The restart of Three Mile Island could signal a shift in the future of nuclear energy as the influence of Big Tech on the power industry continues to grow.

• The restart of Three Mile Island could signal a shift in the nuclear industry's financial outlook, which has been struggling with closures due to economic factors.
• This year, the tech industry has undergone a significant transformation, with the shift towards nuclear power as the primary source of electricity to fuel artificial intelligence.
• Microsoft and the grid will be helped by Constellation Energy's confidence that the plant will restart on schedule in 2028 and supply power.

The Three Mile Island nuclear power plant owner plans to restart operations by the end of the decade, signifying the next phase in the plant's history, which represents both the future potential and past challenges of nuclear energy in the US.

The two cooling towers, which reach over 300 feet above the Susquehanna River near Middletown, Pennsylvania, were shut down in 2019 due to "severe economic challenges."

Over the past decade, a dozen nuclear reactors in the U.S. shut down due to the industry's struggle to compete against inexpensive and plentiful natural gas. However, this year, the fortunes of the nuclear industry have undergone a significant shift as technology companies with deep pockets have turned to nuclear power to meet the immense electricity demands of their future business, artificial intelligence.

The owner of the plant plans to restart Unit 1 in 2028, pending approval from the Nuclear Regulatory Commission. Constellation, based in Baltimore, is the largest operator of nuclear power plants in the U.S., with 21 of the 94 reactors under its control.

"Trevor Orth, the plant manager, informed the NRC at an Oct. 25 meeting that the plant ran exceptionally well and was shut down. He explained the shutdown process and has a clear plan for restarting it."

The Three Mile Island plant, which will be restored by Constellation, will be renamed the Crane Clean Energy Center in honor of the late CEO of Exelon, Chris Crane. The restart will cost $1.6 billion and will be financed by the company's own funds.

Explore the inner workings of the Three Mile Island nuclear power plant in greater detail.

The tech sector's growing role in shaping the future of the U.S. power industry is evident through the agreement to purchase the full electricity output from the plant for 20 years, which has made the restart of Unit 1 possible.

Microsoft announced that the agreement is part of its strategy to reduce carbon emissions from its data centers by using clean energy sources.

The data centers are vital to the U.S. economy, as they host the servers that power cloud computing, which is essential for businesses and consumers to perform their daily digital tasks. Additionally, these data centers are crucial for the advancement of artificial intelligence, a technology that is viewed as vital for the nation's future economic competitiveness and national security.

One of the major uncertainties with four years until the planned restart is whether Constellation will be able to provide the required power to Microsoft on schedule. Nuclear projects are notorious for long delays, significant cost overruns, and cancellations. However, Unit 1 is in good condition, and Constellation is confident that the plant will restart on schedule, as stated by Bryan Hanson, the company's chief generation officer.

During an Oct. 30 tour of Unit 1, Hanson stated that most of the restoration work at the nuclear plant would be routine maintenance that Constellation performs on its fleet of plants regularly.

""The infrastructure is already in place, so no concrete needs to be poured, no rebar needs to be tied, and no cables need to be pulled. The challenge of delays does not exist," the executive stated."

In response to Holtec International's decision to restart its Palisades nuclear plant in Michigan, Constellation has decided to restart Three Mile Island. Palisades is set to become the first reactor to resume operations in the U.S. in 2025 after being shut down.

In the 2030s, Holtec intends to almost double the facility's power capacity by constructing two small modular reactors, which are the latest technology that aims to make nuclear power plants more affordable and easier to set up.

and Google recently announced investments in small modular reactors.

Hanson stated that although Constellation has not yet decided to construct a small modular reactor at any of its plants, the company is willing to collaborate with the tech industry to develop new nuclear reactors in the U.S.

If our customers return and express a desire to collaborate with us on building new nuclear power plants, we will likely work together to find a solution, as Microsoft did.

Lingering fears

The location of the worst nuclear accident in U.S. history is near Unit 1.

The Unit 2 reactor at Three Mile Island experienced a partial meltdown in 1979, which negatively impacted the growth of new nuclear power plants in the U.S. Currently, Unit 2 is being decommissioned by Energy Solutions, a private nuclear services company.

The Office of Nuclear Energy at the Department of Energy shut down Unit 1 due to economic reasons, said Mike Goff, acting assistant secretary.

Pennsylvania state Rep. Thomas Mehaffie stated that his constituents have mixed opinions regarding the restart of Unit 1, particularly those who are old enough to recall the accident at Unit 2.

