# Radiant Says DOE Approved Safety Analysis for Planned Kaleidos Tests

By John Kim

Canonical URL: https://www.tokenpost.com/news/business/46035
Published: 2026-11-02T00:38:47.000Z
Updated: 2026-11-02T00:38:47.000Z
Section: Business

> Fuel loading and nuclear operations remain conditional on a DOE readiness review. Radiant’s five-phase plan calls for 60 effective full-power days.

Radiant Industries said Thursday, Oct. 29, that the U.S. Department of Energy (DOE) approved a safety analysis for its Kaleidos microreactor, clearing the way for a readiness review before planned power tests.

Radiant said the analysis covers initial criticality and operation at power. Kaleidos must pass a DOE Readiness Review before fuel loading and nuclear operations can begin, so the announcement does not mean the reactor has started up.

Radiant plans a five-phase campaign at the Demonstration of Microreactor Experiments (DOME) facility at Idaho National Laboratory. The company’s plan calls for 60 effective full-power days over several months, including at least 150 hours of continuous full-power operation without operator intervention. Radiant gave no dates for the review or the start of testing.

“This approval for full power demonstration is a first within the microreactor industry,” said Dr. Rita Baranwal, Radiant’s chief nuclear officer.

Last Energy announced on Oct. 7 that DOE had approved the safety analysis for its PWR-5 pilot. The pilot’s first phase is limited to initial criticality and low-power tests capped at 100 kilowatts thermal, with no electricity exports to the grid. Each phase requires separate DOE authorization.

Radiant said DOE approved its Preliminary Documented Safety Analysis in February 2026 and that the company shipped Kaleidos to Idaho National Laboratory in August. DOME is a test site for experimental reactors, and its results may support future commercial licensing applications.