Davis-Besse Nuclear Power Station
The Davis-Besse Nuclear Power Station is a single-unit nuclear power plant located on the southern shore of Lake Erie, near Oak Harbor, Ohio. Its Babcock and Wilcox Pressurized Water Reactor, which was commissioned in 1978 and is licensed to operate until 2017, has an installed capacity of 889 MW and generates about 7,700 MWh a year. Jointly owned by Cleveland Electric and Toledo Edison, the plant is operated by the FirstEnergy Nuclear Operating Company. The plant’s facilities, which are adjacent to the Ottawa National Wildlife Refuge, were originally constructed by the Bechtel Group for a partnership that included Cleveland Electric Illuminating and Toledo Edison.
Though no incident at the plant has ever led to the release of radioactive particles, there have been several serious events that have caused concern and warranted further investigation. Indeed, Davis-Besse’s sole reactor was deactivated between 2002 and 2004 for repairs and upgrades that were intended to address some of these problems.
The first of these incidents occurred on September 24, 1977, when the reactor, which had not yet been commissioned and was only operating at 9% power, shut down due to a disruption in the feedwater system that, in turn, caused a relief valve for the pressurizer to lock open. A 2005 review by the Nuclear Regulatory Commission stated that this was the fourth most dangerous safety incident in the history of U.S. commercial nuclear power plant operations. The second major incident occurred on June 9, 1985, when the main feedwater pumps, which supply water to the reactor’s steam generators, shut down. Attempts by a control room operator to activate the auxiliary feedwater pumps resulted in overspeed conditions, causing a trip.
An example of the plant’s safety systems working as planned, however, occurred on June 24, 1988, when an F2 tornado struck the plant and damaged its electrical switchyard. This caused a loss of external power that was compensated for by activation of Davis-Besse’s emergency diesel generators. Though temporarily shut down, the reactor was shortly restored to operation.
A much more serious discovery occurred in March of 2002 when, during an inspection, plant workers found that boric acid had eaten through six inches of the reactor’s carbon steel pressure head, leaving 3/8ths worth of stainless steel to contain the unit’s superheated, pressurized coolant. A rupture in this area would have caused severe damage to the unit that could have led to a full nuclear meltdown.
Though the Davis-Besse plant has avoided any nuclear-related health disasters, it nevertheless was likely one of the many power plants built in the 1960s and 1970s that contained asbestos. This fibrous mineral was used in areas and around machinery that were subjected to extreme heat, particularly in power generation facilities. Though some employers knew of the health risks associated with the inhalation of asbestos fibers, many chose to use it anyway and refrain from informing their employees.