US' meltdown-proof advanced nuclear fuel enters critical testing phase

X-energy, a US company, has initiated a critical 13-month irradiation test of its advanced TRISO-X nuclear fuel at Idaho National Laboratory (INL). This marks the first time the company’s “fuel pebbles” undergo such testing in a US lab, a key milestone toward regulatory approval by the US Nuclear Regulatory Commission (NRC). The TRISO-X fuel features uranium kernels encapsulated in multiple protective carbon and ceramic layers, designed to prevent radioactive release and make the fuel meltdown-proof. During testing at INL’s Advanced Test Reactor, the fuel will be subjected to varied power levels, temperatures, and burnup conditions to simulate real reactor environments, aiming to establish a new safety and reliability standard for nuclear fuel. This fuel qualification is central to X-energy’s commercial plans, including the construction of the TX-1 fuel fabrication facility in Oak Ridge, Tennessee, which could become the first NRC-licensed advanced nuclear fuel plant in over 50 years. The facility will produce fuel for X-energy