ML13317A694
| ML13317A694 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 10/16/1981 |
| From: | Baskin K Southern California Edison Co |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML13317A696 | List: |
| References | |
| NUDOCS 8110200522 | |
| Download: ML13317A694 (2) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 K. P. BASKIN TELEPHONE MANAGER OF NUCLEAR ENGINEERING, (213) 572-1401 SAFETY, AND LICENSING October 16, 1981 Director, Office of Nuclear Reactor Regulation Attention: D. M. Crutchfield, Chief Operating Reactors Branch No. 5 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D.C.
20555 Gentlemen:
Subject:
Docket No. 50-206 Safety Injection System Modification San Onofre Nuclear Generating Station Unit 1 Submitted herewith are five copies of the report entitled, "Safety Injection System Modification, San Onofre Nuclear Generatingo.Station, Unit 1, October, 1981."
The report contains information provided to the Regulatory staff during meetings held on September 15 and 30, 1981.
These meetings were held to discuss the Safety Injection System (SIS) actuation on September 3, 1981 and the failure of two feedwater pump SIS discharge valves to open during the actuation.
We also discussed the corrective actions implemented, including the analyses of the corrective actions. The report also contains information related to (1) changing the valve sequencing, (2) drilling a hole in the feedwater pump discharge check valves, and (3) changing the preoperational and periodic surveillance testing. This information has been discussed with the Regulatory staff.
Specifically, the report discusses:
- 1.
the SIS configuration and operation, including operating and maintenance history.
- 2. the investigation and evaluation to determine the cause of the safety injection valves not opening,
- 3. the corrective actions considered and the corrective actions
- selected,
- 4. the reliability, hydraulic, electric and accident analyses performed am for the selected alternative,
- 5. the preoperational and periodic surveillance testing of the selected alternative, and s
t
- 6. the future plans and commitments to replace the SIS valves and to study the SIS design and-performance.
8110200522 811016 '
PDR ADOCK 05000206 P
Mr. D. -M. Crutchfield
-2 As has been discussed with the Regulatory staff during the aforementioned meetings and documented in the enclosed report, we will demonstrate that the corrective actions implemented will limit the maximum differential pressure under operating conditions to 350 psi.
This differential pressure is well below the maximum differential pressure of 450 psi which is appropriate to eliminate galling. However, if the feedwater pump pressure decay characteristics demonstrated during preoperational testing change in time as a result of service induced changes (i.e., resistances in piping, etc.), we will implement additional differential pressure stroke tests to demonstrate that the increased differential pressure is acceptable (i.e.,
greater than 350 psi but less than 450 psi).
We are currently projecting return to power operation for October 20 or 21, 1981 and are continually reassesing this date as the preoperational testing progresses. Therefore, it is requested that you provide your approval as soon as possible. Accordingly, we are prepared to meet with you to facilitate your review and approval of the enclosed report.
If you have any questions or desire further information concerning the enclosed report, please contact me.
Very truly yours, Enclosures (5) cc: