05000338/FIN-2015001-01
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Finding | |
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| Title | Failure To Follow Procedure For RWST Instruments |
| Description | A self-revealing NCV of 10 CFR 50 Appendix B, Criterion V, Instructions, Procedures, and Drawings, was identified for the licensees failure to follow work management procedures. Specifically, the licensee failed to follow the conduct of maintenance procedure, MM-AA-100, Conduct of Maintenance, Revision 10, where maintenance personnel should use an assortment of techniques and tools to avoid errors during work execution. Attachment 6 step 1b outlines various human error prevention techniques that should have been used during the work execution including self checking and questioning attitude. This issue was entered this into the licensees corrective action program as CR 567185. The licensees failure to follow the conduct of maintenance procedure, MM-AA-100, Conduct of Maintenance, Revision 10, was a performance deficiency. Specifically, on December 10, 2014, maintenance personnel failed to effectively use human error prevention tools when performing the maintenance on the Refueling Water Storage Tank (RWST) level channels which resulted in a loss of the safety function of the Recirculation Spray (RS) system. The performance deficiency was more than minor because it was associated with the configuration control attribute of the Barrier Integrity cornerstone and adversely affected the cornerstone objective to ensure that the physical design barriers (fuel cladding, reactor coolant system, and containment) protect the public from radionuclide releases caused by accidents or events and is therefore a finding. Specifically, the RS system safety function was inadvertently rendered inoperable. The inspectors performed a Phase 1 analysis using the IMC 0609, Appendix A, The Significance Determination Process (SDP) for Findings At- Power , Exhibit 3 Barrier Integrity Screening Questions, dated June 19, 2012 and Appendix H, Containment Integrity Significance Determination Process, dated May 6, 2004, and determined the finding required a detailed risk evaluation because it involved the loss of safety function of the RS system. A detailed risk evaluation was performed in accordance with NRC Inspection Manual Chapter (IMC) 0609, Appendix A by a regional senior reactor analyst using the latest NRC North Anna SPAR model and Saphire risk program. The major analysis assumptions included: a thirty-two minute exposure interval, and a non-recoverable loss of both inside recirculation spray pumps and both outside recirculation pumps. The dominant risk sequence was a small break loss of coolant accident initiator, success of the reactor protection system, success of feedwater, success of high pressure injection, success of secondary side cooldown and failure of recirculation spray resulting in loss of core and containment heat removal capability. The risk was mitigated by the short exposure period. The risk evaluation result was an increase in core damage frequency of <1 E-6/year and an increase in large early release fraction of <1 E -7/year, a GREEN finding of very low safety significance. The finding has a cross-cutting aspect in the area of human performance associated with the work management attribute because the organization failed to implement a process of planning, controlling, and executing work activities such that nuclear safety is the overriding priority. Furthermore, the licensee work process control includes the identification and management of risk commensurate to the work and the need for coordination with different groups or job activities. Specifically, due to poor communication and coordination between the Control Room and the technicians calibrating the RWST level channels, and amongst the team of technicians calibrating the RWST level transmitters, the RS system was inoperable. |
| Site: | North Anna  |
|---|---|
| Report | IR 05000338/2015001 Section 1R12 |
| Date counted | Mar 31, 2015 (2015Q1) |
| Type: | NCV: Green |
| cornerstone | Barrier Integrity |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71111.12 |
| Inspectors (proximate) | G Kolcum R Carrion R Hamilton S Rose T Skaggs-Ryan |
| Violation of: | 10 CFR 50 Appendix B Criterion V |
| CCA | H.5, Work Management |
| INPO aspect | WP.1 |
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Finding - North Anna - IR 05000338/2015001 | |||||||||||||||||||||||||||||
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Finding List (North Anna) @ 2015Q1
Self-Identified List (North Anna)
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