Radiation Protection Dosimetry Advance Access originally published online on January 25, 2008
Radiation Protection Dosimetry 2008 130(2):141-148; doi:10.1093/rpd/ncm494
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Calculated effects of backscattering on skin dosimetry for nuclear fuel fragments
Physics Department, Taif University, Al-Hawiah, Taif, PO Box 888, Kingdom of Saudi Arabia
* Corresponding author: aydarous{at}hotmail.com
Received August 13, 2007, amended November 30, 2007, accepted December 6, 2007
The size of hot particles contained in nuclear fallout ranges from 10 nm to 20 µm for the worldwide weapons fallout. Hot particles from nuclear power reactors can be significantly bigger (100 µm to several millimetres). Electron backscattering from such particles is a prominent secondary effect in beta dosimetry for radiological protection purposes, such as skin dosimetry. In this study, the effect of electron backscattering due to hot particles contamination on skin dose is investigated. These include parameters such as detector area, source radius, source energy, scattering material and source density. The Monte-Carlo Neutron Particle code (MCNP4C) was used to calculate the depth dose distribution for 10 different beta sources and various materials. The backscattering dose factors (BSDF) were then calculated. A significant dependence is shown for the BSDF magnitude upon detector area, source radius and scatterers. It is clearly shown that the BSDF increases with increasing detector area. For high Z scatterers, the BSDF can reach as high as 40 and 100% for sources with radii 0.1 and 0.0001 cm, respectively. The variation of BSDF with source radius, source energy and source density is discussed.