Numerical verification of equilibrium thermodynamic computations in nuclear fuel performance codes

There is an increasing desire to integrate thermodynamic computations directly into multi-physics nuclear fuel performance and safety codes. These computations provide, among other matters, boundary conditions in heat and mass transport modules in predicting fuel behaviour. Precision must be maintained in computations involving fission and activation products with very low concentrations, which may nonetheless have significant radiological consequences. Also, there is the concern about the propagation of numerical errors in multi-physics codes. A method to numerically verify equilibrium thermodynamic computations is therefore necessary to satisfy rigorous quality assurance standards of the nuclear industry without significantly impeding computational performance. A technique is presented that can be applied to systems of any number of phases and system components. The technique is reliable and comprehensive in ensuring that all conceivable equilibrium constants have been satisfied without having to formulate each one of a potentially very large number.