Radiation Protection Factor Calculations Using the VPF Computer Code

Abstract

The Vehicle Potential Factor (VPF) code has been developed to estimate the neutron and gamma-ray radiation protection factors afforded by vehicles and buildings against nuclear weapons-generated radiation fields. VPF was designed as a fast executing, PC-based tool. Execution time during the shielding analysis of the target would have been excessive using Monte Carlo methods. A new method was devised that requires one ANISN transport calculation for each side of the target. Execution time depends on the optical thickness and geometric complexity of the shielding structure being studied, but typically ranges from 15 to 60 minutes, with about 90 percent of this time devoted to the ANISN calculations.