California-based startup Radiant Industries has decided that it will build its first reactor factory on a Manhattan Project site in Oak Ridge, Tennessee, an investment of $280m. With construction expected to start in early 2026, Radiant says it will be on track to deliver its first mass-produced Kaleidos nuclear generator by 2028. Within a few years, it will scale up production to 50 reactors a year and plans to name the new factory R-50.
Radiant’s Kaleidos microreactor design is a transportable high-temperature gas-cooled reactor (HTGR) using high-assay low-enriched uranium (HALEU) tristructural-isotropic (TRISO) fuel, helium gas coolant, and prismatic graphite blocks. It has a capacity of 3 MWt or 1 MWe. Each 70-tonne microreactor will fit into a single shipping container. Radiant says the reactor can set up to be producing power within 48 hours of delivery at a customer site. The reactor has a five-year fuel cycle and a 20-year service life. Refuelling is carried out at a remote maintenance facility.
The land for Radiant’s new factory, which encompasses portions of the historic K-27 and K-29 Manhattan Project sites, was purchased from the Oak Ridge Industrial Development Board. “What was formerly the first Manhattan Project site will now be the site of the first portable nuclear generator production,” said Radiant CEO and Founder Doug Bernauer. “By 2028, we’ll be rolling out the first factory-built nuclear generator, and within a few years we’ll be producing over a dozen per year.”
Tori Shivanandan, Chief Operating Officer of Radiant, said: “We chose Oak Ridge, Tennessee, because of their strong workforce, the community’s rich nuclear heritage and the public’s second-to-none nuclear IQ. Just as importantly, the state’s business-friendly environment gave us the immediate regulatory certainty we needed to move fast and be up and running to meet growing customer demand for our nuclear generators. We’re excited to start building in just a few months.”
Previously Radiant had planned to build the factory in Natrona County, Wyoming but abandoned the plan after facing significant public opposition and regulatory hurdles, including Wyoming state law, in particular its ban on storing used fuel. Natrona County Economic Development Joint Powers Board rescinded its application for a $25m grant to support Radiant’s plans.
Matt Wilson, Radiant’s Senior Director of Operations, noted: “Recent commercial wins, our growing work with the US military, and the speed at which Radiant is moving towards successfully turning on our first reactor next year, all demanded a turnkey location where we could be quickly up and running to meet customer demand. Given that … we had to make a very tough decision to site our first factory in Oak Ridge, Tennessee instead of Wyoming.” He added: “While Radiant will be focused on our future operations in Tennessee, I plan to watch Wyoming’s development from a distance with hope there will be a future where energy innovation is prioritised and encouraged.”
Senator Scott Heiner, who co-chairs the Interim Minerals Committee, said Radiant pressured lawmakers to move too quickly to change state law to accommodate its plans, noting that most lawmakers only learned of the company’s proposal earlier this year. “They’ve made their decision before we’ve had a chance to go through the whole legislative cycle,” he told WyoFile. “We took public testimony, we tabled the decision until later, and they’ve decided to go. They’ve held that over our head for the whole time: ‘If you don’t approve this, then we’re going to go to Tennessee’. Well, something that huge, you don’t rush it.”
Radiant is the sixth company to locate in Tennessee utilising the Tennessee Department of Economic & Community Development’s Nuclear Energy Fund (NEF). The $50m fund was in Governor Bill Lee’s recommended 2023-2024 budget and approved by the Tennessee General Assembly. An additional $10m was allocated and approved in the state’s budget during both the 2024 and 2025 The fund aims to expand the state’s nuclear development and manufacturing ecosystem by providing grants and assistance to support nuclear energy business investment, workforce development programmes, and site development across Tennessee. Radiant received a NEF grant of $2m.
In September, BWXT Enrichment Operations received a grant of 2.37m to expand its fuel facility in Erwin. This followed a grant of 1.2m in April for its planned centrifuge assembly plant in Oak Ridge. In April, Oklo received a grant of $13m to support its planned fuel and reactor facility in Oak Ridge. In April 2024, Orano received $6m for its planned centrifuge uranium enrichment facility in Oak Ridge. A further grant of $5m was allocated to Oak Ridge to facilitate land transfer to Orano. In February 2024, Type One Energy received $4.5m. Type One is planning to construct a stellarator fusion plant at a for coal-fired plant site.
Read more: Radiant completes microreactor design phase
