An approach to radiation shielding evaluations using estimators by expected scoring

It is discussed a Monte Carlo neutral particle transport simulation methodology for shielding evaluations based on unbiased estimators using variance reduction techniques. Several computational radiation shielding evaluation cases are performed, which represent the main computationally problematic categories of neutral particle transport numerical simulation: self-shielded sources, strong-attenuation shielding, labyrinths, skyshine, and complex heterogeneous shields involving tiny holes and cavities. The methodology allows to obtain sufficiently accurate results for these applications, including high-resolution dose rate mappings, by a night-long calculation on a dual-core processor-based machine.