Terrestrial Energy used its fourth-quarter and full-year 2025 earnings call to outline progress on regulatory engagement, supply chain planning, and early commercial project development for its IMSR small modular reactor design, while also reviewing the company’s first financial results as a newly public company following its business combination with HCM II Acquisition (NASDAQ:IMSR).
Market backdrop and IMSR positioning
Chief Executive Officer Simon Irish said 2025 was a “transformational year” and the company’s first as a publicly traded entity. Irish framed the company’s strategy around what he described as “generational and transformative change” in global electricity demand, citing drivers including AI infrastructure, automation, electrification, and reshoring of manufacturing. He also pointed to policy priorities around “national energy security, grid reliability, and affordability,” referencing geopolitical events such as the war in Ukraine and concerns around LNG and oil supply security.
Key technology themes: affordability, flexibility, and scale
Irish highlighted three differentiators he said underpin the company’s commercial strategy:
- Affordability and capital efficiency: Irish said the IMSR plant is “one-sixth the size of a conventional nuclear plant” and modular, with molten salt reactor characteristics that include low-pressure operation and what he described as high inherent safety. He also said the IMSR generates power using steam turbines with “near 50% greater efficiency” than light water reactor-driven turbines.
- Operational flexibility: Irish said the IMSR can provide high-temperature process heat and “strongly load follow,” with output customizable between heat and power. He added that the company estimates its serviceable addressable market to exceed $1.4 trillion.
- Scalability and supply chain approach: Irish emphasized a strategy of using existing nuclear supply chain materials and components where possible. He also noted that the IMSR uses standard nuclear fuel—uranium enriched to less than 5%—and said the company made a strategic choice a decade ago to avoid HALEU fuel. In an “enrichment-constrained environment,” he said that decision reduces fuel supply uncertainty, regulatory complexity, and cost.
Irish also pointed to molten salt reactor history, noting the technology was demonstrated more than six decades ago and that China began operating a molten salt reactor in 2023 based on Oak Ridge National Lab work. He said Terrestrial Energy’s design objective has been to leverage existing knowledge to support the IMSR technical foundation.
Regulatory and DOE-related developments in 2025
Irish said Terrestrial Energy has pursued early and sustained engagement with nuclear regulators, noting that the company applied to the Canadian Nuclear Safety Commission (CNSC) in 2016 for a vendor design review. He said the CNSC completed that review in 2023 and concluded publicly there were “no fundamental barriers” to licensing the IMSR design for commercial use. He added that the company’s U.S. Nuclear Regulatory Commission (NRC) engagement began in 2017.
During 2025, Irish said the NRC completed acceptance of the company’s topical report on the IMSR principal design criteria, which he called a foundational step toward an operating license submission and part of ongoing pre-application engagement.
Irish also said the company received two Other Transaction Authority (OTA) awards from U.S. Department of Energy programs established following presidential executive orders in May 2025 to accelerate advanced reactor development:
- An award under the Advanced Reactor Pilot Program supporting Project TETRA (Terrestrial Energy Test Reactor Assembly), intended to help collect data for a future IMSR license application.
- An award under the Fuel Line Pilot Program supporting TEFLA, a pilot-scale fuel production process intended as an antecedent to a commercial fuel supply facility.
Supply chain activity and commercial project progress
On supply chain activity, Irish said Terrestrial Energy continues to build on relationships with nuclear suppliers including Westinghouse, Siemens Energy, and BWXT, along with other component manufacturers. He noted a further contract with Westinghouse in 2025 to support the IMSR fuel supply program.
Irish also said the company advanced materials work in 2025, including graphite irradiation testing at the NRG Pallas high flux reactor in the Netherlands. He emphasized the importance of in-core testing for Generation IV reactor materials qualification, supplier selection, and licensing readiness.
On commercial projects, Irish said Texas A&M University selected Terrestrial Energy in early 2025 to site a full-scale commercial IMSR plant at its RELLIS Campus after a competitive evaluation. He said this places the project on ERCOT and within an engineering and workforce development ecosystem.
Irish also highlighted a 2025 collaboration with Ameresco to partner on site identification and project development, describing Ameresco as bringing project development expertise and experience with federal energy programs.
2026 expectations and financial results
Looking ahead, Irish said the company expects to announce several developments in 2026, including additional agreements with Texas A&M related to deployment at RELLIS and testing and development work; disclosure of between one and three additional commercial IMSR projects; submission of at least three additional NRC topical reports; and more details on the sites and partners for the TETRA and TEFLA projects.
In the question-and-answer session, Jeff Grampp of Northland Capital Markets asked about the expected maturity of the potential additional commercial project announcements. Irish said an IMSR project is first defined by location—“it’s got a ZIP code”—and by a process beginning with the parties’ declared intention to proceed toward commissioning, but he said the company would reserve details until disclosures are made.
Grampp also asked about the NRC’s Part 53 licensing pathway. Irish said it is an option and described it as graduated, risk-informed, and principles-based, noting similarities to Canadian approaches. However, he said the company’s “central case” for the first couple of plants is a Part 50 two-step approach (construction permit followed by operating license).
Chief Financial Officer Brian Thrasher reviewed financial results and the company’s capital position following the business combination completed on Oct. 28, 2025, with trading on Nasdaq beginning Oct. 29 under the ticker IMSR. Thrasher said trust redemptions were less than 1% and, combined with a $50 million PIPE, the transaction secured more than $292 million in gross proceeds.
For 2025, Thrasher reported:
- Net loss: $28 million, an increase of $17 million versus the prior year, which he attributed to higher engineering, testing, regulatory activities related to TETRA and TEFLA, supply chain development, and organizational expansion tied to public company readiness.
- R&D expense: $10 million, up $5 million, reflecting expanded materials testing and graphite qualification work.
- G&A expense: $14 million, up $10 million, primarily due to personnel expansion, corporate infrastructure, and professional services associated with commercialization and public company readiness.
- Professional fees within G&A: $5 million, up $4 million, excluding $22 million of transaction-related costs presented as an increase to additional paid-in capital.
- Stock-based compensation: approximately $3 million, up $2 million.
- Interest: Thrasher said interest expense of $4 million in 2025 versus $1 million in 2024 reflected larger average debt balances and amortization of a debt discount on legacy convertible notes; the company earned $1 million of interest income in 2025 on cash received from the business combination.
Thrasher said the company ended the year with approximately $298 million in cash and short-term investments, reflecting the business combination proceeds, two financing rounds earlier in the year, and cash exercise of legacy private warrants. He said the capital position supports milestones tied to engineering, regulatory and R&D activities (including TETRA and TEFLA), supply chain development, and commercial project progress.
At year-end, Thrasher said issued and outstanding shares totaled 105.8 million, consisting of 81.8 million common shares and 24.0 million exchangeable shares, which are exchangeable one-for-one into common shares at the holder’s election.
About HCM II Acquisition (NASDAQ:IMSR)
Terrestrial Energy Inc produces carbon free nuclear energy in North Carolina and internationally. The company was founded in 2013 and is headquartered in Charlotte, North Carolina.
