US Navy Selects Radiant Kaleidos Microreactor to Power Naval Weapons Station Crane

The Department of the Navy on October 20, 2026, selected Radiant Industries, Inc. to design, build and deliver a prototype Microreactor Power Plant (MPP) at Naval Weapons Station (NWS) Crane, Indiana, placing the company’s Kaleidos high-temperature gas-cooled microreactor at an installation the Navy describes as critical military infrastructure. The selection runs through the Army’s Janus Program in partnership with the Department of War Innovation Unit (DIU) and aims to give Crane grid-independent, dispatchable power.

The Navy stressed that the Crane reactor is not a new or additional effort. It is accounted for within the Janus awards announced on August 26, 2026, when the Army selected five vendors and five initial installations under agreements worth up to a combined $2.2 billion through fiscal 2031, with more than 20 microreactors expected across Department of War installations. Radiant’s share is a binding agreement worth up to $750 million for 15 Kaleidos units, starting with a three-unit deployment at Fort Benning, Georgia. Janus implements Executive Order 14299 of May 2025, which set a September 2028 target for a first reactor operating on a military installation.

How the Navy Microreactor Plan Leverages the Army Janus Vehicle

Rather than standing up its own acquisition, the Navy is riding the Army’s Janus contracting vehicle and DIU’s commercial innovation framework. The Navy says this approach streamlines the path to deployment. Dr. Jeff Waksman, Principal Deputy Assistant Secretary of the Army for Installations, Energy and Environment, said the program was built from day one to deliver real, reliable hardware “across all of the Services,” adding that the Crane unit will give Indiana its first advanced microreactor.

Janus reactors are contractor-owned and contractor-operated, with the Army regulating them under its own nuclear authorities rather than through the Nuclear Regulatory Commission (NRC). The Navy release describes a slightly broader oversight structure for Crane: experts from the Naval Nuclear Propulsion Program will provide technical support through design refinement, prototype testing, regulatory coordination and site preparation, working alongside the NRC and other partners. The release does not specify which authority will license the Crane plant, its cost, or a target operating date. Those gaps matter for any assessment of schedule risk.

Radiant says the Crane selection makes it the only nuclear company selected by all three U.S. military departments. The Department of the Air Force and DIU earlier selected Kaleidos for Buckley Space Force Base, Colorado, under the Advanced Nuclear Power for Installations initiative, with Radiant targeting delivery there in 2028.

Kaleidos Microreactor Design: Helium-Cooled TRISO Core in a Container

Publicly available specifications describe Kaleidos as a transportable high-temperature gas-cooled reactor rated at roughly 3 megawatts thermal and about 1 megawatt electric. The core uses high-assay low-enriched uranium (HALEU) in tristructural isotropic (TRISO) particle fuel, with helium as coolant. The complete system fits in a single shipping container, is designed to move by road, sea or air, and is rated for up to five years of operation between refuelings over a 20-year service life. Units are fueled and refueled at the factory, and Radiant says no spent fuel remains on site.

Each of those choices carries operational weight. TRISO particles retain fission products at temperatures well above normal operating conditions, the basis for the design’s passive safety case. Factory fueling means no fuel handling on base, a significant consideration at an installation that stores and processes ordnance. Transportability means units can be added or relocated as Crane’s load profile changes.

The design remains unproven at power. The Kaleidos Demonstration Unit arrived at Idaho National Laboratory’s Demonstration of Microreactor Experiments (DOME) facility in August 2026 for a five-phase campaign running from zero-power criticality to full power and a 150-hour continuous run without operator intervention. Radiant’s October 20 announcement describes Kaleidos as in testing at DOME and does not report criticality. In parallel, the NRC is reviewing Radiant’s Part 70 application for the fueling building of its R-50 reactor factory in Oak Ridge, Tennessee, and expects to complete that review by December 18, 2026.

Why NWS Crane Needs Grid-Independent Power for Weapons Work

NWS Crane hosts two tenants with national-level missions. Crane Army Ammunition Activity produces and distributes joint conventional munitions, while Naval Surface Warfare Center, Crane Division supports weapons development, electromagnetic warfare, strategic missions and advanced manufacturing. A grid outage at Crane interrupts work feeding both munitions supply and fleet modernization.

Brendan Rogers, Assistant Secretary of the Navy for Energy, Installations, and Environment, called dedicated, localized microreactor power “a national security imperative.” Radiant’s announcement specifies a single Kaleidos unit for Crane. At roughly 1 MWe, however, that unit would likely carry prioritized critical loads within an installation microgrid rather than the entire base.

Analysis: The Crane selection points to a joint acquisition model for installation nuclear power: one Army-run vendor pool, one contracting vehicle, and service-specific sites layered on top. It spares the Navy a separate procurement and gives Radiant a demand signal large enough to justify serial production at R-50. The trade-off is concentration of technical risk. Fort Benning, Buckley and Crane now depend on the same reactor design, which has yet to publicly demonstrate criticality. A slip in the DOME campaign would ripple across all three services at once.

Next steps at Crane include final environmental reviews, localized site design and regulatory coordination with federal, state and local partners. The near-term markers are Kaleidos criticality and its 150-hour run at DOME, the NRC decision on the R-50 factory license, and Navy disclosure of cost and schedule for Crane, all measured against the September 2028 first-reactor target.