One of the two nuclear reactors at Three Mile Island, the Pennsylvania site of a notorious partial meltdown 45 years ago, could be brought back online in the coming years to provide power to a new Microsoft artificial intelligence data center, officials said Friday.
Constellation Energy, the Baltimore-based provider that spun off Exelon two years ago, has signed a 20-year power purchasing agreement with the tech giant to draw electricity generated at the plant along the Susquehanna River outside Harrisburg and about 85 miles west of Philadelphia.
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Pending regulatory approvals, the newly created Crane Clean Energy Center would become the first nuclear plant in the United States to return to service after being shut down.
The $1.6 billion project will restart Three Mile Island Unit 1, which stopped generating power five years ago because it could not compete with cheaper energy being produced by Pennsylvania's natural gas industry. The reactor can be run independently from Unit 2, where the plant's partial meltdown occurred resulting in the worst nuclear accident in U.S. history on March 28, 1979. That reactor is still in the process of being decommissioned by owner Energy Solutions.
"Before it was prematurely shuttered due to poor economics, this plant was among the safest and most reliable nuclear plants on the grid, and we look forward to bringing it back with a new name and a renewed mission to serve as an economic engine for Pennsylvania," Joe Dominguez, president and CEO of Constellation, said in a statement.
Tech companies favor nuclear power for AI
In the race to develop artificial intelligence applications, tech companies are scrambling to build data centers, which require enormous amounts of electricity to operate. Such facilities are forecast to make up a growing share of the nation's electricity use in the years to come, prompting companies to look at tapping into existing infrastructure to help meet their needs.
Nuclear power is being touted as a cost-effective solution for these data centers that also limits reliance on carbon-producing power sources. Building and directly connecting data centers to nuclear plants is known as co-location, a strategy that industry leaders favor because it's cheaper and faster to do. Proponents also claim it reduces stress on the transmission grids.
During the years the 837-megawatt unit operated at Three Mile Island, the reactor powered about 830,000 homes and businesses. Constellation officials did not say how much of the reactor's power-producing capacity would be dedicated to powering Microsoft's AI data center, but it's not uncommon for such facilities to have energy demands of 1,000 megawatts – or 1 gigawatt.
An economic impact study commissioned by the Pennsylvania Building & Construction Trades Council estimates the restart of Three Mile Island would create 3,400 jobs directly and indirectly related to the plant and generate about $3 billion in state and federal tax revenue.
"Pennsylvania's nuclear energy industry plays a critical role in providing safe, reliable, carbon-free electricity that helps reduce emissions and grow Pennsylvania's economy," Gov. Josh Shapiro said after the deal was announced Friday. "Under the careful watch of state and federal authorities, the Crane Clean Energy Center 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."
Before the plan moves forward, it will need approval from the U.S. Nuclear Regulatory Commission, which will review the plant's safety protocols and environmental impact. State and federal permits also will need to be approved, including rights to use water from the Susquehanna River.
Constellation officials said the reactor's turbine, generator, main power transformer and cooling and control systems all will need to be restored ahead of a targeted restart in 2028.
Concerns linger decades after meltdown
When Constellation signaled interest in restarting Three Mile Island in July, doubts surfaced about the technical feasibility of the project. Not only would it be the first of its kind, but it will have to be accomplished next to another reactor whose clean-up and decommissioning is expected to continue through 2078.
The site also remains politically contentious due to the lasting memory of the 1979 accident, which displaced surrounding communities and left a legacy of fear over whether the radiation released contributed to increased cancer rates in the vicinity. About 2 million people were exposed to radioactive fallout as a result of the meltdown.
Public health researchers from Temple, Penn State and the University of Pittsburgh published a report last year finding that long-term studies into the impact of the meltdown were limited by research flaws.
Despite these concerns, Constellation cited a statewide poll showing strong support for restarting Three Mile Island. The poll conducted by Susquehanna Polling & Research found Pennsylvania residents approve of restarting Three Mile Island by more than 2-1 and 70% favor the ongoing use of nuclear energy in the state.
The federal government also has renewed interest in restarting shuttered nuclear plants as a way to diversify the nation's energy portfolio. Last year, the Biden administration awarded a $1.5 billion loan to reopen Michigan's Palisades nuclear plant, which closed two years ago after more than 40 years of operation.
Including Three Mile Island, Pennsylvania has five nuclear power plants. Constellation already operates the Limerick Generating Station in Montgomery County and the Peach Bottom plant in York County, in addition to more than a dozen others in the U.S.
In Luzerne County, Amazon has faced pushback over another project to co-locate a large data center on land near the Susquehanna Steam Electric Station reactors in Salem Township. Utility companies have opposed plans for a service agreement that would directly provide power from that plant to Amazon's data center, arguing it will strain grid capacity at the expense of rate-payers in the region.
Constellation purchased Three Mile Island's Unit 1 reactor in 1999. At the time, the plant had more than 600 full-time workers and employed thousands of union laborers who performed regular maintenance projects. The company said Friday that Three Mile Island was closed before it could be repositioned to serve the growing demand for nuclear-powered data centers.
"Powering industries critical to our nation's global economic and technological competitiveness, including data centers, requires an abundance of energy that is carbon-free and reliable every hour of every day, and nuclear plants are the only energy sources that can consistently deliver on that promise," Dominguez said.