US DOD Funds Three Mobile Nuclear MicroReactors Designs

BWX Technologies, Inc., Westinghouse and X-energy have contracts to each begin design work on a mobile nuclear reactor prototype under a Strategic Capabilities Office initiative called Project Pele.

After a two-year design-maturation period, one of the three companies may be selected to build and demonstrate a prototype.

They want a system that can be safely and rapidly moved by road, rail, sea or air and for quick set up and shut down, with a design which is inherently safe.

On 9 March 2020, the three development contracts were:

BWX Technologies, of Virginia, for $13.5 million;
Westinghouse Government Services of Washington, D.C. for $11.95 million; and
X-energy of Maryland, for $14.3 million.

The goal is for small nuclear micro-reactor in the 1-5 megawatt (MWe) power range.

China is starting up a 210 MWe HTR-PM pebble bed reactor this year. They used pebble technology from Germany.

Nextbigfuture has covered the Westinghouse Evinci microreactor.

The key benefits of eVinci are attributed to its technology:

Solid Core:

* Encapsulates fuel to significantly reduce proliferation risk
* Enables inherently safe core due to strong negative temperature feedback

Heat Pipes:

* Eliminates the need for reactor coolant pump and all associated auxiliary systems to enable compact packaging and simple design
* Can inherently adjust heat load, thus allowing easier autonomous load following
* Can operate at higher temperatures to enable higher efficient power conversion system and high-grade process heat

Both heat pipes and the solid core together make the eVinci micro reactor a “solid state reactor” with minimal moving parts, which is key to the reliability and maintenance-free design of a long-life decentralized energy generator.

X-Energy has been working on a the Xe-100 high-temperature gas-cooled pebble bed modular reactor design since 2015.

BWXT has shipped 400 nuclear reactor cores to the Naval Nuclear Propulsion Program and has led and/or supported the design of more than 40 nuclear reactor systems. BWX Technologies announced on Oct. 2, 2019 it was restarting its existing TRISO nuclear fuel production line.

Tristructural-isotropic (TRISO) fuel has a series of tiny pellets packed into larger fuel assemblies for a reactor. Each TRISO fuel kernel is coated with layers of three isotropic materials that retain the fission products at high-temperature while giving the TRISO particle significant structural integrity.

A second small nuclear reactor project is being run through the office of the undersecretary of acquisition and sustainment. This is pilot program aiming to demonstrate the efficacy of a small nuclear reactor, in the 2-10 MWe range, with initial testing at a Department of Energy site in roughly the 2023 timeframe.

SOURCES- DOD, BWXT, Westinghouse, X-Energy
Written By Brian Wang,