05000266/FIN-2010008-03
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Finding | |
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| Title | Appendix R Fire Scenario Resulting in Safe-Shutdown Required Capability Not Maintained |
| Description | The following finding that affects 10 CFR 50.48 was identified by the licensee and is a violation of NRC requirements. This finding has been screened and determined to warrant enforcement discretion per the Interim Enforcement Policy Regarding Enforcement Discretion for Certain Fire Protection Issues. A violation of 10 CFR Part 50, Appendix R, Section III.G.2 was identified by the licensee for the failure to ensure safe-shutdown capability for Unit 1. Specifically, the licensee identified that, due to inadequate cable separation, there was a potential for a fire in the Auxiliary Feedwater (AFW) room to propagate to the vital switchgear room, causing a fire in two separate fire areas the loss of all AFW decay heat removal capability for Unit 1. In June 2008 an inadequate cable separation condition was identified by the licensee while performing an NFPA 805 applicability review. As a result of the inadequate cable separation, the potential was identified for a fire in Fire Area A23S, (south area of the AFW room) to propagate to Fire Area A24 (vital switchgear room). A fire in the (south area of the AFW room) could cause a short circuit in a cable that traversed the AFW room and the (vital switchgear room) causing ignition of the cable. The licensee determined that a fire in areas A23S and A24 could cause three of the four AFW pumps to be unavailable, which did not meet the requirements for Appendix R, safe-shutdown capability for Unit 1. A fire in area A23S was assumed to damage the two AFW pumps within the area, pump 1P29 (turbine-driven AFW pump) and pump P38A (electric-driven AFW pump). A postulated secondary fire in area A24 was assumed to damage circuits for pump P38B (electric-driven pump). Under these circumstances, no AFW pump would have been available to satisfy a 10 CFR Part 50, Appendix R safe shutdown function (decay heat removal) for Unit 1. The licensee reported this deficiency in LER 2008-003-00. The licensee identified that the direct current (DC) control power for switchgear breakers were located in the same fire area (A23S) as the respective power cables. A fire in A23S could first disable the respective bus 125 DC breaker control power and short circuit the associated power cable. With the loss of breaker control, the power cable protection would be defeated. The cable damage sequence assumed that a secondary fire would occur electrically upstream of the fault location (in fire area A24) due to the cable-withstand rating being exceeded. The licensee completed an extent of condition evaluation in March 2009 that identified six areas where an inadequate cable separation condition could potentially result in a loss of significant equipment in areas beyond that postulated in the initiating fire area. The result of this evaluation was documented in LER 2008-003-01. Following the identification of this issue, the licensee implemented corrective actions (AR 1131517) that included establishing twice-per-shift fire rounds in the affected fire areas, performing thermographs of equipment in the affected zones, and providing additional guidance for enhancing the transient combustibles and hot work controls. |
| Site: | Point Beach  |
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| Report | IR 05000266/2010008 Section 4OA3 |
| Date counted | Jun 30, 2010 (2010Q2) |
| Type: | Violation: Severity level Enforcement Discretion |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | R Daley R Langstaff A Dahbur C Moore D Passehl L Jones |
| INPO aspect | |
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Finding - Point Beach - IR 05000266/2010008 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Point Beach) @ 2010Q2
Self-Identified List (Point Beach)
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