The mPower, designed by Babcock and Wilcox (B&W) in the USA, is a scalable and modular system in which the nuclear core and steam genera­tors are contained within a single vessel. It is a modular reactor designed to match customer demand in 125 MWe increments. mPower employs an integral nuclear system design, passive safety systems, a 4.5-year operating cycle between refueling, 5% enriched fuel, secure underground contain­ment, and spent fuel pool capacity for the life of the plant. A scaled proto­type of mPower using electric heating instead of nuclear heating is currently under construction in the USA to verify the reactor design and safety per­formance, supporting its licensing activities with the US Nuclear Regulatory Commission.