of the offsite power systems of nuclear power plants and in particular, the loss of offsite power events at your facility. One aspect of this review concerns the history of experienced total and partial power outages and attendent voltage or frequency conditions of the grid.
In our review, of this matter we have drawn upon the information provided to us via Licensee Event Reports and followup letters which you have sent to us.
Our review of these reports indicated the loss of offsite power events have occurred at San Onofre Nuclear Generating Station, Unit 1 on June 7, 1973.
To complete our review of loss of offsite power events we require the additional information concerning the station offsite grid indicated in the enclosure-to this letter.
Please provide your response to the attached questions for the San Onofre Nuclear Generating Station within 90 days of receipt of this letter.
Sincerely, "Original Signed by Thomas V.
Wambach" Dennis L. Ziemann, Chief Operating Reactors Branch T#2 Division of Operating Reactors Enclos ure:
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- U.S.
GOVERNMENT PRINTING OPFICU: 1978 - 265 -769
Mr. James H. Drake 2 -
September 25, 1979 cc Charles R. Kocher, Assistant General Counsel Southern California Edison Company Post Office Box 800 Rosemead, California '91770 David R. Pigott Samuel B. Casey Chickering & Gregory Three Embarcadero Center Twenty-Third Floor San Francisco, California 94111 Jack E. Thomas Harry B. Stoehr San Diego Gas & Electric Company P. 0. Box 1831 San Diego, California 92112 U. S. Nuclear Regulatory Commission ATTN:
Robert J. Pate P. 0. Box 4167 San Clemente, California 92672 Mission Viejo Branch Library 24851 Chrisanta Drive Mission Viejo, California 92676
ENCLOSURE REQUEST FOR ADDITIONAL INFORMATION LOSS OF OFFSITE POWER A. For losses of offsite power where less than all offsite power was lost:
- 1. How many circuits to the offsite network are normally available and how many were lost during the event?
- 2. What was the cause of the event?
- 3. Why did the other lines not fail when some did fail?
- 4. Was any voltage increase or decrease experienced just prior to or during the outage? If so, please give details, voltages reached, affects, etc.
- 5. Was any frequency decay experienced just prior to or during the outage? If so, please give details, lowest frequency reached, decay rate, affects on equipment operation, etc.
- 6. How long was power unavailable from the circuit?
- 7. Date of Event.
B. For losses.of all offsite power:
- 1. How long was the power off? How long for partial recovery?
Please give details.
- 2. If turbine trip occurred, how soon after did loss of offsite power occur?
- 3. If power was recovered promptly (10 minutes or less), was it due to automatic or manual actions?
- 4. Was any voltage increase or decrease experienced just prior to or during the outage? If so, please give details, voltages reached, affects, etc.
- 5. Was any frequency decay experienced just prior to or during the outace? If so, please give details, lowest frequency reached, decay rate, affects on equipment operation, etc.
- 6. Date of Event.
C. Were there any other loss of offsite power events other than we have listed? If so, please give details of each event.