IMSR

EX-99.1

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EX-99.1

Exhibit 99.1

Terrestrial Energy Reports Second Quarter 2026 Results

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~ NRC Approves PIE Methodology Topical Report, Advancing the IMSR Licensing Basis ~

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~ Texas A&M Agreements Signed Covering Development Activities and Ground Leases Providing Site Control for Completion of-Characterization Work at RELLIS ~

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~ Updates to Estimated Unit-Economics Raises Lifetime Revenue Per Plant to $2.7 Billion from $2.1 Billion with Blended Gross Margin Raised to 33% ~

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~ Expands Serviceable Addressable Market Estimate to $2.3 Trillion by 2050 ~

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CHARLOTTE, N.C. — August 11, 2026 — Terrestrial Energy Inc. (NASDAQ: IMSR) (“Terrestrial Energy” or “the Company”), a developer of small modular nuclear plants using its Generation IV Integral Molten Salt Reactor (IMSR), today announced its financial results for the second quarter ended June 30, 2026.

“This quarter we reported developments across all three pillars of our business plan. We secured site control at the Texas A&M-RELLIS site, advanced projects TETRA and TEFLA, and received NRC approval of our Postulated Initiating Events methodology,” said Simon Irish, Chief Executive Officer of Terrestrial Energy. “Engineering progress has allowed us to re-estimate our unit economics, particularly for our two principal businesses of IMSR Core-unit and Fuel Salt supply. We now estimate $2.7 billion of cumulative lifetime revenue per IMSR Plant, up from $2.1 billion, with a blended gross margin of 33%. This lifts our serviceable addressable market to $2.3 trillion by 2050. These economics achieved with a capital-light business model, illustrate the value of IMSR Core-unit and Fuel Salt supply.”

Engineering and Regulatory Highlights:

●U.S. Nuclear Regulatory Commission (NRC) approved the Company's Postulated Initiating Events (PIE) methodology Topical Report, following its earlier approval of the IMSR Principal Design Criteria (PDC) Topical Report. Together these Topical Reports establish foundational elements of the IMSR licensing basis and can be referenced in future applications without re-evaluation.

●Continued to advance Project TETRA, the Company’s test reactor pilot project, and Project TEFLA, its fuel line pilot project, both partnership projects with the U.S. Department of Energy.

●Added irradiation cycles to the Company’s graphite testing and qualification program at NRG Petten, supporting materials’ qualification, licensing readiness and supplier down-selection.

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●Appointed Kathy McCarthy to the Board of Directors, who has a career in nuclear technology and major project development at leading national laboratories. Concurrently, Pamela Cowan joined as EVP of Engineering, with more than 35 years of nuclear industry engineering experience, including senior leadership roles at Westinghouse and Holtec.

Supply Chain Developments:

●Continued Westinghouse engagement for the supply of uranium tetrafluoride (UF4) at standard enrichment, a key component in IMSR Fuel Salt supply.

●Signed an engineering service agreement with Zachry Nuclear to support site characterization and data-collection at the Texas A&M-RELLIS site.

Commercial Pipeline of IMSR Plant Projects:

●Signed ground lease and research agreements with Texas A&M University System for use of 77 acres at the Texas A&M-RELLIS site, securing site control and the path to complete site characterization work and environmental evaluation work for the IMSR Plant and other facilities.

●Executed a Memorandum of Understanding with Riot Platforms, Inc. (NASDAQ: RIOT) to co-locate IMSR Plants with Riot data centers. The parties are evaluating a natural gas fuel bridge for early electricity supply and added resiliency during full plant operation.

Unit Economics Update:

●Estimate of cumulative lifetime revenue per IMSR Plant increased to $2.7 billion from $2.1 billion on a blended gross margin of 33%. 79% of lifetime revenues occurs after construction of the IMSR Plant from Core-unit and Fuel Salt supply under long term contract. Gross margins for the Core-unit and Fuel Salt supply businesses estimated to be 33% and 40%, respectively.

●Updated 2050 serviceable addressable market to $2.3 trillion.

Performance, Liquidity and Capital Structure:

●Reported a net loss of $9.4 million for second quarter, compared to a net loss of $10.5 million for first quarter. This change was primarily driven by:

◦$1.1 million decrease in R&D, reflecting timing and scope variances on key tests, including additional graphite irradiation cycles at NRG Petten.

◦$0.7 million increase in G&A due to increased personnel-related expenses and stock-based compensation.

