ML20129J020
| ML20129J020 | |
| Person / Time | |
|---|---|
| Issue date: | 07/05/1985 |
| From: | Heltemes C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Wells R C-E OPERATING PLANTS OWNERS GROUP, NORTHEAST UTILITIES SERVICE CO. |
| Shared Package | |
| ML20129H990 | List: |
| References | |
| NUDOCS 8507220148 | |
| Download: ML20129J020 (2) | |
Text
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R f DC9 g JUL 0 5 M Mr. R. Wells, Chainnan CE . Owners ' ' Group ' _
Northeast Utilities Service Company P.O. Box 270
- Hartford, Connecticut 06101
Dear Mr.- Wells :
Subject:
Request for Peer Review Comments - Preliminary Case Study Report --
Decay Heat Removal Problems at U.S. Pressurized Water Reactors A preliminary case study on DHR losses at operating PWRs is attached. The study analyzes 130 losses of DHR systems at U.S. PWRs between 1976 and 1983 and notes that for some likely events, a loss of DHR can result in core uncovery within one to three hours.
Our case study report indicates the root causes of the DHR losses, and it _
' examines specific actions that have been taken at several plants to improve the availability of their DHR systems. The report makes six recommenda-tions, which if implemented, will significantly reduce the frequency, duration and severity of loss-of-DHR events.
In accordance with our " peer review" process prior to the finalization and distribution of our case study reports, we are providing NRR, IE, Regional Offices, RES, NSAC and INPO with a copy of a preliminary report for review and comment, particularly regarding accuracy and completeness of the technical details. Changes to the findings, conclusions, and recommendations will be considered only if the underlying information concerning the details of plant design or systems' operation is in error. Therefore, comments are being solicited on the technical accuracy of the report. The findings, conclusions, and recommendations are provided for your infonnation in order that you may understand the significance AE00 places on these events'and, therefore, obtain a more complete picture of the total report. We would welcome conments either infonnally by telephone or fonnally by memorandum.
.Since we wish to. finalize and issue'the report shortly, we ask that any comments be received by us within 30 days from receipt of the preliminary
' copy. Should you require some additional time beyond that point, please
-let us know; otherwise, it will be assumed that there are no comments.
8507220148 850705 PDR PfISC 8507220107 PDR
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Mr. R. Wells As you may know, AEOD reports do not represent an official NRC position or the position of the responsible NRC program office. Our reports are one input to an ongoing review and evaluation process, and any recommendation contained in our final report will be considered and perhaps modified or eliminated by the responsible NRC office.
A copy of the preliminary report and this letter are being placed in the Public Document Room at 1717 H Street, N.W., Washington, D.C. 20555.
If you have any questions regarding this study, please feel free to contact Dr. Hal Ornstein at (301)'492-4439.
Sincerely, h
C. J. Heltemes, Jr., Director Office for Analysis and Evaluation of Operational Data
Enclosure:
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