US firm's mass-producible Kaleidos nuclear reactor gets key approval

Radiant, a US-based manufacturer of portable nuclear microreactors, has received critical approval from the Department of Energy (DOE) for its DOE Authorization Request for Kaleidos (DARK). This approval, serving as a Preliminary Documented Safety Analysis (PDSA), is the second of three safety milestones under the DOE’s Authorization Pathway for Nuclear Facilities and enables Radiant to proceed toward a full-power test of its 1-megawatt electric Kaleidos microreactor. The reactor, designed for diverse environments, produces 1.9 megawatts of thermal power and features an innovative cooling system that uses fans and an air jacket for natural convection, eliminating the need for on-site water. The Kaleidos units are portable, fitting within standard shipping containers for transport by truck or aircraft, and have a 20-year lifespan. Radiant plans to produce 50 Kaleidos units annually at its upcoming R-50 factory in Oak Ridge, Tennessee, aiming for a commercial release in 202