Neutron reflection and leakage models for one,dimensional reactor computations

Exact discrete ordinates interface conditions were derived for neutron reflection and leakage for one-dimensional nuclear reactor computations with anisotropic scattering. The key to our derivation is a suitable reformulation of exact discretized equations - spectral nodal equations defined in the nonactive surrounding regions of nuclear reactor cores. As a result, interface conditions are obtained that can advantageously replace the nonactive surrounding regions of a nuclear reactor core in reactor computations. Numerical experiments with a representative one-dimensional code and an axial core model with anisotropic scattering were performed in order to illustrate the improvements that can be experienced by most one-dimensional discrete ordinates nuclear reactor codes with our interface conditions.