The Nuclear Energy Agency (NEA) Working Group on Analysis and Management of Accidents (WGAMA) marked a milestone in September, when it celebrated its 25th Anniversary and held its 28th plenary meeting.
On 8-11 September 2025, WGAMA members and international experts convened for intensive discussions, technical updates and strategic planning on nuclear safety subjects. WGAMA Chair Hideo Nakamura, of the Japan Atomic Energy Agency, opened the meeting with remarks that set the stage for a comprehensive review of ongoing and future activities intended to shape accident analysis. The plenary meeting started with members providing national updates and exploring priority activities and planning. Leaders of various Task Groups presented progress on major activities, such as the CSNI Code Validation Matrix, International Standard Problems (ISP-51, ISP-52, ISP-53), and ongoing work in thermal-hydraulics, computational fluid dynamics (CFD), and severe accidents. Updates were also shared regarding workshops and conferences, including ERMSAR 2026, SWINTH, and the upcoming CFD4NRS-10 workshop, with calls for participation and expressions of interest. The group considered future activities, including new research proposals on in-vessel melt retention, passive system reliability, and NEA joint projects like PRIME. Reports from the NEA joint projects, the International Atomic Energy Agency, the European Commission, and other international organisations emphasised the importance of global collaboration in nuclear safety research on emerging new reactor designs including small modular reactors (SMRs).
On 11 September 2025, WGAMA members gathered for a special event commemorating the 25th anniversary of the group. Established in by the Committee on the Safety of Nuclear Installations (CSNI) through the merger of two principal working groups, WGAMA had its first meeting in 2000. Since then, it played a key role in strengthening the technical basis for accident management and analyses across thermal-hydraulics, severe accidents and CFD.
The celebration featured a series of presentations. Mr Nakamura offered historical reflections, tracing WGAMA’s origins and achievements, and highlighting milestones from the early days to today’s integrated approach. Success stories were shared through presentations by three leading experts that showcased advances in deterministic safety analysis (DSA), CFD applications, and severe accident management (SAM). A lively panel discussion with eight international leaders, both in person and online, explored WGAMA’s future in the evolving nuclear energy landscape, moderated by Martina Adorni (of the NEA) and WGAMA Vice-Chair Ahmed Bentaib (of France’s Authority for Nuclear Safety and Radiaion Protection, or ASNR). The event also included recognition and awards honouring the dedication of past and present chairs, bureau members, task leaders and contributors.
Looking ahead, WGAMA remains committed to advancing nuclear safety through collaborative research, knowledge transfer, and innovation. The 28th Plenary Meeting and anniversary celebration underscored the continuing value of international co-operation in addressing the complex challenges of accident analysis and management.
For more information on WGAMA and upcoming activities, visit the NEA WGAMA webpage.