ML20202H620
| ML20202H620 | |
| Person / Time | |
|---|---|
| Issue date: | 06/17/1986 |
| From: | Heltemes C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Harold Denton, Minogue R, Taylor J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE), Office of Nuclear Reactor Regulation, NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| Shared Package | |
| ML20202H594 | List: |
| References | |
| NUDOCS 8607160389 | |
| Download: ML20202H620 (2) | |
Text
Dr. A. David Rossin We would welcome your comments either informally by phone or formally by letter. Since we wish to finalize and issue the report shortly, we ask that any comments you may wish to make be brought to our attention within 30 days from receipt of this letter.
As you may know, AE0D 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 Roorn at 1717 H Street, N.W. , Washington, D.C. 20555.
If you or your staff have any questions relating to this report, please feel free to contact Frank Ashe of my staff. Mr. Ashe can be reached at 301/492 4442.
Sincerely, ortemisenedDa c.L w ~ 's. A C. J. Heltemes, Jr. , Director Office for Analysis and Evaluation of Operational Data
Enclosure:
As stated Distribution PDR AE00 CF ROAB CF R0AB SF FAshe MChiranal SRubin KBlack WLanning Chief, PTB FHebdon 8607160389 860617 PDR CHe1temes ORG NEXD PDR OFC :ROAB y,g, :SC:ROAB y :AC:ROAB :DD:AEOD :D:AEOD : :
NAME :FAshe:as :MChiramal :SRubin :FHebdon :CHeltemes : :
DATE :05/s2/86 :05/n,/86 :05//2/86 .:.04_____:___)Ad____:..___..___:____
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OFFICIAL RECORD COPY
June 17, 1986 MEMORANDUM FOR: Harold R. Denton, Director Office of Nuclear Reactor Regulation James M. Taylor, Director Office of Inspection and Enforcement Robert B. Minogue, Director Office of Nuclear Regulatory Research Thomas E. Murley, Regional Administrator, Region I J. Nelson Grace, Regional Administrator, Region II James G. Keppler, Regional Administrator, Region III Robert D. Martin, Regional Administrator, Region IV John B. Martin, Regional Administrator, Region V FROM: C. J. Heltemes, Jr. , Director Office for Analysis and Evaluation of Operational Data
SUBJECT:
PRELIMINARY CASE STUDY REPORT--0PERATIONAL EXPERIENCE INVOLVING LOSSES OF ELECTRICAL INVERTERS The Office for Analysis and Evaluation of Operational Data has performed a study of reported operating events involving losses of electrical-inverters.
The study primarily addresses events which occurred during calendar years 1982, 1983, and 1984. Our enclosed preliminary report-documents the review and evaluation of these events. Based on this review, the study concludes that a major contributing cause for the occurrence of many of these events was incom-patibility between actual plant service conditions and the service conditions assumed in the design for these units. The two parameters which appear to be dominant contributors to failure are high ambient temperature and/or humidity within inverter enclosures, and voltage spikes and perturbations at inverter terminals. Other contributing factors or causes are inadequate maintenance and testing procedures or inappropriate personnel actions. The study also. finds that technical specifications which address inverters and/or attendant buses for comparable plant designs are not consistent. In addition, inverter-related operating experiences indicate that a portion of the electrical circuitry l
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Multiple Addresses -2 associated with a specific type of reactor protection system should be reassessed for acceptability. Our preliminary report contains specific recommendations which are aimed at addressing these items.
In accordance with AE0D's " peer review" process, prior to the finalization and distribution of our case study reports, we are providing a copy of the pre-liminary 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, systems operation or sequence of events is in error. Therefore, your comments are being solicited on the technical accuracy of the report. The findings, conclusions, and recommendations are provided for your information in order that you may understand the significance which AE0D places on this issue and therefore obtain a more complete picture of the total report. We would welcome comments either informally by phone or formally 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 i
report. Should your office require some additional time beyond that point, please let us know, otherwise it will be assumed that there are no comments.
We are also placing a copy of the preliminary report in the Public Document Room. If you or your staff have any questions relating to this report, please contact Frank Ashe of my staff. Mr. Ashe can be reached at 301/492-4442.
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C.J. N &
1 C. J. Heltemes, Jr. , Director Office for Analysis and Evaluation of Operational Data
Enclosure:
As stated cc w/ enclosure:
I. Villalva, RI, Lacrosse V. Thomas, IE T. Gibbons, RII D. Falconer, RII i
- 0. Chopra, NRR q-D. Thatcher, NRR Distribution PDR MChiramal FHebdon AE0D CF SRubin CHeltemes ROAB CF KBlack ROAB SF WLanning FAshe Chief, PTB 0FC :ROAB y, A, :5C:ROAB J : AC:ROAB : DD:AEOD : D:AEOD : :
_____:____________:________ g :__________ .:____________:____________:____________:___________
NAME :FAshe:as :MChiramal : SDRubi -
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_____: ___________:__________e :____________: .
DATE :05/a /86 :05/12./86 : 05/12/86 : 0 s/86 : 0E 6 : :
0FFICIAL RECORD COPY