Beta-Ray Dose Assessment from Skin Contamination Using a Point Kernel Method

Abstract

In this study, a point kernel method to calculate beta-ray dose rate from skin contamination was introduced. The beta-ray doses rates were computed by performing numerical integration of the radial dose distribution around an isotropic point source of monoenergetic electrons called as point kernel. In this study, in-house code, based on MATLAB version 7.0.4 was developed to perform a numerical integration. The code generated dose distributions for beta-ray emitters from interpolated point kernel, and beta-ray dose rates from skin contamination were calculated by numerical integration. Generated dose distributions for selected beta-ray emitters agreed with those calculated by Cross et al within 20 %, except at a longer distance where there are differences up to more than 100 %. For a point source, calculated beta-ray doses were agreed well with those derived from Monte Carlo simulation. For a disk source, the differences were up to 17 % at a deep region. Point kernel method underestimated beta-ray doses than Monte Carlo simulation. The code will be improved to deal with a three-dimensional source, shielding by cover material, air gap and contribution of photon to skin dose. For the sake of user's convenience, the code will be equipped with graphic user interface.

Evaluation of External Beta Absorbed Dose for Contamination of the Skin

“…Fell [8]. Moreover, Sang-hyun Park et al [9] used a point kernel method to calculate the beta-ray dose rate from skin contamination by performing numerical integration of the radial dose distribution around an isotropic point source of mono-energetic electrons. In this paper, the integro-differential transport equation is solved analytically using a semi-empirical point dose rate function introduced in previous study [8] and then apply this solution using the data collected from the Second Research Reactor of the Atomic Energy Authority, Egypt [10] 150mSv y  from [2].…”