A Model for an Effective Equation of State of Irradiated Fast Reactor Fuel

A bubble dynamics and mass transfer model GASBUB is presented that describes the pressure buildup in irradiated fuel above the melting point during energetic transients. The model describes the evaporation of fuel into pure vapor bubbles and into fission gasfilled bubbles. It is tested against the effective equation of state (EEOS) experiments jointly carried out by Sandia National Laboratories and Kernforschungszentrum Karlsruhe. In these experiments, fuel samples are heated up to ∼8000K. The model provides a basis for constructing an EEOS for irradiated fuel.