Response of irradiated nuclear fuel rods to quasi-static and dynamic loads

Abstract

This paper presents the methodology applied for the experimental and numerical investigation of the mechanical response of spent nuclear fuel rods under static and dynamic loads. The experimental activities were conducted at the JRC Karlsruhe where a 3-point bending test device and an impact tower have been developed and commissioned at the hot-cell facilities. Results are provided for two PWR samples. Load-displacement curves describe the mechanical response of the sample in the 3point bending tests, whereas an image analysis methodology has been developed to comprehend the sample's behaviour under dynamic loads (recorded using a high-speed camera). Finite Element Analysis (FEA) are used to simulate the rod's response based on static and transient structural models in ANSYS Mechanical.

Extension of the Offbeat Fuel Performance Code to Finite Strains and Validation Against Loca Experiments

“…However, some scenarios of interest in the field of fuel behavior do not fall within the small-strain approximation domain, as they are characterized by large deformations or rotations. Some examples include the bowing of fuel assemblies in a PWR core (Wanninger et al, 2018), the cladding deformation in the presence of missing pellet surface defects (Spencer et al, 2016), the failure of aspherical TRISO particles (Jiang et al, 2022) or the bending experiments performed on spent fuel rods to assess their structural integrity (Vlassopoulos et al, 2018). Most notably large deformations become relevant for some postulated Design Basis Accidents (DBA) conditions such as Loss Of Coolant Accidents (LOCA).…”