US Microreactor Passed Initial Stage of Preliminary Safety Review

Microreactor startup Radiant Industries has announced that the US Department of Energy has reviewed and approved the Safety Design Strategy for Kaleidos microreactor in the National Reactor Innovation Center’s Demonstration of Microreactor Experiments (DOME) test bench at Idaho National Laboratory (INL).

The Radiant company based in California develops the 1 MW Kaleidos high-temperature gas-cooled portable microreactor, which will use a graphite core and TRISO fuel.

The Safety Design Strategy, which describes the accepted approach to Kaleidos reactor safety analysis, is the initial stage of a comprehensive safety review that has to be performed by each microreactor developed before a fueled test at DOME.

Testing is scheduled to begin in 2026 within financing of the US Department of Energy in the amount of 3.9 million USD received by the company to develop and test its designs on a new DOME test bench at INL. According to the company, this will allow it to gather data important to safety and performance to support the future commercial licensing process with the US Nuclear Regulatory Commission (US NRC).

After successful completion of reactor testing on a DOME test bench and receival of licenses from the US NRC, Radiant is planning to deliver a limited amount of pre-order Kaleidos units in 2028.

The DOME test bench will repurpose the Experimental-Breeder Reactor-II containment structure at INL. The reactor operated in 1964-1994 and was originally constructed to demonstrate a complete sodium-cooled breeder reactor power plant. It was later modified to test other reactor designs and to test materials and fuels for fast reactors, as well as to generate power and heat for the site. Though reactor and much of its supporting equipment were dismantled, the remaining 70-foot diameter and 80-foot height containment structure is particularly suited to host reactor demonstration and other nuclear designs.