Some unexpected operational issues have temporarily forced two Midwest nuclear reactor units offline, according to Nuclear Regulatory Commission (NRC) data posted Dec. 4.
Event reports filed with NRC indicate that both the NextEra Energy (NYSE:NEE) Point Beach 1 facility in Wisconsin and the Ameren (NYSE:AEE) single-unit Callaway plant in Missouri were recently forced to suspend power generation.
At Point Beach 1 a manual reactor trip was implemented “due to imminent failure of 1P-25B Condensate Pump. Unit 1 had commenced a rapid down power due to the degradation of the pump,” NRC reported.
“Auxiliary feedwater system actuation was due to low steam generator water levels in both ‘A’ and ‘B’ Steam Generators, an expected system response during a reactor trip,” according to the NRC Point Beach 1 report. “Decay heat removal is by forced circulation and is being controlled by auxiliary feedwater system and condenser steam dumps.”
“Unit 1 is in a normal shutdown electrical lineup. There was no effect on Unit 2,” at Point Beach, NRC reported.
Point Beach 1 was listed at 15% generation early Dec. 4, according to NRC’s daily reactor status report. That’s a sign that the reactor could be resuming commercial power generation already.
Point Beach 1 is a roughly 600-MW capacity pressurized water reactor (PWR) that started commercial operation in 1970. Point Beach 2 is slightly newer, having been commissioned in 1972. The Point Beach nuclear station had a roughly 85% capacity factor in 2012, according to GenerationHub data.
As for Callaway, there was “an unexpected main turbine trip causing a reactor trip occurred on 12/03/2014 [at 0022 CST] with the plant operating in Mode 1 at 100 percent power,” NRC reported.
“As part of the plant design, an expected, valid actuation of the Auxiliary Feedwater System occurred in response to the reactor trip. As part of the Auxiliary Feedwater actuation, the ‘B’ Motor Driven Auxiliary Feedwater Pump to ‘D’ Steam Generator throttle valve did not throttle as expected and was manually isolated,” at Callaway, NRC reported.
“All other systems functioned normally in response to the plant conditions. The plant is currently stable in Mode 3 at 0 percent power. Safety related buses are receiving normal off-site power and the grid is currently stable,” according the NRC report on Callaway.
Callaway was still list at zero generation early Dec. 4 in the reactor status report. Callaway is a PWR commissioned in 1984. It has a capacity of roughly 1,200 MW. It had a capacity factor of roughly 99% in 2012, according to GenerationHub data.
Callaway underwent a refueling and maintenance outage this fall. The company is currently seeking a 20-year license renewal from NRC for the Callaway nuclear plant.