Orano two-tier dry storage system in loading 'first'

07 November 2023

Orano has loaded the first used fuel into the upper modules of the two-tiered NUHOMS MATRIX horizontal dry storage system at the Wolf Creek nuclear power plant in Kansas.

A sealed used fuel canister is moved remotely from the transfer cask into a MATRIX module (Image: Orano)

The Wolf Creek Nuclear Operating Company in 2018 contracted Orano TN - a business line of Orano USA - to design, construct and commission an interim used fuel storage facility, and to transfer used fuel from the plant's storage pool to the new dry storage facility. According to Orano, the two-tier compact horizontal storage system being used at Wolf Creek reduces the footprint requirements by as much as 45% compared with other Independent Spent Fuel Storage Installation (ISFSI) facilities storing the same number of canisters.
Over the course of three weeks, three Extended Optimized Storage (EOS) 37PTH canisters were each filled with 37 used nuclear fuel assemblies in the reactor's used fuel pool and then transferred into the upper modules of the MATRIX dry storage system. A joint team of Orano and Wolf Creek worked together to complete three loadings after training which included dry runs with the equipment on-site and at a full-scale MATRIX mock-up at the Orano TN Fabrication facility in Kernersville, North Carolina, where the eight EOS 37PTH storage canisters were manufactured.

Left: The transfer cask containing the EOS 37PTH canister is lowered into the reactor storage pool, where used fuel assemblies are loaded underwater. All moisture is purged from inside the canister before it is sealed for dry storage in one of the MATRIX system's modules. Right: Loaded canisters of used nuclear fuel, inside a shielded cask, are transferred from the Wolf Creek reactor building to the MATRIX dry storage system using the self-propelled SEFIRO motorised transporter. (Images: Orano)

The company has shared a video of the process.

With five canisters loaded into the lower tier of the system in 2022, eight of the available 11 modules in the constructed MATRIX system have now been filled. Future loading campaigns will be conducted after the MATRIX system has been expanded by the addition of further modules, starting in Spring 2024, Orano said.

The NUHOMS MATRIX used nuclear fuel dry storage system at Wolf Creek: Inlets at the bottom of each round module opening allow inspection equipment to completely examine the stored canister when the module is closed. Each module also has an inspection port to aid in visual inspection of the canister. (Image: Orano)

An ISFSI is a US Nuclear Regulatory Commission-licensed facility for the storage of used fuel which has been allowed to cool for several years in a reactor's used fuel pool before being transferred to dry storage.

Wolf Creek, a single-unit 1200 MWe (net) pressurised water reactor, is the only nuclear power plant in Kansas. According to information from the US Nuclear Energy Institute, nuclear energy provides 14.3% of the state's electricity and 23.3% of its carbon-free electricity, complementing wind and solar.

Researched and written by World Nuclear News