◦$0.9 million increase in Other Income (Expense) due to decreased Interest Expense and an increase in Interest and Dividend Income.

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•Ended second quarter with $283.4 million in cash, cash equivalents and investments.

•Reported cash burn of $6.4 million, a decrease of $1.5 million compared to first quarter. The decrease lar

EX-99.1

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EX-99.1

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Exhibit 99.1

Terrestrial Energy Reports First Quarter 2026 Results

Completed OTA contract with Department of Energy supporting IMSR pilot reactor and IMSR fuel pilot plant projects

Collaboration with Riot Platform for a best-in-class pairing of data center and co-located nuclear plant to deliver up to 4GW of nuclear power capacity for hyperscale AI operation

NRC approved Topical Report on IMSR Postulated Initiating Event methodology and issued Safety Evaluation Report

CHARLOTTE, N.C. — May 14, 2026 — Terrestrial Energy Inc. (NASDAQ: IMSR) (“Terrestrial Energy” or “the Company”), a developer of Generation IV small modular nuclear power plants, today announced its financial results for the first quarter ended March 31, 2026.

“During the quarter, Terrestrial Energy delivered against the three-pillar framework outlined in March – IMSR engineering and regulatory programs, including our key project engagements with the U.S. Department of Energy, supply chain development, and our commercial pipeline of IMSR Plant projects,” said Simon Irish, CEO of Terrestrial Energy. “These developments move us closer to serving large industrial markets and the opportunity to power AI, advanced manufacturing, and the broader U.S. economy.”

Engineering and Regulatory Highlights:

•Terrestrial Energy signed two Other Transaction Authority (OTA) agreements with the U.S. Department of Energy advancing TETRA, the reactor pilot project, and TEFLA, the fuel line pilot project. The projects support engineering and regulatory programs for IMSR plant commercial operation and infrastructure development for IMSR plant fuel supply.

•The U.S. Nuclear Regulatory Commission (NRC) approved the Company’s Postulated Initiating Events methodology (PIE) Topical Report and issued its Safety Evaluation Report (SER). This follows the NRC’s acceptance of the Company’s final Topical Report submission announced in April 2026. The NRC’s approval of Terrestrial Energy’s PIE methodology delivers the framework to identify and evaluate events that may challenge the safe operation of IMSR nuclear plant. This analysis is foundational to nuclear safety and represents another important regulatory milestone as Terrestrial Energy systematically executes on its nuclear regulatory program with the NRC.

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•The PIE Topical Report follows on from the NRC’s September 2025 approval of IMSR’s Principal Design Criteria Topical Report. Together, these two Topical Reports establish foundational elements of the IMSR licensing basis for commercial operation. In addition they can now be referenced in future licensing applications without re-evaluation, reducing the scope of subsequent technical review and increasing confidence of the licensing critical path.

Supply Chain Developments:

•The Company’s materials’ testing and qualification programs continued during the quarter, including graphite irradiation at one of the world’s most powerful test reactors. These activities are essential for reactor materials’ qualification, supplier selection, and licensing readiness.

•Relationships with nuclear industry suppliers remained in active execution for materials, component and services supply, supporting the fabrication of reactor components and the development of fuel supply infrastructure.

Commercial pipeline of IMSR Plant Projects:

•On May 6, 2026, the Company executed a Memorandum of Understanding with Riot Platforms, Inc. (NASDAQ: RIOT), a leader in large-scale data center development, to co-locate IMSR Plants with Riot-developed data centers and create a best-in-class data center – nuclear plant pairing to serve AI and high-performance compute applications. The collaboration contemplates deployment of multiple IMSR Plants representing up to 4GW of nuclear power capacity across multiple sites. The companies will jointly evaluate sites and the opportunities to incorporate a natural gas fuel bridge for fast commercial power supply and to enhance supply resiliency during full nuclear power plant operation.

Performance, Liquidity and Capital Structure:

●For the quarter, Terrestrial Energy reported a net loss of $10.5 million, compared to a net loss of $6.2 million for the fourth quarter 2025. This change was primarily driven by:

o$3.2 million increase in R&D as the Company progressed fuel development and graphite testing programs.

o$4.0 million increase in G&A due to increased personnel-related expenses and stock-based compensation.

o$2.8 million increase in Other Income (Expense) due to decreased Interest Expense and an increase in Interest and Dividend Income.

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The Company ended the quarter with a strong balance sheet, reporting $289.9 million in cash and investments as of March 31, 2026. This liquidity provides a substantial runway to deliver important developments across the three pillars of the IMSR plant development and commercialization.

