ML13333A434
| ML13333A434 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 11/16/1979 |
| From: | Baskin K Southern California Edison Co |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7911270317 | |
| Download: ML13333A434 (3) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROV.E AVENUE ROSEMEAD, CALIFORNIA 91770 K. P. BASKIN November 16, 1979 TELEPHONE
- MANAGER, GENERATION ENGINEERING 213-572-1401 Director, Office of Nuclear Reactor Regulation Attention:
Mr. D. L. Ziemann, Chief Operating Reactors Branch #2 Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Gentlemen:
Subject:
Docket No. 50-206 Surveillance Tests of the Safeguards System San Onofre Nuclear Generating Station Unit 1 By letter dated September 21, 1979, we were requested to review several aspects of our policies and procedures in regard to surveillance tests of the reactor safeguards system and to initiate appropriate action in order to minimize errors which would lead to unnecessary challenges to the system. By letter dated November 13, 1979, we indicated that a reply to your request would be submitted by November 16, 1979.
The enclosure to this letter provides the response to your September 21, 1979 letter.
In addition, a schedule for completion of appropriate followup actions which have resulted from our review of the subject as it applies to San Onofre Unit 1 is provided in the enclosure.
If you have any questions or desire additional information, please contact me.
Sincerely, Enclosure
-'07 all A
ENCLOSURE Surveillance Testing Reactor Safeguards Systems Reference (1) Letter D. G. Eisenhut to All. Pressurized Water Reactors; dated June 26, 1979, Subject, Multiple Equipment Failures and Surveillance Testing Errors.
(2) Letter D. G. Eisenhut to All Pressurized Water Reactors, dated September 21, 1979, Subject, Multiple Equipment Failures and Surveillance Testing Errors.
INTRODUCTION Reference (2) retransmits reference (1) and requires all pressurized Water Reactor Operators to perform the following actions:
- 1. Required Action You and your plant supervisors should review the events described in the letter, to determine whether similar errors have occurred or could occur at your facility and whether the potential exists for a problem associated with occurrences that you have not previously considered.
Response
The results of the review conducted indicate that errors in performing surveillance or other testing have resulted in several unit trips.
The initial sequence of events for these incidents is generally similar to that of references (1) and (2), such that during a routine test, a unit trip or a safety system initiation occurred due to testing error.
In order to determine whether the potential exists for a problem associated with occurrences that have not been previously considered and to determine what revisions are required, a systematic review of all reactor safeguard surveillance test procedures will be completed by February 1, 1980.
- 2. Required Action In addition, it is requested that management policies and procedures be reviewed and strengthened as necessary to assure that multiple equipment failures in safety-related systems will be vigorously pursued and analyzed to identify potential failure modes not previously considered that could lead to a significant reduction in the ability of safety systems to function as required.
Response
The results of our review indicate that existing policies and procedures already require an examination of the cause of an incident (such as multiple equipment failures) and the corrective action to be taken to prevent reoccurrence. However, the procedures do not directly address the subject of multiple equipment failures.
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The applicable procedures will be systematically reviewed and revised by January 1, 1980 to include a vigorous program to identify potential failure modes that could lead to a significant reduction in the ability of safety systems to function as required due to multiple equipment failures.
- 3.
Required Action Finally, you are requested to review your engineered safety system surveillance procedures to determine whether appropriate cautions are included and to ensure that plant operators and supervisors are aware of the importance of avoiding challenges to the protective features of your facility.
Response
As noted in item 1 above, following specific incidents, the surveillance procedures were modified to include specific precautions to prevent recurrence. As a part of the review of all reactor safeguards surveillance procedures which will be completed by February 1, 1980, revisions will be made where it is determined that appropriate cautions are necessary. Also, a station memorandum will be prepared and distributed to all operators and supervisors explaining the importance of avoiding challenges to the protective features of the system.