Mono-dimensional mechanical modelling of fuel rods under normal and off-normal operating conditions

摘要

this paper deals essentially with the mono-dimensional mechanical description of pressurised water reactor (PWR) fuel rods under normal and off-normal operating conditions for which a finite element model (MEFISTO) has been Developed and integrated to the METEOR fuel performance application. We describe the basic modelling hypotheses With particular attention being paid to the numerical treatment of non-linear stress relaxation phenomena such as Cracking and creep of oxide fuels, cladding creep and plastic behaviour which are all accounted for.