Antares Secures $96 Million to Advance R1 Microreactor Development

Nuclear technology firm Antares announced the closing of a $96 million Series B funding round supporting the maturation of its R1 microreactor design.

The financing comprised $71 million in equity and an additional $25 million secured through debt financing instruments. The investment was led by Shine Capital, with participation from Alt Capital, Caffeinated, FiftyThree Stations, and Industrious, among other investors. Antares is targeting deployment across commercial, defense, and nascent space-based power generation sectors with its modular unit. The R1 system is engineered to generate between 100 kilowatts and 1 megawatt of continuous electrical output.

This power scale makes the reactor suitable for decentralized energy needs where grid access is impractical or unavailable. The reactor architecture relies on TRISO fuel technology, specifically utilizing uranium encapsulated within carbon and ceramic coatings embedded in a graphite matrix. This fuel type is recognized for its inherent safety characteristics and high-temperature tolerance. This influx of capital reflects broader investor confidence in advanced nuclear solutions for decarbonization and energy resilience.

The sector has seen intensified activity recently, including X-energy’s substantial $700 million Series D round last month. Furthermore, competitors are also attracting resources; Aalo Atomics raised $100 million in August to power data centers, while TerraPower, backed by Bill Gates, closed a $650 million round earlier this year. This trend demonstrates significant appetite for fission-based energy infrastructure outside traditional utility scale.

Antares has been integrated into the Department of Energy’s reactor pilot program, which mandates demonstration operations for select participants by mid-2026. The company has stated an intention to conduct a demonstration of its reactor technology next year. Consequently, the $96 million raise positions Antares to meet aggressive federal timelines, with full-power operational readiness projected for 2027.

Successfully deploying a microreactor in this timeframe would position Antares advantageously in the rapidly evolving domestic energy technology market.