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Fear, hope among mixed reactions as Three Mile Island plans to restart

  • Rachel McDevitt
Three Mile Island pictured on June 3, 2024. (Jeremy Long - WITF)

Three Mile Island pictured on June 3, 2024. (Jeremy Long - WITF)

Wendy Smith was terrified she would never be able to return home after the Three Mile Island nuclear accident in 1979.

The central Pennsylvanian was one of about 80,000 people that evacuated during the partial meltdown – an incident that halted the growth of the U.S. nuclear power industry for decades.

Now, a deal with Microsoft is reviving the plant, which has been shuttered for five years.

Smith does not want to see a restart of the plant that caused such panic.

“I am appalled, horrified, infuriated that this is happening,” Smith said. “This decision is so short-sighted. Do we never learn from our mistakes?”

The meltdown – the country’s most serious nuclear accident – permanently damaged the plant’s Unit 2 reactor and it never reopened.

But Unit 1 was not affected, and operated safely until 2019, when owner Exelon shuttered it for being unprofitable. The single-reactor plant could not compete economically with the state’s cheap natural gas or new renewable sources. An effort in the state legislature to create a subsidy for the plant failed.


READ: A new life is proposed for Three Mile Island supplying power to Microsoft data centers


The Microsoft deal is making the reactor viable again.

That’s proof of the market at work, according to André Béliveau, who oversees energy policy at the conservative-leaning Commonwealth Foundation. He called the restart deal a victory for reliable energy and market-driven solutions.

“Refiring the closed reactor through private investment demonstrates that Pennsylvania does not need subsidies for nuclear power. The market will deliver reliable, affordable, and clean power far better than government central planning, and here is a case study demonstrating it,” Béliveau said.

The move is also being hailed by those who want to cut climate pollution and by people who expect an economic benefit from the plant running. But it’s opposed by people concerned about the risks of radiation from nuclear power and waste.

Going nuclear for the climate

Nuclear is now more appealing in the market to those who want to cut dependence on fossil fuels. Nuclear plants don’t emit the planet-warming pollution that coal- and gas-burning plants do. Scientists say we must cut emissions rapidly to avoid the worst effects of climate change.

Microsoft made the agreement as part of its efforts to reduce greenhouse gas emissions. It wants the plant’s electricity to power its data centers within the PJM electric grid, which includes Pennsylvania.

The tech company has an ambitious goal to go “carbon-negative” by 2030, meaning it would remove more emissions from the atmosphere than what is created by powering all its operations.

Constellation – which was formed when Exelon divided its business, and now owns TMI Unit 1 – hopes to have the plant back online by 2028. To do that, it will need to go through a safety and environmental review and get approval from federal and state regulators. The restarted plant will be rebranded as the Crane Clean Energy Center, named after a former Constellation CEO.

Jesse Jenkins, who studies energy systems at Princeton University, said demand for power is growing across the country because of technology needs, electrification efforts for buildings and transportation, and manufacturing.

To reduce emissions, he said we need to add a lot of clean power to the grid.

“Restarting this old nuclear plant that was recently idled is one way to get a very large amount of clean energy onto the grid quickly,” he said.

Nuclear plants can operate 24 hours a day, and they generate a lot of power – TMI will create more than 800 megawatts. So, experts say, they’re a good complement to renewable sources like wind and solar, which are variable.

By buying power from the plant, Microsoft will avoid increasing demand for fossil fuel power.

“One way to think about it is that Microsoft is effectively neutralizing the impact of their data center on the grid by ensuring that when they add this new demand, they’re also adding an equivalent amount of new, round-the-clock clean electricity supply,” Jenkins said.

There are very few retired nuclear plants where this effort could be replicated. One other closed nuclear plant – Palisades, in Michigan – is also trying to restart.


Reactions on the TMI restart from about 40 members of StateImpact’s climate news text club were mixed, though several said it’s important to reduce emissions.

Jason Asbell of Lancaster said he supports the restart.

