On June 29th, FirstEnergy Nuclear Operating Company's (FENOC) Davis-Besse atomic reactor on the Lake Erie shore near Toledo experienced an emergency shutdown.
The event notification report posted on the U.S. Nuclear Regulatory Commission (NRC) website states:
'AUTOMATIC REACTOR TRIP DUE TO REACTOR COOLANT PUMP TRIP
"Automatic trip of Reactor Coolant Pump 1-2 due to an electrical differential current fault resulted in an RPS actuation on Flux/Delta Flux/Flow. Startup Feedwater Valve 1 did not respond as expected post-trip and has been placed in manual control. All secondary side steam reliefs initially re-seated following reactor trip. Subsequent Main Steam Line #1 Safety Valve leakage mitigated during post-trip recovery actions. All other systems have functioned as expected. The plant is stable in Mode 3 - Hot Standby."
All rods inserted into the core during the trip. Decay heat is being removed via turbine bypass valves to the main condenser with normal feedwater to the steam generators. The plant is in its normal shutdown electrical lineup. The licensee characterized the trip as uncomplicated.
The licensee will be notifying Lucas and Ottawa counties, the State of Ohio and will be issuing a press release. They have notified the NRC Resident Inspector.'
Helpfully translating that Nukespeak into plain English, David Lochbaum, Union of Concerned Scientists' Director of Nuclear Safety, has prepared a powerpoint presentation to explain what happened at Davis-Besse.
Vanessa McCray at the Toledo Blade has reported on this story. She quotes Beyond Nuclear's Kevin Kamps:
'...Kevin Kamps, a radioactive-waste specialist for Beyond Nuclear, said the most recent incident is another worry.
“A lot of plants have problems, but often times it’s a single problem a plant will have ...,” he said. “But for Davis-Besse, they have just a whole long list of problems, and that’s what concerns us too —that those might line up one day in a very bad way.”...'
A U.S.-Canadian environmental coalition, including Beyond Nuclear and Citizen Environment Alliance of Southwestern Ontario, has challenged both Davis-Besse's proposed 20-year license extension, as well as its risky steam generator replacements.