ZEPrompt: An Algorithm for Rapid Estimation of Building Attenuation for Prompt Radiation from a Nuclear Detonation

Abstract : This report describes an estimation algorithm called ZEPrompt developed to assess the effects of urban terrain on prompt radiation transport and propagation. The ZEPrompt algorithm is a parameterization of data from an ensemble of artificial city models for the purpose of creating a fast-running estimate of the prompt neutron and photon dose in an urban environment given the urban geometry and an open-field calculation of the source term. The ZEPrompt tool is demonstrated to calculate the radiation level ground range to mean contours of 0.05 Gy, for detonations between 5 kT and 50 kT, to within 30% of first-principles code (MCNP) for complicated cities and 10% for simpler cities.