Miriam D’Onofrio

Miriam joined X-energy in April 2025 as the Senior Director for International Markets and Policy. In this role, Miriam is responsible for developing and executing X-energy’s strategic partnerships with international customers, suppliers, and investors.

Miriam most recently served in multiple roles in the White House National Security Council, including as Acting Senior Director for Energy and Investment and Director for Nuclear and Clean Energy Partnerships. In these positions, she focused on reestablishing U.S. leadership in the nuclear sector and strengthening the United States’ ability to export high-quality infrastructure and energy technology to the world.

Before joining the White House, Miriam was the Senior Advisor for Energy Affairs at the U.S. State Department and served in various roles at the U.S. Department of Energy (DOE). At the State Department, she led energy diplomacy efforts with the People's Republic of China (PRC), encompassing energy efficiency, transmission and distribution, civil nuclear energy, renewable energy, and storage technologies. During her seven-year career with DOE, she managed uranium modernization projects for DOE’s Defense Programs, facilitated nuclear security cooperation programs with Russia and China, and served as DOE’s Attache for Nuclear Energy and Security at U.S. Embassy Beijing.

Miriam has a master’s degree in international economics and Russian and Eurasian Studies and a bachelor's degree in East Asian Studies both from Johns Hopkins University. She graduated as Valedictorian of her international high school in Qingdao, China, and speaks fluent Mandarin Chinese, intermediate Russian, and beginner Spanish and Korean.