ML13331B235
| ML13331B235 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 11/16/1989 |
| From: | Ray H Southern California Edison Co |
| To: | Zimmerman R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| NUDOCS 8912120138 | |
| Download: ML13331B235 (3) | |
Text
Southem Callfornia Edison Company C
23 PARKER STREET IRVINE, CALIFORNIA 92718 C O HAoLD B. RAY O
V 1 TE~pONE V-CEPRESIDENT 14-458-4400 November 16, 1989 Mr. Roy Zimmerman, Director Division of Reactor Safety and Projects U. S. Nuclear Regulatory Commission, Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 94596-5368
Dear Mr. Zimmerman:
Subject:
Docket No. 50-206 Application of Technical Specification Requirements San Onofre Nuclear Generating Station, Unit 1 The purpose of this letter is to describe Edison's policy with respect to application of Technical Specification requirements to system functions and components which may have been added and/or taken credit for subsequent to issuance of the relevant Technical Specification provisions.
As discussed by NRC Senior Resident Inspector Caldwell in an exit interview at San Onofre on November 6, 1989, review of the licensing record demonstrates that the Hot Leg Recirculation (HLR) function and components are taken credit for by Edison to satisfy important Safety Injection System requirements. On this basis, I had previously indicated to Mr. Caldwell that Edison agrees that the provisions of the Technical Specifications should and do apply to HLR. In order to make clear how they should apply, Edison will propose a change to the Technical Specifications to explicitly address HLR.
The need to clarify applicability of the Technical Specifications to HLR is based on an event which occurred on August 23, 1989.
On that date, a component failure rendered valve CV-304 inoperable. This valve is required to operate in order for the normal HLR flowpath to perform its intended function.
In reviewing the Technical Specifications at the time of the failure, Edison concluded that, since HLR was not explicitly included in the Technical Specifications, a 72-hour action statement would be applied, such that shutdown of the unit would be required if CV-304 was not returned to operable status within that period.
8912120138 891116 PDR ADOCK 05000206 P
PNU
0 Mr. Roy Zimmerman November 16, 1989 Although the use of a 72-hour action statement recognized that HLR performs an important safety function, it was nonconservative with respect to the Technical Specifications for two reasons.
o CV-304 is not included among the components listed which are permitted to be inoperable for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> without requiring reactor shutdown. Edison believed that this was because HLR in general is not explicitly addressed by the Technical Specifications. However, a more conservative application of the Technical Specifications would have been to enter the T.S. 3.0.3 action requirement.
o The alternate HLR flowpath, which would be relied upon in the event the normal flowpath did not function due to failure of CV-304, includes components which are to be fully upgraded to meet EQ requirements at the next refueling outage.
In view of the fact that these upgrades have not yet been completed, reliance should not have been placed on that flowpath during the 72-hour period allowed to correct the inoperability of CV-304.
Pending revision of the Technical Specifications to include functions and components which have been added and/or taken.
credit for subsequent to issuance of the relevant Technical Specification provisions, Edison will seek to strengthen its response to situations where interpretation of existing requirements may be necessary. In this instance, valve CV-304 was repaired and returned to operability in approximately 43 hours4.976852e-4 days <br />0.0119 hours <br />7.109788e-5 weeks <br />1.63615e-5 months <br />, and the initial interpretation that a 72-hour action statement was appropriate and conservative was not further reviewed by Edison until it was questioned by the NRC.
In this regard, the CV-304 event on August 23 is similar to an event on August 24 which involved the nonconservative and inappropriate application to San Onofre Unit 2 of the guidance in an NRC generic letter, rather than compliance with the existing requirements of the Technical Specifications. The event on August 24 is the subject of an NOV to which a specific response is being provided separately. In general, however, it is Edison policy to:
(1) Conservatively implement the requirements of the Technical Specifications at all times.
(2) Carefully review Technical Specification requirements for applicability and consult with the Office of Nuclear Reactor Regulation staff when the application or interpretation is not sufficiently clear to ensure a conservative implementation.
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Mr. Roy Zimmerman November 16, 1989 (3) Propose changes to the Technical Specifications where necessary to clearly provide requirements for functions and components which have been added and/or taken credit for subsequent to issuance of the relevant Technical Specification provisions.
In the two instances on August 23 and 24, 1989,.item (2) of this policy was not fully implemented in that Edison only discussed its planned course of action with the NRC Resident Inspector. Mr. Bridenbecker and I have discussed with the appropriate management the corrective action required to ensure that it is fully implemented in the future.
If you have any questions or comments, or if you would like additional information concerning this matter, please let me know.
Sincerely, cc:
J. B. Martin, Regional Administrator, Region V C. W. Caldwell, NRC Senior Resident Inspector, San Onofre G. Knighton, Office of Nuclear Reactor Regulation, NRC