During the quarter, the Company reported cash burn of $7.9 million, a

EX-99.1

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EX-99.1

Exhibit 99.1

Terrestrial Energy Announces Fourth Quarter and Full Year 2025 Results

Texas A&M University selected commercial IMSR plant for deployment at RELLIS campus

U.S. Department of Energy selected both Terrestrial Energy reactor pilot and fuel-line pilot projects for advanced reactor programs

NRC Accepted IMSR Principal Design Criteria Including Inherent Reactor Control Mechanisms

Completed business combination, raising approximately $292 million in gross proceeds

CHARLOTTE, N.C. – March 30, 2026 – Terrestrial Energy Inc. (NASDAQ: IMSR) (“Terrestrial Energy” or “the Company”), a developer of small modular nuclear power plants using its Generation IV Integral Molten Salt Reactor (IMSR) technology, today announced its financial results for the fourth quarter and full year ended December 31, 2025.

“The Company made strong progress in 2025 in key areas, regulatory readiness, fuel supply development, and IMSR plant project development from engagements with deployment partners and government stakeholders,” said Simon Irish, CEO of Terrestrial Energy. “We continue into 2026 with the objective to advance with clearly defined development steps and milestones, and from aligning key program elements into a coordinated pathway to deploy IMSR plants at scale and delivering reliable, clean, firm energy to industrial markets.”

Fourth Quarter and Full Year 2025 Highlights:

●Texas A&M University, supported by expertise in its nuclear engineering faculty, selected Terrestrial Energy to site a full-sized commercial IMSR Plant at its RELLIS campus following a competitive and sector-wide evaluation process. This selection positions the RELLIS campus project among the first commercial Generation IV reactor deployments on the ERCOT grid and provides an impressive platform to accelerate IMSR Plant development to commercial operations.

●The Company expanded commercial reach and ability to execute at greater scale across the United States from collaboration with Ameresco, Inc. (NYSE: AMRC), a leading energy solutions provider with strong federal procurement capabilities. This collaboration expands access to new opportunities, supports site identification and IMSR Plant project development, particularly projects benefiting from the IMSR Plant’s customization capabilities. These include integration with other energy systems, such as natural gas, for early commercial operation and improved supply resilience, which strengthens Terrestrial Energy’s ability to deliver competitive solutions for data center energy supply.

●The U.S. Nuclear Regulatory Commission (NRC) completed its safety evaluation and accepts Terrestrial Energy’s Topical Report submission on IMSR Principal Design Criteria, which includes its mechanism for inherent reactor power control, important for load following commercial applications. This is an important step forward in licensing readiness for IMSR plant construction and operation.

●IMSR technology and the Company’s fuel strategy for commercial use received strong validation from the U.S. Department of Energy (DOE) when Terrestrial Energy received two “OTA” awards, one from each of its pilot programs. The first from the DOE’s Advanced Reactor Pilot Program, which supports quick execution of the TETRA project – the Terrestrial Energy Test Reactor Assembly project. The second was from the DOE’s Fuel Line Pilot Program, which supports the Company’s schedule for completion of Fuel Line Assembly project, TEFLA, the antecedent to Terrestrial Energy’s commercial plant for IMSR Plant fuel supply. Together, these two projects provide an accelerated pathway for IMSR Plant licensing, commercial operation and fuel supply.

●Terrestrial Energy entered the concluding phase of its reactor graphite irradiation and supplier selection program at NRG PALLAS’ High Flux Reactor in Petten, the Netherlands. These irradiation tests, conducted in one of the world’s most powerful test reactors, represent a key step in supplier selection and graphite grade qualification required for IMSR Plant licensing and operation.

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●The Company successfully completed its business combination with HCM II Acquisition Corp, raising more than $292 million in gross proceeds, and began trading with a strengthened balance sheet on the Nasdaq under the ticker symbol IMSR.

●Terrestrial Energy announced a manufacturing and supply contract with Westinghouse, strengthening supply-chain readiness, and the company enhanced its senior leadership team to support U.S. commercialization efforts and deepen engagement with federal stakeholders.

Performance, Liquidity and Capital Structure:

●The Company reports a $28 million Net Loss for 2025, representing a $17 million increase from the prior year. The increase is attributable to:

oA $5 million increase in R&D as the Company expanded materials testing and progressed graphite qualification work.

oA $10 million increase in G&A due to increased legal and accoun