US firm to build Gen-4 molten salt reactor for direct heat, power

US-based Terrestrial Energy has entered into an Other Transaction Authority (OTA) agreement with the Department of Energy (DOE) for Project TETRA, which involves building and operating a pilot Integral Molten Salt Reactor (IMSR). This molten salt-fueled, graphite-moderated reactor uses standard assay low-enriched uranium (SALEU) fuel with less than 5% U-235, distinguishing it from other advanced reactors that require high-assay low-enriched uranium (HALEU). The OTA framework allows DOE oversight without traditional federal contracting, facilitating the transition from design to operation. The pilot aims to validate IMSR technology for commercial deployment, demonstrating its ability to generate electricity and provide industrial heat efficiently, operating at 44% thermal efficiency and delivering heat at 700°C for direct industrial use. The IMSR design integrates primary components into a sealed core-unit with an estimated seven-year lifespan to manage graphite moderator degradation, enabling modular replacement without complex maintenance. By using SALEU fuel, Ter