05000410/FIN-2015003-01
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Finding | |
|---|---|
| Title | Use of Incorrect Grounding Cart Results in Loss of Electrical Bus |
| Description | The inspectors identified a self-revealing Green finding (FIN) for Exelon Generation Company, LLC (Exelon) personnels failure to stop when met with unexpected conditions as required by procedure HU-AA-101, Human Performance Tools and Verification Practices. On August 21, 2015, a Unit 2 division of normal switchgear was unintentionally deenergized which required an unplanned down power to 90 percent and special operating procedure entry. The loss of the switchgear was the result of installation of an incorrect sized grounding cart in the electric fire pump breaker cubicle during breaker maintenance. Use of the correct sized grounding cart was discussed during the pre-job brief. This resulted in the loss of the electric fire pump, half of the drywell coolers, a heater drain pump, and unplanned reactivity change. Exelon entered this issue into their corrective action program (CAP) for resolution and developed corrective actions which included developing procedures for the use of grounding carts and evaluating where other skill-of-the-craft work may pose the same risk. This finding is more than minor because it is associated with the human 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. 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, the inspectors determined that this finding is of very low safety significance (Green). The finding has a cross-cutting aspect in the area of Human Performance, challenge the unknown, because Exelon personnel failed to stop when faced with uncertain conditions. Specifically, after having been briefed on the different stab sizes for 1200 amp and 2000 amp grounding carts, Exelon personnel failed to stop and notify supervision when faced with unlabeled grounding carts stored in the same location, Exelon personnel failed to notify supervision or compare stab sizes to ensure the correct grounding cart was used. |
| Site: | Nine Mile Point  |
|---|---|
| Report | IR 05000410/2015003 Section 4OA3 |
| Date counted | Sep 30, 2015 (2015Q3) |
| Type: | Finding: Green |
| cornerstone | Initiating Events |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | B Bollinger C Franklin C Graves D Schroeder E Miller G Stock K Kolaczyk N Floyd S Hammann |
| CCA | H.11, Challenge the Unknown |
| INPO aspect | QA.2 |
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Finding - Nine Mile Point - IR 05000410/2015003 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Nine Mile Point) @ 2015Q3
Self-Identified List (Nine Mile Point)
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