ML13308B497
| ML13308B497 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 06/18/1976 |
| From: | Fogarty D SOUTHERN CALIFORNIA EDISON CO. |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| NUDOCS 8103060567 | |
| Download: ML13308B497 (2) | |
Text
Southern California Edison, Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE DAVID J. FOGARTY ROSEMEAD, CALIFORNIA 91770 TELEPHONE June 18, 1976 213-572-2796 U. S. Nuclear Regulatory Commission Kuv Region V Office of Inspection and.Enforcement Walnut Creek Plaza, Suite 202 00 1990 North California Boulevard Walnut Creek, California 94596 Attention:
R. H. Ehgelken, Director Docket No. 50-206 San Onofre Unit 1
Dear Sir:
This letter describes a reportable occurrence concerning the San Onofre Nuclear Generating Station Unit 1 Instrumentation and Control System. It is submitted in accordance with the reporting requirements stipulated in section 6.9.2.b of the Technical Specifications.
On May 20, 1976 at 12:45 a.m., "B" steam generator steam flow indication decreased approximately 15%.
This resulted in a nonconservative change in the set point for the steam feed water flow mismatch reactor trip. The steam generator feedwater system was transferred to manual control and continuous operator surveillance was initiated as specified in Technical Specifica tion 3.5, Table 3.5.1.
The reduction of steam flow indication was caused by a leak in the steam flow transmitter high side blow down valve.
A plug was installed in the valve to correct the leakage and the blow down valve will be replaced during the next outage.
Sincerely,
Attachment:
Licensee Event Report
.cc:
Director, NRC Office of Inspection and Enforcement Director, NRC Office of Management Information and Program Control.
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE DAVID J. FOGARTY ROSEMEAD, CALIFORNIA 91770 TELEPHONE June 18, 1976 213-572-2796 U. S. Nuclear Regulatory Commission Region V Office of Inspection and Enforcement Walnut Creek Plaza, Suite 202 1990 North California Boulevard Walnut Creek, California 94596 Attention:
R. H. Engelken, Director Docket No. 50-206 San Onofre Unit 1
Dear Sir:
This letter describes a reportable occurrence concerning the San Onofre Nuclear Generating Station Unit 1 Instrumentation and Control System.
It is submitted in accordance with the reporting requirements stipulated in section 6.9.2.b of the Technical Specifications.
On May 20, 1976 at 12:45 a.m., "B" steam generator steam flow indication decreased approximately 15%.
This resulted in a nonconservative change in the.set point for the steam feed water flow mismatch reactor trip. The steam generator feedwater system was transferred to manual control and continuous operator surveillance was initiated as specified in Technical Specifica tion 3.5, Table 3.5.1.
The reduction of steam flow indication was caused by a leak in the steam flow transmitter high side blow down valve.
A plug was installed in the valve to correct the leakage and the blow down valve will be replaced during the next outage.
Sincerely, rJUN 24 19 7 6,P>
Attachment:
Licensee Event Report cc:
Director, NRC Office of Inspection and Enforcement
- Director, NRC Office of Management Information and Program Control 6383