The Davis-Besse nuclear power plant, operated by FirstEnergy Nuclear Operating Company, is located on the shores of Lake Erie about 20 miles east of Toledo, Ohio. The 908-MWe pressurized water reactor came online on July 31, 1978.
On October 1, 2011, the plant shut down so that a new reactor vessel head could be installed. During preparations for installation, FirstEnergy identified cracks in the outermost shield building, the concrete structure that protects the steel reactor containment vessel from adverse outside conditions. The U.S. Nuclear Regulatory Commission has conducted numerous inspections of the shield building and determined that the cracks do not affect the integrity of the shield building, and that the plant is safe for continued operation.
This interesting video released by the NRC takes viewers inside Davis-Besse to see the installation of the new reactor head, and includes interviews with NRC inspectors who oversaw its installation and testing, and conducted the safety reviews of the reactor shield building.
More detailed information at the NRC blog.
FirstEnergy recently opened a $6 million advanced Emergency Operations Facility dedicated for Davis-Besse emergency training and exercises.
Davis-Besse is under consideration for a 20-year operating license renewal from the NRC. Despite the NRC's determination that the plant is safe for continued operation, the cracks in the shield building concrete remain a point of contention in regard to the license renewal, and the Atomic Safety and Licensing Board will hear oral arguments November 5-6 by intervenors on the issue.