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On April 18, 2004, while at 0 percent powe … On April 18, 2004, while at 0 percent power and shutting down for a refueling outage, personnel were performing steam generator feedwater pump (SGFP) turbine testing. As the reactor coolant system temperature and pressure decreased, a caution in the operating procedure required disabling of the auxiliary feedwater (AFW) actuation signal that is initiated from a trip of both SGFPs, prior to breaking condenser vacuum. However, this would have prevented completion of the SGFP turbine testing, so the AFW actuation signal was not disabled at that time. Since problems were encountered, the testing was delayed as allowed by the surveillance procedure. Later, at 1238 EDT, the Unit Shift Supervisor (USS) directed the Balance-Of-Plant Operator (BOP) to break condenser vacuum. This was not in compliance with the caution in the procedure to ensure the AFW actuation signal was disabled. When condenser vacuum was broken, the SGFPs tripped which then generated an AFW actuation signal. The AFW discharge valves went fully open and operators acted to throttle these valves, maintaining proper SG water levels.</br></br>The cause of this event was the failure of the control room staff to adequately sequence the work activities associated with the start of the refueling outage.BBriefings will be held with all shifts of control room operators, discussing this event and reinforcing management expectations.t and reinforcing management expectations. +
April 18, 2004 +
On April 18, 2004, while at 0 percent powe … On April 18, 2004, while at 0 percent power and shutting down for a refueling outage, personnel were performing steam generator feedwater pump (SGFP) turbine testing. As the reactor coolant system temperature and pressure decreased, a caution in the operating procedure required disabling of the auxiliary feedwater (AFW) actuation signal that is initiated from a trip of both SGFPs, prior to breaking condenser vacuum. However, this would have prevented completion of the SGFP turbine testing, so the AFW actuation signal was not disabled at that time. Since problems were encountered, the testing was delayed as allowed by the surveillance procedure. Later, at 1238 EDT, the Unit Shift Supervisor (USS) directed the Balance-Of-Plant Operator (BOP) to break condenser vacuum. This was not in compliance with the caution in the procedure to ensure the AFW actuation signal was disabled. When condenser vacuum was broken, the SGFPs tripped which then generated an AFW actuation signal. The AFW discharge valves went fully open and operators acted to throttle these valves, maintaining proper SG water levels.</br></br>The cause of this event was the failure of the control room staff to adequately sequence the work activities associated with the start of the refueling outage.BBriefings will be held with all shifts of control room operators, discussing this event and reinforcing management expectations.t and reinforcing management expectations. +
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June 16, 2004 +
April 18, 2004 +
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