ML20207N272
| ML20207N272 | |
| Person / Time | |
|---|---|
| Issue date: | 01/12/1987 |
| From: | Heltemes C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Beckjord E, Grace J, Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I), NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II), NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| Shared Package | |
| ML18041A146 | List: |
| References | |
| AEOD-C605, NUDOCS 8701140091 | |
| Download: ML20207N272 (6) | |
Text
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!roa N UNITED STATES NUCLEAR REGULATORY COMMISSION N WASHINGTON. D. C. 20555 e .*
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JAN 12 ..._ AE00/C605 MEMORANDUM FOR: Eric S. Beckjord, 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 i 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:
CASE STUDY REPORT - OPERATIONAL EXPERIENCE INVOLVING LOSSES OF ELECTRICAL INVERTERS
-The Office for Analysis and Evaluation of Operational Data (AE0D) has finalized its case study report on operational experience involving losses of electrical inverters. The report addresses the peer review comments provided by NRR, RES, the Regions, INP0, and Brookhaven National Laboratory. The final report also includes a brief analysis and evaluation of inverter loss events that occurred in calendar year 1985 which was not included in the preliminary report. We have enclosed a copy of our final report for your information and use as you may deem appropriate.
The study was initiated based primarily on the observation of a lack of overall
- industry-wide improvement in the operational performance of safety and nonsafety-l related inverters. The study indicates that events involving inverter losses l raises two principal concerns: (1) increased frequency of plant transients, and l (2) inoperable or improper functioning of both safety-related and other important plant equipment.
Based on a review of events which occurred during calendar years 198?, 1983, and 1984, the study concludes that a major contributing cause for inverter loss events is incompatibility between the actual equipment service conditions and the service conditions assumed in the design of these units. The two factors which appear to be dominant contributors to such failures are high ambient temperature and/or humidity within inverter enclosures and voltage spikes and perturbations at inverter terminals. The study notes that these two factors have potential common cause implications. Other contributing factors or causes are inadequate maintenance and testing procedures or inappropriate personnel actions. In addition, the study finds that technical specifications
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> that address inverters and/or attendant buses for comparable plant designs are not consistent. Further, inverter-related operating experiences indicate that a portion of the electrical circuitry associated with the Westinghouse Reactor Protection System (SSPS) should be reassessed for acceptability. The enclosed report contains specific recommendations to address the study's findings and conclusions. A separate memorandum is being sent to NRR and IE requesting consideration of these recommendations.
If you have any questions regarding this report, please contact Frank Ashe of my staff. Mr. Ashe can be reached at 492-4442.
capasi sened by
- c. J. Hemames,Jr.
C. J. Heltemes, Jr., Director Office for Analysis and Evaluation of Operational Data
Enclosure:
As stated cc w/ enclosure:
D. Ross, RES S. Aggarwal, RES S. Ebneter, RI C. Anderson, RI T. Gibbons, RII D. Falconer, RII C. Paperiello, RIII D. Hunnicutt, RIV J. Crews, RV cc w/o enclosure:
D. Humenansky, OCM Distribution:
POR S. Rubin AE00 CF M. Chiramal AE0D SF F. Ashe ROAB CF M. Williams ROAB SF K. Black J. Heltemes W. Lanning F. Hebdon
- See next' sheet for previous concurrence OFC : AEOD:ROAB : AE00:ROAB : AEOD:ROAB : AEO(:DD : AE0D:D : :
_____:..._________:.____ ._____:___________.:____g.__.___:_. gg.._:.__________:.__________
NAME : FAshe:cg : MChiramal : SRubin : FHebdon : CJ. Itemes : :
DATE : 12/ 10/86 * : 12/ 19/86 * : 12/ 19/86* : 12/31/86 : 12/3l/86 : :
OFFICIAL RECORD COPY
, Multiple Addressees which address inverters and/or attendant buses for comparable plant designs are not consistent. Further, inverter-related operating experiences indicate that a portion of the electrical circuitry associated with the Westinghouse Reactor Protection System should be reassessed for acceptability. The enclosed report contains specific recommendations to address the study's findings and conclu-sions. A separate memorandum is being sent to NRR and IE requesting considera-tion of these recommendations.
If you have any questions regarding this report, please contact Frank Ashe of my staff. Mr. Ashe can be reached at 492-4442.
C. J. Heltemes, Jr. , Director Office for Analysis and Evaluation of Operational Data
Enclosure:
As stated cc w/ enclosure:
D. Ross, RES S. Aggarwal, RES S. Ebneter, RI C. Anderson, RI T. Gibbons, RII D. Falconer, RII C. Paperiello, RIII D. Hunnicutt, RIV J. Crews, RV cc w/o enclosure:
D. Humenansky, OCM l
Distribution: e PDR S. Rubin AE0D CF M. Chiramal AE00 SF F. Ashe ROAB CF M. Williams ROAB SF K. Black J. Heltemes W. Lanning F. Hebdon 0FC : AEOD:ROAB : AEOD:ROAB : AEOD:ROAB : AE00:DD : AE00:D : :
_ _ _ _ _ : _ _ .L A t . . _ _ _ : k, NAME : FAshe:cg : MChiramal : : FHebdon : CJHeltemes :
SRubink:___________:..._________:_______
DATE : 12/4 /86 : 12/11/86
- 12/N/86 : 12/ /86 : 12/ /86 : :
0FFICIAL RECORD COPY
gllS AE0D/C605 MEMORANDUM FOR: Eric S. Beckjord, 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:
CASE STUDY REPORT - OPERATIONAL EXPERIENCE INVOLVING LOSSES OF ELECTRICAL INVERTERS The Office for Analysis and Evaluation of Operational Data (AE0D) has finalized its case study report on operational experience involving losses of electrical inverters. The report addresses the peer review comments provided by NRR, RES, the Regions, INPO, and Brookhaven National Laboratory. The final report also includes a brief analysis and evaluation of inverter loss events that occurred in calendar year 1985 which was not included in the preliminary report. We have enclosed a copy of our final report for your information and use as you may deem appropriate.