Mehaffie, who represents the communities around Three Mile Island at the state legislature in Harrisburg, stated that there has always been concern among those who were present during that time frame and are older. His father, a union electrician, played a role in building the nuclear plants.

Hanson said the nuclear industry has learned from this chapter of its history.

Hanson stated that the 1979 accident showed that our standards were not accurate at the time. He added that the U.S. nuclear industry currently has the highest safety, reliability, and operational standards globally.

Although some people have reservations, others recognize the economic benefits that restarting Unit 1 will bring, Mehaffie stated. A study by the Pennsylvania Building & Construction Trades Council estimates that the restart will result in approximately 3,400 jobs in the region.

Grid reliability

Restarting Three Mile Island Unit 1 will provide 835 megawatts of carbon-free electricity, equivalent to the consumption of more than 600,000 homes, and help ensure the region's electric grid remains reliable, Mehaffie said.

PJM Interconnection, which operates the grid in Pennsylvania and 12 other states, warned in July that electricity demand is exceeding supply due to the retirement of coal-powered power plants at a faster rate than new capacity is being constructed.

"Grid reliability is everything," Mehaffie said.

By 2039, electricity demand is predicted to increase by nearly 40% due to the growth of data centers, manufacturing, and the electrification of industry and transportation. However, 21% of PJM's installed capacity, or 40 gigawatts of power generation, is at risk of retirement by 2030.

During a public hearing on Nov. 1, Mark Christie, a commissioner at the Federal Energy Regulatory Commission, stated that there is a possibility of catastrophic early retirements of dispatchable resources.

Tech companies' direct-to-data-center power deals could worsen supply shortages and jeopardize grid stability, according to concerns of federal energy regulators.

Microsoft will not use the electricity it purchases from Unit 1 to power its data centers directly, but instead will feed it into the grid to support the grid's overall power supply. Alistair Speirs, senior director of global infrastructure for Microsoft's Azure cloud platform, stated that Microsoft is committed to strengthening the grid as it secures power for its data centers.

If we fail to stabilize and add resiliency to the grid while operating in the community, it becomes challenging for us to maintain our social license to operate, according to Speirs.

While Microsoft is not responsible for the physical restoration of the plant, Constellation is providing updates to the company.

Restoration and restart timeline

In its first public meeting with the Nuclear Regulatory Commission on Oct. 25, Constellation revealed its plan to restart the plant. Although Wall Street is optimistic about the restart, Citi has warned that the company may encounter difficulties in completing the project on schedule.

According to Citi analyst Ryan Levine, who spoke to clients on Oct. 14, the regulatory and physical challenges that [Constellation] faces are likely to result in some delays and cost overruns during the restart process.

In October, Citi began covering Constellation with a neutral rating due to delay concerns, despite the stock's gain of over 90% since the beginning of the year and 12% following the Three Mile Island restart announcement on Sept. 20.

The stock is rated a buy or strong buy by the vast majority of analysts, with an average price target predicting more than 23% upside.

The steam generators and main power generator, which are crucial and expensive equipment, have been inspected and maintained by Constellation and are in good condition, according to Hanson.

The main power generator, constructed by General Electric over 50 years ago, has been cleaned and requires routine maintenance, he stated.

Hanson stated that the replacement of the main power transformers of the plant, which is estimated to cost between $75 million and $100 million, is expected to occur in late 2026.

The cooling tower will be refurbished, while the analog control room will undergo some rewiring, according to Hanson.

To restore the simulator that mimics the control room, plant operators must undergo NRC certification training, which takes approximately 18 months, according to Hanson.

The NRC has prohibited Constellation from operating and loading fuel into the reactor vessel at the permanently shut-down plant. However, Constellation intends to submit an exemption request in November to lift these restrictions if it is approved.

Dennis Moore, senior manager of licensing at Constellation, informed the NRC that "our restart activities will officially begin with that."

In February, Constellation intends to submit a request to rename the plant from Three Mile Island to the Crane Clean Energy Center. The company will later submit technical specifications, environmental impact, emergency plan, and site security plan for NRC review in 2025.

The NRC will receive an operational readiness letter from Constellation by July 2027, after which the company will commence testing and resume operations if the NRC deems the plant ready and grants permission to load fuel into the reactor.

The NRC does not require permission from Constellation to begin restoration work at the plant, said Scott Burnell, a spokesperson for the regulator. The NRC will monitor the work to ensure compliance with its requirements.

Goff stated that Three Mile Island and Palisades are likely to obtain NRC approval.

Goff stated in September that although they are an independent agency, he anticipates they will approve safety cases if they are presented.