ML20137Z377
| ML20137Z377 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 04/22/1997 |
| From: | Nunn D SOUTHERN CALIFORNIA EDISON CO. |
| To: | Bateman W NRC (Affiliation Not Assigned) |
| References | |
| NUDOCS 9704240127 | |
| Download: ML20137Z377 (3) | |
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An EDISON INT {RNATIOWL Company April 22, 1997 U. S. Nuclear Regulatory Commission Attention: William H. Bateman, Director Project Directorate IV-2 Washington D. C. 20555
Dear Mr. Bateman:
Subject:
Docket Nos. 50-361 and 50-362 Amendment Application Nos. 167 and 153 San Onofre Nuclear Generating Station, Units 2 and 3 This responds to your letter of April 18, 1997, requesting that Southern California Edison (Edison) explain why it took three months to submit a Technical Specification (TS) amendment and the need for exigent action.
i As you are aware in January, February, and March of this year, Edison perfomed an extensive review of all TS Surveillance Requirements (SRs) against the implementing procedures. The issue related to testing of the alternate offsite power source (SR 3.8.1.8) was identified as a result of this review. Additionally, during the course of this review, Edison initiated preparation of a TS amendment request to provide an overall enhancement of TS 3.8.1, Electrical Power Systems.
Edison planned to include the change to SR 3.8.1.8 as part of this overall TS amendment request.
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The effort to complete the electrical power systems amendment has proven to be challenging for a number of reasons. As noted in our letters dated February 21, 1997, and March 21, 1997, additional time was required to complete this amendment request. One contributor to the delay has been the ability to focus resources on this project.
During this time, the Unit 2 outage continued into April, the SR review program extended through March, and the Generic Letter 96-01 review program was ongoing.
Another contributor to the amendment's delay has been that the review of the electrical SRs has been more involved than anticipated. The result was that the submittal of the overall TS 3.8.1 amendment request, including SR 3.8.1.8, has been significantly delayeg A n n, n pg 9704240127 970422 PDR ADOCK 05000361 P
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William H. Bateman, Director As explained in our license amendment submittal, the-proposed revision to SR 3.8.1.8 would allow Edison to credit overlap testing for performance of this SR, when it is desired to use the Unit Auxiliary Transformer of a shutdown unit as the alternate offsite power source for an operating unit.
The benefit of overlap testing is avoidance of an unnecessary challenge to safety systems by performing an actual transfer of the safety related buses of the operating unit to the Unit Auxiliary Transformer of the shutdown unit.
Planning for an actual test has been taking place. Although we believe that this transfer would be successful, it does pose an unnecessary challenge to the offsite power connection of the operating unit. Whereas, overlap testing will provide the same confidence that the transfer will be successful, but would add no challenge to the offsite power connection. We have attempted to quantify the risks associated with each testing method but have been unable.
Both risks, we believe are small.
Edison admits that we should have recognized sooner the need to pull SR 3.8.1.8 from the overall amendment request. This would have resulted in an earlier submittal of the requested change. However, notwithstanding this, at the time when we did recognize this need, Ediso'1 was faced with-two choices:
(1) request an exigent change to the SR, or (2) perform the transfer test.
Although there may be no quantifiable safety advantage to either choice, there is at least a perception that performing the test should be avoided if possible. Therefore, during the Onsite Review Committee meeting to discuss the transfer test, Edison concluded that the appropriate course of action was the requested exigent change.
Receipt of this amendment by mid-May 1997 will permit Edison to credit the Unit 3 Unit Auxiliary Transformer as the Unit 2 alternate source of offsite power. This in turn will permit preventive maintenance on the Unit 3 Reserve Auxiliary Transformers and. associated hardware, during the current Unit 3 refueling outage.
Because the Unit 3 Reserve Auxiliary Transformers are normally in service and provide the normal source of offsite power for Unit 3 and the alternate source of offsite power for Unit 2, Edison feels it is important to be able to perform preventive maintenance on these transformers during.the current outage.
Receipt of the requested license amendment will provide the necessary flexibility to perform all of the desired maintenance.
Without the amendment, maintenance will be constrained by the TS Action statement on Unit 2 for one required offsite circuit inoperable; i.e.,
72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
Edisonunderstandsthatinaccordancewith10CFR50.91(a)(6)(vi),theNRC will use its normal public notice and comment procedures "if it determines
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William 41.Bateman, Director,
that the licensee has failed to use its best efforts to make a timely application for the amendment in order to create the exigency and to take i
advantage of this procedure." This paragraph seems to imply some degree of
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l intent on the part of the licensee "to create the exigency and to take
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advantage of this procedure."
In the case of our proposed change to SR 3.8.1.8, Edison could have submitted the request sooner.
However, as explained above, the failure to do so, was not in order to create an exigency situation nor was there an attempt to take advantage of the exigency procedure.
Edison recognizes the additional burden associated with processing an exigent change both administratively and technically.
Nevertheless, in this situation, Edison believes the appropriate course of action is to request an exigent change.
4 Based on the above information, it is requested that the NRC process the requested change to SR 3.8.1.8 on an exigent basis.
If you have any questions on this information, please let me know.
Sincerely,
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I cc:
E. W. Merschoff, Regional Administrator, NRC Region IV
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K. E. Perkins, Jr., Director, Walnut Creek Field Office, NRC Region IV J. A. Sloan, NRC Senior Resident Inspector, San Onofre Units 2 & 3 M. B. Fields, NRC Project Manager, San Onofre Units 2 and 3 i
U. S. NUCLEAR REGULATORY COMMISSION, DOCUMENT CONTROL DESK
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