He then attended law school at the University of California, Los Angeles, graduating in 1973 with a JD. He started his legal career with the firm of Pillsbury, Madison and Sutro in San Francisco, and while there he became involved with restructuring a major uranium mining entity, Pathfinder Mines, and became Vice President, General Counsel and Secretary of Pathfinder upon its becoming an independent entity. In 1982, Cogema (now named AREVA) acquired that entity, and in 1988 Mr. Pennington moved to Bethesda, MD to accept the position of Vice President, General Counsel and Secretary of the AREVA entity that is the parent of Pathfinder. During his career, Mr. Pennington has been involved in providing legal assistance on a wide variety of activities relating to the nuclear cycle, as well as corporate matters, for the AREVA Group. He is a veteran, having served with the US Army, with a military occupational specialty title of combat field medic.