05000382/FIN-2012007-02
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Finding | |
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| Title | Failue to Calculate Adequate Cooling Provided to Diesel Generator B within Required Time |
| Description | The team identified a Green non-cited violation of License Condition 2.C.9 and the fire protection program for the failure to perform a post-fire safe shutdown analysis design calculation. Specifically, the team determined that the licensee had not calculated the time available to establish component cooling water to prevent damaging the emergency diesel generator when providing power to post-fire safe shutdown components. The licensee documented this deficiency in Condition Report 2012-00818. The team reviewed the post-fire safe shutdown analysis that supported time critical operator actions (performed in the first 60 minutes) related to control room evacuation because of a fire. During this review, the team identified that the licensee had not completed a post-fire safe shutdown analysis calculation that determined the actual time available to initiate component cooling water prior to damage occurring in Emergency Diesel Generator B. The team determined this calculation was needed to support the 1O-minute time critical action related to establishing component cooling water flow to the emergency diesel generator jacket water system. Procedure OP-901-502 specified that operators must establish component cooling water to the emergency diesel generator jacket water within ten minutes. The component cooling water cools the jacket water system, which provides a heat sink for the emergency diesel generator by rejecting heat to the component cooling water system. The team determined that the licensee had completed a design calculation related to automatic start and loading of the emergency diesel generators for a loss of coolant accident. Under these conditions, operators had three minutes to establish cooling to the jacket water to prevent damage to the emergency diesel generator. Procedure OP-901-502 directed the operators to shed loads supplied by Emergency Diesel Generator B and start the Component Cooling Water Pump B. if needed following a control room evacuation because of a fire. Consequently, the team assumed that fire damage initiates an automatic start of the emergency diesel generator and failed to load Component Cooling Water Pump B. Based on actual times determined during the Procedure OP-901-502 walk downs, the team determined that the emergency diesel generator would be running loaded for approximately 5.5 minutes prior to operators manually shedding the loads. After the load shedding, a mini-sequencer will start and load post-fire safe shutdown components needed to safely shutdown of the plant. Since Component Cooling Water Pump B will not be started by the mini-sequencer because the relays will not reset, the procedure directs the operator at the alternative shutdown panel to manually start Component Cooling Water Pump B prior to 10 minutes to prevent damage to the emergency diesel generator. The team determined that engineers had identified the 1O-minute response time for starting a component cooling water pump as a corrective action in a condition report documenting a similar issue identified at another facility. The corrective action evaluation did not provide an adequate basis for establishing cooling within 10 minutes. The team also identified that the evaluation did not take into account spurious operation of plant components as required during the control room fire evacuation scenario, which would increase the diesel generator loading and cause a higher heat-up rate. The team concluded the licensee should have revised their post-fire safe shutdown analysis to demonstrate the ability to meet the required response time. The team determined that the loading on the emergency diesel generator in this scenario would be significantly less than the design basis loading documented in their loss of coolant accident calculation. Further, the capacity of the component cooling water system will provide a large heat sink to allow for operator response time. From review of the evaluation contained in the condition report and with the lower loading of the emergency diesel generator, the team determined that operators would have time to initiate component cooling water to the jacket water system before failure of the emergency diesel generator. The licensee documented the failure to determine the actual diesel generator loading and heat rejection to the component cooling water system in Condition Report 2012-00818. The failure to perform a design calculation evaluating the ability to remove heat based upon emergency diesel generator loading following a control room fire was a performance deficiency. The performance deficiency was more than minor because it was associated with the protection against external events (fire) 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. The team evaluated the significance of this finding using Manual Chapter 0609, Appendix F. The performance deficiency affected the fire protection defense-in depth strategies involving post-fire safe shutdown systems. Using Appendix F, the team assigned this finding a low degradation rating because the system was expected to display nearly the same level of effectiveness and reliability as it would had the degradation not been present. Specifically, the component cooling water system could accommodate the heat in the jacket water system of a lightly loaded diesel generator. This finding screened as very low safety significance (Green) in the Phase 1 evaluation. Because the original failure to perform a design calculation had occurred longer than three years prior to this inspection, this finding did not reflect current licensee performance. 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 through Supplement 9. Final Safety Evaluation Report, Section 9.5.1.6.3 specifies Procedure UNT-005-013, Fire Protection Program, describes responsibilities, control and implementing requirements for the Waterford 3 fire protection program. Procedure UNT-005-013, Section 5.12.1, states, Post-Fire Safe Shutdown has been analyzed and is described in Calculation EC-FOO-026. Calculation EC-FOO-026, Appendix D states, All safe shutdown functions will be evaluated as required to permit the operation of equipment used for safe shutdown functions. Contrary to the above, from August 2007 until February 17, 2012, the licensee failed to comply with License Condition 2.C.9 and implement and maintain in effect all provisions of their fire protection program in that the licensee did not properly evaluate all post-fire safe shutdown functions. Specifically, the licensee failed to perform a post-fire safe shutdown analysis as part of Calculation EC-FOO-026 to demonstrate that the emergency diesel generator would not be damaged prior to the time specified for operators to restore component cooling water. This finding does not qualify for enforcement discretion as described in the Interim Enforcement Policy Regarding Enforcement Discretion for Certain Fire Protection Issues (10 CFR 50.48) since this finding was not identified during their transition process. Because this finding is of very low safety significance and has been entered into the corrective action program (Condition Report 2012-00818), this violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the NRC Enforcement Policy: NCV 05000382/2012007-02, Failure to Calculate Adequate Cooling Provided to Diesel Generator B within Required Time. |
| Site: | Waterford  |
|---|---|
| Report | IR 05000382/2012007 Section 1R05 |
| Date counted | Mar 31, 2012 (2012Q1) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.05 |
| Inspectors (proximate) | G Miller M Young J Mateychick E Uribe |
| INPO aspect | |
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Finding - Waterford - IR 05000382/2012007 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Waterford) @ 2012Q1
Self-Identified List (Waterford)
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