The power purchase agreement is the easy part. When Constellation Energy signed its 20-year deal with Microsoft to revive Three Mile Island Unit 1 in Pennsylvania, the headline wrote itself. Microsoft committed to a 20-year power purchase agreement tied to the restart of the Crane Clean Energy Center (formerly Three Mile Island Unit 1), a roughly 835-megawatt unit that Constellation has said it expects to bring back online in 2028. What got less attention was the list of things that still had to go right before a single electron reached a data center.

Three restarts are now active simultaneously. Palisades Nuclear Plant in Michigan, which closed in 2022, has cleared major regulatory steps, including the NRC issuing a final environmental assessment for the restart application in 2025. Crane in Pennsylvania has advanced through key federal approvals, including an NRC license amendment in July 2026 allowing the site to receive and possess new nuclear fuel. Duane Arnold in Iowa is furthest out, with NextEra Energy materials describing a planned commercial operation date by the first quarter of 2029 under a long-term offtake arrangement.

Federal money is flowing. In November 2025, the DOE closed a $1 billion loan to Constellation to help finance the Crane Clean Energy Center restart, an 835-megawatt reactor that was shut down in 2019. The DOE has also closed a loan of up to $1.9 billion to help NextEra Energy restart the Duane Arnold Energy Center near Cedar Rapids, with Google entering into a 25-year agreement to purchase the plant’s 615-megawatt output that NextEra and trade publications have described as supporting a restart plan announced in October 2025.

The bottleneck nobody talks about is people. Under NRC rules, operator licenses are plant-specific, and an NRC operator license can expire after six years or earlier if employment is terminated or the facility determines the individual no longer needs to maintain a license. When Crane shuttered for economic reasons in 2019, its qualified operating crew scattered. Constellation has said it plans to hire more than 600 employees ahead of the restart. That months-long to years-long operator qualification path, including training and NRC examinations, is not something a tech balance sheet can simply compress on command.

Analysis commissioned by the National Center for Energy Analytics and conducted by the USC Marshall School of Business indicates it will be very difficult to provide the needed workforce based on current trends, with the gap between skilled workers needed and those available widening rapidly. The pool of skilled trades is shrinking, and the nuclear share is the hardest part to fill. The American Welding Society projects roughly 320,500 new welders will be needed by 2029 just to keep pace with retirements.

None of this means the projects fail. Palisades has begun fuel-loading-related activities, with Holtec reporting fuel loading started on August 30, 2026. The regulatory environment is the most permissive it has been in decades. But the gap between a signed PPA and electrons on the grid runs straight through a workforce that cannot be hired faster than it can be trained. That is where the nuclear revival will actually be won or lost.