05000338/FIN-2015004-03
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Finding | |
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| Title | Licensee-Identified Violation |
| Description | Procedure CM-AA-FPA-100, Fire Protection/Appendix R (Fire Safe Shutdown) Program, Revision 10, Attachment 2, Section 3.12, step n.1 states, Fire doors must be closed and latched at all times. Contrary to Section 3.12, step n.1 of CM-AA-FPA-100, the licensee failed to ensure the fire door to the ESGR was closed and latched at all times. Specifically, on October 7, 2015, when security personnel conducted their periodic round, the ESGR door, a fire boundary, was found to not be fully latched. The ESGR door, a HELB boundary, was determined to not be fully latched for approximately 46 minutes. This finding was identified by the license and entered in the licensees corrective action program as CR1012468. The inspectors performed a significance determination using NRC Inspection Manual 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, Exhibit 1 dated July 1, 2012. Because the Transient Initiator was a HELB that would impact both trains of mitigation equipment required to transition the plant to a stable shutdown condition, a detailed risk evaluation was required. A bounding risk evaluation was performed by a regional SRA which assumed that all pipe failures in turbine building high energy lines with enough energy to create a harsh environment would lead to failure of all equipment within the ESGR and result in a conditional core damage probability of 1.0. The systems considered were main steam, main steam drain, auxiliary steam, extraction steam, low pressure steam, blowdown, feedpump discharge and feedpump recirculation piping. Pipe mean failure rate data from EPRI report 102186 was used. No isolation of the pipe ruptures were assumed and no credit was allowed for operations to realize that a HELB had occurred and for closing the door. An exposure period of 46 minutes was utilized. The phase 3 SDP risk assessment determined the risk of the performance deficiency was an increase in core damage frequency of <1E-6, very low safety significance (Green). The short exposure period mitigated the risk of the performance deficiency. |
| Site: | North Anna  |
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| Report | IR 05000338/2015004 Section 4OA7 |
| Date counted | Dec 31, 2015 (2015Q4) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | Licensee-identified |
| Inspection Procedure: | |
| Inspectors (proximate) | B Bishop D Bacon G Croon G Kolcum S Rose |
| Violation of: | License Condition - Fire Protection |
| INPO aspect | |
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Finding - North Anna - IR 05000338/2015004 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (North Anna) @ 2015Q4
Self-Identified List (North Anna)
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