New ADOPT fuel pellets: higher performance and safety for nuclear power plants

Westinghouse has produced the first uranium pellets with a higher enrichment level than those currently used in commercial reactors. These fuel pellets, known as Low Enriched Uranium Plus (LEU+) Advanced Doped Pellet Technology (ADOPT), are designed to increase the output and safety of nuclear power plants.

LEU+ ADOPT fuel contains up to 8% of the uranium-235 isotope (U-235) and additives that improve the fuel’s safety characteristics compared with standard uranium dioxide (UO2). Compared with the 3-5% U-235 enrichment used in conventional power reactor fuel, LEU+ ADOPT can generate more thermal energy with fewer fuel assemblies in the reactor core, improving the economics of the nuclear fuel cycle.

Production and testing of physical properties

The first LEU+ ADOPT fuel pellets were pressed at Westinghouse’s plant in Springfields, Lancashire, in northwest England. The company said it achieved this milestone in collaboration with US utility Southern Nuclear and with support from the US Department of Energy (DOE).

The pellets were made from uranium dioxide powder enriched to a higher level of U-235, prepared by Idaho National Laboratory. This is the first use of material produced at a DOE facility to manufacture commercial uranium dioxide fuel enriched above 5%.

The first LEU+ ADOPT fuel pellets will now be processed into fuel rods and loaded into four test assemblies. Next year, these fuel assemblies will be sent to the US for irradiation testing in Unit 2 of the Vogtle nuclear power plant, operated by Southern Nuclear in Georgia.

Approval for fuel enriched above 5%

In March 2023, the US Nuclear Regulatory Commission (NRC) approved the use of Westinghouse’s ADOPT fuel pellets in US pressurized water reactors. In October, Southern Nuclear announced that it had received NRC authorization to use advanced nuclear fuel enriched to up to 6% U-235 in Vogtle Unit 2. This is the first time a US commercial reactor has been approved to use fuel enriched above 5%.

According to Westinghouse, demand for LEU+ ADOPT fuel enriched to between 5-10% will rise significantly in the coming years. This will be driven mainly by longer fuel cycles at power reactors and fewer outages.

ADOPT fuel is one of several accident-tolerant fuel concepts. It is one of a number of projects supported by the DOE program to develop new fuel pellets and cladding that could be commercialized before the end of this decade.