Three Mile Island marks sixth announced nuclear plant retirement in seven years
At the end of last month, Exelon announced the planned retirement of its Three Mile Island Nuclear Generating Station in southeastern Pennsylvania, which marks the sixth announced nuclear plant retirement in the last seven years.
Exelon said it would retire the plant in 2019 unless it receives assistance from the state to keep the facility economically viable.
There are currently 99 nuclear reactors at 60 nuclear power plants in operation in the United States. Since the first commercial U.S. nuclear reactor began operating in 1957, more than 30 nuclear reactors have retired. Some of these retired facilities were test projects or experimental designs, but most provided commercial power for at least part of their operation.
Prior to 2013, no nuclear plants had been retired since 1998. In 2013, the Crystal River, Kewaunee, and San Onofre nuclear power plants retired. Vermont Yankee shut down in 2014 and Nebraska’s Fort Calhoun ceased operation in 2016. The approximately 5,000 megawatts (MW) those plants produced was most often replaced with electricity generation from natural gas and coal.
Six more plants are scheduled to retire within the next nine years. Four of those plants, including Three Mile Island, have planned retirement dates that are more than a decade before their operating licenses expire.
Economic factors have been a major factor in the decision to retire many nuclear plants. Affordable energy from natural gas and renewables and slowing electricity demand growth have made it more difficult for nuclear plants to compete in the energy market.
Before its announced retirement, Three Mile Island had not been profitable for the past five years, Exelon said. The companies sought subsidies from Pennsylvania in an effort to keep the plant open. New York and Illinois have enacted programs, which are currently subject to legal challenges, that provide financial support to certain nuclear plants.
