05000400/FIN-2014005-01
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Finding | |
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| Title | Failure to Adequately Implement the Equipment Clearance Procedure |
| Description | The NRC identified a Green non-cited violation (NCV) of Technical Specification (TS) 6.8.1, Procedures and Programs, for the licensees inadequate implementation of procedure OPS-NGGC-1301, Equipment Clearance, when they failed to identify required compensatory measures for a clearance to support installation of a plant modification. This resulted in an unanalyzed condition with no compensatory measures for internal flooding. The licensee entered this into the corrective action program (CAP) as Action Request (AR) #696331 and AR #726784 and took immediate corrective actions to restore the sump pumps to their design configuration. The licensees failure to adequately implement Procedure, OPS-NGGC-1301, Equipment Clearance, Section 9.8, step 3 was a performance deficiency. Specifically, if an internal flood had occurred in the Diesel Fuel Oil Storage Tank (DFOST) building during this period, it could have resulted in both trains of the safety-related fuel oil transfer pumps being inoperable. The performance deficiency was more than minor because it is associated with the Human Performance Attribute of the Mitigating Systems cornerstone and it adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences (i.e., core damage). Using Manual Chapter 0609, Significance Determination Process, Appendix A, Exhibit 2 Mitigating Systems Screening Question, Section B, and Exhibit 4, the finding was determined to require a detailed risk evaluation because the loss of this equipment during an internal flooding initiating event would degrade two or more trains of a multi-train system that supports a risk significant system or function. A detailed risk evaluation was performed by a regional senior risk analyst in accordance with the guidance of NRC IMC 0609 Appendix A, using the Shearon Harris Standardized Plant Analysis Risk (SPAR) model. The major analysis assumptions included: A 28-hour exposure period, the finding was modelled as a non-recoverable common cause failure to run of the Emergency Diesel Generators (EDG), pipe failures of fire protection piping was assumed to result in EDG inoperability and pipe failure data was taken from Electric Power Research Institute (EPRI) Pipe Failure Frequencies for Internal Flooding PRAs, Revision 1. The dominant sequence was a station blackout with auxiliary feedwater system failure and no recovery of the EDGs or offsite power leading to loss of core heat removal and core damage. The risk was mitigated by the short exposure period and the low probability of pipe ruptures resulting in EDG inoperability. The analysis determined that the finding led to an increase of core damage frequency of <1E-6/year, a Green finding of very low safety significance. The finding had a crosscutting aspect of Challenge the Unknown, as described in the area of Human Performance because the licensee allowed the clearance order (CO) to be hung in the plant without properly evaluating and managing the associated risk through the use of compensatory measures (H.11). |
| Site: | Harris  |
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| Report | IR 05000400/2014005 Section 1R15 |
| Date counted | Dec 31, 2014 (2014Q4) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | G Hopper J Austin J Rivera P Lessard |
| Violation of: | Technical Specification - Procedures Technical Specification |
| CCA | H.11, Challenge the Unknown |
| INPO aspect | QA.2 |
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Finding - Harris - IR 05000400/2014005 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Harris) @ 2014Q4
Self-Identified List (Harris)
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