TheTechno Optimist.

IMSRTerrestrial Energy—Terrestrial Energy executes OTA agreement for Project TETRA with DOE Advanced Reactor Pilot ProgramTerrestrial Energy—Terrestrial Energy begins trading on Nasdaq under ticker IMSR following completion of HCM II mergerIMSRTerrestrial Energy—Terrestrial Energy executes OTA agreement for Project TEFLA fuel salt production facility

Terrestrial Energy

IMSR, integral molten salt reactor, SMR

CA/US$292M deal valueest. 2013terrestrialenergy.com (opens terrestrialenergy.com)Checked 10 Oct

The brief

Analyst view
  • Terrestrial Energy went public on Nasdaq (IMSR) in October 2025 via HCM II merger, raising $292M.
  • The NRC approved its IMSR principal design criteria in 2025, the first for molten salt reactors.
  • Texas A&M selected Terrestrial to build a commercial IMSR at RELLIS, targeting early 2030s operation.

Technical approach

As reported
Reactor

Integral design with no separate systems

The IMSR combines fuel, coolant, and heat exchanger in one vessel. This eliminates piping failures and simplifies operation compared to split designs.

Fuel

Low-enriched uranium dissolved in salt

The IMSR uses standard-assay low-enriched uranium (SALEU, <5% U-235) dissolved in molten salt, not weapons-grade fuel. This reduces proliferation concerns.

Power

195–390 MWe depending on configuration

One core unit produces 195 MWe; two deliver 390 MWe. Can extract 150°C+ heat for desalination and hydrogen production.

Factory

Designed for modular construction

Reactor cores are built in a factory and transported to site, reducing on-site construction time and cost.

Primer