Can Existing Nuclear Reactors Power AI Data Centers Faster?

Increasing the output of existing nuclear reactors could provide more reliable, low-carbon electricity for data centers in a relatively short time. But how much additional power can nuclear power plants generate through upgrades?

What Is a Nuclear Power Uprate?

Operators can increase the capacity of existing nuclear power plants by upgrading equipment and changing how the plant operates. This process is known as a power uprate.

U.S. operators have pursued power uprates since the 1970s. However, the projects became less common in recent years as electricity demand peaked and inexpensive natural gas put financial pressure on nuclear power plants. Some plants were shut down, while investing in additional generation capacity did not make economic sense at others.

From 2001 to 2010, the U.S. Nuclear Regulatory Commission approved more than 80 power uprates. Between 2011 and 2020, it approved 33.

AI Is Renewing Interest in Nuclear Power Upgrades

The rapid growth of artificial intelligence and the resulting increase in electricity demand are changing the economics of nuclear power uprates. Shuttered facilities such as Palisades and Three Mile Island are racing to reopen, while operating nuclear plants are considering ways to increase their output.

Some uprates are relatively minor and involve changes to equipment settings or plant calculations. More extensive modifications can increase reactor power by as much as 20%, but they require the replacement or upgrade of major equipment.

How Nuclear Reactor Uprates Generate More Electricity

Increasing the amount of fuel in a reactor—either by using more concentrated fuel or loading larger amounts of fresh fuel—can produce more steam. That steam turns a turbine to generate electricity.

To manage the additional energy, operators may need to upgrade the main turbine and other equipment, including pumps, motors, generators and transformers.

Browns Ferry Project Increased Capacity by 14%

The most recent significant power uprate approved in the United States was for three reactors at the Browns Ferry nuclear power plant in Alabama. The $475 million project increased the plant’s power-generation capacity by 14% between 2018 and 2019.

Constellation Plans $4.3 Billion Nuclear Upgrade

The nuclear industry could soon see a new wave of uprate projects. Constellation recently announced plans to spend more than $4.3 billion upgrading 11 of its nuclear reactors. The additional capacity is expected to generate enough electricity to power approximately 700,000 U.S. homes.

Big Tech investment is helping drive the plans. Google has agreed to purchase electricity from the plants under a 20-year agreement, which was a major factor in the planned rate increases.

Constellation CEO Joe Dominguez told The New York Times: “Frankly, these are capital-intensive, labor-intensive projects that require different price points than market transactions.”