05000382/FIN-2009006-03
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Finding | |
|---|---|
| Title | Failure to ensure post-fire safe shutdown valves could be operated |
| Description | The team identified a violation of License Condition 2.C.9 related to the capability to complete required manual actions, following a control room fire, because of potential fire damage to some motor-operated valves. Specifically, the licensee failed to evaluate the susceptibility of fire damaging circuits in motor-operated valves that needed to be manually operated for post-fire safe shutdown. The licensee did not recognize that the circuits could cause the valves to become stuck. The team determined licensee personnel would not be able to reposition motor-operated valves as specified in plant procedures. The team determined this violation met the Interim Enforcement Policy Regarding Enforcement Discretion for Certain Fire Protection Issues (10 CFR 50.48) conditions for receiving enforcement discretion (EA-09-171). The licensee implemented their alternative shutdown for a control room fire in accordance with Procedure OP-901-502, Evacuation of Control Room and Subsequent Plant Shutdown, Revision 16. Procedure OP-901-502, Attachment 2, Step 4, required that operators close Valves MS-119A/B, Train A/B main steam isolation valve upstream drip pot startup drain valves, to prevent uncontrolled cool down of the plant. Also, Attachment 4, Step 5, required that operators open Valves BAM-113A/B, Train A/B boric acid make-up tank gravity feed valves, to provide a source of borated water to the reactor coolant system. The team determined that both attachments required operators to use the motor-operated valve hand wheel to manually reposition these valves in the event of a spurious actuation resulting from fire damage. The licensee identified these actions as time-critical in the event of a control room evacuation. Information Notice 92-18, Potential for Loss of Remote Shutdown Capability during a Control Room Fire, described the potential for fire damage to motor-operated valves to prevent operation following a control room evacuation. The information notice described that a valve without thermal overloads could be damaged and not be operated after a control room evacuation. The industry information further described the potential need to rewire circuits to ensure that a hot short would not bypass the torque and limit switches whether a valve had thermal overloads or not. Further, the information notice provided diagrams indicating how a circuit would allow damage and how to rewire the circuit to ensure the torque and limit switches continue to function if a hot short were to occur. The licensee documented their evaluation of Information Notice 92-18 in an internal memorandum dated March 17, 1993. The licensee evaluated whether the forces generated by the motor-actuator at locked rotor current, which would trip the thermal overload, exceeded forces the licensee determined would be needed to fail the motor-operated valve weak link under accident conditions. The licensee had performed valve weak link calculations so that they could modify the valves to withstand the forces generated under accident conditions. The team determined from interviews and review of the evaluation that these calculations demonstrated the motor-operated valves would not cause the failure of the pressure boundary. The licensee did not determine whether the forces generated with the motor-actuator at locked rotor torque would push the valve disc in the seat such that operators could not reposition the valve using the manual hand wheel. This condition would result if a hot short bypassed the torque switch, which could occur under the current control circuit configuration. The team determined that the licensee did not ensure that the required post-fire safe shutdown valves would remain functional as a result of a fire-induced hot short. The team determined that it was possible that the valve disc would be driven into the valve seat with such force that mechanical damage would occur and the valve would not be able to be repositioned, as required by post-fire safe shutdown procedures. The licensee documented this deficiency in Condition Reports 2009-02249 and 2009-02472. The team verified that the licensee had scheduled an evaluation of Information Notice 92-18 during their transition to National Fire Protection Association 805. After the team identified the deficiency in the existing evaluation, the licensee initiated the following actions: (1) confirming the population of post-fire safe shutdown valves affected; (2) performing further evaluations to determine whether they could open the valves manually using the hand wheel; (3) for any valve unable to be opened, the licensee will identify routing of the control cables through the plant; and (4) after identifying the cable routing, the licensee will use fire modeling to identify if the valves would be subjected to fire damage. The team determined the licensee will perform a risk evaluation, if needed, to total all contributions to core damage that result from this performance deficiency. The failure to ensure that safe shutdown equipment could be operated as required during control room fire events was a performance deficiency. The team determined that this finding was more than minor because it is associated with the protection against external factors attribute of the mitigating systems cornerstone and adversely affected the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Because this violation meets the discretion criteria of the Interim Enforcement Policy Regarding Enforcement Discretion for Certain Fire Protection Issues (10 CFR 50.48) for a noncompliance identified during the transition to National Fire Protection Association 805, the team determined that discretion to take no enforcement action is appropriate at this time, as described in the Enforcement Policy. License Condition 2.C.9 states EOI shall implement and maintain in effect all provisions of the approved fire protection program as described in the Final Safety Analysis Report for the facility and as approved in the Safety Evaluation Report. Final Safety Evaluation Report, Section 9.5.1.4.1 specifies alternate shutdown capability is provided that meets the criteria of Appendix R, Sections III.G.3 and III.L.Section III.L.3 specifies, in part, procedures shall be in effect to implement the alternative shutdown capability. Procedure OP-901-502, Attachment 2, Step 4, directs operators to close Valves MS-119A/B using the manual hand wheel. Attachment 4, Step 5 direct operators to open Valves BAM-113A/B. Contrary to the above, from February 1993 through May 22, 2009, the licensee failed to implement the requirements of License Condition 2.C.9, as specified in Final Safety Analysis Report, Section 9.5.1.4.1 and Appendix R,Section III.L.3. Specifically, the licensee failed to ensure that valves susceptible to fire damage could be manually operated as specified in Procedure OP-901-502, which implemented their alternate shutdown capability. Because the licensee committed to adopting National Fire Protection Association 805 and changing their fire protection program license basis to comply with 10 CFR 50.48(c), this issue is eligible for the enforcement discretion described in the Interim Enforcement Policy Regarding Enforcement Discretion for Certain Fire Protection Issues (10 CFR 50.48). Specifically, although identified by the team, the licensee: (1) would have evaluated this issue during the conversion to National Fire Protection Association 805, (2) had entered this issue into their corrective action program and implemented appropriate compensatory measures, (3) would not have likely identified this through routine licensee efforts, and (4) had not committed the error willfully. The team determined that this violation meets the criteria for enforcement discretion for plants in transition to a risk-informed, performance-based fire protection program as allowed per 10 CFR 50.48(c) (EA-09-171). Since all the criteria were met, the NRC is exercising enforcement discretion for this issue and documenting the issue as a finding: FIN 05000382/2009006-03, Failure to ensure post-fire safe shutdown valves could be operated |
| Site: | Waterford  |
|---|---|
| Report | IR 05000382/2009006 Section 1R05 |
| Date counted | Jun 30, 2009 (2009Q2) |
| Type: | Finding: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.05 |
| Inspectors (proximate) | G Pick N O'Keefe S Alferink E Uribe B Correll Z Bailey |
| INPO aspect | |
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Finding - Waterford - IR 05000382/2009006 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Waterford) @ 2009Q2
Self-Identified List (Waterford)
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