“A repeat of past issues is low risk, and climate change is a certainty,” he said. “We need an ‘all of the above’ approach for non-carbon energy production.”

Jeff Keyser of East Pennsboro Township, Cumberland County, said the announcement is positive and negative.

“Nuclear power has almost no greenhouse gas footprint, so reopening this plant should be a tremendous step towards addressing global warming,” Keyser said, but because Microsoft is buying the power to feed data centers, “this really isn’t progress, just not making things worse.”

The Biden Administration has encouraged the maintenance of the country’s nuclear fleet as a way to clean up the electric grid. The Inflation Reduction Act included a tax credit for nuclear plants, and the Bipartisan Infrastructure Law established a credit program to maintain or restart reactors. The credits are available to plants at risk of closing that can show climate pollution would increase if the plant closed.

Constellation said the TMI project will be funded with private investment from the company, a 20-year power purchase agreement with Microsoft, and federal tax credits available to all new emissions-free energy projects.

‘Nuclear is not the answer’

Some groups have called for an end to nuclear power in central Pennsylvania since the 1979 accident. They say restarting the undamaged reactor raises the risk of another incident. They also don’t want taxpayer money to be used to restart the plant and are worried about any potential impact on electricity ratepayers.

Brandy Donaldson, a spokesperson for Constellation, said the TMI project will not be funded by ratepayers and it has not received any financial support from Pennsylvania.

She said, earlier this year, there were discussions in Harrisburg about allowing the project to apply for an investment tax credit, but only after it generated the required jobs, taxes and economic impacts.

“Those discussions have been tabled and any claims that PA residents would have to cover the costs of a state tax credit are false,” Donaldson said.

Jeff Schmidt, a former director of the Pennsylvania chapter of the Sierra Club, said he has serious concerns about safety.

“Human error or mechanical failures could result in release of dangerous levels of radiation. But my primary concern is related to the increase in radioactive waste that will need to be isolated from the environment for millennium,” Schmidt said. “What kind of legacy will we leave to future generations?”

Eric Epstein of the watchdog group Three Mile Island Alert said governments should focus on cleaning up the damaged Unit 2 reactor instead of restarting Unit 1.

“Nuclear energy is not the answer. We have a diverse energy portfolio in Pennsylvania, and we should refrain from putting our thumb on the energy scale. We need to focus on internal sources of energy and deploying renewable energy,” Epstein said.

Three Mile Island pictured on June 3, 2024. (Jeremy Long – WITF)

TMI Unit 2 is owned by TMI-2 Solutions and is undergoing cleanup. The company hopes to finish by 2037.

David Allard, chair of TMI-2 Solutions’s Community Advisory Panel, said it’s unclear at this point if Unit 1 restarting will affect the pace of Unit 2’s cleanup. He said an active reactor will have different security concerns than a retired one.

Allard is a former director of the Pennsylvania Bureau of Radiation Protection and said he “always felt comfortable that Unit 1 ran very well.”

He noted people can conflate the two reactors, so it will be helpful for the owners of both to communicate with the public to head off confusion.

Good for business

Government officials – at the federal, state, and local level – say TMI’s reopening is good news.

State Rep. Tom Mehaffie (R-Dauphin) said the reopening could transform the local economy.

“This is a valuable opportunity to invest in clean, carbon-free and affordable power — on the heels of the hottest year in Earth’s history,” he said.

John Podesta, a clean energy advisor to President Joe Biden, said the announcement shows clean energy can create good-paying, union jobs. He said the White House is proud of the role federal tax credits played in supporting the restart.

Constellation said reopening will create 600 permanent jobs at the site in Londonderry Township, Dauphin County. A study commissioned by the Pennsylvania Building & Construction Trades Council found the plant will generate more than $3 billion in state and federal taxes.

Londonderry Township Manager David Blechertas said he is excited to learn more about Constellation’s plans.

“Three Mile Island was always a good partner for the community and for the township for decades,” Blechertas said. “They had a great workforce, and contributed positively to the local economy.”

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