The Department of Energy’s Office of Environmental Management said that crews at the Idaho National Laboratory site are making “significant progress” decommissioning the Submarine 1st Generation Westinghouse (S1W) reactor, the prototype pressurized water reactor that supported the development of the USS Nautilus, the world’s first operational nuclear-powered submarine.
Workers have also begun early deactivation and decommissioning activities at the Aircraft Carrier 1st Generation Westinghouse (A1W) prototype reactor, with D&D work on the ancillary buildings around the A1W aircraft carrier prototype, DOE-EM added.
Earlier this year, DOE-EM reached an agreement with the Office of Naval Reactors Idaho Branch Office, the Environmental Protection Agency, and the Idaho Department of Environmental Quality to remove the defueled naval prototype reactors and structures.
S1W progress: According to DOE-EM, crews with cleanup contractor Idaho Environmental Coalition are currently dismantling the S1W’s hull and engine compartments. They have also begun deactivating the reactor compartment and associated systems by removing shielding components to prepare the reactor vessel for eventual disposal at the on-site Idaho CERCLA Disposal Facility.
To date, the project has sent an estimated 250 tons of uncontaminated metals out for recycling. The S1W D&D project is scheduled for completion in November 2025.
A1W progress: At A1W, crews have demolished an uncontaminated concrete retention basin and one of the massive steam condensers for the reactor, according to DOE-EM. This early work has cleared space to support equipment staging for future D&D work inside the prototype.
DOE-EM said that turnover of the main A1W facility for D&D, which remains on schedule, is being done in a phased approach in close coordination with Naval Reactors contractors.
The history: The land-based S1W prototype was built inside a section of a submarine hull at the Naval Reactors Facility on the Arco Desert, west of Idaho Falls. In addition to serving as a prototype reactor, S1W was used to train naval officers and enlisted personnel to operate the propulsion plants of nuclear-powered submarines and aircraft carriers and to test nuclear propulsion technology. The S1W prototype was shut down in 1989.
As the navy’s need for nuclear-powered surface ships evolved, the A1W nuclear prototype was built at the Naval Reactors Facility to test new technology. Operating from 1958 to 1994, the reactor was the prototype for the A2W reactor used in the world’s first nuclear-powered aircraft carrier, the USS Enterprise.