This vOlume contains the invited and contributed papers pre sented at the American Nuclear Society (ANS) meeting on Decontamina tion and Decommissioning (D & D) of Nuclear Facilities, held Septem ber 16-20, 1979, in Sun Valley, Idaho. This was the first U. S. meeting of the ANS which addressed both of these important and related subjects. The meeting was attended by more than 400 engineers, scientists, laymen, and representatives of federal, state, and local governments, including participants from eleven foreign countries. The technical sessions included several sessions concentrating on ongoing D & D programs in the U. S. and abroad. In addition, "new ground" was broken in such areas as decommissioning costs and cost recovery, advanced programs on reactor coolant filtration, and other areas of continuing and increasing importance to the nuclear industry and to consumers. The dual sponsorship of the meeting (The ANS Reactor Operations Division and the Eastern Idaho Section of the ANS) helped spur a high quality program, a pleasant location, and a high degree of suc cess in technical interchange between the attendees. As guest speaker, we were honored to have Mr. Vince Boyer of Philadelphia Electric Company. Mr. Boyer is both a past chairman of the ANS Reactor Operations Division and a past president of the American Nuclear Society. His views on the nuclear industry and of its current status were informative and interesting."