The Department of the Army is authorized to build and operate nuclear reactors for defense purposes under Paragraph 91b of the Atomic Energy Act of 1954. As part of the Army Reactor Program, the United States Army Corps of Engineers (Corps) is responsible for nuclear reactor engineering and design, reactor construction, and decommissioning design and implementation. The Corps is currently focused on ensuring the safety and security of the Army's three deactivated power reactors and planning for their final decommissioning. To support decommissioning cost projections, the Corps is gathering information on the residual radiological and chemical hazards associated with each reactor, starting with the MH-1A reactor on the Sturgis Barge. Because the Sturgis Barge is moored in the James River Reserve Fleet, there were unique challenges that had to be overcome during the characterization survey and others that will become a concern when final decommissioning is to be per formed.