TVA’s Clinch River Nuclear Power Project: Where Things Stand Today

The Tennessee Valley Authority (TVA) has for many years been evaluating emerging nuclear technologies, including small modular reactors, as part of technology innovation efforts aimed at developing the energy system of the future. TVA—the largest public power provider in the U.S., serving more than 10 million people in parts of seven states—currently operates seven reactors at three nuclear power plants: Browns Ferry, Sequoyah, and Watts Bar. Meanwhile, it’s also been investing in the exploration of new nuclear technology by pursuing small modular reactors (SMRs) at the Clinch River Nuclear site in Tennessee.

“TVA does have a very diverse energy portfolio, including the third-largest nuclear fleet [in the U.S.],” Greg Boerschig, TVA’s vice president for the Clinch River project, said as a guest on The POWER Podcast. “Our nuclear power plants provide about 40% of our electricity generated at TVA. So, this Clinch River project and our new nuclear program is building on a long history of excellence in nuclear at the Tennessee Valley.”

Clinch River Nuclear (CRN) Site

TVA completed an extensive site selection process before choosing the Clinch River Nuclear (CRN) site as the preferred location for its first SMR. The CRN site was originally the site of the Clinch River Breeder Reactor project in the early 1980s. Extensive grading and excavation disturbed approximately 240 acres on the project site before the project was terminated. Upon termination of the project, the site was redressed and returned to an environmentally acceptable condition.

The CRN property is approximately 1,200 acres of land located on the northern bank of the Clinch River arm of the Watts Bar Reservoir in Oak Ridge, Roane County, Tennessee (Figure 1). The property includes the CRN site, which is approximately 935 acres, and the Grassy Creek Habitat Protection Area, which is approximately 265 acres and located north of the CRN site. The property itself is owned by the federal government and is managed by TVA in accordance with the Watts Bar Land Management Plan.

The CRN site has a number of significant advantages, which include two existing power lines that cross the site, easy access off of Tennessee State Route 58, and the fact that it is a brownfield site previously disturbed and characterized as a part of the Clinch River Breeder Reactor project. Furthermore, it is immediately adjacent to the U.S. Department of Energy’s Oak Ridge Reservation (ORR), which was established in the early 1940s as part of the Manhattan Project, a secret undertaking that produced materials for the first atomic bombs. ORR consists of approximately 37,000 acres of federally owned land, the majority of which has remained undeveloped in a relatively natural state.

The Oak Ridge area is also noted to have a skilled local workforce, including many people familiar with the complexities of nuclear work. “The community acceptance here is really just phenomenal,” said Boerschig. “The community is very educated and very well informed.”

TVA began exploring advanced nuclear technologies in 2010. In 2016, it submitted an application to the Nuclear Regulatory Commission (NRC) for an Early Site Permit for one or more SMRs with a total combined generating capacity not to exceed 800 MW of electricity for the CRN site. In December 2019, TVA became the first utility in the nation to successfully obtain approval for an Early Site Permit from the NRC to potentially construct and operate SMRs at the site. While the decision to potentially build SMRs is an ongoing discussion as part of the asset strategy for TVA’s future generation portfolio, significant investments have been made in the Clinch River project with the goal of moving it forward.

GE Hitachi BWRX-300 Technology

TVA selected GE Hitachi Nuclear Energy’s (GEH’s) BWRX-300 SMR as the preferred technology for the CRN site. “The decision to pursue GE was made about three years ago,” Boerschig explained, noting that Generation IV technology still had a lot of unknowns at the time. Fuel was a significant factor behind the decision to go with GEH. Many advanced reactors require high-assay low-enriched uranium (HALEU) fuel, but the BWRX-300 does not. In 2022, the war in Ukraine had made many industry observers wary of HALEU’s availability because much of the potential supply was expected to come from Russia. There was legitimate concern around how embargos and other potential complications could affect HALEU supplies in the future.

“The [GEH] fuel is American made. It’s the same fuel assemblies as you’ll have in its Gen I and II counterparts,” said Boerschig. In fact, it’s the same exact fuel assemblies that are used in TVA’s Browns Ferry units. Concerning the BWRX-300, Boerschig also noted there were fewer first-of-a-kind features in the design and that the supply chain was more established. “GE’s supply chain is somewhere between 85% and 90% intact,” he said. “So, when you look at the risks of different technologies, for us—and I think it’s important to say, for how this technology fit into our enterprise needs—it was the right choice.”

Collaboration Reduces Risks

In March 2023, GEH, TVA, Ontario Power Generation (OPG), and Synthos Green Energy (SGE) agreed to team up to advance the global deployment of the BWRX-300 SMR. Through a technical collaboration agreement that was announced in Washington, D.C., TVA, OPG, and SGE agreed to invest in the development of the BWRX-300 standard design and detailed design for key components, including the reactor pressure vessel and internals. GEH, meanwhile, said it was committed to standard design development and anticipated a total investment of about $400 million associated with the development.

Each contributor said it would fund a portion of GEH’s overall cost and collectively would form a “Design Center Working Group” with the purpose of ensuring the standard design would be deployable in multiple jurisdictions. The long-term goal is for the BWRX-300 design to be licensed and deployed in Canada, the U.S., Poland, and beyond.

Notably, OPG has a BWRX-300 project well underway at its Darlington New Nuclear Project site in Clarington, Ontario, with construction expected to be complete by the end of 2028. This is expected to be the first grid-scale SMR in North America. While OPG is developing its project in parallel with the design process, TVA expects to wait for more design maturity before launching its CRN project. “As far as the standard design is concerned, we’re at the same pace, but overall, their project is about two years in front of ours,” said Boerschig. “And that’s by design—they are the lead plant for this effort.”

In the meantime, there are two primary items on TVA’s to-do list. “Right now, the two biggest things that we have on our list are completing the standard design work, and then the construction permit application,” Boerschig said, noting the standard design is “somewhere north of 75% complete” and that TVA’s plan is to submit the construction permit application “sometime around mid-year of this year.”

To hear the full interview with Boerschig, which contains much more about the CRN project, the development of a domestic nuclear supply chain, the role government leaders have played in supporting advanced nuclear technology, and the importance of the project to furthering U.S. competitiveness on the world stage, listen to The POWER Podcast. Click on the SoundCloud player below to listen in your browser now or use the following links to reach the show page on your favorite podcast platform:

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—Aaron Larson is POWER’s executive editor (@AaronL_Power, @POWERmagazine).