ML13330A218
| ML13330A218 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 02/20/1981 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Dietch R Southern California Edison Co |
| References | |
| TASK-06-07.A1, TASK-6-7.A1, TASK-RR LSO5-81-02-041, LSO5-81-2-41, NUDOCS 8102260460 | |
| Download: ML13330A218 (3) | |
Text
FEB 2 0 Docket No. 50-206 Mr. R. Dietch Vice President Nuclear Engineering and Operations Southern California Edison Company 2244 Walnut Grove Avenue Post Office Box 800 Rosemead., California 91770
Dear Mr. Dietch:
SUBJECT:
SAN ONOFRE - SEP TOPIC VI-7.A.1,, ECCS REEVALUATION TO ACCOUNT FOR INCREASED VESSEL UPPER HEAD TEMPERATURE The safety objective of this topic is to ensure that correct upper head temperatures were used in the lossof-coolant-accident (LOCA) analysis.
Originally, LOCA analyses for all Westinghouse reactors were conducted assuming that the temperature of the water in the upper head region of the reactor vessel was the same as the inlet watertemperature because of a bypass flow from the downcomer to the upper head. Temperature measurements made by Westinghouse indicate that the actual temperature of the upper head fluid is almost as high as the hot leg (outlet) temperature. All operating reactors were required to resubmit LOCA analyses using hot leg temperature for the upper head volume.
The staff's safety evaluation of Amendment No. 25 to Provisional Operating License No. DPR-13, dated April 1, 1977, accepted revised analyses with upper head fluid temperature equal to the hot leg (outlet) temperature.
Since this approved analysis satisfies the safety objective of SEP Topic VI-7.A.1, this topic is considered to be complete. This letter is provided only to document topic status; no response is required.
Sincerely, Dennis M. Crutchfield, Chief Operating Reactors Branch #5 Division of Licensing cc:
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WASHINGTON, D. C. 20555 FF P9 Docket No. 50-206 LS05-81-02-041 Mr. R. Dietch Vice President Nuclear Engineering and Operations Southern California Edison Company 2244 Walnut Grove Avenue Post Office Box 800 Rosemead, California 91770
Dear Mr. Dietch:
SUBJECT:
SAN ONOFRE - SEP TOPIC VI-7.A.1, ECCS REEVALUATION TO ACCOUNT FOR INCREASED VESSEL UPPER HEAD TEMPERATURE The safety objective of this topic is to ensure that correct upper head temperatures were used in the loss-of-coolant-accident (LOCA) analysis.
Originally, LOCA analyses for all Westinghouse reactors were conducted assuming that the temperature of the water in the upper head region of the reactor vessel was the same as the inlet water temperature because of a bypass flow from the downcomer to the upper head. Temperature measurements made by Westinghouse indicate that the actual temperature of the upper head fluid is almost as high as the hot leg (outlet) temperature. All operating reactors were required to resubmit LOCA analyses using hot leg temperature for the upper head volume.
The staff's safety evaluation of Amendment No. 25 to Provisional Operating License No. DPR-13, dated April 1, 1977, accepted revised analyses with upper head fluid temperature equal to the hot leg (outlet) temperature.
Since this approved analysis satisfies the safety objective of SEP Topic VI-7.A.1, this topic is considered to be complete. This letter is provided only to document topic status; no response is required.
Sincerely, Dennis M. Crutchfiel Chief Operating Reactors Branch #5 Division of Licensing cc:
See next page.
4 6X 12 6O0
Mr R. Dietch SAN ONOFRE NUCLEAR GENERATION STATION, UNIT NO. 1 DOCKET NO. 50-206 cc Charles R. Kocher, Assistant Director, Technical Assessment General Counsel Division Southern California Edison Compary Office of Radiation Programs Post Office Box 800 (AW-459)
Rosemead, California 91770 U. S. Environmental Protection Agency David R. Pigott Crystal Mall 12 SSamuel B. Casey Arlington, Virginia 20460 Chickering & Gregory Three Embarcadero Center U. S. Environmental Protection Twenty-Third Floor Agency San Francisco, California 94111 Region IX Office ATTN:
EIS COORDINATOR Jack E. Thomas 215 Freemont Street Harry B. Stoehr San Francisco, California 94111 San Diego Gas & Electric Company P. 0. Box 1831 San Diego, California 92112 Resident Inspector c/o U. S. NRC P. 0. Box AA Oceanside, California 92054 Mission Viejo Branch Library 24851 Chrisanta Drive Mission Viejo, California 92676 Mayor City of San Clemente San Clemente, California 92672 Chairman Board of Supervisors County of San Diego San Diego, California 92101 California Department of Health ATTN:
Chief, Environmental Radiation Control Unit Radiological Health Section 714 P Street, Room 498 Sacramento, California 95814