Working Group on Fuel Safety Margins (WGFSM)

Mandate

The main mission of this working group was to advance the understanding and address the safety issues related to fuel safety margins.

The specific mandate was as follows:

The group reported to the Committee on the Safety of Nuclear Installations (CSNI), assisted the committee with its work and carried out a programme of work approved by the CSNI.
Assessed the technical basis for safety criteria and their applicability to high burnup (above 50 MWd/kg), including new fuel designs and materials. The assessment focused on anticipated transients and postulated accident conditions. Information relevant to fuel performance under normal operating conditions were considered only to the extent necessary to assess the safety behaviour.
Determined the 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 quantifying safety margins.
From the safety point of view, reviewe dmethodologies used for different core assessments as related to complex core configurations. Cores with different fuel assembly, designs and those with mixed-oxide (MOX) fuel were considered. Neutronic, thermal-hydraulic and materials aspects were considered as they related to core safety assessment.
Provided a forum where safety relevant fuel issues emerging from operating experience and research work could be addressed and resolved in an effective manner.