Fitting-based resonance database method for resonance self-shielding calculations of large-scale task considering depletion and intra-pin distribution

A fitting-based resonance database method is proposed to perform self-shielding calculation for large-scale problems. The intra-pin radial effects are also treated by this method. The new method is mainly divided into two steps. First, the operating conditions of different pin-cells existing in the target problem are simulated by the adjustments of the parameters of single pin-cell cases. The ultra-fine-group slowing-down solving process is performed for these pin-cells and the resonance database for the target problem is fitted using the obtained results. Second, the target problem is calculated using the resonance database generated. Transport calculations are performed at both steps to establish the equivalence relationship between the target problems and the single pin-cell cases. Several techniques are adopted to evaluate the resonance interference and radial effects. Numerical tests prove that the method is capable to give the accurate prediction for the spatial-dependent resonance self-shielded cross-sections in an efficient way.