MIDDLETOWN, Pennsylvania, October 8, 2024 (ENS) – Constellation, an energy company based in Baltimore, Maryland has signed a power purchase agreement with Microsoft that will restore the one undamaged reactor at the Three Mile Island nuclear power plant to power Microsoft data centers. The company has agreed to purchase the plant’s entire electric generating capacity over the next 20 years.
But, there is a dark history to the Three Mile Island nuclear power plant near Middletown. The most serious accident in U.S. commercial nuclear power plant operating history occurred at Three Mile Island power plant on March 28, 1979. A combination of equipment failure and operator error led to the partial meltdown of the power plant’s Unit 2 reactor that resulted in the release of a small amount of radioactive material.
Three Mile Island is located 10 miles (15 km) southeast of Harrisburg, Pennsylvania’s capital city, and 75 miles (120 km) west of Philadelphia, the state’s most populous city.
“This agreement is a major milestone in Microsoft’s efforts to help decarbonize the grid in support of our commitment to become carbon negative. Microsoft continues to collaborate with energy providers to develop carbon-free energy sources to help meet the grids’ capacity and reliability needs,” said Bobby Hollis, VP of Energy, Microsoft.
Under the agreement, Microsoft will purchase energy from the refurbished Unit 1 at Three Mile Island as part of its goal to help match the power used by its data centers in the independent nonprofit PJM power pool with carbon-free energy.
The deal will allow the nuclear facility to produce 835 megawatts of carbon-free energy, enough to power 700,000 homes, providing clean energy for Microsoft’s data centers in the PJM energy market. PJM stands for the three original states in the pool, Pennsylvania, New Jersey, and Maryland. The pool now includes all or parts of 14 states.
When Three Mile Island was originally built, there were two nuclear reactors at the power plant – TMI-1 and TMI-2.
Unit 1 (800 megawatt capacity) came online in 1974 and generated electricity until autumn 2019 when it was closed and scheduled for decommissioning. TMI Unit 1 is a fully independent facility, and its long-term operation was not impacted by the Unit 2 meltdown, Constellation says.
Unit 2 (906 MGW capacity) began operations in December 1978 and was shut down after its meltdown on March 28, 1979.
The Department of Energy emphasizes that, “No injuries, deaths or direct health effects were caused by the accident.” Cleanup of Unit 2 took 14 years and cost the plant owners approximately $1 billion.
In 1990, 150 tons of radioactive debris from the melted core was shipped to the Idaho Cleanup Project for long-term storage.
The Idaho National Laboratory says that things are different today. After the Three Mile Island accident, the nuclear industry formed the Institute of Nuclear Power Operations, INPO, with a mission to promote the highest levels of safety and reliability in the operation of nuclear power plants. In 1985, INPO formed the National Academy for Nuclear Training, which reviews and accredits training programs at nuclear power plants.
Federal regulators confirm there has been steady improvement in TMI Unit 1’s performance in the more than four decades since the Three Mile Island accident.
The nuclear power plant will be renamed the Crane Clean Energy Center in honor of Chris Crane, CEO of Constellation’s former parent company, Exelon, who passed away in April of this year. Crane was instrumental in shaping the industry and rebuilding public support for nuclear technology. Crane helped build the Institute for Nuclear Power Operations and served on the boards of the Nuclear Energy Institute and the World Association of Nuclear Operators.
A recent economic impact study commissioned by the Pennsylvania Building & Construction Trades Council found that the new Crane Clean Energy Center, CCEC, will create 3,400 direct and indirect jobs and add more than 800 megawatts of carbon-free electricity to the grid. The report, produced by the Boston-based Brattle Group, also found that restarting the plant will add $16 billion to the state’s GDP and generate more than $3 billion in state and federal taxes.
To prepare for the restart, major investments will be made to restore the plant, including the turbine, generator, main power transformer and cooling and control systems. Restarting a nuclear reactor requires U.S. Nuclear Regulatory Commission approval following a comprehensive safety and environmental review, as well as permits from relevant state and local agencies.
Through a separate request, Constellation will pursue license renewal that will extend plant operations to at least 2054. The newly refurbished Three Mile Island reactor, renamed the Crane Clean Energy Center, is expected to be online in 2028.
Featured image: Three Mile Island Nuclear Power Plant, located 10 miles (15 km) southeast of Harrisburg, Pennsylvania’s capital city, and 75 miles (120 km) west of Philadelphia, the state’s most populous city. The photo, taken before 2019, shows the power plant’s Unit 1 in operation. (Photo courtesy U.S. Dept. of Energy)
