Antares

What Antares does

Antares Nuclear, Inc. (formerly Antares Industries) is a Torrance, California-based advanced nuclear energy startup founded in 2023 that designs and manufactures factory-produced fission microreactors for U.S. defense and civil space customers. Its core product is the R1 microreactor—a 100 kWe to 1 MWe transportable reactor using high-assay low-enriched uranium (HALEU) TRISO fuel in a prismatic graphite core, sodium heat-pipe passive cooling, and a nitrogen closed recuperated Brayton cycle power conversion system, capable of 6+ years of operation without refueling and deployment without connection to the commercial power grid or requirement for water cooling.

The company executes an iterative develop-build-test program through the Mark-0 zero-power criticality demonstrator (initial criticality achieved at Idaho National Laboratory on June 4, 2026 under the DOE Reactor Pilot Program), the planned Mark-1 electricity-producing reactor targeted for 2027, and R1 production units for deployment to U.S. military installations and lunar surface missions starting in 2028. Antares is vertically integrated at the 322,000 sq-ft Antares Prime facility, with in-house nuclear-grade graphite machining, automated control systems, and hardware-in-the-loop digital twins that have compressed the concept-to-criticality timeline to less than 12 months. The company is pre-revenue commercially, with current income from federal R&D and demonstration contracts (notably a $40M+ Idaho National Laboratory partnership), and the business model is anchored on direct sales of reactors and long-term operations/refueling/decommissioning services to U.S. federal agencies and, eventually, allied markets. Customers are concentrated in the U.S. Department of Defense (Army Janus Program; Air Force/DIU ANPI initiative at Joint Base San Antonio), NASA (Fission Surface Power for the lunar surface by 2030), and the Department of Energy, with fuel secured via a long-term HALEU enrichment services agreement with Urenco.

Name

Antares

Legal name

Antares Nuclear, Inc.

Website

https://antaresindustries.com

Company type

Private

Founded year

2023

Operating status

Operating

Headcount range

101–250 employees

Short description

Antares Nuclear designs and manufactures factory-produced sodium heat-pipe-cooled fission microreactors (R1, 100kWe–1MWe, TRISO fuel) for U.S. defense and civil space customers, having achieved first private advanced-reactor criticality at Idaho National Laboratory in June 2026.

Ownership category

akta.pro rank

Product category

Advanced Nuclear Microreactor Manufacturing

NAICS

Nuclear Electric Power Generation (221113), Electric Power Generation (22111), Power Boiler and Heat Exchanger Manufacturing (332410)

SIC

Engines & Turbines (3510), Cogeneration Services & Small Power Producers (4991)

akta.pro primary industry

Gen IV / Advanced Reactor Systems (SFR, LFR, GFR, MSR, HTGR, Microreactors) (EUAKADAC)

akta.pro secondary industries

Reactor Core Design, Neutronics & Thermal-Hydraulics Engineering Tools (EUAKADAD), Reactor Vessel, Internals & Primary Circuit Components (RPV, piping, pumps, valves) (EUAKADAE)

Keywords

• Nuclear microreactor design
• Factory-produced fission reactors
• Advanced nuclear energy
• Defense nuclear power systems
• TRISO fuel microreactor

Headquarters

HQ city

Los Angeles

HQ country

United States

HQ region

North America

Offices3 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Infrastructure, Personnel, Supply Chain, Marketing or Sales, Operations

