Three Mile Island to reopen for Microsoft data centers

Constellation Energy and Microsoft announced an agreement last Friday to restart Three Mile Island, a nuclear power plant near Harrisburg, Pennsylvania. It’s a victory for reliable energy and shows the ability of the market to meet the needs of private investment.

The nuclear power plant would produce power exclusively for Microsoft’s data centers for 20 years. The deal was announced on the fifth anniversary of the plant’s closure in 2019. Reviving the reactor would require approval by the U.S. Nuclear Regulatory Commission, then would be expected to return to operation in 2028.

Tech giants like Microsoft and Amazon Web Services are seeking nuclear power for affordable and reliable electricity that is also low carbon. Powering data centers with wind and solar would be well and good if the wind was always blowing and the sun always shining, but data centers need more than intermittent power — and tech giants know it.

USA Today reports:

When Three Mile Island was shuttered for economic reasons in 2019, it had a generating capacity of 837 megawatts, enough to power more than 800,000 homes. Once brought back online, Constellation Energy said that it expected to once again generate more than 800 megawatts of electricity for Microsoft, as well as potentially add up $16 billion to Pennsylvania’s GDP along with 3,400 direct and indirect jobs.

No U.S. nuclear power plant has ever reopened after being decommissioned, which could make the Three Mile Island plant a first once it is brought back to operational status.

The Unit 2 reactor of the Three Mile Island plant suffered a partial nuclear meltdown on March 28, 1979. The accident was caused by a combination of “equipment failure and the inability of plant operators to understand the reactor’s condition at certain times during the event.” Fortunately, the accident “caused no injuries or deaths,” and the amount of radiation released was “too small to result in discernible direct health effects.” More than a dozen epidemiological studies have borne this out. The Unit 1 reactor was shut down in 2019. The Three Mile Island accident spurred anti-nuclear activists, but it also spurred safety and efficiency advancements.

It’s heartening to see private investment bringing back reliable sources of energy to the grid.