Dual Historic Naval Reactors Prototype Demolitions Highlight Idaho Expertise

Demolition crew members sit inside the below-grade basin of the Submarine 5th Generation General Electric prototype, where they performed deactivation activities to prepare the prototype for demolition.

IDAHO FALLS, Idaho — Idaho Cleanup Project (ICP) crews are hard at work advancing decommissioning and demolition (D&D) on two Navy Nuclear Propulsion Program prototypes: the Submarine 5th Generation General Electric (S5G) and the Aircraft Carrier 1st Generation Westinghouse (A1W) prototypes.

Since 2024, the U.S. Department of Energy’s Office of Environmental Management has focused on characterization, isolation and deactivation of the S5G prototype at the Naval Reactors Facility (NRF). This includes removal of hazardous materials like asbestos, lead and polychlorinated biphenyls.

Recently, crews removed large components from the S5G prototype basin and hull, and added 5,000 cubic yards of a cement mixture to the basin. The prototype sits below grade in the large basin.

An action memorandum calls for removal of the prototype and for the basin to be filled with concrete. These actions will allow the Office of Naval Reactors to repurpose the facility for future use. The work also reduces the environmental footprint at the Idaho National Laboratory Site.

Meanwhile, ICP and contractor Idaho Environmental Coalition (IEC) are progressing on above-ground demolition of the A1W prototype. To date, crews have completed the teardown of the A1W offices, laboratory and other buildings and support areas. Crews are performing deactivation work on the building’s interior areas such as the primary component maintenance area, A1W’s reactor compartments and both reactor vessels.

In coming months, IEC expects to topple the A1W crane house, which is a mobile facility previously used for refueling and maintenance of the prototype. Crews also will demolish the crane that sits atop the building.

“Our team is very talented and has demonstrated incredible efficiency in performing D&D at both the A1W and S5G prototypes,” IEC D&D and Capital Projects Senior Director Mike Swartz said. “Their expertise and their ability to find solutions to complex problems allow us to complete work ahead of schedule.”

NRF served as a training ground for prospective nuclear operators. Nearly 40,000 sailors and other Navy personnel were trained at the A1W, S5G and Submarine 1st Generation Westinghouse (S1W) prototypes.

Crews completed D&D of the S1W in 2025. IEC expects to complete demolition of the A1W and S5G over the next six years.

-Contributor: Carter Harrison