SPIZWURZ: Stress-induced hydrogen rearrangement in fuel rod cladding during long-term interim storage
Gesellschaft für Anlagen- und Reaktorsicherheit gGmbH (GRS)
Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (KIT-INE)
Karslruhe Institute of Technology, Institute for Applied Materials (KIT-IAM)
The collaborative project SPIZWURZ focuses on experimental and theoretical studies on the behaviour of hydrogen in fuel rod cladding materials and the stress state of Zircaloy-4 cladding in contact with high burn-up spent nuclear fuel to assess the impact on cladding integrity under dry interim storage conditions. For this purpose, long-term and detailed studies on non-irradiated cladding materials and samples will be performed by other project partners within workpackage 1. In workpackage 2, KIT-INE focusses on determining the geometry of an irradiated nuclear fuel rod segment by means of a laser scan micrometre before and after removal of the fuel. The variation of the cladding geometry allows to determine the hoop stress in the cladding, exerted by the fuel pellet. The experimental work is further supported by simulations and theoretical modelling performed by the German Association for Plant and Reactor Safety (GRS). Moreover, the Company for Interim Storage (BGZ) is involved in the project as an observer.