Dosage Calculations of The Initial Radiation Due to Low-Altitude Nuclear Fission Explosion

After a nuclear explosion, we observe radiations like alpha, beta, gamma, and neutron rays, which emerge directly or indirectly from the explosion. Considering the importance of studying nuclear radiations and their range, these radiations are divided into initial and residual types. Apart from neutron and gamma rays, other radiations due to their physical nature are not significant in long-range studies. In this study, equivalent dose of the reference data’s initial radiation is calculated for benchmarking. On the basis of their power, initial neutron sources, secondary gamma sources caused by neutron interaction in the air, and gamma sources from fission products for the first minute after the explosion have been identified. By simulating the transport of these particles in the environment using Monte Carlo MCNPX Code, the equivalent doses in the tissue from 300 to 3800 meters have been calculated. Safe distance for exposure to 1KT weapon is equal to 1900 meters according to simulation results, and equal to 1800 meters based on the reference dose..