Preparations begin for demolition of prototype reactor

The S1W was a 70 kW (thermal) pressurised water reactor which reached first criticality in May 1953. The prototype supported development of the USS Nautilus, the world's first operational nuclear-powered submarine, launched in 1954. It was also 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 prototype was shut down in 1989.

The Naval Reactors Facility is under the cognisance of the Office of Naval Reactors, and the project is the first in a partnership between Department of Energy Office of Environmental Management and the Office of Naval Reactors at the Idaho National Laboratory site. Connie Flohr, manager of the Idaho Cleanup Project for the department, said the agreement enables it to use its expertise to remediate the Office of Naval Reactors' environmental liabilities such as unused infrastructure and excess facilities across the complex.

The interior of the S1W facility, pictured during the 1950s (Image: DOE EM)

Demolition of S1W support buildings, as well as preparations for deactivation of the reactor plant, including asbestos removal and characterisation of other building components to confirm facility contents and any associated risks, will begin this month. Deactivation and demolition of S1W itself is expected to begin in fiscal 2023. An engineering evaluation and cost analysis for deactivating and decommissioning the prototype will be released for public comment.