05000220/FIN-2013002-04
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Finding | |
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Title | Inadequate Procedure Change Review Results in Reactor Scram |
Description | A self-revealing finding (FIN) was identified for Constellations failure to perform a cross-disciplinary engineering review in 2003, as required by station procedures, of the amplidyne excitation system operation setting. On September 20, 2012, Unit 1 experienced electrical oscillations at the main generator that required operators to take the automatic voltage regulator (AVR) from automatic to manual. As a result of the incorrect amplidyne operation setting at 10 to 20 volts boost, operators were unsuccessful at mitigating the electrical oscillations at the main generator, ultimately leading to a reactor scram. Constellation entered this issue into their CAP as CR-2012-008673. This finding is more than minor because it is associated with the equipment performance attribute of the Initiating Events cornerstone and affected the cornerstone objective of limiting the likelihood of those events that upset plant stability and challenge critical safety functions during power operations. Specifically, contrary to procedures NIP-PRO-04, Procedure Change Evaluations and Future Procedure Enhancements, Revision 14, and NIP-PRO-03, Preparation and Review of Technical Procedures, Revision 14, Constellation failed to perform a cross-disciplinary engineering review to identify the inadequate amplidyne operation setting. As a result, the default set point of the AVR was not correct, and when electrical oscillations occurred at the Unit 1 main generator on September 20, the main generator became under excited when the AVR was placed in manual, resulting in a reactor scram. This finding was evaluated in accordance with IMC 0609.04, Initial Characterization of Findings, and Exhibit 1 of IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power, issued June 19, 2012. The inspectors determined that this finding is of very low safety significance (Green) because while the performance deficiency caused a reactor scram, it did not result in the loss of mitigation equipment relied upon to transition the plant from the onset of the trip to a stable shutdown condition. The inspectors did not assign a cross-cutting aspect to this finding because the performance deficiency is not indicative of present performance because it did not occur within the last 3 years. |
Site: | Nine Mile Point |
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Report | IR 05000220/2013002 Section 4OA3 |
Date counted | Mar 31, 2013 (2013Q1) |
Type: | Finding: Green |
cornerstone | Initiating Events |
Identified by: | Self-revealing |
Inspection Procedure: | IP 71153 |
Inspectors (proximate) | D Schroeder K Kolaczyk B Haagensen J Laughlin T Ziev B Dionne E Miller |
INPO aspect | |
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Finding - Nine Mile Point - IR 05000220/2013002 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Nine Mile Point) @ 2013Q1
Self-Identified List (Nine Mile Point)
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