Nils J. Diaz received a Bachelor’s’ Degree in Mechanical Engineering from the University of Villanova in Havana, Cuba before emigrating to the United States. Based in Florida, Diaz received a Ph.D. and M.S. in Nuclear Engineering Sciences from the University of Florida.

On April 2003, President George W. Bush designated Dr. Nils J. Diaz as Chairman of the Nuclear Regulatory Commision. His role included being the principal executive officer of the NRC, as well as the official spokesman. Diaz had been a Commissioner of the NRC since 1996.

Diaz has been a leader in security issues pertaining to the NRC licenses and was instrumental in strengthening security post-9/11.

He has also served as professor of Nuclear Engineering Sciences at the University of Florida, Director of the Innovative Nuclear Space Power Institute (INSPI) and President and principal engineer of Florida Nuclear Associates. He has published more than 70 refereed papers on national and international journals, and is a fellow of the American Nuclear Society, the American Society of Mechanical Engineers and the American Association for the Advancement of Science.