05000254/FIN-2012003-01
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Finding | |
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| Title | Bus Energized With Grounding Device Installed |
| Description | A finding of very low safety significance with an associated NCV of TS 5.4.1.a, Procedures, was self-revealed on March 24, 2012, when operators energized an electrical bus in the switchyard with a grounding device still installed on that bus. OP-AA-109-101, Clearance and Tagging, and have operations place a danger tag on a grounding strap installed on 345 kV Bus 9 resulted in a significant voltage perturbation and operating transient on Unit 1. The licensee entered the issue in the CAP as IR 1345302 and immediate actions included clearing the fault and restoring plant equipment. Individual qualifications were removed for parties involved in the event, and a root cause evaluation was performed. The finding was determined to be more than minor because it impacted the Human Performance attribute of the Initiating Events Cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, the Human Performance attribute was challenged because the human error resulted in a voltage transient that produced an operational transient on Unit 1 and could have resulted in a more severe challenge to both units. The inspectors performed a SDP Phase 1 screening for the finding using IMC 0609, Table 4a, for the Initiation Events Transient Initiators and determined that the finding did not contribute to both the likelihood of a reactor trip and the likelihood that mitigation equipment or functions will not be available. The duration of the event, separation of divisional and emergency power supplies, and redundancy of equipment supplying safety functions were considered for this determination. Therefore, the finding screened as Green, or very low safety significance. The inspectors identified that this finding has a cross-cutting aspect in the area of Human Performance - Decision Making because both the station supervisor overseeing the electrical bus realignment and the clearance holder took action based on non-conservative assumptions that could easily have been validated before placing the electrical system at risk. |
| Site: | Quad Cities  |
|---|---|
| Report | IR 05000254/2012003 Section 1R20 |
| Date counted | Jun 30, 2012 (2012Q2) |
| Type: | NCV: Green |
| cornerstone | Initiating Events |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.2 |
| Inspectors (proximate) | R Orlikowski C Matthews M Ring D Jones J Mcghee B Cushman A Shaikh E Sanchez-Santiago |
| CCA | H.14, Conservative Bias |
| INPO aspect | DM.2 |
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Finding - Quad Cities - IR 05000254/2012003 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Quad Cities) @ 2012Q2
Self-Identified List (Quad Cities)
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