Natural radioactivity in building materials: dose determination in dwellings using hybrid Monte Carlo-deterministic approach

Abstract
Walls and other masonry structure protect us from external radiation effects present in atmosphere but they do become a source of radiation also if they contain radioactivity in their composition. Presence of small radioactivity in building material give rise to both, internal and external exposure of the inhabitant of dwellings. A hybrid Monte Carlo deterministic approach have been developed to compute the dose rates due to external exposure of gamma rays, emitted from the radionuclide present in the walls. Monte Carlo simulations were used to compute the flux of gamma photon at the wall surface. Once the flux of photons was obtained at the wall surface simple deterministic approach have been used to compute the dose rates at the center of the room. Anisotropic effects on distribution of photons while passing through the wall medium are also considered. Calculations were performed on ⁴⁰K, ²²⁶Ra and ²³²Th using a hypothetical dwelling model. The results thus obtained were compared with those already presented in literature.