US nuclear operators seek power uprates to meet AI data centre demand

American nuclear power plant operators are increasingly seeking regulatory approval to increase the maximum power output of existing facilities. These uprates are designed to bridge the energy gap while new nuclear capacity is under development. The Nuclear Regulatory Commission (NRC) oversees the maximum power levels permitted for commercial nuclear plants, which are detailed in each facility’s license and technical specifications. Operators must request permission from the NRC to alter these limits. The agency evaluates applications based on safety, requiring modifications to reactor instrumentation, controls, and power-generation systems before granting approval.

Over the past two decades, the NRC has authorised uprates that have added six gigawatts of power to the US electricity grid, a capacity equivalent to six large reactors. Analysts estimate that increasing output from existing plants could add between six and eight gigawatts of clean power. Although these upgrades can cost billions of dollars, they allow operators to produce more electricity significantly faster than building new facilities. Many upgrades can be completed within five years. To implement these changes, plant operators must upgrade components such as controls, turbines, and pumps.

Constellation Energy, the largest nuclear power plant operator in the United States, announced plans in October to invest over $4.3 billion to refurbish 11 reactors at six plants in Illinois, Pennsylvania, and New Jersey. This investment is expected to add 890 megawatts of power, sufficient to supply 700,000 homes. Google has agreed to purchase electricity from these plants at an undisclosed price. Separately, the US Department of Energy announced it would conditionally loan $4.2 billion to Vistra to uprate three nuclear plants in Pennsylvania and Ohio, adding 430 megawatts of capacity. Amazon has also completed an agreement to uprate Constellation’s Calvert Cliffs Nuclear Power Plant in Maryland, while Google announced plans to increase production from four reactors in Georgia.

These projects are part of a broader response to rising US power demand driven by the rapid rollout of artificial intelligence data centres. The Trump administration, which has announced plans to quadruple US nuclear power capacity by 2050, supports these initiatives. Energy Secretary Chris Wright stated that increasing output from existing plants would deliver more affordable, reliable, and around-the-clock energy. While operators previously struggled to secure funding during a period of plateaued demand and poor public perception, the current surge in demand has encouraged tech companies to invest heavily in energy projects, including nuclear, gas, and renewable sources.

The NRC expects to receive 31 power uprate applications between 2026 and 2032, totalling 7.3 gigawatts thermal and 2.4 gigawatts electric. The agency is anticipated to approve several of these projects, as many applicants have decades of experience in US nuclear power development. However, some operators are cautious because uprate work requires stopping power production for several months. Despite this, the willingness of tech companies to invest in nuclear energy may convince more companies to pursue these upgrades. Uprating operations are unlikely to detract from plans to develop new nuclear plants, but they offer a rapid way to expand capacity while new facilities are designed, licensed, and constructed.