More than 400 new and returning Constellation (formerly Exelon) employees and Pennsylvania building trades members gathered at the Crane Clean Energy Center (formerly Three Mile Island NPP) to mark progress towards the plant’s restart. They were addressed by Pennsylvania Governor Josh Shapiro, local officials, and Microsoft and Constellation executives. The celebration followed reports that the plant could restart as early as 2027. This followed approval of an early interconnection request by grid operator PJM and significant progress made on hiring, reactor operator training and major equipment purchases.
In September 2024, Constellation Energy announced plans to restart unit 1 at the Three Mile Island (TMI) NPP in order to sell the power to Microsoft for its data centres to support the growing demand for artificial intelligence (AI). Microsoft agreed to purchase electricity from TMI-1 in a 20-year agreement to match the energy its data centres consume. Constellation at that time expected the unit to come back online in 2028, subject to approval by the Nuclear Regulatory Commission (NRC) and also planned to apply to extend the plant’s operations to at least 2054.
TMI comprises two pressurised water reactors (PWRs). The 819 MWe unit 1 operated from 1974 to 2019. The 906 MWe unit 2 began operation in 1978 but was permanently closed the following year following a partial core meltdown due to a cooling malfunction. TMI-2 Solutions plans to continue assessing the level of radioactivity in the reactor building, including using robots to take samples of concrete walls in the building’s basement. The company plans to start removing what remains of TMI-2’s damaged core by mid-2022. It expects to complete the entire clean-up process by 2037. Some 99% of TMI-2’s fuel has been moved to Idaho since the 1979 accident. But officials say removing the last 1% of fuel is challenging.
“Today we begin a new chapter for reliable, emissions-free nuclear energy, returning thousands of good jobs and billions in economic opportunities for Pennsylvania families and businesses,” said Joe Dominguez, Constellation President & CEO. “With PJM’s action, Microsoft’s historic investment, and strong support from Governor Shapiro, elected officials and members of this community, we’re on track to make history ahead of schedule, helping America achieve energy independence, supercharge economic growth, and win the global AI race.”
Governor Shapiro who lobbied PJM last year for approval of an early interconnection request, noted: “My Administration has worked closely with Constellation and PJM on the Crane Clean Energy Center since 2023 in order to get this new generation online as quickly as possible, ensure the reliability of our grid, and cement the Commonwealth’s energy future. This restart will safely take advantage of existing infrastructure while creating thousands of energy jobs and strengthening Pennsylvania’s legacy as a national energy leader.”
He added: “My proposed energy plan would spark the next generation of energy production here in Pennsylvania, and projects like this are going to help us continue to create energy jobs and build a more reliable, affordable energy grid. I look forward to continuing to bring people together to get stuff done for Pennsylvanians and speed up the development of new energy resources in the Commonwealth.”
Bobby Hollis, Vice President for Energy at Microsoft said: “As Microsoft continues its path to become a carbon negative company, this agreement brings a significant supply of new, reliable, carbon-free electricity back to the PJM power grid. This will help address the grids’ capacity and reliability needs in the regions we operate.”
Constellation says it continues to make strong progress toward the restart of the Crane Clean Energy Center. The facility is now more than 64% staffed, with nearly 400 full-time employees on board and 58 additional hires with start dates in the coming weeks. Significant technical milestones have also been reached, including the successful inspection of the plant’s diesel generator, steam generator, main generator, turbines, and other major systems.
Many of Crane’s office buildings have been renovated and enhancements to the training centre and control room simulator are nearly complete. The site’s new main power transformers will be delivered next year utilising the skills of hundreds of rigging experts, local skilled labour, and electrical specialists. Constellation remains on track with its regulatory filings and recently submitted key licensing amendments to NRC. In May, NRC approved a licence request to rename TMI unit 1 as the Crane Clean Energy Center.
An independent study by the Brattle Group, published last year by the Pennsylvania State Building & Construction Trades Council, found that Constellation’s $1.6bn investment to restart the Crane Clean Energy Center is expected to create 3,400 direct and indirect jobs; add $16bn to Pennsylvania’s GDP; and generate more than $3bn in state and federal tax revenue.
