Outcome of the VIKING project: status and perspectives of numerical modeling of flow-induced vibrations of nuclear power plant components

Crucial nuclear power plant (NPP) components, such as fuel assemblies and steam generators, are exposed to flow-induced vibrations (FIV), potentially leading to fatigue problems and fretting wear of the material. Damage or failure of these components may lead to safety issues, thereby potentially necessitating unplanned outages of the reactor, resulting in substantial repair and standstill costs. With FIV being one of the leading causes of damage to these components, it is important to assess its impact on the integrity of fuel rods and steam generator tubes during the early design phase. While such an assessment has historically been done using semi-empirical models, due to the rise in computing power and capabilities, numerical tools are used more frequently, in particular in the last 10–15 years. To assess and further advance the current state-of-the-art of studying FIV in NPPs, the joint industry VIKING (Vibration ImpaKt In Nuclear power Generation) project was launched at the beginning of 2020. In this project, nine organizations collaborated for almost four years on FIV of configurations representative of steam generators and fuel rods and assemblies. This was done by performing numerical benchmark studies on five different experimental facilities. The current paper describes the main results and conclusions obtained from each numerical benchmark. Based on the individual findings, the status and perspectives of numerically simulating FIV of the aforementioned NPP components are presented.