The Energy Multiplier Module (EM² or EM squared) is a nuclear fission power reactor under development by General Atomics.
[1] It is a fast-neutron version of the Gas Turbine Modular Helium Reactor (GT-MHR) and is capable of converting spent nuclear fuel into electricity and industrial process heat.
The reactor unit is coupled to direct-drive helium closed-cycle gas turbine which drives a generator to produce electricity.
EM2 is expected to achieve a thermal efficiency of above 50% due to its high core outlet temperature and closed Brayton power cycle.
The Brayton cycle eliminates many expensive components, including steam generators, pressurizers, condensers, and feedwater pumps.
[8] Each module can be manufactured in either U.S. domestic or foreign facilities using replacement parts manufacturing and supply chain management with large components shipped by commercial truck or rail to a site for final assembly, where it will be fully enclosed in an underground containment structure.
EM2 utilizes passive safety systems designed to safely shutdown the reactor in emergency conditions using only gravity and natural convection.