Microsoft's AI Ambitions Accelerate Three Mile Island Nuclear Plant Restart

Three Mile Island may return to service earlier than thought

A revamped Three Mile Island nuclear plant could be fueling Microsoft's AI datacenters sooner than first thought, according to Constellation Energy executives. In September 2024, Microsoft signed a 20-year power purchase agreement (PPA) with Constellation Energy to bring the shuttered TMI Unit-1 reactor -- not to be confused with the Unit-2 reactor that had a partial meltdown back in 1979 -- online in 2028. But now, the CEO is making noises about being ready early. "Two years from now... when PJM gets this thing interconnected, we're going to be ready," Constellation Energy CEO Joe Dominguez said during a press conference [Video] on Wednesday. PJM, which stands for Pennsylvania-New Jersey-Maryland, is the local grid operator for the portion of Pennsylvania where the plant is located. Constellation retired the 837-megawatt reactor back in 2019 after it failed to get subsidies it said were necessary for the plant to compete with cheaper fossil fuels. "We made 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," Dominguez said. As we previously reported, bringing the reactor back online won't be as simple as flipping a switch. While TMI Unit 1 has only been inactive for six years, the reactor itself is more than 50 years old, and the turbine, generator, transformers, and cooling and control systems will all need to be overhauled before it starts churning out electricity. The reopening will also need approval from the US Nuclear Regulatory Commission -- although that should be a known quantity for Constellation considering it already operates a fleet of 21 nuclear reactors across the United States. Faced with AI's seemingly insatiable thirst for power, Microsoft is one of several hyperscalers that have thrown their weight behind nuclear, and more specifically Constellation, over the past year. In June, Meta signed a 20-year PPA with Constellation to extend operations at its 1.1 gigawatt nuclear plant in DeWitt County, Illinois. The Clinton Clean Energy Center faced a similar fate as Three Mile Island's Unit 1 reactor once the state's zero-emission credit program expired in 2027. Prior to the deal, Meta had solicited proposals for between one and four gigawatts of nuclear energy deliverable by 2030. Amazon Web Services (AWS) has also sought refuge in the power of the atom, dropping $650 million to acquire Cumulus Data's nuclear bit barns, located alongside Talen Energy's 2.5 gigawatt Susquehanna nuclear power plant in northeast Pennsylvania. The original deal ensured Amazon access to a minimum of 480 megawatts of clean behind-the-meter energy, but was revised this spring after opposition from local utilities concerned about grid stability. So, rather than getting its energy directly from the nuclear plant, Talen will now provide AWS's datacenters in the region with up to 1.92 gigawatts of grid power through the end of 2042, with the potential for small modular reactors (SMRs) to boost the plant's output further. Alongside existing nuclear plants, SMRs have garnered considerable attention from hyperscalers, including Microsoft, Google, Amazon, and Oracle as a source of datacenter power. That said, most of these miniaturized reactors aren't expected to come online until the early 2030s. ®

Shut Three Mile Island nuclear plant may restart in 2027, owner says

THREE MILE ISLAND, Pennsylvania, June 25 (Reuters) - The former Three Mile Island nuclear power plant in Pennsylvania may restart in 2027, about a year ahead of schedule after being put on a fast track to connect to the regional grid, executives with the plant's owner Constellation Energy said on Wednesday. Constellation (CEG.O), opens new tab struck a deal last September to power Microsoft (MSFT.O), opens new tab data centers, paving the way to reopen Three Mile Island, widely known as the site of a partial meltdown in 1979 that chilled the nuclear industry. Constellation's 20-year power purchase agreement with Microsoft is emblematic of the dramatic lengths Big Tech has been willing to go to fuel its artificial intelligence expansion, which began to intensify a year-and-a-half ago. The reactor re-entering service at Three Mile Island, which is being renamed the Crane Clean Energy Center, was not part of the 1979 accident, and shut in 2019 for economic reasons. "We're on track to make history ahead of schedule, helping America achieve energy independence, supercharge economic growth, and win the global AI race," Constellation CEO Joe Dominguez said. At the time of the restart announcement last year, Constellation said it expected the plant to re-open in 2028. Officials with the company said they expected the process to be slowed by wait times associated with connecting power projects to the regional grid, which is operated by PJM Interconnection. Power projects can linger in PJM's queue, which is essentially the application and engineering study process to hook up a power plant to the broader grid. PJM's territory spans 13 states and the District of Columbia, covering about 67 million customers. As a way to alleviate some of that bottleneck, particularly as data centers rapidly proliferate on PJM's territory, the country's largest grid operator has fast-tracked its interconnection process for select projects. As the technology industry drives U.S. electricity demand to record highs, nuclear power has broadly seen a resurgence of interest after decades in decline. New York said this week it plans to build a new nuclear power plant, which would be one of the first to be constructed in a generation. Despite the enthusiasm, nuclear power plant projects have historically been far over budget and behind schedule. No fully shut nuclear power plant has been restarted, but at least one other attempted restart - of the Palisades nuclear plant in Michigan - is under way. Reporting by Laila Kearney; Editing by Sonali Paul Our Standards: The Thomson Reuters Trust Principles., opens new tab Suggested Topics:Artificial IntelligenceGrid & InfrastructureNuclearClimate Change

