Large Transformer Arrives for Restart Project at US Three Mile Island Unit 1

August 21 news, Constellation Energy, the company overseeing the refurbishment of the Three Mile Island nuclear plant, said this week that a transformer weighing approximately 262 tons, shipped from South Korea to Pennsylvania, USA, has arrived at the plant site in Middletown. This is the first of three large transformers planned for delivery to the site.

Constellation Energy is advancing the restart of Unit 1 at Three Mile Island and plans to rename the project the Crane Clean Energy Center. The unit has been shut down since 2019. Constellation Energy stated that the arrival of the transformer is a key milestone in its effort to restore 835 megawatts of reliable, zero-emission electricity supply by 2027.

The restart plan is linked to a partnership announced in 2024 between Constellation Energy and Microsoft. Under the agreement, Microsoft will sign a 20-year power purchase agreement with Constellation Energy to support the electricity needs of its data centers. As artificial intelligence business grows, data centers' demand for stable power supply continues to rise, drawing increased attention to nuclear plant restart projects.

Three Mile Island Unit 1 is adjacent to Unit 2. In March 1979, Unit 2 at Three Mile Island experienced a partial core meltdown, becoming one of the most consequential accidents in U.S. nuclear power history. Following the accident, surrounding areas were temporarily evacuated, and cleanup efforts continued for years.

There remains local opposition to the Unit 1 restart. Eric Epstein, chairman of Three Mile Island Alert, stated that the organization opposes the restoration and restart of Unit 1 at Three Mile Island and has filed a lawsuit in federal court on related matters, while also challenging the Pennsylvania Department of Environmental Protection's decision to approve relevant permits.

Epstein also raised objections to the project's water usage. He said that although the Susquehanna River Basin Commission allowed the Three Mile Island project to increase water withdrawals, nearly all of the 440 public comments received were opposed. Opponents worry that data centers and nuclear projects could lead to higher electricity prices, water resource stress, and environmental impacts on surrounding communities.

Pennsylvania Governor Josh Shapiro recently signed new regulations related to data center development, requiring developers to take on greater responsibility toward local residents and meet corresponding requirements before construction. The Governor's office stated that the state government continues to support the partnership between Constellation Energy and Microsoft and believes the project will help supply electricity to the grid.

Currently, Constellation Energy still needs to pass multiple regulatory reviews by the U.S. Nuclear Regulatory Commission (NRC) before it can formally resume operations at Three Mile Island Unit 1.