Sorry to have been silent for a while, but I got a new job that’s keeping me pretty busy. But this last two weeks have been busy at the nation’s nuclear power plants. These are just the reactor shutdowns:
1. Early in the morning of Sunday, October 12, operators at the Oyster Creek nuclear power plant were attempting to restart the unit’s sole reactor when the water level in the reactor began to decline. With power at 1 per cent of full output, operators initiated a manual scram of the reactor.
Oyster Creek’s single boiling water reactor is among the oldest in the country, having come online just before Christmas in 1969. The Nuclear Regulatory Commission granted an extension of the unit’s operating license until 2029, but current plans call for the reactor to cease operations on December 31, 2019.
On October 17, Oyster Creek amended its Event Report to indicate that an automatic reactor shutdown occurred before operators could complete a manual shutdown.
2. On the same morning that Oyster Creek was scrammed, operators at the Vogtle nuclear power plant in Georgia were compelled to shut down the Unit 2 reactor after the wrong group of control rods inserted during startup activities. Apparently, plant procedures require that when Button D is pushed, control rod assemblies in Group D are expected to insert, not those from Group A. Can’t these people afford a label maker?
3. On Monday, October 13, Unit 2 at the Surry nuclear power plant in Virginia suffered an automatic shutdown due to what turned out to be a false indication of rising temperature in the reactor core. The reactor’s auxiliary feedwater pumps actuated during the shutdown.
During the incident, one set of radiation sensors did not activate automatically, as they should during a scram. The sensors had to be manually activated by station personnel.
4. The next day, operators at Alabama’s Farley nuclear power had to shut down the Unit 2 reactor when the Reactor Coolant Pumps lost power due to the loss of a Start Up Transformer. The incident occurred as a line of severe thunderstorms with lightning was passing over the plant. The reactor was operating at 83 per cent power at the time of the incident.
5. On Friday, October 17, the Unit 1 reactor at the River Bend nuclear power plant in Louisiana shut itself down after a suspected malfunction in the reactor’s Electrohydraulic Control System caused the Average Power Range Monitor to initiate a shutdown. The sudden shutdown triggered the reactor’s recirculation pump A.
6. On Monday, October 20, another New Jersey nuke had to scram a reactor when operators at the Salem nuclear power plant had to shut down the Unit 1 reactor following detection of falling steam generator water levels. Oddly enough, the emergency occurred as operators were attempting to execute a planned scram prior to a refueling outage. The event was reportable as an unplanned manual reactor shutdown because of the steam generator irregularity. Sort of like tripping over a curb and saying: “I meant to do that.”
7. And on that same day, Ohio’s Perry nuclear power plant reported that the facility’s sole reactor shut itself down after a loss of feedwater. The High Pressure Core Spray and Reactor Core Isolation Cooling systems activated to provide emergency cooling to the boiling water reactor.