“…Among many high-fidelity simulation methods, the Monte Carlo (MC) method is widely regarded as the most accurate method and is usually used for validations of other methods. The MC method has two major advantages: one is the usage of accurate continuous-energy crosssections, and another is the precise 3-dimensional (3D) geometry modeling based on constructive solid geometry (CSG) or computer-aided design (CAD) geometry (Wilson et al, 2010;Davis et al, 2020;Deng et al, 2022). MC codes such as MCNP 10.3389/fenrg.2022.1010482 (Goorley et al, 2012), Serpent (Leppänen et al, 2015), OpenMC (Romano et al, 2015), and RMC (Wang et al, 2015) are widely used in new reactor designs, which have disparate features from normal nuclear reactors in geometry, material, and spectra.…”