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Kaleidos

Artist rendering with Radiant and logo above the reactor design with the primary heat exchangers, helium circulators, control drum, core, and vessel shell pointed out.


Project Overview

The U.S. Nuclear Regulatory Commission (NRC) is currently engaged in pre-application activities with Radiant Industries, Inc. (Radiant), starting in October 2022. Radiant is an El Segundo, CA company developing its Kaleidos design, a transportable micro-reactor designed to generate 3MWth and approximately 1MWe. The Kaleidos micro-reactor is a high-temperature gas-cooled reactor (HTGR) using TRISO fuel, helium gas coolant, and prismatic graphite blocks. Each micro-reactor will be fully contained in a single shipping container.

For more information, please see the Radiant pre-application documents (NRC Docket 99902106).

To subscribe to the Radiant Kaleidos email service, select Radiant Kaleidos from the Advanced Reactors list after entering your email into the GovDelivery system.

Pre-Application Activities

ProductTypeReference Status
Radiant Kaleidos Micro-reactor Pre-application Regulatory Engagement Plan – October 2023Regulatory Engagement PlanML23286A328No review requested
10 CFR 70 Gap AnalysisWhite PaperML24115A321ML24262A066
10 CFR Part 50 and 52 Gap AnalysisWhite PaperML24250A206ML25013A338
10 CFR Part 100 Gap AnalysisWhite PaperML24275A261ML25017A130
10 CFR Part 51 Gap AnalysisWhite PaperML24298A242ML25023A086
10 CFR Part 55 Gap AnalysisWhite PaperML25188A228Under Review
Kaleidos Fleet Operator Training White PaperWhite PaperNon-public proprietaryUnder Review
Kaleidos Factory Fueling OperationsWhite PaperML25226A241No Review Requested
Kaleidos Development Unit Commissioning PlanWhite PaperNon-public ProprietaryUnder Review
Radiant Regulatory Plan Engagement UpdateWhite PaperNon-public ProprietaryUnder Review
Radiant R-50 Microreactor Facility Greater than Critical Mass Application for Kaleidos Reactor ProductionMaterials LicenseML26058A374
ML26074A001
ML26107A169
ML26110A219
Accepted
ML26112A019

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Contacts

Contacts for the Kaleidos Pre-Application Review
Lead Project ManagerKevin Roche
Contact a Public Affairs Officer

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Page Last Reviewed/Updated Monday, May 11, 2026

Page Last Reviewed/Updated Monday, May 11, 2026