The Idaho Cleanup Project (ICP) is progressing with deactivation and demolition (D&D) of two historic Naval Nuclear Propulsion Program prototypes at the Naval Reactors Facility (NRF). This is continuing a partnership between the US Department of Energy (DOE) Office of Environmental Management (EM) and the Office of Naval Reactors (NR) to reduce the environmental footprint at the Idaho National Laboratory (INL) site.
“Our project crews work very efficiently and that has allowed us to work an accelerated timeline at all three prototypes,” said Shawna Burtenshaw, operations director for deactivation and demolition projects for ICP clean-up contractor Idaho Environmental Coalition (IEC).
The three protypes are Submarine 1st Generation Westinghouse (S1W): Aircraft Carrier 1st Generation Westinghouse (A1W) and Submarine 5th Generation General Electric (S5G).
S1W has already been demolished. The facility building was brought down using targeted explosives in May 2025. Prior to this, the defueled reactor vessel that once powered a land-based version of the USS Nautilus (the first nuclear-powered submarine) was removed and disposed of at the onsite Idaho CERCLA Disposal Facility (ICDF). In 1953, S1W simulated a 96-hour voyage from Newfoundland to Ireland, proving nuclear power’s ability to operate indefinitely without surfacing.
A1W was the prototype for the USS Enterprise, the world’s first nuclear-powered aircraft carrier. It featured a dual-reactor design powering a single engine room. It included “dump condensers” that simulated the sudden steam demand of aircraft catapult launches. Most of the ancillary structures around the main prototype have been demolished to ground level. Crews are currently removing large components from inside the facility. The crane house, used for mobile refuelling, is also scheduled to finish deactivation this year. Full D&D of this dual-reactor carrier prototype is expected to continue through fiscal year 2031.
S5G was the prototype for the USS Narwhal, a unique “silent” submarine. It tested natural circulation, allowing coolant to flow without noisy pumps. This technology eventually became the foundation for the Ohio-class ballistic missile submarines. S5G is undergoing characterisation and deactivation. Following its official transfer to the clean-up office in October 2024, teams began removing hazardous materials and packaging items from the below-ground water basin where the prototype sits. Unlike S1W and A1W, the S5G building will be preserved for future use after the internal prototype and reactor vessel are removed.
Crews are currently focusing on the demolition of several areas around A1W, including the facility’s generator building, administrative office areas and other buildings. Above-grade demolition in these areas is nearly complete, and removal of large, heavy mechanical components is underway, with anticipated completion later this year. Crews will also finish deactivating the crane. It featured a dual-reactor design powering a single engine room. It included “dump condensers” that simulated the sudden steam demand of aircraft catapult launches.
Burtenshaw noted that early work at the A1W prototype at the Naval Reactors Facility began in 2023, thanks to progress on S1W. IEC’s efficient decommissioning and demolition approach has allowed teardown of the defueled A1W and S5G prototypes to progress ahead of initial projections.
“Characterisation and deactivation are crucial phases of any demolition project and focus on ensuring safety of the workers, the public and the environment,” said Burtenshaw. “These efforts are in progress and include the identification and removal of hazardous material like asbestos or polychlorinated biphenyls, and the isolation of electrical and mechanical components.”
EM and IEC assumed responsibility for D&D of the three legacy Navy prototypes starting in 2022. Work will continue at A1W and S5G through fiscal year 2031. A1W, which began nuclear operation in 1958, and S5G launched in 1965 played a vital role in advancing naval nuclear research and training tens of thousands of Navy and civilian students.
The ICDF is an onsite, 390,000-cubic-metre engineered landfill designed specifically to consolidate and contain waste from INL clean-up projects. Demolished materials are categorised. Low-level radioactive debris, including the massive reactor vessels, are transported directly to the ICDF for permanent burial. Hazardous “mixed waste” (such as radioactive lead shielding) that cannot go in the landfill is shipped to specialised facilities outside Idaho.
The facility uses a liners-and-pond system with an active leachate treatment plant capable of processing 400 gallons of water per minute. This ensures that any rain or snowmelt that touches the waste is captured and treated before it can reach the Snake River Plain Aquifer. Because the facility was nearing 80% capacity, a new disposal cell is projected to open in 2026, adding 530,000 cubic metres of space to support another 25 years of clean-up.
