ML13308B501
| ML13308B501 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 09/12/1975 |
| From: | Fogarty D SOUTHERN CALIFORNIA EDISON CO. |
| To: | Anthony Giambusso Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8103060579 | |
| Download: ML13308B501 (2) | |
Text
REGUIATOY DOCKET FILE coP Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE DAVID J. FOGARTY ROSEMEAD, CALIFORNIA 91770 TELEPHONE VIC~ESIDNT ~213-572-2796 September 12, 1975 StP24 1975 o
Mr. Angelo Giambusso, Director M
Division of Reactor Licensing 4 0ry Office of Nuclear Reactor Regulation can*
U. S. Nuclear Regulatory Commission Mail Code:
BETH:042 D ?
Washington, D. C.
20545 Docket No. 50-206 San Onofre Unit 1 No. 2 Diesel Generator
Dear Sir:
V 17 This report describes an incident experienced at the San Onofre Nuclear Generating Station concerning the No. 2 diesel generator.
In accordance with Station Order S-0-19 which outlines the testing of auxiliary protective equipment, the two diesel generators are tested semi-annually.
These tests are in addition to the weekly and refueling interval testing required by Technical Specifications 4.4 A and B. The semi-annual test requires that both diesel generatorsbe operated at rated load of 600 KW for one-hour.
During this test conducted August 13, 1975, the No. 2 diesel generator tripped because of high cooling water temper ature after 20 minutes of operation.
The ensuing investigation disclosed that the sealing surface of the cap closure on the coolant system standpipe was allowing leakage.
Sufficient pressure and coolant capa city were not maintained in the cooling.system, resulting in a reduced cooling capability. The leakage from the cap closure was piped to a drain and the leakage was not visible to operating personnel.
The drain line on both diesel generators was modified to facilitate identification of leakage from the system.
The cap sealing surface was repaired and the No. 2 diesel generator was subsequently test operated at its rated load of 600 KW for one hour without difficulty.
O/63 O57 111
-2 To ensure that Technical Specification requirements were satisfied during the period the No. 2 diesel generator was out of service, operability of the No. 1 diesel generator was demon strated by completion of a partial load test.
Sincerely, cc:
Director, Region V Office of Inspection & Enforcement