ML13331A498
| ML13331A498 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 10/16/1990 |
| From: | Ray H SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML13331A499 | List: |
| References | |
| NUDOCS 9010190170 | |
| Download: ML13331A498 (2) | |
Text
Southern California Edison Company 23 PARKER STREET IRVINE, CALIFORNIA 92718 HAROLD B. RAY TELEPHONE SENIOR VICE PRESIDENT October 16, 1990 714.458-4oo U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket No. 50-206 Amendment Application No. 184 Reactor Coolant Leakage, Technical Specification 3.1.4 San Onofre Nuclear Generating Station Unit 1 This letter provides Amendment Application No. 184 which is a request to revise the Basis of Technical Specification 3.1.4, "Leakage and Leakage Detection Systems."
This change will clarify the Basis for Technical Specification 3.1.4 by removing a statement erroneously basing the six gallon per minute (gpm) reactor coolant leakage rate on the ability to remove decay heat during a loss of all alternating current power event lasting 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
The correct basis for the six gpm limitation is the long term limitations of the gas handling portion of the radwaste system. The radwaste system limitations are discussed in the existing Basis of Technical Specification 3.1.4 and are being clarified by this amendment application.
Submittal of Amendment Application No. 184 satisfies part of the corrective actions for Licensee Event Report (LER) 1-90-004, Revision 1. LER 1-90-004, which was transmitted to you on April 25, 1990, identified a potential for Reactor Coolant System (RCS) leakage through the three letdown system orifice isolation valves which exceeds the six gpm maximum allowed by Technical Specification 3.1.4 during a loss of power event. The corrective actions for LER 1-90-004 require a revision to the Basis of Technical Specification 3.1.4.
The assumption of a 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> loss of offsite power event, or station blackout, is not consistent with our current analysis which assumes a two hour event.
Additionally, in response to 10 CFR 50.63, we have developed a new station blackout analysis which postulates a duration of four hours. This new analysis, which was submitted on April 17, 1989 and supplemented on May 1, 1990, is currently under NRC review. When the new analysis is approved, new or revised technical specifications specifically addressing station blackout concerns may be required. Currently however, it is not appropriate to address station blackout concerns in the existing leakage technical specification because it was designed to control leakage from the RCS during normal operating conditions. For these reasons, the discussion of a loss of power event in the Basis of Technical Specification 3.1.4 will be removed altogether.
9010190170 901016 PEIR ADOCK 05000206 P
PEIC i/,
Document Control Desk October 16, 1990 LER 1-90-004 also limited the identified and unidentified RCS leakage to one gpm. As part of the LER corrective actions a calculation is being developed to quantify the maximum allowable leakage for a station blackout event.
The calculation will be completed prior to return to service from the current refueling outage. The leakage limits for the letdown system isolation valves are monitored by the In-Service Testing program (as described in the LER) and will be adjusted as applicable based on the results of the calculation.
If you have any questions in this matter, please let me know.
Very truly yours, Enclosure cc:
J. B. Martin, Regional Administrator, NRC Region V C. Caldwell, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3 J. H. Hickman, California Department of Health Services