The NEA Working Group on the Analysis and Management of Accidents (WGAMA) held its annual meeting in person on 12-14 September 2022 to discuss its ongoing work and activities related to potential accidental situations in nuclear power plants. The meeting brought together over 60 delegates from 24 member countries, as well as representatives from the International Atomic Energy Agency (IAEA) and the European Commission.
The working group aims to assess and enhance the technical basis needed for the prevention, mitigation and management of potential accidents in nuclear power plants. It also facilitates international collaboration on the management of accidents and strategies. In this context, the group currently focuses on three main fields: nuclear thermal-hydraulics, computational fluid dynamics (CFD) for nuclear reactor safety and severe accident.
During the meeting, members held an extensive discussion on the 12 ongoing activities in the three main fields with the aim to discuss their progress identify next steps. Members also focused on the group’s achievements during the ongoing period. One focal point included a specialist meeting on transient thermal-hydraulics in water-cooled nuclear reactors (SM-TH) and a benchmark on fluid-structure interaction (FSI) based on experiments to validate coupled CFD and computational structural dynamics (CSD) calculations.
The group also discussed proposals for two potential new activities: a benchmark on thermal mixing and fatigue in a T-junction with a dead leg - validation of CFD based on experiments carried out in a new test rig for the purpose, and a specialist workshop on advanced instrumentation and measurement techniques for nuclear reactor thermal hydraulics and severe accidents (SWINTH-2024).
Another highlight of the meeting was the session dedicated to the NEA’s nuclear safety research experimental activities, including the next phase of the Fukushima Daiichi nuclear power plant Accident Information Collection and Evaluation (FACE). Even if the overall severe accident phenomenology is relatively well known for both in and ex-vessel configurations, modelling of some physical phenomena needs to be enhanced to reduce uncertainties on severe accident calculations for reactor applications. Based on this, the group agreed to support a new joint project on COrium Properties for reactor Simulation and uncertainties (COPS).
The group were pleased to have been able to hold the meeting in person which allowed for strong discussions around each subject. The next meeting’s direction will be shaped from on input gathering from the members and cooperation with international organisations and others NEA groups.
For more information on the working group, click here.