Former Department of Energy Secretary Ernest Moniz has joined the board of a nuclear fusion company in Foothill Ranch.

Moniz, a physicist and the 13th U.S. Secretary of Energy, joins an influential board of directors at Tri-Alpha Energy Inc., including former Morgan Stanley Chairman and Chief Executive John Mack; Richard Meserve, who chaired the U.S. Nuclear Regulatory Commission under President Bill Clinton and George W. Bush; and Tri Alpha Chief Executive Steven Specker, who spent 30 years at GE, leading its nuclear and digital energy businesses.

Moniz served as energy secretary in the second term of President Barack Obama’s administration.

He entered the national energy policy arena in 1995, when he served as associate director for Science in the Office of Science and Technology Policy in the Executive Office of the President. He later oversaw the Department of Energy’s science, energy and security programs as under secretary from 1997 to 2001. He was also a member of the President’s Council of Advisors on Science and Technology from 2009 to 2013 and received the Department of Defense Distinguished Public Service Award in 2016.

Moniz has served on several public and private boards, including the Department of Defense Threat Reduction Advisory Committee and the Blue Ribbon Commission on America’s Nuclear Future.

Moniz, an outspoken critic of the energy policies of President Donald Trump, is a member of the Council on Foreign Relations and a fellow of the American Association for the Advancement of Science, the American Academy of Arts and Sciences, the Humboldt Foundation, and the American Physical Society.

Tri Alpha bills itself as the world’s “largest private fusion company” and is aiming to develop a commercially competitive fusion power plant, combining advanced particle accelerator and plasma physics to produce energy that’s compact, aneutronic, safe, carbon-free and sustainable.

Tri Alpha has raised some $500 million since it started in 1998, but has kept its plans quiet since then, until recently.