ML13333B990
| ML13333B990 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 11/28/1983 |
| From: | Zukor D NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | |
| Shared Package | |
| ML13333B989 | List: |
| References | |
| TASK-AE, TASK-T338 AEOD-T338, NUDOCS 8312140307 | |
| Download: ML13333B990 (1) | |
Text
0F AEOD TECHNICAL REVIEW REPOR*
UNIT:
San Onofre 1 TR REPORT NO. AEOD/T338 DOCKET NO.: 50-206 DATE: November 28, 18 LICENSEE:
Southern California Edison EVALUATOR/CONTACT: Zukor NSSS/AE:
Westinghouse/Bechtel
SUBJECT:
WATER LEAK THROUGH CONTAINMENT SPRAY BLOCK VALVES EVENT DATE(S):
11/20/81
SUMMARY
This event was re-screened in response to a request for category codes from Critical Mass.
This TR was written because considerable time was spent at tempting to determine how the hot-leg recirculation line could affect the event. A slightly open isolation valve in the recirculation piping allowed an interconnection between the loop A letdown line and the containment spray block valves.
The event was not significant.
DISCUSSION The reactor was at 86% power in steady state operation. During a test of the refueling water pumps, the water level in the refueling water tank de creased and one of the sphere sump pumps actuated. Leakage by one or both of the containment spray block valves was suspected which would cause water to leak through to the containment spray valves.
See attached diagram.
The licensee found that a slightly open hot-leg recirculation valve allowed pressure to build up to 350 psig in the spray system from the letdown line of loop A. It is believed that the pressure from the pump operation with the open hot-leg recirculation valve raised the containment spray header pressure to a value higher than normal resulting in leakage by the containment spray block valves.
FINDINGS The slightly open hot-leg recirculation isolation valve allowed an inter connection between the containment spray block valve and the loop A let down line.
CONCLUSIONS The event was not significant and the licensee's corrective action was ap propriate.
Attachments: 1. LER No. 206/82-006/99X-0
- 2. San Onofre 1 Final Safety Analysis Report.
Containment Spray and Safety Injection System Diagram. Sheet 1.
- This document supports ongoing AEOD and NRC activities and does not re present the position or requirements of the responsible NRC program office.
6312140307 E831128 PDR ADOCK 05000206 S