NEA CFD-Task Group members at a meeting hosted by Forschungszentrum Jülich (FZJ), Germany on 11-12 July 2024.
Computational fluid dynamics (CFD) can be used to solve three-dimensional flows, with some advantages compared to more global models but also challenges that hinder their use in nuclear safety applications. For over two decades, the NEA Working Group on Analysis and Management of Accidents (WGAMA) has been exploring the potential for CFD to be used to enhance nuclear safety.
This work has specifically been conducted through the CFD-Task Group. The group is now in its 6th phase and on 11-12 July 2024 nearly 40 experts from 13 countries convened at a meeting hosted by the German national research institute Forschungszentrum Jülich (FZJ).
During the meeting, the group discussed activities related to supporting the expanded use of computational fluid dynamics for nuclear reactor safety.
The group finalised a report on uncertainty quantification when CFD results are applied to the nuclear safety assessment. Despite CFD solving the most basic equations of fluid dynamics, the identification of uncertain parameters of a given study, the so-called input uncertainties, is not straightforward. Recommendations have been formulated to tackle errors based on numeric sources, as well as computational cost. Reducing uncertainty for CFD depends mainly on the quality of the experimental data used in the validation process.
The group also discussed data preservation, large volumes of which are needed for the safe operation of nuclear installations. The application of CFD needs new and more stringent requirements concerning experimental data. Thus, databases needed for the verification and validation of CFD codes should be identified and verified for applicability for the specific purpose of nuclear safety.
Short technical documents that aim to enable end users to assess whether the CFD approach is suited to their work will be soon shared with the interested experts.
Finally, the group discussed the organisation of a workshop on computational fluid dynamics for nuclear power plant safety (the so-called CFD4NRS workshop). The workshop aims to establish a forum where numerical analysts, modelers and experimentalists can exchange information on the application of CFD for nuclear safety and advanced reactor issues.
The first CFD4NRS workshop was held in Garching, Germany in 2006. The next, the 10th in the series (called CFD4NRS-10), will be co-organised with the Japan Atomic Energy Agency and will be held in Mito, Japan on 10-12 December 2025.
Visit the webpage for updates on the work of the Working Group on Analysis and Management of Accidents.
Opening of the CFD Task Group meeting by the local organiser and CFD-TH co-leader Stephan Kelm (FZJ) (left) and WGAMA Chair Hideo Nakamura (JAEA) (right).
