America’s coal communities could help the US triple its nuclear power

The planned restart of Three Mile Island is a step forward for nuclear power, but the U.S. needs to build new plants to keep up with rising electricity demand, one of the nation’s top nuclear officials said this week.

The U.S. needs to at least triple its nuclear fleet to keep up with demand, reduce carbon dioxide emissions and ensure the nation’s energy security, said Mike Goff, Acting Assistant Secretary of the Energy Department’s Office of Nuclear Energy .

The US currently has the largest nuclear fleet in the world, with 94 operational reactors with a total output of about 100 gigawatts. The fleet provided more than 18% of the nation’s electricity consumption in 2023.

The US needs to add 200 gigawatts of nuclear power, Goff told CNBC in an interview. This is roughly equivalent to building 200 new plants, based on the current average reactor size in the US fleet of about one gigawatt.

“It’s a huge undertaking,” Goff said. The US led a global coalition in December that formally committed to meeting the goal by 2050. Financial institutions including Goldman Sachs and Bank of America backed the target at a climate conference in New York this week.

Constellation EnergyHis plan to restart Three Mile Island by 2028 is a step in the right direction, Goff said. The plant operated safely and efficiently, closing only in 2019 for economic reasons, he said.

The reactor that Constellation plans to reopen, Unit 1, is not the one that partially melted down in 1979.

Microsoft will buy electricity from the plant to power its data centers. Goff said the emergence of large data centers that consume up to a gigawatt of electricity only reinforces the need for new reactors.

“A lot of data centers are coming in and saying they need clean, 24/7, basic electricity,” Goff said. “Nuclear is obviously a perfect fit for that,” he said.

But restarting U.S. reactors will provide only a fraction of the nuclear power needed, he said. There are only a handful of closed factories that are potential candidates for restarts, according to Goff.

“It’s not a big number,” Goff said of the potential restarts. “We need to really move forward on the installation of the facilities as well,” he said.

US coal communities could provide a runway to build large numbers of new nuclear plants. Utilities in many parts of the U.S. are phasing out coal as part of the transition to clean energy, creating a supply gap in some regions because new generation isn’t being built fast enough.

Recently closed coal plants, those expected to retire and plants currently operating without an estimated closing date could provide room for up to 174 gigawatts of new nuclear power in 36 states, according to a published Energy Department study at the beginning of this month.

Coal plants already have transmission lines, allowing reactors at those sites to avoid the lengthy process of placing new grid connections, Goff said. The plants also have people with experience in the energy industry who could transition to work at a nuclear facility, he said.

“We can actually get a significant cost reduction by building at a coal plant,” Goff said. “We can get a 30 percent cost reduction compared to just going to new ground.”

Cost overruns and long timelines are major obstacles to building new nuclear power plants. Expanding the Vogtle plant in Georgia with two new reactors, for example, cost more than $30 billion and took about seven years longer than expected.

Expanding operating nuclear plants and building at retired U.S. sites could create a path for up to 95 gigawatts worth of new reactors, according to the DOE study. Between coal and nuclear sites, the U.S. has room for up to 269 gigawatts of additional nuclear power.

Potential capacity would depend on whether advanced, smaller reactors or larger reactors of a gigawatt or more are built at the sites.

More electricity could be generated if the smaller reactors were rolled out on a large scale because there is room for more, according to the DOE study. Some of these smaller advanced models, however, are still several years away from commercialization.

But growing demand for electricity from data centers, manufacturing and the electrification of the economy could provide a catalyst for building larger factories, according to Goff. Rebooting Three Mile Island, for example, would bring back just under a gigawatt of power to meet Microsoft’s needs.

“It’s this increased power demand that will lead to an additional push to those gigawatt-sized reactors as well,” he said.

While restarting the reactor is not a silver bullet, sustaining and maintaining the existing fleet is crucial, Goff said. The US went through a decade long period of reactor shutdowns because they could not compete with cheap and abundant natural gas.

The economy is changing, however, with tax support from the Inflation Relief Act and nuclear is increasingly valued for its carbon-free attributes, Goff said.

“One of the economic problems, particularly in unregulated utilities, was that there wasn’t necessarily any value for clean, base-load electricity,” he said. “There is much greater recognition of the need for a clean, robust and reliable baseload for nuclear”

Constellation’s decision to restart Three Mile Island follows in the footsteps of Palisades Nuclear Power Plant in Michigan. The private owner, Holtec International, is building to restart Palisades in 2025. The two restarts are subject to review and approval by the Nuclear Regulatory Commission.

“They’re an independent agency, but I expect if the safety cases are presented, they’ll approve it,” Goff said of those potential restarts.

“Constellation has obviously operated the Three Mile Island plant for years and has a very large fleet of reactors that they have operated safely and efficiently,” he said. “They will continue to have great experience in moving those plants to continue their safe operation.”

But finding additional plants to restart could prove difficult, said Doug True, nuclear director at the Nuclear Energy Institute.

“It’s getting harder and harder,” True previously told CNBC. “Many of these plants have already begun the deconstruction process that comes with decommissioning, and the facility was not set up so well in a way that needed to be restarted in any way.”