ML13322B125
| ML13322B125 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 03/26/1990 |
| From: | Tatum J Office of Nuclear Reactor Regulation |
| To: | Ray H Southern California Edison Co |
| Shared Package | |
| ML13322B126 | List: |
| References | |
| NUDOCS 9004060330 | |
| Download: ML13322B125 (5) | |
Text
March 26, 1990 Docket No. 50-206 DISTRIBUTION
~ocketFile LKokajko NRC & LPDRs DFischer CTrammell (2)
JCalvo Mr. Harold B. Ray JZwolinski RLobel Vice President PShea CHarbuck Southern California Edison Company OGC-White Flint Irvine Operations Center PD5 Plant File 23 Parker EJordan Irvine, California 92718 BGrimes ACRS (10)
JTatum (2)
Dear Mr. Ray:
SUBJECT:
10 CFR 50.59 REVIEW METHODOLOGY SAN ONOFRE NUCLEAR GENERATING STATION, UNIT NO. 1 (TAC NO. 76040)
By letter dated February 2, 1990, you summarized your application of NSAC/125 guidance in satisfying the requirements of 10 CFR 50.59 for a change that was identified relative to auxiliary feedwater flow rate (LER 89-031). We have reviewed your letter and the 10 CFR 50.59 evaluation that was completed (NCR SO1-P-7441, Rev. 1); and, while we agree with your operability assessment, we do not agree with your implementation of NSAC/125. Although you made reference to certain parts of NSAC/125 in your 50.59 evaluation, you failed to implement the methodology suggested by NSAC/125 in focusing your review efforts.
Consequently, it is not possible for us to draw a conclusion with respect to whether an unreviewed safety question is involved based on the evaluation that was performed.
Although we take exception to your methodology for completing your 50.59 evaluation in this particular instance, we recognize that you have taken the initiative to improve the quality of your review efforts. Therefore, as to this letter, we have included specific comments for your consideration. For completeness, we have also included NCR SO1-P-7441 Rev. 1 as Enclosure 2. We do not consider our comments to be all inclusive, but we believe they may be helpful in improving your review efforts.
We do not expect you to submit your revised 50.59 evaluation for our review, as the resident inspectors will review your efforts in this regard. Addi tionally, we do not request a specific response to this letter.
Sincerely, original signed by 9Q04()6.3'C) 900::26 James E. Tatum, Project Manager PER
,DOCK 05000206 Project Directorate V P
PDC Division of Reactor Projects - III, IV, V and Special Projects Office of Nuclear Reactor Regulation
Enclosure:
As stated cc w/enclosures:
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U UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 March 26, 1990 Docket No. 50-206 Mr. Harold B. Ray Vice President Southern California Edison Company Irvine Operations Center 23 Parker Irvine, California 92718
Dear Mr. Ray:
SUBJECT:
10 CFR 50.59 REVIEW METHODOLOGY SAN ONOFRE NUCLEAR GENERATING STATION, UNIT NO. 1 (TAC NO. 76040)
By letter dated February 2, 1990, you summarized your application of NSAC/125 guidance in satisfying the requirements of 10 CFR 50.59 for a change that was identified relative to auxiliary feedwater flow rate (LER 89-031).
We have reviewed your letter and the 10 CFP 50.59 evaluation that was completed (NCR SO1-P-7441, Rev. 1); and, while we agree with your operability assessment, we do not agree with your implementation of NSAC/125. Although you made reference to certain parts of NSAC/125 in your 50.59 evaluation, you failed to implement the methodology suggested by NSAC/125 in focusing your review efforts.
Consequently. it is not possible for us to draw a conclusion with respect to whether an unreviewed safety question is involved based on the evaluation that was performed.
Although vie take exception to your methodology for completing your 50.59 evaluation in this particular instance, we recognize that you have taken the initiative to improve the quality of your review efforts. Therefore, as to this letter, we have included specific comments for your consideration. For completeness, we have also included NCR SO1-P-7441 Rev. 1 as Enclosure 2. We do not consider our comments to be all inclusive, but we believe they may be helpful in improving your review efforts.
