The revived Three Mile Island nuclear plant, set to power Microsoft’s AI data centers across the region, may be ahead of schedule, according to Constellation CEO Joe Dominguez.

At a press conference on Wednesday (25 June), Dominguez said: "Two years from now… when PJM gets this thing interconnected, we're going to be ready."

Constellation and Microsoft signed a 20-year Power Purchase Agreement (PPA) last September, where the tech giant agreed to offtake the entire capacity of the plant's unit one reactor, which has a capacity of 837MW.

The reactor located near Harrisburg, Pennsylvania, was retired back in 2019, following a failure to acquire the subsidies needed for the plant to compete with cheaper alternatives.

In the press conference, Dominguez noted that it had been a “mistake in shutting down this plant. But we're not here to dwell on that mistake. We're here to look to the future."

Restarting the reactor is expected to be quite an arduous task, as it will require a renovation of much of its inner workings, including the turbine, generator, transformers, and cooling and control systems. However, given Dominguez’s upbeat tone, it seems that Constellation is ahead of schedule on the renovation works. Works to restart the reactor are expected to cost around $1.6 billion.

Constellation acquired unit one of the plant in 1999, and intends to pursue a license renewal that will extend plant operations to at least 2054. The project will be renamed the Crane Clean Energy Center and was initially expected to come online in 2028. However, if Dominguez is to be believed, it could reach operational status in 2027 instead.

Before the reactor can come into service, it will require approval from the US Nuclear Regulatory Commission.

Constellation is the US’s largest provider of nuclear energy, with a fleet of 21 operational nuclear reactors. In June, the company signed a 20-year PPA with Meta for the entire output of the 1.121GW Clinton Clean Energy Center, in Clinton, Illinois. Marking the second major deal the company has inked with a hyperscale customer. The PPA is expected to commence in June 2027 and will support the expansion of the plant by a further 30MW through uprates.

The deals follow a prevailing trend in the data center sector of developers seeking long-term nuclear energy supply agreements. Earlier this month, AWS and Talen Energy signed a 17-year PPA for 1.92GW of energy from the 2.5GW Susquehanna nuclear power plant.

The PPA is contracted until 2042 and contains an option to extend. The agreement nixed a proposed behind-the-meter agreement for the same plant, which had been rejected by the Federal Energy Regulatory Commission last November, due to concerns it could raise public power bills and affect the grid's reliability. The rejection was upheld following an appeal, leading the companies to explore a different approach.

Data center firms have also invested heavily in the small modular reactor (SMR) and microreactor sector to support the technology's commercialization. In the last 12 months, Amazon Web Services, Google, and Data4 have all signed deals with SMR firms.