ML13308B388
| ML13308B388 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 07/14/1976 |
| From: | Fogarty D SOUTHERN CALIFORNIA EDISON CO. |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| NUDOCS 8103180580 | |
| Download: ML13308B388 (1) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE DAVID J. FOGARTY ROSEMEAD, CALIFORNIA 91770 TELEPHONE July 14, 1976 213 572 -2796 U. S. Nuclear Regulatory Commission Region V Suite 202, Walnut Creek Plaza 1990 North California Boulevard Walnut Creek, California 94596 Attention: R. H. Engelken, Director
Dear Sir:
Docket No. 50-206 San Onofre Unit 1 This 'letter describes a reportable occurrence concerning the San Onofre Nuclear Generating Station Unit 1 Instrumentation and Control System. Sub mittal is in accordance with the reporting requirement stipulated in section 6.9.2.b(2) of the Technical Specifications.
On June 28, 1976 at 4:16 a.m., Unit I'tripped while carrying 330 MWe.
The reactor tripped from a spurious low reactor coolant flow signal from the loop C flow transmitter. All plant tripping schemes initiated by the spurious low flow signal functioned as designed.
. Following removal of the transmitter from containment, limited operation was resumed while effecting repairs. Reactor thermal power was maintained below sixty percent in accordance with Technical Specification requirements.
The unit was subsequently removed from service to replace the repaired trans mitter. Unrestricted operation resumed June 28, 1976.
Generation of the spurious low flow signal was due to failure of the feedback motor in the flow transmitter. The feedback motor was replaced and the device successfully calibrated prior to replacement.
Sincerely, Attachment cc: Director, NRC Office of Inspection and Enforcement Director, NRC Office of Management Information and Program Control
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