05000382/FIN-2015007-05
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Finding | |
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| Title | Violation of Technical Specification 6.8.1.f for the failure to implement and maintain adequate written procedures covering fire protection program implementation |
| Description | The team identified a violation of Technical Specification 6.8.1.f for the failure to implement and maintain adequate written procedures covering fire protection program implementation. Specifically, the team identified four examples where the licensee failed to maintain an alternative shutdown procedure that successfully mitigated all postulated alternative shutdown scenarios. This finding affects 10 CFR 50.48 and has been screened and determined to warrant enforcement discretion per the Interim Enforcement Policy Regarding Enforcement Discretion for Certain Fire Protection Issues (10 CFR 50.48). The licensee used Procedure OP-901-502, Evacuation of Control Room and Subsequent Plant Shutdown, Revision 28, to shut down the reactor from the remote shutdown panel in the event a control room or cable vault fire required evacuation of the control room. This alternative shutdown procedure provided steps for operators to transfer control of the credited safe shutdown equipment away from the control room to the remote shutdown panel and to achieve and maintain safe shutdown conditions from the remote shutdown panel. The team performed a timed walkdown of the alternative shutdown procedure. Based on the walkdown results, the team determined that the alternative shutdown procedure was not adequate to ensure that operators could successfully mitigate all postulated alternative shutdown scenarios. In particular, the team identified the following four scenarios where operators may not be able to achieve and maintain a safe shutdown: Example 1: Potential Loss of Credited Safe Shutdown Pumps The first scenario involved fire damage resulting in blown fuses for either the component cooling water or emergency feedwater pumps. In this scenario, the team determined the operators would be unable to control the affected pump from the remote shutdown panel, but the operators would be able to control the affected pump by manually operating the breakers that supplied power to the motors. The team noted that the alternative shutdown procedure did not provide any steps for operators to manually operate the breakers to control these pumps, which were required for safe shutdown. Example 2: Potential Spurious Opening of the Atmospheric Dump Valves The second scenario involved the spurious actuation of two atmospheric dump valves. The team noted that the licensee previously had a 10-minute requirement for operators to mitigate the spurious actuation of two atmospheric dump valves by taking manual control of an open atmospheric dump valve locally and then manually closing the valve. The team determined that the alternative shutdown procedure provided steps for operators to manually close an open atmospheric dump valve; however, the licensee removed the 10-minute requirement for operators to be able to perform this action. The licensee removed the 10-minute requirement based on its understanding that the spurious actuation of only one atmospheric dump valve was required to be analyzed and mitigated. The team referred to guidance in Regulatory Guide 1.189, Revision 2, which stated, in part, after control of the plant is achieved by the alternative or dedicated shutdown system, single or multiple spurious actuations that could occur in the fireaffected area should be considered... The team reviewed the licensees method for isolating the atmospheric dump valves from the effects of a control room or cable vault fire. The team determined that the circuits responsible for isolating the atmospheric dump valves were located within the control room complex and, therefore, could not be relied upon to isolate the atmospheric dump valves in the event of a control room fire. The team concluded that the licensee should have maintained the 10-minute requirement in the alternative shutdown procedure for operators to manually close a spuriously open atmospheric dump valve. During the timed walkdown of the alternative shutdown procedure, the team determined that it would take operators approximately 13 minutes to close a spuriously open atmospheric dump valve. Example 3: Potential Spurious Opening of a Pressurizer Spray Valve The third scenario involved the spurious opening of a pressurizer spray valve. In this scenario, the open pressurizer spray valve results in a rapid depressurization of the reactor coolant system, which could negatively impact the ability to achieve and maintain natural circulation. The licensee considered this scenario in the safe shutdown analysis. The licensee did not perform an analysis or calculation to determine the amount of time operators had available to mitigate this scenario. Instead, the licensee used engineering judgment to specify that operators had 10 minutes available to secure the spurious spray flow. The team was concerned that the 10-minute limit may not be sufficient to ensure that operators could achieve and maintain natural circulation. In response to the teams concern, the licensee modeled this scenario on the simulator. The team noted that the use of the simulator was not a preferred method; however, it provided a reasonable estimate for the amount of time available. The results of the simulator run indicated that the reactor coolant system would reach saturation pressure in less than 8 minutes. Once the reactor coolant system reaches saturation pressure, voiding begins in the reactor coolant system. This voiding could then negatively impact the ability to achieve and maintain natural circulation. The team determined that the alternative shutdown procedure provided steps for operators to trip the reactor coolant pumps, which would mitigate this scenario by eliminating flow through the pressurizer spray valves. During the timed walkdown of the alternative shutdown procedure, the team determined that it would take operators approximately 9 minutes and 15 seconds to trip all of the reactor coolant pumps. Scenario 4: Potential Overfilling of the Steam Generators The fourth scenario involved the potential overfilling of the steam generators. In this scenario, the open main steam isolation valves continue to provide steam to the turbinedriven main feedwater pumps, which continue to inject feedwater into the steam generators until they overfill. The team noted that the action to close the main steam isolation valves prior to evacuating the control room was an operator action within the fire area. The team determined that this action was not credited in the plants approved fire protection program; therefore, the operators must take action outside of the control room to ensure that the main steam isolation valves were closed. Because the licensee did not have an analysis establishing a time limit, the team was concerned the operators may not perform this action prior to main feedwater overfilling the steam generators. In response to the teams concern, the licensee modeled this scenario on the simulator. The team noted that the use of the simulator was not a preferred method; however, it provided a reasonable estimate for the amount of time available. The results of the simulator run indicated that the continued injection of main feedwater at full flow could overfill the steam generators in approximately 2 minutes and 30 seconds. The team noted that overfilling the steam generators would negatively impact the ability to remove decay heat. The team determined that the alternative shutdown procedure provided steps for operators to close the main steam isolation valves from outside the control room, which would mitigate this scenario by eliminating steam flow to the turbine-driven main feedwater pumps. During the timed walkdown of the alternative shutdown procedure, the team determined that it would take operators approximately 4 minutes and 30 seconds to close all of the main steam isolation valves. |
| Site: | Waterford  |
|---|---|
| Report | IR 05000382/2015007 Section 1R05 |
| Date counted | Jun 30, 2015 (2015Q2) |
| Type: | Violation: Severity level Enforcement Discretion |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.05 |
| Inspectors (proximate) | G Werner J Mateychick R Kopriva S Alferink |
| Violation of: | 10 CFR 50.48 Technical Specification - Procedures |
| INPO aspect | |
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Finding - Waterford - IR 05000382/2015007 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Waterford) @ 2015Q2
Self-Identified List (Waterford)
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