General aspects of modelling transient molten fuel motion in a channel using the two-phase-flow fluid equations

Hypothetical core-disruptive fast-breeder reactor accidents may lead to the failure of fuel pins and the dispersal of molten fuel by fuel vaporization and/or fission gas release. The CABRI series of experiments is designed to study the effects of such hypothetical accidents on a single fast-breeder fuel pin placed in a cylindrical containment channel. Analysis of the CABRI experiments requires the development of computer codes and one such code is that required for molten fuel dispersal in a sodium voided channel. The paper presents a brief general discussion of the channel two-phase-flow fluid equations with a mass source term. An illustration of the connection between homogeneous and slug type models is also derived. (author)