Terrestrial Energy

Terrestrial Energy is a U.S. nuclear technology company working on Generation IV nuclear technology.^[1] The nuclear plant is designed to produce cost-competitive, high-temperature thermal energy with zero emissions.

Terrestrial Energy

Industry	Nuclear Power
Founded	2012
Headquarters	Charlotte, North Carolina, United States
Key people	Simon Irish (CEO)
Website	https://www.terrestrialenergy.com/

The company is developing a 2x195 MWe Integral Molten Salt Reactor (IMSR) plant design.^[2] The Canadian Nuclear Safety Commission^[3] completed its programmatic Pre-Licensing Vendor Design Review^[4] of the IMSR plant design successfully in 2023.^[5]

The IMSR uses molten salt reactor technology and is one example of a small modular reactor (SMR) characteristic of Generation IV nuclear reactor designs.

History

Terrestrial Energy announced plans to go public^[6] in March 2025 via special purpose acquisition company HCM II Acquisition Corp.

Terrestrial Energy and The Texas A&M University System announced plans in February 2025 to site an IMSR plant^[7] at the Texas A&M-RELLIS campus about 9 miles west of Texas A&M University in College Station.

The company announced an agreement with EnergySolutions^[8] in December 2024 to explore possible siting of IMSR plants at EnergySolutions-owned sites. In October 2024, Terrestrial Energy signed an agreement with Viaro Energy^[9] to develop an IMSR plant in the United Kingdom.

Design

Terrestrial Energy claims several advantages for the IMSR over legacy nuclear power plants. It claims that its 585 degrees Celsius high-temperature heat supply enables a nearly 50% improvement on electricity generating efficiency with a steam Rankine cycle, compared to a similarly sized plant using LWR technology. As a consequence of its modular design, the power plant construction time is expected to be shortened to four years, versus 8-12 for legacy designs.

The Terrestrial Energy IMSR plant is designed to generate either electricity or industrial steam. The basic IMSR cogeneration plant design uses two reactors to generate just under 400 MW of electricity (net) or just over 800 MW of thermal energy, or a customized mix of the two.

The reactor uses molten salt/uranium blend as both fuel and coolant,^[10] the signature characteristic of molten salt reactor technology.

Terrestrial Energy’s IMSR is one of the very few Generation IV nuclear plant designs that uses standard-assay low-enriched uranium fuel rather than high-assay low-enriched uranium (HALEU) fuel and claims to leverage proven technologies in a unique way. Terrestrial Energy says that this is intended to reduce licensing and timeline risks that have slowed the adoption of other approaches.