Revenue model

1. Government Reactor Procurement (Planned): Planned revenue from sale or delivery of factory-produced R1 microreactors and successor variants to U.S. federal customers including the Department of the Army (Janus Program), Department of the Air Force (ANPI initiative), NASA (Fission Surface Power program), and other federal agencies. First commercial production deployments targeted for 2028.
2. Federal Program Awards and R&D Contracts: Current revenue from U.S. government R&D and demonstration contracts, including a $40M+ agreement with Idaho National Laboratory to build and demonstrate the Antares R1 microreactor and establish a permanent testing facility. Pre-revenue commercial; capital raised (~$140M+ to date) funds ongoing operations.
3. Long-Term Operations, Refueling, and Decommissioning Services (Planned): Planned recurring/managed services revenue from siting, licensing, constructing, operating, and decommissioning deployed R1 microreactors at customer sites such as Joint Base San Antonio, with multi-year refueling intervals of 6+ years supporting long-term service relationships.
4. Pre-Revenue Development Stage: Company is pre-revenue; first electricity-producing reactor targeted for 2027 and initial customer production deployments targeted for 2028, with funding to date provided by venture capital rather than product sales.

Pricing tiers

Go-to-market motion3 records

Distribution channels5 records

Marketing channels6 records

Core offering

Antares Nuclear designs and manufactures factory-produced sodium heat-pipe-cooled fission microreactors, centered on the R1 platform delivering 100 kWe to 1 MWe for 6+ years of operation without refueling. The reactor uses TRISO-coated particle fuel in a prismatic graphite core with passive sodium heat-pipe cooling and a nitrogen closed recuperated Brayton cycle, and is designed for transportable, off-grid deployment on Earth, in space, and underwater. The company is pre-revenue, with planned initial military deployments in 2028 and Mark-1 electricity-producing demonstration targeted for 2027.

Product overview

Antares offers a vertically integrated nuclear microreactor platform centered on the R1 Microreactor — a transportable, sodium-heat-pipe-cooled reactor delivering 100 kWe to 1 MWe for 6+ years, using TRISO fuel in a prismatic graphite core with a nitrogen closed recuperated Brayton cycle. The platform is realized through an iterative development program across three products: the Mark-0 Demonstrator Reactor (zero-power criticality achieved June 4, 2026 at INL), the Mark-1 Electricity-Producing Reactor (full-power prototype planned for 2027 at the same INL facility using the same TRISO fuel), and the R1 production microreactor for deployment to military bases (e.g., Joint Base San Antonio under ANPI), space (NASA Fission Surface Power for lunar surface power by 2030), and other strategic customers starting in 2028. Underpinning capabilities — Special Purpose Reactors, Heat Pipes & Thermal Management, Control Systems, and in-house nuclear-grade Graphite Machining — are co-located at Antares Prime to enable rapid design-manufacture-test iteration, supported by HALEU fuel from BWX Technologies and a long-term Urenco enrichment services agreement.

Differentiator

Problem solved

Functional benefit

Brands

• R1 Microreactor: Antares' primary factory-produced sodium heat pipe-cooled fission microreactor product line, designed for defense and space applications with power output from 100 kWe to 1 MWe.
• Antares Prime
• Mark-0
• Mark-1

Products and services

• R1 Microreactor Factory-produced, transportable, sodium-heat-pipe-cooled fission microreactor delivering 100 kWe to 1 MWe for 6+ years without refueling, for defense and space applications on Earth, in space, and underwater.
• Mark-0 Demonstrator Reactor Full-scale-core zero-power fueled criticality demonstration reactor built to validate reactor physics, neutronics, reactivity control, and I&C systems for the R1/Mark-1 program; uses TRISO fuel fabricated by BWX Technologies.
• Mark-1 Electricity-Producing Reactor Planned full-power, electricity-producing advanced reactor scheduled for testing in 2027 at the same INL test facility using the same batch of HALEU TRISO fuel compacts as Mark-0; validates full-power system performance and closed Brayton cycle power conversion.
• Antares Prime Manufacturing Facility Vertically integrated 322,000 sq-ft headquarters and manufacturing facility in Torrance, CA that integrates design, manufacturing, and testing for the R1 microreactor and future reactor variants; at steady state designed to support manufacturing the first 50 reactors.

Quantifiable outcome

• First private advanced non-light-water reactor to reach criticality in the U.S. in over four decades
• +5 more outcomes

Named customers6 records

Segments4 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration1 record

Feature10 records

Partnerships

Twelve partnerships are on record, tiered flagship / core and core.

