05000400/FIN-2013004-01
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Finding | |
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| Title | Failure to Compensate for a Blocked Open Fire Door |
| Description | The inspectors identified a Green non-cited violation (NCV) of the Shearon Harris Nuclear Power Plant Operating License NPF-63 condition 2.F, Fire Protection Program, and 10 CFR 50.48(c), National Fire Protection Association (NFPA) Standard 805, for failing to implement required compensatory measures per licensee procedure FPP-013, Fire Protection. Specifically, the licensee failed to establish an hourly fire watch and stage backup fire suppression equipment for a blocked open fire door (FD- 241) between the A and B safety related switchgear rooms on September 9, 2013. The licensee took corrective action by restoring the fire door to functional. The licensee entered this into the corrective action program (CAP) as Action Request (AR) #627493. The failure to implement fire compensatory measures in accordance with licensee procedure FPP-013, Fire Protection during the two hour exposure period when the fire door between Switchgear Rooms A and B was propped open was determined to be a performance deficiency. The performance deficiency was determined to be more than minor because it was associated with the protection against external factors (fire) attribute of the Mitigating Systems Cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, this failure inadvertently bypassed a three hour fire barrier and created the potential for a fire to affect both safety related switchgear rooms. The finding was screened in accordance with NRC Inspection Manual Chapter (IMC) 0609 attachment 4 which determined that an evaluation using NRC IMC 0609 Appendix F (Fire SDP) was required. The propped open door constituted a high degradation condition per NRC IMC 0609 appendix F Attachment 2 which required a detailed risk evaluation. A bounding phase 3 risk analysis was done by a regional SRA using a hand calculation and guidance from NRC IMC 0609 Appendix F. The major analysis assumptions included a duration factor of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, an ignition frequency of 2E- 2/year, a base case conditional core damage probability (CCDP) of 0.1 (assumed large single SWGR room fire would require alternate safe shutdown), a non-conforming case CCDP of 1.0 (assumed a dual SWGR fire scenario would result in core damage), and a probability of non-suppression (PNS) of 1E-3. The dominant sequence was a challenging SWGR room fire which remained unsuppressed long enough to develop into a damaging hot gas layer scenario which would fail SSD equipment in both SWGR rooms A and B due to the open fire door and result in core damage. The licensees fire PRA produced similar results. The short exposure period, ability to close the fire door, and the low PNS mitigated the risk. The analysis result was an increase in core damage of < 1E-6/year, a finding of very low safety significance (Green). The finding had a cross-cutting aspect of Work Planning, as described in the Work Control component of the Human Performance cross-cutting area because the licensee failed to identify the need for a compensatory action due to the blocked open fire door. |
| Site: | Harris  |
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| Report | IR 05000400/2013004 Section 1R05 |
| Date counted | Sep 30, 2013 (2013Q3) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.05 |
| Inspectors (proximate) | G Hopper J Rivera-Ortiz J Austin M Bates P Lessard |
| Violation of: | 10 CFR 50.48 |
| CCA | H.5, Work Management |
| INPO aspect | WP.1 |
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Finding - Harris - IR 05000400/2013004 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Harris) @ 2013Q3
Self-Identified List (Harris)
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