A Three Mile Island nuclear reactor could restart under a new deal with Microsoft

Reactor operators Brian Bowers (left) and Bryan Bricking, in the control room of Three Mile Island reactor in 2017.
TMI reactor 2 is still shut down after the partial nuclear meltdown accident in 1979.
Reactor 1, this unit was shut down in 2019.Clem Murray / Staff Photographer

by Andrew Seidman
Updated Sept. 20, 2024, 12:51 p.m. ET |  Published Sept. 20, 2024, 7:00 a.m. ET

Five years after a nuclear reactor at the Three Mile Island plant in central Pennsylvania closed amid financial troubles, its owner wants to bring it back online.

Baltimore-based Constellation Energy Corp. said Friday that it has signed a 20-year agreement with Microsoft under which the technology company will purchase power from Three Mile Island Unit 1. That reactor is located at an independent facility from Unit 2, which closed in 1979 after experiencing a partial meltdown.

Constellation said it would spend $1.6 billion to restart Unit 1 — and won’t seek “a penny in grant money” from the state or federal governments — which the company said “operated at industry-leading levels of safety and reliability for decades.” Federal regulators would need to approve a restart, though it already has support from Gov. Josh Shapiro. The company said it expects the reactor to come online by 2028.

“I think policymakers have recognized that a strategy that is dependent just on wind, solar, batteries isn’t going to fully get us there and meet the needs of the system from a reliability standpoint,” Joe Dominguez, Constellation’s president and CEO, said in an interview.

The Three Mile Island power plant complex in Middletown, Pa. Unit 2, on the left, infamously shut down in 1979 after an accident. Unit 1, on the right, was shut down in 2019.Clem Murray / Staff Photographer

For Microsoft, buying energy from the renewed plant, dubbed the Crane Clean Energy Center, will “help match the power its data centers in PJM use with carbon-free energy,” according to a news release. Valley Forge-based PJM Interconnection, a regional transmission organization, operates the electric grid in 13 states, including Pennsylvania and New Jersey.

The plan to reopen Three Mile Island is likely to face some opposition from groups critical of the nuclear industry. “We will challenge this proposal at every venue that is available for us,” said Eric Epstein, a former chairman of Three Mile Island Alert, a nonprofit that says it promotes “safe-energy alternatives to nuclear power.”

“This is another chapter in a nightmare that won’t end,” he said.

Exelon Generation pulled the plug on 837-megawatt Unit 1 in 2019 after state lawmakers declined to support legislation that would have directed hundreds of millions of dollars in subsidies from Pennsylvania electric customers to the state’s nuclear industry. Exelon at the time said it couldn’t compete in markets dominated by low-cost natural gas. Constellation’s predecessor company split from Exelon in 2022.

Dominguez said multiple factors have contributed to a changing landscape for the nuclear industry since the Three Mile Island reactor closed five years ago. In addition to reliability questions with regard to wind and solar, he pointed to incentives in the Inflation Reduction Act in 2022, Russia’s war in Ukraine, and the pandemic. “We saw this effort … to bring in and onshore a lot of critical supply,” he said.

Constellation said in a regulatory filing Friday that its investment would be eligible for federal nuclear production and clean energy tax credits.

A study commissioned by the Pennsylvania State Building & Construction Trades Council — which supports the restart and represents more than 115 local unions — estimated that the project would create 3,400 jobs, including 600 direct jobs at the plant in Londonderry Township, south of Harrisburg.

The study projected that over 20 years, the Crane Clean Energy Center — named after the late Exelon CEO Chris Crane — would generate $3.6 billion in state and federal tax revenues and reduce carbon emissions by an average of 3 million metric tons per year, “offsetting about 10% of Pennsylvania’s passenger vehicle emissions.”

Thomas Webler, senior research fellow at the Social and Environmental Research Institute, challenged the projected offset of auto emissions in Pennsylvania because the restart won’t be powering electric vehicle chargers. Pennsylvania emitted 258 million metric tons of carbon dioxide equivalent into the atmosphere in 2021, the most recent year for which data is available, according to state data.

Shapiro, a first-term Democrat, said in a statement that the facility “will safely utilize existing infrastructure to sustain and expand nuclear power in the commonwealth while creating thousands of energy jobs and strengthening Pennsylvania’s legacy as a national energy leader.”

Pennsylvania has five nuclear power plants, according to the state Department of Environmental Protection. Constellation, which is publicly traded, owns Limerick Generating Station in Montgomery County and Peach Bottom Atomic Power Station in York County.

Restarting Unit 1 would require approval from the U.S. Nuclear Regulatory Commission and permits from state and local agencies, according to Constellation. The company said it also plans to seek a license renewal “that will extend plant operations to at least 2054.”

Dominguez, the CEO, said the plant remains in “pretty good condition,” though the company needed to replace the main transformer. Other tasks include ordering key components, hiring staff, and connecting the plant to PJM, he said.

Asked about potential safety concerns, Dominguez said TMI “will always be remembered by some people as the industry’s point of greatest failure in the United States.”

“But for those of us who worked and have worked in the industry for decades, Three Mile Island represents something very different,” he said. “It represents the place where we learned hard lessons and the birthplace of the resolve, the new processes, new equipment, new designs through construction activities that ultimately transformed the industry.”

Epstein, the antinuclear power activist, said the focus at the site should be on cleanup.

Ninety-nine percent of TMI 2 reactor’s fuel has been moved to Idaho since the 1979 accident. But officials say removing the last 1% of fuel is challenging. “First things first, remove the waste from the island, and clean up TMI 2,” Epstein said.