The Tennessee Valley Authority (TVA), the largest federally owned utility in the United States, has received approval from the Nuclear Regulatory Commission (NRC) to construct a small modular nuclear reactor at its Clinch River site near Knoxville, Tennessee. This marks the second time U.S. regulators have authorized the building of a next-generation commercial reactor, following a March approval for a project in Wyoming supported by Bill Gates' TerraPower.
The TVA’s permit authorizes the construction of a BWRX-300 reactor, designed by GE Vernova Hitachi Nuclear Energy. This small reactor generates approximately 300 megawatts of power, roughly one-fourth the capacity of conventional reactors such as those at the Vogtle nuclear plant in Georgia. The TVA is exploring the possibility of building up to four such reactors at Clinch River, aiming to leverage smaller designs that proponents say could be more cost-effective and quicker to build than traditional large-scale nuclear plants.
Mike Skaggs, the TVA’s interim president, described the permitting milestone as a pivotal step for the future of American nuclear energy. While the TVA has not provided a timeline for construction, past estimates suggested the initial small reactor could cost up to six times more than a similarly sized gas-fired plant. However, officials expect costs to decline with experience and through subsequent builds.
Interest in nuclear power in the United States has grown amid rising electricity demand partly driven by the expansion of AI data centers. Both former President Trump’s administration and many lawmakers across party lines have expressed support for expanding nuclear energy, citing its ability to provide continuous power without greenhouse gas emissions. Nevertheless, challenges remain, including the significant costs and long timelines historically associated with nuclear construction projects. For instance, the Vogtle reactors have been completed years behind schedule and at double the original budget, underscoring the risks involved.
The TVA’s project is part of a broader wave of activity involving small modular reactors (SMRs). Ontario Power Generation in Canada, for example, is also developing BWRX-300 units and recently laid the foundation for its first reactor. Other U.S. companies, like Blue Energy and Kairos, are pursuing different SMR designs to power data centers and other applications, often emphasizing factory-built components and innovative cooling methods to enhance safety and efficiency.
Additionally, TerraPower is constructing a sodium-cooled SMR to complement renewable power sources, while some start-ups and the U.S. Army are exploring smaller reactors for military use. Despite renewed enthusiasm for nuclear energy, larger conventional reactors, such as the AP1000 design employed at Vogtle, remain on the table, with the Energy Department recently offering substantial loan guarantees to support new builds.
The NRC’s process for assessing the TVA’s construction permit took 14 months, ahead of its scheduled deadline, reflecting congressional and administrative efforts to expedite nuclear licensing without compromising safety, a balance that has drawn debate among stakeholders. Although the construction permit is now secured, TVA must still obtain a separate operating license before the reactor can go online.
Founded in 1933 as part of the New Deal, the TVA currently operates three nuclear plants in Tennessee and Alabama. Its most recent addition, Watts Bar Unit 2, achieved commercial operation in 2015 after nearly four decades of delays. The agency’s move toward smaller reactors signals a potential shift in the U.S. nuclear landscape, seeking to overcome past challenges while addressing future energy demands.