The Department of Defense has found no issues that would prevent the defueled reactor compartments of the world's first nuclear-powered naval aircraft carrier from being disposed of at Hanford.
The Department of Energy agreed with the Finding of No Significant Impact report.
The report, based on a completed environmental assessment, clears the way for a final decision to send the USS Enterprise reactor compartments to Hanford.
The Navy has used a trench in central Hanford since 1986 to dispose of reactor compartments and other reactor components from 114 nuclear-powered submarines and cruisers.
The eight reactor compartments from Enterprise would be added to that Naval debris in Hanford's Trench 94 in central Hanford, about seven miles from the Columbia River.
However, it will be years before the reactor compartments arrive at Hanford, under the proposed plan.
The Navy would begin decommissioning of Enterprise in mid-2013. It would be defueled at Newport News (Va.) Shipbuilding before being towed to the Puget Sound Naval Shipyard and Intermediate Maintenance Facility in Bremerton in about 2017.
Then the reactor compartment disposal would require six to eight years.
Enterprise's eight reactors are in four pairs of reactor compartments that would be separated by cutting through a structural space between the two reactor compartments. A containment structure would be built around the reactor compartments, enclosing them to form a package.
A barge would be used to ship the reactor compartments through the Puget Sound, along the Pacific Coast and then up the Columbia River to the Port of Benton to be unloaded for the trip across Hanford.
The packaged compartments could be up to 47 feet tall, making clearance potentially tight under the cable bridge.
The environmental assessment concluded that Enterprise's reactor compartments would be similar to those of cruisers, so there would be no additional environmental impact beyond those already studied for cruisers.
The environmental assessment calls Enterprise the oldest operating ship in the Navy. It was commissioned in 1961 and will end 51 years of service in an inactivation ceremony Dec. 1.
It served during the Cuban Missile Crisis, the Vietnam War and the Iraq War.