The first full-scale transportable microreactor prototype will be completed and delivered in 2024 for testing at the Idaho National Laboratory (INL).

Transportable microreactors can deliver clean, zero-carbon energy where and when it is needed in a variety of austere conditions (Image: BWXT)

The US Department of Defense (DOD) Strategic Capabilities Office (SCO) announced in April its decision to proceed with the project to build and demonstrate a TRISO-fuelled prototype mobile microreactor at the INL site following the release of a final environmental impact statement (EIS) for the reactor. Two companies - BWXT and X-Energy - were selected in 2019 to develop a final design for the prototype reactor.

BWXT has now been awarded a contract by SCO to complete and deliver the reactor in 2024. The prototype will be built under a cost-type contract worth around USD300 million, depending on options selected, by BWXT Advanced Technologies LLC in facilities in Lynchburg, Virginia and Euclid, Ohio. Some 120 employees are expected to work on the project over the next two years, the company said.

"We are on a mission to design, build and test new nuclear technology to protect the environment while providing power, and we are thrilled with this competitively bid award after years of hard work by our design and engineering team," BWXT Advanced Technologies President Joe Miller said. "The entire nuclear industry recognises that advanced reactors are an important step forward to support growing power needs and significant carbon reduction imperatives."

SCO has partnered with the Department of Energy to develop, prototype and demonstrate a transportable reactor in what has been described as a whole-of-government effort, also drawing on the expertise of the Nuclear Regulatory Commission, US Army Corps of Engineers, NASA and the National Nuclear Security Administration. Transportable reactors that can deliver clean, zero-carbon energy where and when it is needed can provide a resilient power source for DOD operational needs, but can also potentially be used in the civilian and commercial sectors for disaster response and recovery, power generation at remote locations, and deep decarbonisation initiatives.

The high-temperature gas-cooled reactor (HTGR) will operate at between 1 and 5 MWe and will be transportable in commercially available shipping containers, BWXT said. It will be powered by TRISO (TRIstructural-ISOtropic) high-assay low-enriched uranium (HALEU) fuel that can withstand extreme heat and has very low environmental risks.

The transportable design consists of multiple modules that contain the microreactor's components in 20-foot (6-metre) long, ISO-compliant CONEX shipping containers, BWXT said. The reactor is designed to be safely and rapidly moved by road, rail, sea or air, and the entire reactor system is designed to be assembled on-site and operational within 72 hours. Shut down, cool down, disconnection and removal for transport is designed to take less than seven days.

Team effort

BWXT is the prime contract and integration lead, responsible for reactor module manufacture, with Northrop Grumman, Aerojet Rocketdyne, Rolls-Royce LibertyWorks and Torch Technologies, Inc amongst other companies playing key roles in the project.

The reactor and fuel will be shipped separately to the test site, where fuelling will take place. The system will then undergo up to three years of testing at INL to confirm performance and operability. It will also be disassembled and re-assembled to prove its transportability.

As the project is not commercial, the prototype reactor will be tested and operated under Department of Energy authorisation. The US Nuclear Regulatory Commission is also taking part in the project to provide accurate, current information on applicable regulations and licensing processes.

Researched and written by World Nuclear News