ML13326A796
| ML13326A796 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 07/10/1991 |
| From: | Kalman G Office of Nuclear Reactor Regulation |
| To: | Ray H SOUTHERN CALIFORNIA EDISON CO. |
| References | |
| TAC-45171, TAC-74629, NUDOCS 9107190109 | |
| Download: ML13326A796 (3) | |
Text
Docket No. 50-206 JUL 1 0 1991 Mr. Harold B. Ray Senior Vice President Southern California Edison Company Irvine Operations Center 23 Parker Street Irvine, California 92718
Dear Mr. Ray:
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION, INADEQUATE CORE COOLING MONITORING SYSTEM, SAN ONOFRE NUCLEAR GENERATING STATION, UNIT NO. 1 (TAC NOS. 45171 AND 74629)
The NRC staff is reviewing your proposed design for the San Onofre Nuclear Generation Station, Unit No. 1 Inadequate Core Cooling Monitoring Systems as described in a submittal dated January 2, 1990. Enclosure 1 to this letter includes a list of questions generated by the staff following review of your submittal.
Please provide a response to these questions to help us complete the review.
This requirement affects fewer than 10 respondents and, therefore, is not subject to Office of Management and Budget review under Public Law 96-511.
Sincerely, ORIGINAL SIGNED BY 4d 'f'_
George Ka man, Senior Project Manager Project Directorate V Division of Reactor Projects III/IV/V Office of Nuclear Reactor Regulations
Enclosure:
As stated C
L cc w/enclosure:
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- 7/0n/91 OFFICIAL RECORD COPY Document Name:
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Mr. Harold B. Ray San Onofre Nuclear Generating Southern California Edison Company Station, Unit No. 1 cc:
Mr. Phil Johnson Mr. Richard J. Kosiba, Project Manager U.S. Nuclear Regulatory Commission Bechtel Power Corporation Region V 12440 E. Imperial Highway 1450 Maria Lane, Suite 210 Norwalk, California 90650 Walnut Creek, California 94596 Mr. Robert G. Lacy Manager, Nuclear Department San Diego Gas & Electric Company P. 0. Box 1831 San Diego, California 92112 Resident Inspector, San Onofre NPS c/o U.S. Nuclear Regulatory Commission P. 0. Box 4329 San Clemente, California 92674 Mayor City of San Clemente 100 Avenida Presidio San Clemente, California 92672 Chairman, Board of Supervisors County of San Diego 1600 Pacific Highway, Room 335 San Diego, California 92101 Regional Administrator, Region V U.S. Nuclear Regulatory Commission 1450 Maria Lane, Suite 210 Walnut Creek, California 94596 Mr. John Hickman Senior Health Physicist Environmental Radioactive Mgmt. Unit Environmental Management Branch State Department of Health Services 714 P Street, Room 616 Sacramento, California 95814 Mr. Don J. Womeldorf Chief, Environmental Management Branch California Department of Health Services 714 P Street, Room 616 Sacramento, California 95814 (9)
ENCLOSURE 1 REQUEST FOR ADDITIONAL INFORMATION SAN ONOFRE NUCLEAR GENERATING STATION, UNIT NO. 1 INADEQUATE CORE COOLING MONITORING SYSTEM Please respond to the following:
- 1. What is the distance between the heated junction thermocouples (HJTC) in the level monitoring system probe assembly?
- 2. What is the overall measuring range of the probe?
- 3. What is the distance between the top HJTC and the top of the active fuel region?
- 4. Provide system specifications for the following functions;
- a. measuring sensitivity (indicated level error band)
- b. response time (time delay between actual level increase or decrease and indication)
- c. time delay between system activation (electric power on) and system operation
- d. power supplies and power requirements for heaters.
- 5. Provide a copy of the HJTC calibration procedure.
- 6. Your letter dated November 29, 1990, included a list of HJTC failures at San Onofre Units 2 & 3 and at other facilities. Please provide the root cause of the failures and the corrective actions.
- 7. What is the current status and reliability history of the core exit thermocouples?