Determination of optimum thickness of tungsten container for Ir-192 HDR brachytherapy source using MCNP software

Abstract

Determination of Optimum Thickness of Tungsten Container for Ir-192 HDR Brachytherapy Source Using MCNP Software. Determination of the optimum thickness of tungsten container for Ir-192 high dose rate (HDR) brachytherapy source has been carried out by an MCNP6 (Monte Carlo N-Particle 6) software simulation. The container is used to store the source of a cylindrical rod shaped Ir-192 gamma ray transmitter with 10 Ci activity covered in AISI 316L stainless steel cladding. The container was modeled according to its actual conditions, in terms of its geometric shape and material. The simulations were carried out to determine the amount of gamma ray exposure from Ir-192 source with 15 Ci activity within the tungsten container covered in air. The gamma ray exposure was measured using a 1 mm thick spherical shell shaped water detector at a distance of 1 meter from the Ir-192 source. In accordance with Regulation of the Head of the Nuclear Energy Regulatory Agency (BAPETEN) Number 4 of 2013 concerning Radiation Protection and Safety in Nuclear Energy Utilization, the average effective dose of radiation officers is 20 mSv/year. The simulation result shows that the optimum thickness of the tungsten container is 4.2 cm with an effective dose received at a distance of 1 m of 15.153 mSv/year with an error of 1.19%. It can be concluded that the container made of tungsten with a thickness of 4.2 cm can be used as a recommendation in the manufacture of containers for Ir-192 HDR brachytherapy sources with an activity of up to 15 Ci.