The Nuclear Regulatory Commission (NRC) said this week that the Davis-Besse nuclear power plant in Ohio would not be allowed to restart its single reactor until the agency has a chance to complete its investigation of hairline cracks in the unit’s containment structure.
The cracks were discovered after a hole after plant owner FirstEnergy cut a hole in the concrete containment structure in order to install a replacement reactor vessel head. The vessel head was a replacement for one which was found to be cracked. The cracked head had replaced the original vessel head, which had suffered severe corrosion.
The Toledo Blade reported yesterday:
After the concrete was cut, workers discovered an “indication” of a 30-foot hairline crack, and subsequent tests revealed similar “indications” throughout the structure. FirstEnergy later said most such cracks were in decorative “architectural” concrete attached to the building’s exterior to give it texture, but also disclosed that it was investigating several “indications” of cracks of a different nature in the concrete.
The Davis-Besse plant also had to declare an alert Wednesday morning of this week when a small fire broke out in an electrical control panel. The plant had been at cold shutdown at the time of the fire, due to the reactor vessel head replacement.
The Blade also reported:
Viktoria Mytling, spokesman at the NRC’s regional office in Chicago, said … no timetable is in place for restarting the plant.