05000220/FIN-2012005-01
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Finding | |
|---|---|
| Title | Failure to Develop Adequate Inspection Requirements for Main Transformer Modification Results in Reactor Scram |
| Description | A self-revealing Green finding (FIN) was identified for Nine Mile Point Nuclear Station, LLC. (NMPNSs) failure to develop adequate inspection requirements for the Unit 1 main transformer replacement. As a result, improper configuration of the main transformer current transformers (CT) 11 and 12 bus bars went undetected. On October 29, 2012, the improper configuration of the CT bus bars combined with an electrical transient due to a lightning arrestor collapse in the 345kV switchyard resulted in a reactor scram. Following the scram, an investigation revealed the improper configuration of the CT bus bars. NMPNS took immediate corrective actions to correct the configuration of the CT 11 and 12 bus bars. NMPNS entered the issue into their corrective action program (CAP) as condition report (CR)-2012-009820. This finding is more than minor because it adversely affected the design control 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. The 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 finding has a cross-cutting aspect in the area of human performance, work practices, because NMPNS did not ensure proper supervisory or management oversight of the Unit 1 main transformer replacement. Specifically, NMPNS failed to ensure proper oversight of the main transformer modification by not developing adequate inspection requirements, as required by NEP-DES-09, Engineering Specification. |
| Site: | Nine Mile Point  |
|---|---|
| Report | IR 05000220/2012005 Section 1R04 |
| Date counted | Dec 31, 2012 (2012Q4) |
| Type: | Finding: Green |
| cornerstone | Initiating Events |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71111.04 |
| Inspectors (proximate) | D Dempsey K Kolaczyk G Dentel P Presby S Kennedy B Sienel M Schneider E Burket B Dionne E Miller |
| CCA | H.2, Field Presence |
| INPO aspect | LA.2 |
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Finding - Nine Mile Point - IR 05000220/2012005 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Nine Mile Point) @ 2012Q4
Self-Identified List (Nine Mile Point)
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