Constellation Energy Corp. announced a 20-year deal with Microsoft to supply regional data centers with power from what is described as a $1.6-billion revamp and restart of the Three Mile Island nuclear plant Unit 1 reactor near Harrisburg, Pa., which was shuttered in 2019 “for economic reasons,” after 20 years of operation, said firm CEO Joe Dominguez.
The unit is adjacent to but not connected with the plant’s Unit 2, which closed in 1979 after a near meltdown and is being decommissioned by its new owner, Energy Solutions. A restart of Unit 1, renamed the Crane Clean Energy Center, would be the first such reactivation of a closed U.S. nuclear plant if the plan, announced Sept. 20, is approved by the federal Nuclear Regulatory Commission.
Constellation, which told media it had not yet applied to the agency for restart permission, said it also will seek license renewal to extend plant operations to at least 2054.
Also seeking commission OK to restart, as early as late 2025, is the Palisades nuclear reactor in Michigan, owned by operator Holtec since 2022. According to the firm, the effort had gained a conditional $1.52-biilon federal loan guarantee in March.
The revamped Three Mile Island unit, set to operate in 2028, would add 835 MW of energy over 20 years to the area grid operated by PJM Interconnection to match power used by the Microsoft data centers.
The recommissioning process will require “significant investments” in Unit 2 plant systems, including the turbine, generator, main power transformer and cooling and control systems, said Constellation.
A company spokesperson did not respond to ENR by story posting time to confirm the status of project engineering and construction support procurement.
"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, Microsoft vice president of energy.
Constellation did not disclose financial details of the Microsoft deal, but is expected to seek federal clean energy tax credits under the 2022 Inflation Reduction Act to offset restart costs, according to The Washington Post, which said that Energy Secretary Jennifer Granholm had previously estimated the incentives could cut those expenses by up to half.
Constellation touted a regional building trades-sponsored study that said the restart would create 3,400 direct and indirect jobs and generate regional economic benefits, and said it has committed $1 million over the next five years to support regional workforce development and other community investment.
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