Draft EIS released for Project Pele mobile microreactor demo at INL

Background: In March 2021, the DOD announced that it had selected two of three teams from a preliminary design competition to move ahead with the development of a final design of a prototype mobile microreactor capable of producing 1–5 MWe (a reduction from the initial project specs, which called for a reactor producing 1–10 MWe). The designs—submitted by BWXT Advanced Technologies and X-energy—are both for small, high-temperature gas-cooled reactors using high-assay low-enriched uranium (HALEU) TRISO fuel.

Both designs would consist of a microreactor module, a power conversion module, and a control module, each housed in a 20-foot-long CONEX shipping container ready for air, sea, or ground transport. A fourth CONEX container could be used to house ancillary equipment, such as pipes, cables, and connectors.

Following a final design review in early 2022, one of the two companies may be selected to build a prototype reactor during a 24-­month construction and demonstration phase.

Construction and demo plan: The mobile microreactor would be fabricated at either BWXT Advanced Technologies or X-energy facilities and would be transported to Idaho National Laboratory for demonstration testing. Demonstration would go beyond simply starting up and operating the reactor. After initial testing, the reactor would be shut down, transported to a second test location at INL, and restarted. At the second testing location, the mobile microreactor system would be connected to a small, isolable microgrid with diesel generators and load banks attached.

Reactor fuel would be produced from DOE stockpiles of high-enriched uranium located at the Y-12 Plant in Oak Ridge, Tenn., that would be converted to an oxide form and down-blended to HALEU before it is fabricated into TRISO fuel at BWXT’s Lynchburg, Va., facility.

Questions of deployment: Mobile military microreactors have been suggested as an alternative to the diesel generators often used to supply electricity to Army operations because they could eliminate the need for expensive and hazardous transports of diesel fuel to remote locations or forward operating bases. The draft EIS describes the 2016 findings of a Defense Science Board report commissioned by the DOD, saying that the board “evaluated available energy technologies before concluding that electrical generating capability for forward operating bases, remote operating bases, and expeditionary bases can best be met by a less than 10 MWe microreactor system that can be safely and rapidly moved by road, rail, sea, or air for quick set up and shut down.”

The Army also requires reliable electricity at large domestic and international bases, and some have suggested that those more established bases would be better suited to microreactor deployments. A report published in June by a National Academies committee (also commissioned by the DOD), titled Powering the U.S. Army of the Future, examines multiple energy sources used by the Army. In a brief discussion of Project Pele, the report states, “The Pele nuclear power plant program now underway may prove appropriate for domestic and permanent overseas bases. It will not, however, adequately meet the needs of expeditionary and defensive operations due to its limited power rating and mobility concerns.”

The report goes on to recommend that “the detailed safety and regulatory requirements of a nuclear power plant be clearly defined and agreed to by all appropriate government agencies before prototype definition proceeds further,” adding that “use cases for these reactors need to be carefully defined, given the limited power and mobility of the envisioned systems.”

Public input: The publication of the draft EIS by the Environmental Protection Agency in the Federal Register on September 24 will mark the opening of a 45-day public comment period that will end on November 9. According to the DOD’s schedule, the notice of availability of the final EIS is expected in January 2022, and a record of decision on the project is expected in March 2022.

The DOD Strategic Capabilities Office will host two public hearings on the draft EIS featuring identical content on October 20 in Fort Hall, Idaho. The meetings will be livestreamed and recorded. Additional information about the project and the public hearings can be found at mobilemicroreactoreis.com.