Unit 2 of Southern Nuclear’s Vogtle NPP in Georgia has received first-of-a-kind approval from the US Nuclear Regulatory Commission (NRC) to be the first US commercial reactor authorised to use Accident Tolerant Fuel (ATF), exceeding 5% enrichment of uranium-235. Southern said this milestone underscores the industry’s effort to optimise fuel, enabling increased fuel efficiency and long-term affordability for nuclear power plants.

Southern Nuclear President Pete Sena said nuclear power accounts for almost half of US clean energy, “and Southern Nuclear is committed to pushing for innovative, game-changing technologies like the deployment of Accident Tolerant Fuel that will advance performance and further support our ability to strengthen grid reliability with 24/7 generation”. He added: “Realising the significant role nuclear power plays in our country’s energy infrastructure, I especially want to recognise the NRC’s thorough yet timely review of this installation to support the future of commercial nuclear power in our country.”

In 2022, Southern Nuclear signed an agreement with Westinghouse to load four lead test assemblies (LTAs) with next-generation fuel features into Vogtle 2. The LTAs use key components from Westinghouse’s High Energy Fuel initiative and the EnCore Fuel programme. These features include ADOPTTM uranium dioxide pellets, AXIOMTM fuel rod cladding and chromium-coated cladding combined with Westinghouse’s advanced PRIMETM fuel assembly design. With regulatory authorisation, Southern Nuclear and Westinghouse are moving forward with the manufacturing these first-of-a-kind fuel assemblies with planned installation in early 2025.

“Members of Congress and the Department of Energy have demonstrated their deep understanding of the positive impacts of Accident Tolerant Fuel, and their support has been critical to our ability to advance fuel technology with higher burnup rates,” said Tarik Choho, Westinghouse President of Nuclear Fuel. “We are grateful to Southern Nuclear for their trust and look forward to delivering advanced technologies that will bolster the light water fleet and support the low-cost generation of nuclear power in the long term.”

Authorisation of enrichments above 5 wt.% uranium-235 is part of broader efforts by industry to develop and deploy batch quantities of advanced fuel technologies which are a set of new technologies that enable higher enrichment and have the potential to enhance safety at NPPs by offering better performance during normal operation, transient conditions and accident scenarios.

The enrichment authorisation is a component of a broader LTA programme that will demonstrate performance of advanced fuel assemblies developed by Westinghouse with significant support from the Department of Energy’s enhanced ATF programme.

Southern Nuclear has led the commercial nuclear industry in incremental deployment of enhanced ATF technology, having been the first in the world to install GE-Hitachi ATF fuel cladding technologies in 2018 at Plant Hatch unit 1 with samples subsequently discharged and shipped to Oak Ridge National Lab for further testing in 2020. At Vogtle 2 in 2019, Southern installed four Framatome-developed GAIA lead fuel assemblies containing enhanced accident-tolerant features applied to full-length fuel rods.

Southern said that, along with DOE, fuel suppliers and peer utilities, it is executing “a coordinated, overarching, multi-year effort through the Nuclear Energy Institute’s ATF Working Group to expand the regulatory paradigm to meet the industry goal of safely and economically enabling 24-month cycle operations for all operating plants with enhanced ATF features”.

Image: Southern Nuclear has received authorisation to load the Vogtle 2 nuclear reactor with first-of-a-kind fuel assemblies (courtesy of Southern Nuclear)