US Defense Department invites comment on microreactor

03 March 2020

The US Department of Defense (DOD) is seeking public comment on a proposal to construct and demonstrate a prototype advanced mobile nuclear microreactor to support its domestic and operational energy demands. This is expected to be a small advanced gas reactor using high-assay low enriched uranium tristructural isotropic (TRISO) fuel and air cooling.

INL's Materials and Fuels Complex is one of the sites under consideration for the prototype reactor (Image: INL)

The DOD issued a Request for Information in January last year to identify concepts for a "small mobile reactor" design to address electrical power needs in rapid response scenarios. In a notice published yesterday in the Federal Register, it said it intends to prepare, in partnership with the US Department of Energy, an Environmental Impact Statement (EIS) for the prototype reactor. The DOD's proposed action includes construction of the prototype microreactor and demonstration activities, as well as the planned disposition of the reactor following operation.

"DOD installations need the capability to reduce their present reliance on local electric grids, which are highly vulnerable to prolonged outages from a variety of threats, placing critical missions at unacceptably high risk of extended disruption," it said in the Federal Regiser. "Backup power is often based on diesel generators that have limited on-site fuel storage, are undersized for new homeland defence missions, are not prioritised to critical loads, and are inadequate in duration and reliability. Advanced nuclear power is capable of meeting the DOD's need to increase energy security and resilience, but must demonstrate its technical and safety specifications at full size and power."

The microreactor must keep radiation exposure during power operation, abnormal operations, or "upset conditions", as low as reasonably achievable, DOD said, and minimise consequences to the nearby environment and population "in case of kinetic or non-kinetic action affecting structural integrity or release of contamination". It must also utilise materials that, if damaged, "do not generate and impose excessive training and equipping burdens on forward area first responders, site medical facilities, or supported military personnel and the civilian population".

Two locations are needed for the prototype construction and demonstration: one would be inside an existing structure, and the second would be outdoors. The DOD Strategic Capabilities Office (SCO) has identified Idaho National Laboratory and Oak Ridge National Laboratory as potential locations.

The public has until 1 April to comment on the scope of the EIS. After considering all comments received during scoping, SCO will prepare a draft EIS for the construction and demonstration of the prototype microreactor which it expects will be available for public review and comment in 2021.

Researched and written by World Nuclear News