THREE MILE ISLAND, Pennsylvania, Oct 16 (Reuters) - Constellation Energy (CEG.O) , opens new tab has ordered a main power transformer for the Three Mile Island nuclear reactor it is attempting to restart in Pennsylvania, pushing ahead with work critical to the plant's revival, Reuters learned on a tour of the site on Wednesday.

The transformer is expected to be the biggest single piece of equipment that will need to be replaced for restart of the plant. It will cost about $100 million, said Constellation, the owner of the plant, which is investing $1.6 billion to revive the operation over the next four years.

When deciding whether to move forward with a restart, Constellation surveyed the site to determine the condition of essential infrastructure and equipment, much of which has sat idle since the plant shut in 2019.

"I have walked the facility top to bottom, every floor," Constellation Vice President of Generation Bryan Hanson said from inside the turbine deck at Three Mile Island, which is being renamed Crane Clean Energy Center. "The plant is in great condition."

Constellation announced last month that it signed a 20-year power contract with Microsoft (MSFT.O) , opens new tab to help restart the plant. The nuclear reactor, which is located on an island in the Susquehanna River in Pennsylvania, is expected to supply 835 megawatts of power to offset Microsoft's data center electricity consumption.

The sudden and voracious energy needs of Big Tech to power an expansion of artificial intelligence and cloud computing has doubled the country's projected electricity demand and led to a spate of unusual deals between power companies and the technology industry in the past year.

No modern U.S. nuclear power plant has been restarted after fully shutting down, according to regulators. Three Mile Island is largely known as the site of the worst nuclear power accident in U.S. history.

In 1979, a unit at the plant experienced a partial meltdown, which caused no deaths, but released small amounts of radioactive gases and raised concerns about the potential health effects on surrounding communities, including the state capital. That unit will not be restarted.

Separate Unit 1, which Constellation wants to resurrect, shut in 2019 for economic reasons. Constellation expects Unit 1 to begin producing power in 2028, but there is a series of physical hurdles, along with U.S. and local regulations, that must be completed first.

Among other major investments in resuming operations at the plant are work on the reactor's turbine, generator and cooling systems.

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https://www.reuters.com/business/energy/constellation-orders-100-million-transformer-three-mile-island-restart-2024-10-16/