We do not expect you to submit your revised 50.59 evaluation for our review, as the resident inspectors will review your efforts in this regard. Addi tionally, we do not request a specific response to this letter.
Sincerely, Jimes E. Tatum, Project Manager P-'Project Directorate V Division of Reactor Projects - III, IV, V and Special Projects Office of Nuclear Reactor Regulation
Enclosure:
As stated cc w/enclosures:
See next page
Mr. Harold B. Ray San Onofre Nuclear Generating Southern California Edison Company Station, Unit No. 1 cc David R. Piqott Mr. Richard J. Kosiba, Project Manaqer Orrick, Herrinqton & Sutcliffe Bechtel Power Corporation 600 Montgomery Street 12440 E. Imperial Highway San Francisco, California 94111 Norwalk, California 90650 Mr. Robert G. Lacy Mr. Phil Johnson Manager, Nuclear U.S. Nuclear Requaltory Commission San Diego Gas & Electric Company Region V P. 0. Box 1831 1450 Maria Lane, Suite 210 San Diego, California 92112 Walnut Creek, California 94596 Resident Inspector/San Onofre NPS U.S. NRC P. 0. Box 4329 San Clemente, California 92672 Mayor City of San Clemente San Clemente, California 92672 Chairman Board of Supervisors County of San Dieqo 1600 Pacific Highway Room 335 San Diego, California 92101 Regional Administrator, Reqion V U.S. Nuclear Requlatory Commission 1450 Maria Lane, Suite 210 Walnut Creek. California 94596 Mr. John Hickman Senior Health Physicist Environmental Radioactive Manaqement Unit Environmental Management Branch State Department of Health Services 714 P Street, Room 616 Sacramento, California 95814 Mr. Don Womeldorf Chief Environmental Management California Department of Health 714 P Street, Room 616 Sacramento, California 95814
ENCLOSURE 1 COMMENTS RE:
10 CFR 50.59 EVALUATION (NCR S01-P-7441, REV.1)
- 1. NSAC/125 (page 3-1 and Attachment A) breaks the 50.59 evaluation down into seven questions. This technique provides focus for the evaluation effort and the licensee is less likely to be side tracked if this methodo logy is implemented. SCE apparently did not use this methodology and, in several instances (discussed below), the licensee's evaluation was not properly focused.
- 2. In discussing the probability of occurrence of an accident or malfunction of equipment, SCE did not identify those accidents or that equipment relevant to the evaluation. A determination must be made as to whether the oriainal accident assumptions have been affected by the change. An independent reviewer should be able to identify the following information in the evaluation:
- a. Relevant accidents and equipment under consideration.
- b. Probabilities of accident occurrence or equipment malfunction originally assumed by the accident analyses, and how these assumptions are affected by the change.
- c. Logic that was used in reaching a conclusion.
- 3. The consequences of an accident and malfunction of equipment should be addressed in terms of off-site dose (NSAC/125, pg 3-5).
Off-site dose did not appear to be a primary consideration in the licensee's evaluation.
- 4. Recognizing that San Onofre Unit 1 is an older plant and the accident analyses may not be well defined, particular attention should be directed to NSAC/125, pg 3-7:
"The possible accidents or malfunctions of a different type are limited to those that are as likely to happen as those considered in the SAR."
The evaluation should define those accidents and equipment malfunctions that could occur and how these scenarios are bounded by the current accident analyses.
-2
- 5. When addressing reductions in the margin of safety, the licensee defined the following basis for Technical Specification 4.1.9:
"...the design of the AFWS ensures sufficient AFW flow without exceeding water hammer limits for all applicable design basis events with or without a LOP and a single active failure."
The licensee did not define the "margin of safety," however, and how that margin is affected by the change.