ML13324A663
| ML13324A663 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 07/01/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML13324A662 | List: |
| References | |
| GL-83-28, NUDOCS 8507030330 | |
| Download: ML13324A663 (2) | |
Text
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION GENERIC IMPLICATIONS OF SALEM ATWS EVENT GENERIC LETTER 83-28, ITEM 4.1 SAN ONOFRE NUCLEAR GENERATING STATION - UNIT 1 DOCKET NO. 50-206 I. INTRODUCTION On February 25, 1983, during startup of the Salem Unit 1 plant, both circuit breakers in the Reactor Trip System failed to open automatically upon receipt of a valid trip signal.
As a result of that event, the NRC's Office of Inspection and Enforcement issued IE Bulletin 83-01 which described the event and requested specified prompt corrective and preventive actions by licensees.
As the cause and ramifications of the event were more clearly developed, the NRC's Office of Nuclear Reactor Regulation issued on July 8, 1983, Generic Letter 83-28, "Required Actions Based on Generic Implications of Salem ATWS Events."
This letter addressed issues related to reactor trip system reliability and general management capability. The letter was sent to all licensees of operating reactors, applicants for operating licenses and holders of construction permits.
One of the areas of reactor trip system reliability considered in Generic Letter 83-28 (GL 83-28), is that of vendor-recommended modifications.
This is identified in GL 83-28 as Item 4.1.
This evaluation addresses the acceptability of the response to this item provided by the Southern California Edison Company (the licensee) for San Onofre Nuclear Generating Station, Unit 1 (the facility).
II. EVALUATION Item 4.1 of GL 83-28 states that "All vendor-recommended reactor trip modifications shall be reviewed to verify that either: (1) each modification has, in fact, been implemented; or (2) a written evaluation of the technical reasons for not implementing a modification exists."
This item of GL 83-28 also states that licensees should submit a statement confirming that this action has been implemented.
By letter dated November 28, 1983, the licensee responded to a number of GL 83-28 items, including Item 4.1. In response to Item 4.1, the licensee stated all vendor-recommended reactor trip breaker modifications had been implemented in Design Change No. 72-05. The licensee also stated that the modifications recommended in the March 31, 1983 Westinghouse letter for DS-416 breakers did not apply to the San Onofre Unit I reactor trip breakers.
8507030330 950701 PDR ADOCK 05000206 P
-2 III. CONCLUSION Based on the licensee's confirmation that the facility has implemerted all vendor-recommended modifications existing at the time of issuance of the generic letter, we conclude the licensee has satisfactorily completed for San Onofre Unit 1, the actions prescribed by Item 4.1 of Generic Letter 83-28. Accordingly, this item is closed.
Principal Contributor:
G. Zwetzig Dated:
July 1, 1985