05000338/FIN-2013005-01
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Finding | |
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| Title | Failure to Follow Work Instructions for the Replacement of Protective Relays Causes a Unit 1 Reactor Trip Due to Loss of Station Service Bus Transformer After Start of 1C Condensate Pump |
| Description | A Green, self-revealing finding was identified for failure to follow procedure for the replacement of protective relays that resulted in a Unit 1 trip. Specifically, the instructions in work order (WO) 59102618778 stated to Have Control Ops install shorting screws for CT circuit, and Have Control Ops remove shorting screws for CT circuit. Maintenance personnel failed to remove the current transformer terminal block shorting screws installed inside the 1C switchgear breaker 15C2 cubicle and caused the turbine to trip and the reactor to trip from the loss of the 1C station service transformer after the start of the C condensate pump. This was entered into the licensees CAP as CR528984. The inspectors determined that the licensees failure to follow work instructions in WO59102618778 which stated to Have Control Ops install shorting screws for CT circuit, and Have Control Ops remove shorting screws for CT circuit for the replacement of protective relays was a performance deficiency. The performance deficiency was more than minor because it was associated with the Initiating Events cornerstone attribute of equipment performance and adversely affected the associated cornerstone objective in that maintenance personnel left the current transformer terminal block shorting screws installed inside the 1C switchgear breaker cubicle which caused the turbine trip and subsequent reactor trip from the loss of the 1C station service transformer after the start of the C condensate pump. Using Inspection Manual Chapter 0609, Attachment 4, Initial Characterization of Findings, issued June 19, 2012, the finding was determined to be of very low safety significance (Green) because it was a transient initiator, but did not contribute to both the likelihood of a reactor trip and the likelihood that mitigation equipment or functions would not be available. In addition, this finding involved the cross cutting area of human performance, the component of resources, and the aspect of complete, accurate, and an up-to-date work instructions, H.2(c), because the work order job steps did not contain adequate means for documenting the installation and removal of shorting screws, which resulted in a loss of configuration control for the 1C switchgear 15C2 breaker cubicle. |
| Site: | North Anna  |
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| Report | IR 05000338/2013005 Section 4OA2 |
| Date counted | Dec 31, 2013 (2013Q4) |
| Type: | Finding: Green |
| cornerstone | Initiating Events |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71152 |
| Inspectors (proximate) | D Bacon G Kolcum J Laughlin J Reece K Miller M King R Clagg |
| CCA | H.7, Documentation |
| INPO aspect | WP.3 |
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Finding - North Anna - IR 05000338/2013005 | ||||||||||||||||||||||||||||||||||||||
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Finding List (North Anna) @ 2013Q4
Self-Identified List (North Anna)
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