ML13331A505
| ML13331A505 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 11/01/1990 |
| From: | Morgan H SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML13331A506 | List: |
| References | |
| NUDOCS 9011070345 | |
| Download: ML13331A505 (2) | |
Text
Southern California Edison Company P. 0.
BOX 128 SAN CLEMENTE, CALIFORNIA 92672 H. E. MORGAN TELEPHONE VICE PRESIDENT AND SITE MANAGER 714-368 -9470 SAN ONOFRE Nvember 1,
1990 U. S. Nuclear Regulatory Commission Attention:
Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket No. 50-206 Amendment Application No. 188, Supplement 1 San Onofre Nuclear Generating Station Unit 1
Reference:
Amendment Application No. 188, dated August 31, 1990 Enclosed is a supplement to our Amendment Application 188. The supplement provides the safety analysis for a proposed action statement time limit. The new action statement would allow operation of the Component Cooling Water System (CCW) with one of two heat exchangers out of service for more than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Our August 31, 1990 submittal requested a 31 day period, based on our safety assessment which had not been fully completed at that time. We have since completed a Probabilistic Risk Assessment (PRA) study evaluating the impact of the extended period of operation with only one CCW heat exchanger.
The results of the study are described in the enclosed safety analysis, and conclude that a seven day limit would be more appropriate. Therefore, we are revising our request for a 31 day action statement limit to a seven day limit.
The enclosed supplement is a revision to our request to revise Section 3.3, "Safety Injection and Containment Spray Systems," Section 3.5.5, "Containment Isolation Instrumentation," and Section 4.2, "Safety Injection and Containment Spray System," of the Appendix A, Technical Specifications for San Onofre Nuclear Generating Station (SONGS), Unit 1. This supplement only affects proposed Specification 3.3.7, "Component Cooling Water System," of the original amendment application. The other sections submitted in the referenced application are not affected by this change.
The August 31 submittal was made, in part, because of the general lack of guidance and specific action statements in the existing Technical Specifications. The existing specifications do not provide clear guidance for the removal of a CCW heat exchanger from service. The proposed seven day action statement will preclude entry into Technical Specification 3.0.3, and the subsequent plant shutdown for maintenance of the CCW heat exchangers. We believe that the seven day period provides a reasonable amount of time to perform maintenance on the heat exchangers and is not a safety concern since our PRA results show the increased impact on overall risk of core damage is about 0.7%.
9011070345 901101 PDR -ADOCK 05000206, P
w Document Control Desk November 1, 1990 If you have any questions or desire further information, please contact me.
Very truly yours, H. E. Morgan Vice President and Site Manager LSR/pcn151cvr cc:
J. B. Martin, Regional Administrator, NRC Region V C. Caldwell, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3 C. Townsend, NRC Resident Inspector, San Onofre Unit 1 J. H. Hickman, California Department of Health Services