Methods of calculating thermal characteristics of fast reactors with dissociating coolant

The possibility of application of mathematical models for calculation of thermohydraulic characteristics of reactors cooled by the N2O4-dissociating gas has been considered. Such a model presents a set of equations of energy concervation for fuel, cladding coolant and an equation of mass concervation for components of the chemically reacting mixture. The above equations were solved by the alternative direction method for the case of ultimately streamlined triangular lattice of fuel elements. The velocity field is supposed given. The approximate methods of calculation of thermohydraulic ractor characteristics, based on the application of local heat transfer coefficients are also considered, because a direct numerical solution requires much computer time. The comparison of results obtained confirmed the reliability of approximate methods consuming little time