Transport-corrected flux-moment homogenization method for generating P0 multigroup cross-section based on continuous energy Monte-Carlo

Abstract

The scattering anisotropy multigroup cross-section (MGXS) with respect to the outgoing angle, as well as the anisotropy of the total MGXS with respect to the incident angle, are critical for generating high-precision MGXS used in transport core calculations. A TC-MHT method based on continuous energy Monte-Carlo is developed to generate high-accuracy P₀ MGXS. This method addresses scattering anisotropy using transport correction (TC) and handles the anisotropy of total cross-section through the flux-moment homogenization technique (MHT). This method is validated using the Megapower benchmark. In reactivity calculations, the bias is decomposed and the reasons for the bias are analyzed. The bias is reduced to less than 160 pcm by using the TC-MHT method. For calculations of control drum worth, the bias does not exceed 0.2%. In power calculations, the maximum pin-by-pin power distribution deviation is within 4%. This demonstrates that TC-MHT method can generate high-precision, highly adaptable MGXS for deterministic code.