Our Leadership | National Nuclear Security Administration

Dr. Donald L. Cook

Dr. Donald L. Cook serves as the Deputy Administrator for Defense Programs at the National Nuclear Security Administration. Appointed to the position by President Barack Obama, Dr. Cook was sworn in as NNSA’s 5th Deputy Administrator in June 2010. He is responsible for managing the U.S. nuclear security enterprise of laboratories and manufacturing facilities. One of the primary missions of NNSA is to maintain and enhance the safety, security and reliability of the U.S. nuclear weapons stockpile. NNSA, through its Office of Defense Programs, ensures that the U.S. nuclear arsenal meets the country’s national security requirements and continues to serve its essential deterrence role.

Admiral John M. Richardson

Admiral Richardson graduated from the U.S. Naval Academy in 1982 with a Bachelor of Science in Physics.  He also holds Masters Degrees from the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution, and the National War College.

Richardson served in USS Parche (SSN 683), USS George C. Marshall (SSBN 654) and USS Salt Lake City (SSN 716).  He commanded USS Honolulu (SSN 718) in Pearl Harbor, Hawaii and was awarded the James Bond Stockdale Leadership Award.

Joseph J. Krol Jr.

Joseph J. Krol, Rear Admiral, United States Navy (Retired), is the Associate Administrator for NNSA's Office of Emergency Operations. In this role, he is the Director of the Office of Emergency Operations, which is responsible for emergency management policy and execution of emergency management support across the Department of Energy's complex. Within the National Nuclear Security Administration, he also is responsible for emergency operations, involving nuclear, and radiological emergencies, both within the United States and abroad.

Bruce Diamond

Bruce Diamond became the General Counsel for the NNSA in February, 2011.  Before that, Bruce was DOE Assistant General Counsel for Environment, the senior career environmental attorney for the Department dealing principally with complex issues regarding the clean-up of the nuclear complex and implementation of National Environmental Policy Act obligations.  In addition, he was responsible for addressing health and safety issues.

Dr. Steven Aoki

Steven Aoki is the Associate Administrator and Deputy Under Secretary for Counterterrorism and Counterproliferation.  In this position, Dr. Aoki is responsible for coordinating counterterrorism policy throughout the U.S. Department of Energy. He reports to Thomas D’Agostino, Administrator of the National Nuclear Security Administration. Much of the focus of the department’s counterterrorism efforts centers on the nuclear security enterprise, but also cuts across many organizations in the DOE.