Title:	Radiation dose due to exposure in urban environment
DNr:	NAISS 2024/5-389
Project Type:	NAISS Medium Compute
Principal Investigator:	Jalil Bahar Gogani <jalil.bahar.gogani@foi.se>
Affiliation:	Totalförsvarets forskningsinstitut
Duration:	2024-09-02 – 2025-10-01
Classification:	10301
Keywords:

Abstract

In the event of a nuclear fallout, the inhabitants of an urban environment may be exposed to considerable amount of ionising radiation and the related health risks thereof. Determining the radiation dose in the complex geometry of an urban environment is a challenging undertaking. Most of the generic radiation dose data available, involving human exposure, are produced using human-like phantoms coupled with radiation transport simulations where the environment above ground is modelled as plain air. The current project involves radiation transport simulations for determining radiation dose to human-like phantoms in urban environments where the scattering and attenuation impact of objects in such environments on ionising particles is taken into account. Two tetrahedral mesh-based phantoms (adult female and male) are used for organ and effective dose simulations due to radiation source distributed in air and on the ground. Three urban environments in Sweden are considered for the simulations representing a small town and, a mid-size and a large city. In a study prior to the current project, the radiation dose due to environmental photon exposure was determined using mathematical anthropomorphic MIRD-5 (Medical Internal Radiation Dose) phantoms. In the current project, the environmental exposure from monoenergetic electrons with energies ranging from 0.01 to 3 MeV is considered. The radiation transport code PHITS (Particle and Heavy Ion Transport code System) designed by JAEA (Japan Atomic Energy Agency) is utilised for the calculations. The output from the simulations is energy imparted in organs and different tissues of the human body, which are used to calculate the organ- and effective dose according to the formalism outlined by the ICRP (International Commission on Radiological Protection).