TMI owner says Pa. nuclear plant is on track to reopen next year

Constellation Energy crews have been laboring since 2024 to reopen Three Mile Island’s Unit 1 nuclear plant to meet spiking electricity demand. Planned data centers and other new demands have materialized since 2019, when the plant was shut because generating power there was too expensive to compete with cheap natural gas.

Now Constellation has moved up its own deadlines and says it’s approaching its goal to load uranium next spring and add electricity to the grid later in 2027.

That’s despite naysayers such as Neil Chatterjee, President Donald Trump’s former Federal Energy Regulatory Commission chair.

“It will never work” because of TMI’s aging technology and the complex U.S. and Pennsylvania energy bureaucracies, Chatterjee wrote in January in The Hill, which neglected to note Chatterjee had become a solar-power lobbyist.

In testimony submitted to regulators, environmental groups, including Eric Epstein’s TMI Alert, called the utility’s plans rushed and incomplete. Montgomery County-based PJM, which oversees power distribution for 13 states and the District of Columbia, warned it could be 2031 before the plant could connect to the power grid, Constellation chief executive Joe Dominguez told analysts and investors in March.

But Dominguez minimized that warning. “Normally, they start off with a pretty long timeline and shorten that up,“ he told investors in a conference call May 11, adding that he would work with states to speed connections.

Dominguez has moved up the original 2028 target date to next year, in part because of supporters like President Donald Trump and Pennsylvania Gov. Josh Shapiro, and because Microsoft has promised to buy as much power as the plant produces to run a growing array of data centers.

So Constellation is paying an army of builders, lawyers, and plant operators to prepare the plant.

Earlier this month, PJM agreed to speed up its process for connecting new power plants in states where regulators agree to approve sites faster.

Here’s an update on what’s happening at TMI:

Constellation bought three building-sized replacement transformers from manufacturer Hyundai in South Korea, to be delivered later this month, after reinforcing the bridge to the island to bear their weight. Two will be installed “later this year,” one kept as a spare, said spokesperson Paul M. Adams.

The company says crews are repairing the partly dismantled Bravo cooling tower and inspecting the reactor building and diesel motors on the site. They are restoring controls — originally analog systems made by manufacturers in Reading and other Pennsylvania cities.

The company has scheduled enriched-uranium fuel assembly deliveries from its supplier Framatome in Richland, Wash., later this year, so fuel can be loaded into the reactor core next spring. The uranium is sourced from U.S. and foreign mines.

Microsoft has promised to buy power equal to the plant’s entire production at prices above today’s levels for 20 years.

But that doesn’t mean the software and data-center giant is going to run wires to new, power-burning facilities in the neighborhood.

The Microsoft deal supports Constellation’s regulatory and investor arguments in favor of reopening. It confirms this major data-center operator will need more power in years to come.

Constellation says more than 3,000 construction workers will help bring the plant, which it now calls the Crane Clean Energy Center, into service.

The company also has hired hundreds of permanent workers for plant, named after the late Exelon Corp. CEO who spun off Constellation and championed nuclear power. More than 550 full-time employees are on site, including the current class of 80 operators being trained in federal Nuclear Regulatory Commission procedures.

About 145 of those employees are “boomerang” staff who worked at Three Mile Island before its 2019 shutdown, according to Constellation.

More than 400 hires live within 25 miles of the plant. They include about a dozen recent graduates of the Penn State Harrisburg campus nearby.

In November, the U.S. Department of Energy Loan Programs Office approved a $1 billion low-interest government loan to help Constellation reopen the Three Mile Island plant.

Supporters of nuclear loan and subsidy programs say federal money ensures long-term operation at reasonable financing costs. Critics such as the Cato Institute, which generally opposes subsidies, say the government shouldn’t help pay for power that would otherwise be unprofitable.

Shapiro, U.S. Energy Secretary Chris Wright, U.S. Interior Secretary Doug Burgum, U.S. Sen. Dave McCormick (R., Pa.), U.S. Rep. Scott Perry (R., Pa.), state legislators and local officials have toured the plant to tout job and energy creation.

With permit applications pending before the NRC and other agencies, Constellation says it is “on track” to restart the plant next spring and deliver energy into the grid by summer or fall.

In early June, the Federal Energy Regulatory Commission agreed to an unusual switch: It will let Constellation transfer “Capacity Interconnection Rights” from its diesel- and natural gas-burning electric power plants at Eddystone, Delaware County, to Three Mile Island, to speed the process of bringing the nuclear plant back online.

Constellation says it can do this without having to shut the Eddystone complex because the Trump administration gave the company special permission to keep Eddystone open, along with other fossil-fuel plants that were earlier scheduled for closing under a long-term program to reduce carbon-burning. It no longer needs the rights at Eddystone and can apply them at Three Mile Island.

The Susquehanna River Basin Commission in early June approved Constellation’s plan for using river water at the restarted Three Mile Island nuclear plant.

Constellation plans to pull 73 million gallons per day from the river to control temperatures at the plant. That’s about one-third of 1% of the river’s average flow; an equivalent volume of water will be released and won’t, on average, cause “significant adverse impact to the ecosystem and other users,” notes commission spokeswoman Stacey Hanrahan.

“Of course, we do not review a project based on average daily flow,” but on days the river is low, for example during a drought, she added. If the river gets too low for too long, Constellation could be ordered to stop using it.