• U.S. Department of the Armyflagship / coreStrategic or Co-development Partner · 4 June 2026Integrated throughout the Mark-0 reactor demonstration at Idaho National Laboratory as a future end user, supporting the Army Janus Program. Antares cited as a key supplier of advanced nuclear microreactors for military installations with goal of delivering power to warfighters by 2028.
• Urencoflagship / coreStrategic or Co-development Partner · 21 May 2026Signed a long-term enrichment services agreement for High-Assay Low-Enriched Uranium (HALEU) for Antares' factory-produced microreactors, described as the world's first multi-year contract for HALEU supply. Fuel to be produced at Urenco's U.K. HALEU enrichment facility (on schedule to be one of the first Western licensed facilities, coming online 2031), supporting North American and allied market deployments.
• CPS EnergycoreStrategic or Co-development Partner · 8 May 2026Announced a partnership with Joint Base San Antonio (selected as the third potential ANPI site) to support the development of a nuclear microreactor at the military installation. Provides utility-side coordination and supports energy resilience against cyber attacks and natural disasters.
• U.S. Department of the Air Forceflagship / coreStrategic or Co-development Partner · 22 April 2026Selected Antares under the Advanced Nuclear Power for Installations (ANPI) initiative for proposed deployment of a prototype Antares R1 nuclear microreactor at Joint Base San Antonio, Texas. Antares anticipates siting, licensing, constructing, operating, and decommissioning R1 microreactors, with systems targeted for deployment by 2028 or earlier.
• Defense Innovation Unit (DIU)coreStrategic or Co-development Partner · 22 April 2026Joint program partner with the Department of the Air Force for selecting Antares for the ANPI initiative at Joint Base San Antonio. Evaluates bases based on infrastructure, land availability, and critical mission requirements; supports microreactor deployment by 2030 or earlier.
• U.S. Army Project Pele (Strategic Capabilities Office)flagship / coreStrategic or Co-development Partner · 26 January 2026Antares' Mark-0 fuel design is based on TRISO compacts previously supplied for the U.S. Army's Project Pele transportable microreactor program, contributing verification and validation data back to Project Pele. Validates decades of DOE investment in the AGR-2 TRISO specification and the Project Pele fuel supply chain at BWXT.
• NASAflagship / coreStrategic or Co-development Partner · 2 December 2025Target customer and program partner under NASA's Fission Surface Power program, which aims to land a 100-kWe reactor on the lunar surface by 2030. Program requirements align with Antares' manufacturing core competencies and design, positioning Antares to compete in sector-defining federal programs across the Department of the Army, NASA, and other federal agencies.
• NASA Marshall Space Flight CentercoreStrategic or Co-development Partner · 20 November 2025Host site for Antares' first Electrically-Heated Demonstration Unit (EDU-1) test campaign in 2025, used to validate the interface between graphite moderator blocks and sodium heat pipes at temperature, heat pipe throughput, and nitrogen heat exchanger performance.
• Savannah River National Laboratory (SRNL) Advanced Manufacturing CollaborativecoreStrategic or Co-development Partner · 14 August 2025Industry partner at the new SRNL Advanced Manufacturing Collaborative on the University of South Carolina Aiken campus. Government, industry, and academia collaborate side-by-side to strengthen the U.S. industrial base and deliver manufacturing innovations. Ribbon-cutting attended by Secretary of Energy Chris Wright, Senator Lindsey Graham, and Representative Joe Wilson.
• U.S. Department of Energy (DOE)flagship / coreStrategic or Co-development Partner · 13 August 2025Selected Antares for the DOE Nuclear Reactor Pilot Program (one of 10/11 projects fast-tracking advanced test reactors to deployment). Executed an agreement in September 2025 to take an advanced reactor critical on American soil by July 4, 2026. Authorizes Mark-0 under DOE-1271 standard in lieu of NRC commercial licensing during testing phase.
• BWX Technologies (BWXT)flagship / coreStrategic or Co-development Partner · 30 July 2025Fabricated TRISO nuclear fuel for the Mark-0 reactor at the company's Lynchburg, Virginia facility using high-assay low-enriched uranium (HALEU) feedstock from NNSA scrap materials. The fuel specification was matured through BWXT's prior work on the U.S. Army's Project Pele transportable microreactor program. BWXT is a foundational fuel supply chain partner and co-developer for both Mark-0 and Mark-1.
• Idaho National Laboratory (INL)flagship / coreStrategic or Co-development Partner · 30 July 2025Signed two contracts with INL: a $40M+ agreement (one of the largest partnerships in INL history) to build and demonstrate the Antares R1 microreactor in an existing facility at INL (Building 793 / RACE), and a second contract moving toward establishing and siting a permanent testing facility at INL for ongoing reactor testing and operation prior to field deployment.

