Kaleidos Development Unit
In Development
Radiant Nuclear
Overview
The first full-scale Kaleidos article, the same design, size, and commercial fuel load intended for customers, built in El Segundo and shipped by trailer to INL's DOME facility for a five-phase campaign: install and fuel, zero-power criticality, 1 MW thermal, full-temperature/full-power operation, and a minimum 150-hour unattended run.
Left El Segundo on August 12, 2026. TRISO fuel fabricated by Standard Nuclear has been at DOME since July 1. Radiant targeted completing the campaign in Q3 2026. As of September 18, 2026 it had not announced criticality or any later phase. DOE awarded Radiant exclusive DOME access for a full year.