05000275/FIN-2013002-03
From kanterella
Jump to navigation
Jump to search
Finding | |
|---|---|
| Title | Failure to Effectively Evaluate Design Change for High Voltage Bushing |
| Description | The inspectors reviewed a Green self-revealing finding for failure to effectively and accurately evaluate all available resources to procure appropriate equipment for plant modifications. Specifically, design engineering staff was not effective in using applicable station design documents, in conjunction with industry standards to determine minimum creepage distance for high voltage insulators when replacing ceramic bushings with polymer bushings on the main bank transformer. As a result, the licensee approved installation of an insulator stack that did not provide adequate ground protection, which caused a plant trip on October 11, 2012. The licensee entered the condition in their corrective action program as Notification 50518473. Failure to effectively and accurately evaluate all available resources to procure appropriate equipment for plant modifications was a performance deficiency. The performance deficiency was more than minor because it was associated with the design control attribute of the Initiating Events cornerstone and adversely affected the cornerstone objective to limit the likelihood of events that upset plant stability and challenged critical safety functions during power operations, and is therefore a finding. Using Inspection Manual Chapter 0609, Attachment 4, Initial Characterization of Findings, and Appendix A, Exhibit 1, Initiating Events Screening Questions, this finding was determined to be of very low safety significance (Green) because, although it resulted in a reactor trip, it did not result in the loss of mitigating equipment relied upon to transition the plant from the onset of the trip to a stable shutdown condition. This finding had a cross-cutting aspect in the area of human performance, associated with the decision making component, because the licensee did not use conservative assumptions in decision making when considering the suitability of the design for the environment. |
| Site: | Diablo Canyon  |
|---|---|
| Report | IR 05000275/2013002 Section 1R18 |
| Date counted | Mar 31, 2013 (2013Q1) |
| Type: | Finding: Green |
| cornerstone | Initiating Events |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.18 |
| Inspectors (proximate) | L Ricketson N O'Keefe T Hipschman J Laughlin I Anchondo P Jayroe L Micewski D You |
| CCA | H.14, Conservative Bias |
| INPO aspect | DM.2 |
| ' | |
Finding - Diablo Canyon - IR 05000275/2013002 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Diablo Canyon) @ 2013Q1
Self-Identified List (Diablo Canyon)
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||