Scale indicators10 records

Recent moves9 records

Expansion highlights5 records

Direct peers

• Westinghouse (eVinci Microreactor): Westinghouse is developing the eVinci microreactor, a heat-pipe-cooled solid-core design in the same 200 kWe–5 MWe class as Antares' R1. Both companies are selected for the DOE Reactor Pilot Program and pursue U.S. defense and remote-power customers, making them direct head-to-head competitors in the microreactor procurement landscape.
• Oklo: Oklo is developing the Aurora microreactor (1.5 MWe) using a heat-pipe / sodium-cooled fast-spectrum design — architecturally the closest analog to Antares' R1. Oklo is also a DOE Reactor Pilot Program participant and pursues both defense and commercial customers, making it a directly comparable peer.
• Aalo Atomics: Aalo Atomics is a sodium-cooled microreactor startup also selected for the DOE Reactor Pilot Program, targeting DOE testbed and data-center power customers. It is a near-direct peer to Antares in mission, architecture, and customer set.
• Last Energy: Last Energy is developing the L.E. microreactor, a small modular pressurized-water design targeting private and European commercial customers. It is part of the same wave of private advanced reactor companies competing for similar procurement programs and HALEU allocations.
• Radiant Nuclear: Radiant Nuclear is developing the Kaleidos microreactor, a high-temperature gas reactor in the ~1 MWe range, also selected for the DOE Reactor Pilot Program. It competes directly with Antares for defense, remote-site, and microgrid customers.
• TerraPower: TerraPower is developing the Natrium sodium-cooled fast reactor and is a DOE Advanced Reactor Demonstration Program awardee. Although at a larger MWe scale than Antares' microreactor, TerraPower is a DOE Pilot Program peer competing for advanced-reactor fuel allocations and federal program slots.
• Kairos Power: Kairos Power is developing the fluoride-salt-cooled high-temperature reactor (Hermes / KP-FHR) and is also a DOE Pilot Program participant. Kairos shares Antares' focus on non-LWR designs, HALEU fuel qualification, and the DOE testbed pathway.
• X-energy: X-energy is developing the Xe-100 high-temperature gas reactor and the TRISO-X fuel fabrication business. As a TRISO-fuel-led competitor and DOE Advanced Reactor Demonstration Program awardee, X-energy is a directly comparable peer in fuel architecture and federal-customer focus.

Broad incumbents

• BWX Technologies (BWXT): BWXT is Antares' foundational TRISO fuel supply partner (via the Project Pele lineage) but is also a broad incumbent nuclear defense contractor developing its own microreactor (Project Pele). BWXT is simultaneously a key collaborator and a competitor for defense microreactor contracts.

Emerging players

• Valar Atomics: Valar Atomics is an emerging advanced reactor startup co-invested alongside Antares in Balerion Space Ventures' frontier-technology portfolio. It is an early-stage competitor pursuing overlapping DOE / defense microreactor opportunities.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks7 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/antares-industries
• Xx.com/AntaresNuclear

Compliance3 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles11 records

Funding overview

Funding rounds6 records

Investors16 records

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M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Antares