The Antares R1 Mark-0 Reactor Project at Idaho National Laboratory (INL) involves deploying and operating the Antares R1 Mark-0, a small, high-temp…
Office of NEPA Policy and Compliance
January 26, 2026The Antares R1 Mark-0 Reactor Project at Idaho National Laboratory (INL) involves deploying and operating the Antares R1 Mark-0, a small, high-temperature heat pipe reactor configured for zero-power criticality testing. This version of the reactor is not equipped with power conversion or heat removal systems and is designed to serve as a validation platform for advanced nuclear reactor technologies. The primary objective of this project is to demonstrate the feasibility, safety, and efficiency of the reactor design under various operational conditions.