Feasibility Study of LS-DYNA for FSI Analysis: Integration into the FRM II Fuel Conversion Programme Workflow

In this presentation, I will discuss my MSc thesis, which I carried out during a thesis exchange at the FRM II research reactor in Garching, within the Applied Nuclear Technology Group, as part of the HEU-to-LEU fuel conversion programme. The work investigates the use of LS-DYNA as a structural solver within FRM II's existing fluid-structure interaction workflow, benchmarking a quasi-static implicit analysis against Ansys Static Structural and using a transient explicit analysis to study the fuel plate's response to sudden load changes. LS-DYNA reproduced the Ansys results within 0.75% for all nominal load cases, and it also captured the transient response under the most severe loading case; together, these results provide a basis for future two-way FSI coupling in the LEU core licensing assessment.