Radiant's Kaleidos Microreactor Shipped to Idaho National Laboratory for Testing

On August 13, Radiant announced that its 1-MW-class portable microreactor Kaleidos has departed its facility in El Segundo, California, and is being transported by trailer to Idaho National Laboratory (INL). The unit will undergo testing at INL's Microreactor Experimental Demonstration Facility (DOME).

According to Radiant, the Kaleidos transport distance exceeds 1,000 miles. The company stated that the unit shipped to INL is not a scaled test article, but rather a reactor model consistent in design, dimensions, and commercial fuel loading with the units planned for delivery to customers.

The DOME facility has completed modifications for microreactor testing. Following a competitive selection process by the U.S. Department of Energy, Radiant was awarded a one-year usage arrangement at the facility. The company stated that Kaleidos will undergo phased testing at DOME, including criticality, 1-MW thermal power operation, full-power operation, and continuous operation, with the ultimate goal of achieving at least 150 hours of full-power, unattended continuous operation by the third quarter of 2026.

Radiant stated that data obtained from this testing will support its license application to the U.S. Nuclear Regulatory Commission (NRC) and reduce risks for subsequent commercial manufacturing and deployment. The company believes that zero-power criticality experiments alone can only validate fundamental neutron physics characteristics, while full-scale, full-power testing more closely approximates commercial deployment conditions.

As planned, upon arrival at Idaho National Laboratory, Kaleidos will be installed in the DOME facility and loaded with specification-customized TRISO fuel under the oversight of the U.S. Department of Energy and INL. The reactor will then proceed progressively through Radiant's five-phase test plan.

Meanwhile, Radiant stated that its license application submitted under Part 70 of U.S. regulations continues to progress on an accelerated review schedule, with a target approval date in the fourth quarter of 2026. The company's approximately 80-acre site in Oak Ridge, Tennessee, will house fuel loading and manufacturing facilities, with the facilities expected to become operational in January 2027.

Radiant has also signed an agreement with the U.S. Air Force to deliver Kaleidos to Buckley Space Force Base by 2028 for a military installation power supply demonstration. The company is positioned in advanced nuclear technology development, with the goal of providing microreactor energy solutions deployable by land, sea, and air for commercial, industrial, and defense customers.