Terrestrial Energy signed an Other Transaction Authority (OTA) agreement with the US DOE in March 2026 for Project TETRA — work to build a pilot IMSR reactor under DOE support. The OTA agreement provides Terrestrial Energy with DOE authorisation and resources to advance its pilot reactor programme. Project TETRA is separate from the Texas A&M RELLIS campus deployment and represents Terrestrial Energy's DOE-backed demonstration pathway. Following the announcement, IMSR stock surged 50% in three days of trading in March 2026. Terrestrial Energy was selected for the DOE Reactor Pilot Program in August 2025, targeting a criticality demonstration by July 4, 2026. The 195 MWe integral molten salt reactor operates at high temperatures, enabling hydrogen production and industrial heat alongside electricity, and the company is pursuing NRC licensing in the US and CNSC licensing in Canada while raising $280 million through a SPAC combination with HCM Acquisition Corp.