Microsoft's rekindling of Three Mile Island nuclear plant is ahead of schedule

The Three Mile Island nuclear power plant could restart as soon as 2027 - a year ahead of its original reopening date of 2028 - but with a key difference compared to its former life. Only Unit 1 will be restarted, because it was not involved in the 1979 meltdown, which affected Unit 2. Although Unit 1 remained open following the incident, it was shut down in 2019 due to economic reasons (not safety concerns). This time around, it's set to be operated by Microsoft, following the company's deal on a 20-year power purchase agreement (PPA), signed in September 2024, in conjunction with Constellation Energy. Microsoft is specifically interested in this nuclear plant because of its rising energy consumption and surging demands, caused by its power-hungry AI data centers. As a result, Redmond and other hyperscalers including Meta, AWS and Oracle have all invested heavily in nuclear energy to meet demand. For example, Meta recently signed a similar 20-year deal for Illinois' Clinton nuclear plant, and AWS invested $650 million in nuclear-powered data centers near the Susquehanna plant in Pennsylvania. Water systems have now been restored to the site and infrastructure inspections completed, according to Reuters reporting. The site is now awaiting grid connection approval from the regional grid operator, with the Nuclear Regulatory Commission set to inspect the site as soon as next month. More broadly, Microsoft's decision to reopen a closed nuclear site is the first of its kind and a reflection of the industry-wide scramble to produce more energy. Record-high US electricity demand is also causing a surge in nuclear plants specifically, thanks to their relatively high output. Constellation CEO Joe Dominguez admitted: "We made a mistake in shutting down this plant, but we're not here to dwell on the past." Looking ahead, as Microsoft and its Big Tech rivals gear up to integrate AI into more aspects of work and personal life, it's clear that more needs to be done not only to generate enough electricity, but also to address the growing environmental concerns.

Three Mile Island nuclear plant reboot fast-tracked to 2027

THREE MILE ISLAND, Pennsylvania (Reuters) -The former Three Mile Island nuclear power plant in Pennsylvania may restart in 2027, about a year ahead of schedule after being put on a fast track to connect to the regional grid, executives with the plant's owner Constellation Energy said on Wednesday. Constellation struck a deal last September to power Microsoft data centers, paving the way to reopen Three Mile Island, widely known as the site of a partial meltdown in 1979 that chilled the nuclear industry. Constellation's 20-year power purchase agreement with Microsoft is emblematic of the dramatic lengths Big Tech has been willing to go to fuel its artificial intelligence expansion, which began to intensify a year-and-a-half ago. The reactor re-entering service at Three Mile Island, which is being renamed the Crane Clean Energy Center, was not part of the 1979 accident, and shut in 2019 for economic reasons. "We made a mistake in shutting down this plant, but we're not here to dwell on the past," said Constellation CEO Joe Dominguez at an event on Three Mile Island, backed by giant cooling towers and the nuclear plant that will be brought back as Crane. The nuclear building is in similar shape to when it shut in 2019, and since the restart announcement, most of the work has been around planning and hiring, Constellation said. The company has ordered several key items for the restart, including its main transformer and fuel. It has also restored water systems needed to run the plant and completed various infrastructure inspections needed for permitting approvals. At the time of the restart announcement last year, Constellation said it expected the plant to re-open in 2028. Officials with the company had said they expected the process to be slowed by wait times associated with connecting power projects to the regional grid, which is operated by PJM Interconnection. "When PJM gets this connected, we're going to be ready," Dominguez said on Wednesday. Despite the enthusiasm, nuclear power plant projects have historically been far over budget and behind schedule. No fully shut nuclear power plant has been restarted, but at least one other attempted restart - of the Palisades nuclear plant in Michigan - is under way. As the technology industry drives U.S. electricity demand to record highs, nuclear power has broadly seen a resurgence of interest after decades in decline. New York plans to build a new nuclear power plant, which would be one of the first to be constructed in a generation. FAST-TRACKED PROJECTS Hundreds of Constellation workers joined Wednesday's event, along with PJM CEO Manu Asthana and Pennsylvania Governor Josh Shapiro, who pushed for the restart to be fast-tracked for approval through PJM. Power projects can linger in PJM's queue, which is essentially the application and engineering study process to hook up a power plant to the broader grid. PJM's territory spans 13 states and the District of Columbia, covering about 67 million customers. As a way to alleviate some of that bottleneck, particularly as data centers rapidly proliferate on PJM's territory, the country's largest grid operator has fast-tracked its interconnection process for select projects. Crane was the largest of the projects expedited by PJM, Shapiro said. "I am focused like a laser beam on the future of Pennsylvania and the future runs through places right here like Crane," he said. More than 400 people have been hired to work at the plant so far, and there are 30 operators who can work in control rooms in training for the reopened plant, according to Dominguez and other Constellation officials. The Nuclear Regulatory Commission is expected to visit Crane in July to observe the training process, they said. (Reporting by Laila Kearney; Editing by Sonali Paul, Liz Hampton and Marguerita Choy)