Effect of windows and doors on the gamma shielding factor for typical houses in Brazil.

This study aims to determine the effect of windows and doors on shielding factors, defined as the ratios of the air kerma indoor to the air kerma in an open field, for typical building materials used in the southeast of Brazil due to radioactive material deposited on the surrounding field, walls, and ceiling external surfaces. The MCNP5 Monte Carlo radiation transport code was used in the simulation of photon shielding. The air kerma indoors for monoenergetic photons of 300 keV, 662 keV, and 3,000 keV has been determined for three different housing patterns, ranging from a poorly constructed house, at a density thickness of 5.5 g cm(-2) for the walls, to a well-constructed house, at a density thickness of 13.1 g cm(-2) for the walls, both with and without the presence of windows and doors. The shielding factor for the poorly constructed house type at an incident photon energy of 300 keV was found to be twice that of the well-constructed house type for the same energy. The presence of windows and doors showed very little or no significant increase on the shielding factors for the building materials studied. The maximum increase was found to be 9% for the well-constructed house type at a incident photon energy of 300 keV.

Gamma shielding factor for typical houses in Brazil.

The housing features in a country depend much on its climate. Dwellings in warm countries are much lighter constructions than in cold ones, which will reflect on the amount of shielding against radiation they provide. In addition to that, wealth is another factor that influences the building's finishing. Great effort has been taken to determine parameters to more accurately estimate dose to a population in case of a radioactive or nuclear accident. Nevertheless, most available data are concerned with typical housing in cold climate countries. This study aims to determine shielding factors for typical building materials used in the southeast of Brazil, a warm area, due to radioactive material deposited on the surrounding field, walls and ceiling of the external surfaces. The shielding factors determination was performed by simulation with the MCNP5 Monte Carlo computer code. The air kerma indoors for the 300, 662 and 3000 keV photon energies have been determined for three different housing patterns, ranging from the very simple to a very complex structure. The shielding factor, defined as the ratio of the air kerma indoor to the air kerma in open field, for the most simple house type and 300 keV photon energy was found to be twice of the best finished one for the same energy.

Effective density and mass attenuation coefficient for building material in Brazil.

This paper presents values for density and mass attenuation coefficient of building materials commonly used in Brazil. Transmission measurements were performed to provide input information for simulations with MCNP4B code. The structure for the clay bricks was simulated as a mix of all material layers and an effective density determined. The mass attenuation coefficients were determined for the 50-3,000 keV gamma-ray energy range. A comparison with results for similar materials found in the literature showed good agreement.