Optimizing spent nuclear fuel cask loading for VVER-440 fuel

The paper explores the management of spent nuclear fuel, focusing on dual-purpose spent fuel casks used to store and transport spent nuclear fuel from VVER-440 reactors. The main goal is to optimize spent fuel cask loading by developing an extensive methodology supported by a powerful tool. Using a multiple-zoning strategy, cooler outside fuel assemblies protect radiation sources from the hotter inner assemblies. An effective tool based on adjoint particle flux calculations is the recently developed OPOS-440 calculation code. This code allows for optimizing the loading pattern and determining dose rates surrounding the spent nuclear fuel cask for a selected fuel loading. The code also thoroughly demonstrates how different fuel assemblies affect the dose rate. These findings have real-world implications for reactor operations, including optimizing cask loading and supporting the licensing procedure for novel fuel types in already-existing spent fuel casks.