The study was initiated based primarily on the observation of a lack of overall industry-wide improvement in the operational performance of safety and nonsafety-related inverters. The study indicates that events involving inverter losses raises-two principal concerns: (1) increased frequency of plant transients, and (2) inoperable or improper functioning of both safety-related and other important plant equipment.
Based on a review of events which occurred during calendar years 1982, 1983, and 1984, the study concludes that a major contributing cause for inverter loss events is incompatibility between the actual equipment service conditions and the service conditions assumed in the design of these units. The two factors which appear to be dominant contributors to such failures are high
, ambient temperature and/or humidity within inverter enclosures and voltage i spikes and perturbations at inverter terminals. The study notes that these two factors have potential common cause implications. Other contributing factors or causes are inadequate maintenance and testing procedures or inappropriate personnel actions. In addition, the study finds that technical specifications
k 2
that address inverters and/or attendant buses for comparable plant designs are not consistent. Further, inverter-related operating experiences indicate that a portion of the electrical circuitry associated with the Westinghouse Reactor Protection System (SSPS) should be reassessed for acceptability. The enclosed report contains specific recommendations to address the study's findings and conclusions. A separate memorandum is being sent to NRR and IE requesting consideration of these recommendations.
If you have any questions regarding this report, please contact Frank Ashe of my staff. Mr. Ashe can be reached at 492 4442. ,
s ow senedtw C.J. Mensmos,Jr.
C. J. Heltemes, Jr. , Director Office for Analysis and Evaluation of Operational Data
Enclosure:
As stated cc w/ enclosure:
D. Ross, RES S. Aggarwal, RES S. Ebneter, RI C. Anderson, RI T. Gibbons, RII D. Falconer, RII C. Paperiello, RIII
D. Hunnicutt, RIV J. Crews, RV cc w/o enclosure:
D. Humenansky, OCM Distribution: ,
PDR S. Rubin AE00 CF M. Chiramal AE0D SF F. Ashe ROAB CF M. Williams ROAB SF K. Black J. Heltemes W. Lanning F. Hebdon
- See next' sheet for previous concurrence OFC : AEOD:ROAB : AE00:ROAB : AEOD:ROAB : AE0 :DD : AE00:0 : :
____ :....__......:.... _______._______. ___..... ______.__ gr..._:......______:.______....
NAME : FAshe:cg : MChiramal : SRubin : FH don : CJ ltemes : :
DATE : 12/ 18/86 * : 12/ 19/86* : 12/ 19 / 86* : 12/31/86 : 12/3 l'86 : :
OFFICIAL RECORD COPY
Multiple Addrasstes -2 which address inverters and/or attendant buses for comparable plant'de igns are not consistent. Further, inverter-related operating experiences indicate that a portion of the electrical circuitry associated with the Westinghouse Reactor Protection System should be reassessed for acceptability. T_he enclosed report contains specific recommendations to address the study's findings and conclu-sions. A separate memorandum is being sent to NRR and IE/ requesting considera-tion of these recommendations.
If you have any questions regarding this report, se contactplea Frank
/ Ashe of my staff. Mr. Ashe can be reached at 492-4442. '
/
C. J[ Heltemes, Jr. , Director Office for Analysis and Evaluation
/of Operational Data
/
Enclosure:
j As stated j
/
CC W/ enclosure: /
D. Ross, RES S. Aggarwal, RES S. Ebneter, RI
/
C. Anderson, RI /
T. Gibbons, RII ,
D. Falconer, RII 4 C. Paperiello, RIII j' D. Hunnicutt, RIV /
J. Crews, RV ,'
cc w/o enclosure: /
D. Humenansky, OCM /
/
i /
Distribution:
PDR S. Rubin AE0D CF / M. Chiramal AE0D SF / F. Ashe R0AB CF M. Williams R0AB SF K. Black J. Heltemes W. Lanning F. Hebdon OFC : AEOD:ROAB : AE00:ROAB : AE00:ROAB : AEOD:DD : AEOD:D
_____:...L As. ____:_________ b ,____________: ___________:____________::____________:___________ :
NAME : FAshe:cg : MChiramal : FHebdon : CJHeltemes : :
SRubin{:
_____:.___________:____________:___________d:____________:____________:____________:___________
~DATE : 12/4/86 : 12/ti/86
- 12/N/86 : 12/ /86 : 12/ /86 : :
0FFICIAL RECORD COPY
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