The NEA Working Group on Analysis and Management of Accidents (WGAMA) Task Group on Computational Fluid Dynamics (CFD) for Nuclear Reactor Safety met on 9–10 June 2026 in Fontenay-aux-Roses, France to launch phase 7 of its activities and advance international collaboration on the use of CFD in nuclear safety.
Hosted by the French Nuclear Safety and Radiation Protection Authority, ASNR, the meeting was held in conjunction with the final workshop of the Tee-Junction benchmark exercise, marking an important milestone in ongoing efforts to strengthen validation and confidence in CFD applications for nuclear reactor safety analysis.
The meeting marked the formal start of phase 7, which focuses on supporting a broader and more consistent application of CFD tools in nuclear safety. Discussions emphasised the continued development of best practice guidelines, high-quality validation datasets, and benchmark exercises to address key safety-relevant phenomena. Participants also reviewed ongoing work from previous phases, such as contributions to best practice documentation and uncertainty quantification activities, including producing brochures to describe capabilities and limitations of CFD to different stakeholder groups.
In this context, the Task Group explored priorities for the upcoming phase, including new benchmark activities and the definition of future work, reinforcing its role as a member-driven platform for advancing CFD methodologies for nuclear safety applications.
Participants also discussed ongoing and future benchmark activities, including the organisation of new exercises and opportunities to expand collaboration across member countries. These benchmarks remain essential for improving confidence in CFD simulations by comparing results against high-quality experimental data and among different modelling approaches.
In conjunction with the main meeting, a co-ordination meeting of the Task Group leadership and key contributors was held at the NEA headquarters in Boulogne-Billancourt, France. This meeting focused on ensuring alignment of ongoing and future activities across phases including discussing upcoming events such as CFD4NRS workshops, and identifying new benchmark topics and collaboration opportunities.
The co-ordination meeting also provided a forum to review organisational aspects, confirm next steps, and prepare the strategic direction of the Task Group, ensuring continuity and coherence of its work programme.
The WGAMA CFD Task Group continues to bring together experts from NEA member countries and international organisations, fostering collaboration on key methodological and technical challenges in nuclear safety analysis.
