Brazil’s nuclear utility Eletronuclear has begun transferring used fuel from unit 1 of the Angra NPP to the Complementary Dry Storage Unit for Used Fuel (UAS – Unidade de Armazenamento Complementar a Seco de Combustível Irradiado). The campaign will last approximately four months.
In April, Brazil’s National Nuclear Energy Commission (CNEN – Comissào National de Energia Nuclear) was granted a 40-year extendable permit for operation of the UAS. The Angra plant comprises two different reactor units. Angra 1 is a Westinghouse-designed 609 MWe pressurised water reactor (PWR), while Angra 2 is a Siemens-designed 1275 MWe PWR. The used fuel storage pools at both units are approaching full capacity. The initial operation authorisation for the UAS was issued to Eletronuclear in 2021.
The storage facility is designed to receive fuel elements from the cooling pools of both units. Under a turnkey contract signed in 2017, US Holtec supplied Eletronuclear with Hi-Storm FW systems and related equipment for dry storage of used fuel from Angra 1&2. Because the units have different architectures and licencing bases, Holtec modified their respective cask handling cranes and equipment for loading the fuel into the multi-purpose canisters, and for moving the canisters to the dry storage facility.
The UAS is designed to hold up to 72 Holtec Hi-Storm FW dry storage casks, with the capacity to receive fuel until 2045. During the first fuel transfer campaign, held between 2021 and 2022, 15 storage casks were taken to the site from both units. In the initial phase of the second campaign, completed in August 2024, 15 more units were added from unit 2. After the completion of the current campaign, which will deal with fuel from Angra unit 1 in 2025 and 2026, the number of storage casks will total 48.
The loading of the first Multi-Purpose Canister with 37 fuel elements has been completed, followed by the welding process of the canister cover – the metal shell that will later be stored in the Hi-Storm concrete and steel hull. The operation also involved water drainage and internal drying, ensuring total safety for storage.
The initial activities take place inside the Angra 1 Fuel Building, in a controlled area, where the elements are prepared for definitive storage. Campaign coordinator Julio Cesar dos Santos, explained that the main objective is to free up space in the pools at the plants enabling them to receive new fuels, ensuring operational continuity. This will increase the life of the Angra 1 pool by 20 years.
