US announces next-gen nuclear reactor experiments on sedan-sized MARVEL

The U.S. Department of Energy’s Idaho National Laboratory (INL) has selected five teams to conduct initial experiments using MARVEL, a sedan-sized microreactor test bed designed to pioneer nuclear power integration into non-traditional applications. MARVEL is a sodium-potassium-cooled microreactor fueled by uranium-zirconium hydride, producing 85 kW of thermal energy and about 20 kW of electricity. Its compact design and advanced cooling system allow it to operate at high temperatures (500°C to 550°C), making it suitable for innovative uses such as powering data centers and advancing water desalination. The reactor will operate at INL’s Transient Reactor Test Facility, providing a unique platform for private-sector innovation in nuclear energy. The selected teams include major industry and academic players aiming to demonstrate MARVEL’s viability in critical sectors. Amazon Web Services plans to integrate MARVEL with modular data centers for defense and government use, while DCX USA and Arizona State University will explore powering