Davis-Besse Nuclear Power Station is a nuclear power plant in Oak Harbor, Ohio, the United States. It has a single pressurized water reactor, also referred to as a light water reactor. As of 2011, it is operated by the FirstEnergy Nuclear Operating Company subsidiary of FirstEnergy Corp. On March 5, 2002, maintenance workers discovered that corrosion had eaten a football-sized hole into the reactor vessel head of the Davis-Besse plant. Although the corrosion did not lead to an accident, this was considered to be a serious nuclear safety incident. The Nuclear Regulatory Commission kept Davis-Besse shut down until March 2004, so that FirstEnergy was able to perform all the necessary maintenance for safe operations. The NRC imposed its largest fine ever -- more than $5 million -- against FirstEnergy for the actions that led to the corrosion. The company paid an additional $28 million in fines under a settlement with the U.S. Department of Justice.

en.wikipedia.org/wiki/Davis-Besse