Generalized Hébert method for double-heterogeneity problem

The double-heterogeneity problem, caused by stochastic media in the dispersion fuel, poses challenges to nuclear reactor physics calculations. Hébert model is a classical double-heterogeneity calculation method derived from collision probability method (CPM), and has been implemented in some lattice physics codes. However, it is not convenient for the Hébert CPM model to calculate the dispersion fuels with complex geometry. A generalized Hébert method is proposed in this paper by introducing the concept of equivalent flux, and it can be easily implemented within any deterministic neutron transport solver. The generalized Hébert method is subsequently implemented in the Laputa code based on method of characteristics (MOC). Finally, a numerical validation is conducted between the Hébert-MOC model and Monte Carlo explicit modeling, as well as the Sanchez-MOC model, demonstrating the generalized Hébert method is very prospective. •The generalized Hébert method is proposed and can be easily implemented within any deterministic neutron transport solver.•The generalized Hébert method is implemented with MOC solver and used in ESSM for resonance treatment.•Numerical results of dispersion fuel indicate that the generalized Hébert method is accurate and prospective.