Seasoned external affairs executive to lead investor and public communications as company advances IMSR commercialization

CHARLOTTE, N.C.--(BUSINESS WIRE)--May 7, 2026-- Terrestrial Energy Inc. (Nasdaq: IMSR) (“Terrestrial Energy” or the “Company”), a developer of proprietary Generation IV small modular nuclear power plants, today announced that Tyler Gronbach has joined the company as Vice President of Investor Relations and Public Relations.

The appointment comes as Terrestrial Energy accelerates commercialization of its Integral Molten Salt Reactor (IMSR) and expands engagement with institutional investors, sell-side analysts and the financial media following its Nasdaq listing last year. Gronbach will report to CEO Simon Irish and lead the company’s IR and PR functions.

“A step-change in commerical performance of Nuclear energy supply will drive its rapid expansion to meet many clear market and policy needs. Our IMSR Plant delivers that, as fission technology choices are fundamental to performance,” said Simon Irish, CEO of Terrestrial Energy. “Tyler brings decades of experience connecting technology and business solutions with investors and the media. He joins the company to ensure that our messaging captures the energy market value of IMSR technology at a time when capital markets are evolving rapidly to price technology fundamentals.”

Gronbach joins Terrestrial Energy from Wolfspeed, Inc. (NYSE: WOLF), where he served as Vice President of External Affairs. At Wolfspeed, he designed and executed an integrated communications platform that supported the company’s transformation from a legacy LED business into a silicon carbide leader serving electric vehicle, industrial and renewable energy markets. His work there helped attract national media attention for the company’s strategic pivot, organized a U.S. Presidential visit and supported more than $6.5 billion in capital raises.

“Terrestrial Energy holds one of the most exciting innnovation stories in the tech sector today – transformative clean, firm energy supply at massive scale. The timing is extraordinary for the nuclear sector,” said Gronbach. “The IMSR’s fission technology and plant design advantages deliver the transformative nuclear energy supply that government and industry are demanding. It’s a compelling story, and I’m eager to put my experience to work telling it.”

Previously, Gronbach served as Vice President of Communications for Pharma Services at Thermo Fisher Scientific (NYSE: TMO), where he led global internal and external communications for a $3 billion business segment. His career spans decades of external affairs work across corporate communications, investor relations, government affairs and marketing for publicly traded companies in the technology, life sciences and energy sectors.

About Terrestrial Energy

Terrestrial Energy is a developer of Generation IV nuclear plants that use its proprietary Integral Molten Salt Reactor (IMSR). The IMSR captures the transformative operating benefits of molten salt reactor technology in a plant design that represents true innovation in capital efficiency, cost reduction, versatility and functionality of nuclear energy supply. IMSR plants are designed to be small and modular for distributed supply of low-cost, reliable, dispatchable, clean, high-temperature industrial heat and electricity and to be customized for a dual-use energy role relevant to many industrial applications, such as petrochemical and chemical synthesis and data center operation. In so doing, IMSR plants extend the application of nuclear energy far beyond electric power markets. Their deployment will support the rapid growth of clean firm heat and power, delivering energy self-reliance, grid reliability and economic growth. Terrestrial Energy uses an innovative plant design together with proven and demonstrated molten salt reactor technology and readily available and inexpensive standard-assay low-enriched uranium in its fuel for a nuclear plant with a unique set of operating characteristics and compelling transformative commercial potential. Terrestrial Energy is engaged with regulators, suppliers, industrial partners and energy end users to build, license and commission the first IMSR plants in the early 2030s.

Forward-Looking Statements

The statements contained in this press release that are not purely historical are forward-looking statements. These forward-looking statements include, but are not limited to, statements regarding our expectations, milestones, hopes, beliefs, intentions or strategies regarding the future. In addition, any statements that refer to projections, forecasts or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking statements. The words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intends,” “may,” “might,” “plan,” “possible,” “potential,” “predict,” “project,” “should,” “will,” “would” and similar expressions may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking.

The forward-looking statements contained in this press release are based on our current expectations and beliefs concerning future developments and their potential effects on the Company. There can be no assurance that future developments affecting the Company will be those that we have anticipated. These forward-looking statements speak only as of the date of this press release and involve a number of risks, uncertainties (some of which are beyond our control) or other assumptions that may cause actual results or performance to differ materially from those expressed or implied by these forward-looking statements. Factors that may cause actual results to differ materially from current expectations include, but are not limited to: (1) risks related to the development, manufacturing and construction of IMSR Plants and key components, including potential delays, cost overruns and contractor performance issues; (2) the Company’s ability to obtain applicable regulatory approvals and licenses on a timely basis or at all; (3) the ability of management to manage growth; (4) the possibility that the Company may be adversely affected by other economic, business, and/or competitive factors, including from alternative energy technologies, energy price volatility, and competition from other advanced reactor developers; (5) potential supply chain constraints and cost inflation for specialized nuclear-grade materials and components; (6) any failure to comply with the laws and regulations governing the use, transportation, and disposal of toxic, hazardous and/or radioactive materials; (7) changes in domestic and foreign business, market, financial and political conditions, and in applicable laws and regulations, including tariffs; (8) the ability to raise additional funding in the future; (9) the outcome of any legal proceedings that may be instituted against the Company; and (10) other risk factors described herein as well as the risk factors and uncertainties described in the documents filed by the Company from time to time with the U.S. Securities and Exchange Commission (the “SEC”).

The foregoing list of risk factors is not exhaustive. You should carefully consider the foregoing risk factors and the other risks and uncertainties described in the documents filed by the Company from time to time with the SEC. In addition, there may be additional risks that the Company presently knows, or that it currently believes are immaterial, that could also cause actual results to differ from those contained in the forward-looking statements. Nothing in this communication should be regarded as a representation or warranty, either express or implied, by any person that the forward-looking statements set forth herein will be achieved or that any of the contemplated results of such forward-looking statements will be achieved. You should not place undue reliance on forward-looking statements, which speak only as of the date they are made.

In addition, the information contained in this press release is provided as of the date hereof and may change, and the Company and its representatives and affiliates specifically disclaim any obligation to, and do not intend to, update or revise any forward-looking statements, whether as a result of new information, inaccuracies, future events or otherwise, except as may be required under applicable securities laws. Information contained on our website is not a part of or incorporated into this press release.

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Terrestrial Energy Investor Center:
https://www.terrestrialenergy.com/investors
Terrestrial Energy Media & Investor Contact:
media@terrestrialenergy.com
investor@terrestrialenergy.com

Source: Terrestrial Energy Inc.