Simon Irish has served as Terrestrial Energy’s Chief Executive Officer and a member of the board of directors of Terrestrial Energy and its predecessors since 2014. Mr. Irish brings more than 20 years of finance and investment management experience across a broad range of market sectors and industries, both domestically and internationally. Previously, Mr. Irish held senior positions for nearly 8 years at Man Global Strategies (“MGS”), including head of MGS in North America. MGS is the strategic investment division of Man Group Plc (“MAN”), a leading global investment management business. During his time at MGS, Mr. Irish was responsible for building and managing the largest and most active strategic investment and managed account business in North America at the time. Mr. Irish was also a member of MAN’s Investment Committee and responsible for corporate acquisition opportunities in North America. Prior to that, Mr. Irish was a derivatives structurer and trader at Credit Suisse Financial Products, a London-based investment firm and a leading global bank in the derivatives sector. Mr. Irish holds an MA in Natural Sciences from Cambridge University and an MSc in Finance from the London Business School.
Dr. David LeBlanc has served as Chief Technology Officer of Terrestrial Energy and a member of the Terrestrial Board since 2013. Dr. LeBlanc is a globally recognized expert and leader on molten salt reactors and has dedicated his career to the improvement and realization of advanced nuclear power systems, in particular MSR technologies. Dr. LeBlanc is the sole private sector member of the Gen IV International Forum, an intergovernmental research group focused on advanced reactors. In 2008, Dr. LeBlanc founded Ottawa Valley Research Associates Ltd. to advance MSR technologies and has filed patents relating to such technologies that have specific bearing on improving and broadening the commercial application of the MSR technology. Dr. LeBlanc is a frequent speaker at international nuclear industry conferences on Molten Salt Reactor design concepts, he has had numerous news media engagements covering MSR technologies, and his numerous academic articles are extensively cited. Dr. LeBlanc holds a Ph.D. and M.Sc. in Physics from the University of Ottawa and a B.Sc. in Physics from the University of New Brunswick.
Brian Thrasher has served as Terrestrial Energy’s Chief Financial Officer since May 2025. Mr. Thrasher has more than 25 years of financial management experience holding executive management positions and serving as an officer at multi-billion dollar public and private companies in the U.S. Before joining Terrestrial Energy, Mr. Thrasher served as Chief Financial Officer of Hilco Transport, Inc., from November 2021 to May 2025. Prior to that, Mr. Thrasher served in various accounting roles at Hanesbrands Inc. from April 2015 to November 2021. Throughout his career, Mr. Thrasher developed expertise in strategic financial planning, public market reporting and financing, budgeting, forecasting, and systems development and implementation. Mr. Thrasher has successfully led cross-functional teams, and played key roles in mergers and acquisitions, capital structuring, and regulatory compliance. Mr. Thrasher was a member of the board of directors of Hilco Transport, Inc, a specialty trucking company, from 2021 until 2025. Mr. Thrasher began his career in public accounting at Ernst & Young before transitioning to industry. His audit work focused primarily on large multi-national public companies. Mr. Thrasher holds a B.B.A. from Acadia University and a M.Acc. from The University of Alabama. He is a CPA licensed in the state of North Carolina and is a member of the North Carolina Association of Certified Public Accountants as well as the American Institute of Certified Public Accountants.
William Smith has served as Chief Operating Officer of Terrestrial Energy since July 2025. Prior to that, Mr. Smith has served as Senior Vice President, Operations and Engineering of Terrestrial Energy since 2016. Throughout his 44-plus years of experience in the energy sector, including over 20 years in the nuclear industry, Mr. Smith has developed deep experience and capability in major project execution, building team capability and managing external interfaces with clients, suppliers and regulators. Prior to joining Terrestrial Energy in 2016, Mr. Smith worked at Siemens Canada, where he eventually became the Senior Vice President of its Canadian energy business. Mr. Smith was responsible for all sales and marketing, manufacturing, service delivery, and project management and successfully helped build the business into a billion-dollar enterprise. Prior to that, from 1981 to 2002, Mr. Smith worked at Ontario Hydro and Ontario Power Generation, where he advanced to the level of Vice President of Supply Chain, where his responsibilities included all nuclear procurement, materials management and source surveillance activities. Mr. Smith holds an M.B.A. from York University and a B. Eng. from Carleton University. He is a Professional Engineer registered with the Professional Engineers of Ontario and with the Association of Professional Engineers and Geoscientists of Alberta.
Mr. Millsap has served as Terrestrial Energy’s General Counsel, Secretary and Chief Compliance Officer since July 2025. Mr. Millsap has more than 27 years of legal experience, including over 24 years as in-house legal counsel at private and publicly traded companies. Before joining Terrestrial Energy, he held senior leadership roles where he led legal functions, worked with cross-functional teams, and served as an advisor on governance, risk management, corporate, commercial, operational, intellectual property, litigation, and compliance matters. Recently, he served as the Vice President, General Counsel, Secretary and Chief Compliance Officer at Divergent Technologies, Incorporated from 2022 to 2025. Prior to that, he served as Senior Vice President, General Counsel, Secretary and Chief Compliance Officer at Global Advanced Metals PTY Limited from 2012 to 2022. Prior to that, he was in-house counsel at Polymer Group, Continental Tire, and CarMax. He began his legal career at the law firms of McGuireWoods and Wright, Robinson, Osthimer & Tatum. He holds a B.A. in Economics from Rollins College, a J.D. from Florida State University College of Law, and an LL.M. in Intellectual Property from the University of New Hampshire Franklin Pierce School of Law.