The main mission of the Working Group on Fuel Safety (WGFS) is to advance the current understanding and address cross-cutting issues related to fuel behaviour in accident conditions, including work on associated aspects of thermal-hydraulics, oxidation, chemistry, mechanical behaviour and reactor physics.

Specifically, the WGFS:

1. Reports to the Committee on the Safety of Nuclear Installations (CSNI), assists the Committee with its work and carries out the programme of work approved by the CSNI.
2. Assesses the technical basis for current safety criteria and their applicability to new fuel designs and materials. The assessment focuses on anticipated transients and postulated accident conditions. Information relevant to fuel performance under normal operating conditions is considered only to the extent necessary to assess the safety behaviour, focussing on mechanical behaviour of fuel assemblies.
3. Determines needs and priorities for future research programmes in the area of fuel safety behaviour, with the aim of understanding and adequately modelling key phenomena and of quantifying safety margins.
4. Reviews, from the safety point of view, the adequacy of fuel codes and methodologies used for different core assessments as related to high burn-up fuel, new fuel designs and materials. Cores with different fuel assembly designs and with MOX fuel are to be considered. Neutronic, thermal-hydraulic and materials aspects are considered as they relate to core safety assessment.
5. Provides a forum where safety-relevant fuel issues emerging from operating experience and research work can be addressed and resolved in an effective manner.

The Working Group aims at facilitating international convergence in fuel safety issues, including experimental approaches, interpretation and use of the experimental data or of other relevant information.

Co-operation with other NEA bodies is actively pursued, as appropriate, e.g. with the Working Group on the Analysis and Management of Accidents (WGAMA) on issues involving thermal hydraulics and/or fuel damage, with the Working Group on Fuel Cycle Safety (WGFCS) on fuel-storage issues and with subsidiary bodies of the Nuclear Science Committee (NSC) working on fuel issues. This results in optimisation of both the resources mobilised by member countries for NEA activities and the quality of the work produced.

The Working Group performs its activities mainly through organising topical meetings on specific subjects or through task forces dedicated to covering specific programme items.