ML20202H590
| ML20202H590 | |
| Person / Time | |
|---|---|
| Issue date: | 06/17/1986 |
| From: | Heltemes C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Lyon P INSTITUTE OF NUCLEAR POWER OPERATIONS |
| Shared Package | |
| ML20202H594 | List: |
| References | |
| NUDOCS 8607160377 | |
| Download: ML20202H590 (2) | |
Text
_ _ _ _
June 17 1986 Mr. Peter W. Lyon, Group Vic.9 President Analysis and Engineering Institute of Nuclear Power Operations 1100 Circle 75 Parkway, Suite 1500 Atlanta, Georgia 30339
Dear Mr. Lyon:
Subject:
Preliminary Case Study Report--Operational Experience Events 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 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 incompati-bility 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 unit designs are not consistent. In addition, inverter related operating experiences indicate that a portion of the electrical circuitry associated with a specific type of reactor protection I system should be reassessed for acceptability. Our preliminary report contains specific recommendations which are aimed at addressing these items.
The purpose of this letter is to provide you with the opportunity to review the report, particularly with regard to its completeness and accuracy, prior to the issuance of the AE0D final report. Changes to the findings, conclusions, and recommendations will be considered only if the underlying information concerning the details of the plant design, systems operation or sequence of events is in error. Therefore, 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 under-stand the significance AE0D places on this issue and therefore obtain a more complete picture of the total report.
8607160377 G60617 l PDR ORG NEXD l PDR J
Mr. Peter W. Lyon -2 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 positicn 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 pre * :ninary report and this letter are being placed in the Public Document Room 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, i
oneinalusaed av
- c. J. Heitemos, Jr.
C. J. Heltemes, Jr., Director Office for Analysis and Evaluation of Operational Data
Enclosure:
As stated Distribution PDR AE0D CF AE0D SF ROAB CF ROAB SF FAshe MChiramal SRubin i KBlack WLanning Chief, PTB FHebdon CHeltemes OFC :ROAB p, g , :SC:ROAB :AC:ROAB :DD:AEOD : D:AEOD : :
_____:____________:________3 6c:________ __:____________:____________:-___________:-__________
NAME :FAshe:as :MChiramal :SRubin :FHebdon : CHeltemes : :
DATE :05/a/86 :05/lL/86 :05//2,/86 :0# %/96 : 05/EN86( : :
V OFFICIALRECORD'DQ l
l
. _ _ _ . _ . _ _ _ _ . _ _ _ . _ _ _ _ _ _ . _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ . _ - . _ _ _ _ _ _ _ _ _ . - _ _ _ _ _ _ . _ _ _ _ . . _ . . . _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ . _ _ _ __