US-based nuclear start-up Terrestrial Energy has merged with HCM II Acquisition Corp, a special purpose acquisition company (SPAC) as a way to take the company public. A SPAC raises capital through an initial public offering (IPO) for the purpose of acquiring an existing operating company.
Terrestrial, which is developing an integral molten salt reactor. (IMSR) expects to net $280m from the deal. Before the SPAC merger, Terrestrial Energy had raised $94m, according to PitchBook. The combined entity intends to list on Nasdaq under the symbol IMSR. The business combination is anticipated to close in the fourth quarter of 2025.
Terrestrial Energy’s reactor design envisages that the core will be entirely replaced every seven years to avoid off some of the problems earlier molten salt reactors experienced such as corrosion. The reactor core includes not only the fuel and graphite modulators that regulate the speed of the fission reactions, but also the heat exchangers and pumps that keep the salt cool and flowing.
The proceeds of the merger will be used to accelerate the commercial deployment of the IMSR technology. The transaction values Terrestrial Energy at a pre-money equity value of $925m with a pro forma enterprise value of the new public company estimated at $1bn and a pro forma equity value of about $1.3bn.
Terrestrial Energy’s leadership, including CEO Simon Irish, will continue to head the company post-merger. The company has partnerships and agreements with, among others, Westinghouse Fuels, Energy Solutions, Schneider Electric, the US Department of Energy (DOE), and Argonne National Laboratory. In 2023, the Canadian Nuclear Safety Commission (CNSC) completed its programmatic Vendor Design Review of the IMSR plant design,
Texas A&M University recently selected Terrestrial Energy to partner on the construction of a commercial IMSR plant at the Texas A&M RELLIS campus, contributing to the university’s goal of achieving 1 GW of generating capacity at the site by the mid-2030s.
Simon Irish, CEO and Director of Terrestrial Energy, said: We believe the proposed business combination with HCM II will accelerate our CAPEX-light business model and deployment strategy, through constructing, licensing, and commissioning of a fleet of IMSR plants.” Shawn Matthews, Chairman and CEO of HCM II, noted: “We believe the business combination with HCM II will further accelerate Terrestrial Energy’s growth and deliver long-term shareholder value.” Terrestrial Energy is not the first nuclear startup to use a SPAC. Oklo completed a similar deal in 2024.
