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This 60-day telephone notification is bein … This 60-day telephone notification is being made under reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1).</br>On March 15, 2008, while resetting the main turbine in preparation for performing 1MST-RPS25R, 'RPS Turbine Stop Valve and Control Valve Closure Chan Cal,' a Group 1 isolation was received. Main Steam Lines (MSLs) A and B were isolated for local leak rate testing, however, the MSLs C and D were not. The inboard and outboard Main Steam Isolation Valves (MSIVs) for the C and D MSL closed as a result of this event.</br>The isolation occurred during work associated with replacement of the main generator output breakers 22A and 22B. In order for the breakers to be removed, wiring that provides breaker position information was disconnected from the turbine control system (EHC). This resulted in a 'breaker closed' input to EHC. When the main turbine was reset, several logic interactions occurred resulting in the Group 1 isolation. No actual plant condition existed which required a Group 1 isolation and, with the Unit in Mode 4, Group 1 isolation is not required to be operable. Therefore, this actuation is considered to be invalid.</br>The affected MSIVs and PCIS instrumentation operated properly. This was a full Group 1 isolation with only the MSIVs associated with the C and D MSLs closing since the A ad B lines were isolated when the actuation occurred. The invalid PCIS actuation was entered into the corrective action program (i.e., NCR 270475). </br>The safety significance of this event was minimal. Plant equipment performed as expected. Group 1 isolation was not required to be operable in Mode 4.</br>The Group 1 isolation was reset and a jumper was installed to prevent a subsequent invalid Group 1 isolation. Procedures will be developed or revised to disable the Group 1 Isolation during modes in which it is not required and to reset the main turbine during outages.</br>The NRC Resident Inspector has been notified at this report.nspector has been notified at this report.
20:35:00, 15 March 2008 +
44,213 +
13:16:00, 14 May 2008 +
20:35:00, 15 March 2008 +
This 60-day telephone notification is bein … This 60-day telephone notification is being made under reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1).</br>On March 15, 2008, while resetting the main turbine in preparation for performing 1MST-RPS25R, 'RPS Turbine Stop Valve and Control Valve Closure Chan Cal,' a Group 1 isolation was received. Main Steam Lines (MSLs) A and B were isolated for local leak rate testing, however, the MSLs C and D were not. The inboard and outboard Main Steam Isolation Valves (MSIVs) for the C and D MSL closed as a result of this event.</br>The isolation occurred during work associated with replacement of the main generator output breakers 22A and 22B. In order for the breakers to be removed, wiring that provides breaker position information was disconnected from the turbine control system (EHC). This resulted in a 'breaker closed' input to EHC. When the main turbine was reset, several logic interactions occurred resulting in the Group 1 isolation. No actual plant condition existed which required a Group 1 isolation and, with the Unit in Mode 4, Group 1 isolation is not required to be operable. Therefore, this actuation is considered to be invalid.</br>The affected MSIVs and PCIS instrumentation operated properly. This was a full Group 1 isolation with only the MSIVs associated with the C and D MSLs closing since the A ad B lines were isolated when the actuation occurred. The invalid PCIS actuation was entered into the corrective action program (i.e., NCR 270475). </br>The safety significance of this event was minimal. Plant equipment performed as expected. Group 1 isolation was not required to be operable in Mode 4.</br>The Group 1 isolation was reset and a jumper was installed to prevent a subsequent invalid Group 1 isolation. Procedures will be developed or revised to disable the Group 1 Isolation during modes in which it is not required and to reset the main turbine during outages.</br>The NRC Resident Inspector has been notified at this report.nspector has been notified at this report.
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00:00:00, 14 May 2008 +
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59.695 d (1,432.68 hours, 8.528 weeks, 1.962 months) +
20:35:00, 15 March 2008 +
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