Radiant Receives First TRISO Fuel Shipment at INL's DOME Facility, Clearing Path to Full-Power, Full-Temperature Testing

Five Phase Testing Program Targets More Than 150 Hours at Full Power Without Operator Intervention

July 1, 2026

July 1st, 2026 – Radiant, a leading developer of advanced nuclear technologies, received its first tranche of nuclear fuel at the National Reactor Innovation Center’s Demonstration of Microreactor Experiments (DOME) facility located at Idaho National Laboratory (INL). The tri-structural ISOtropic (TRISO)-fuel was fabricated by Standard Nuclear in Oak Ridge, Tenn., to Radiant's specifications earlier this year. It will be used to power Radiant’s Kaleidos reactor to conduct a full-power, full-temperature test this summer – kicking-off months of rigorous testing and validation, to support manufacturing and customer delivery by 2028. Testing a reactor powered by the same fuel form and specifications that will be used in our commercial reactors is a key milestone towards advancing nuclear power for the American people.

Radiant is the only developer conducting testing at the DOME facility. The company is embarking on a five-phase reactor development testing program designed to collect critical reactor and fuel performance data, which will help accelerate the commercial licensing process with the U.S. Nuclear Regulatory Commission (NRC). With fuel now on site, Radiant is poised to bring Kaleidos online - progressing through zero-power criticality, 1 MW thermal, full power, and full heat, before operating for a minimum of 150 hours at full power without operator intervention, a crucial milestone in proving commercial readiness.

“We are de-risking a commercial product that will be manufactured and delivered within 18 months,” said Dr. Rita Baranwal, chief nuclear officer at Radiant. “Receipt of our freshly fabricated, modern-pedigree, custom-made fuel is a key milestone toward that goal. Radiant has been very disciplined with our testing program at the DOME; we are testing our prototypic fuel, coolant, and power levels to validate our product and ensure success for our customer deployment by 2028.”

This data collected will also play a key role in supporting Radiant’s Part 70 license application for its R-50 manufacturing facility in Tennessee, which is in accelerated review by the NRC. Once approved, the license will enable Radiant to handle and load fuel for its Kaleidos reactors before shipping to customers across the United States, unlocking standardized mass production.

Radiant is delivering more than just a single operating reactor; it is building a scalable, reliable energy solution that can be transported by land, sea, and air to be deployed wherever it is needed.

About Idaho National Laboratory

Battelle Energy Alliance manages INL for the U.S. Department of Energy's Office of Nuclear Energy. INL is the nation's center for nuclear energy research and development, and also performs research in each of DOE's strategic goal areas: energy, national security, science and the environment. For more information, visit www.inl.gov. Follow us on social media: Facebook, Instagram, LinkedIn and X.