Modeling the indoor gamma-radiation dose: A review of refinements and application

A theoretical model to estimate the gamma-radiation dose rates inside a room is reviewed, refined and applied. The scheme of the model is based on the relative effects of the different room elements that control the amount of radiation. The relative dose rates are simulated by the MCNP5 software. The studied gamma radiation is the one due to the two radioactive decay series ²³⁸U and ²³²Th, and the radionuclide ⁴⁰K. The affecting elements considered are the widths of the parts of the room, the density of the construction material, the lengths and heights of the different parts of the room, radiation from neighboring rooms, the uncertainty in the equilibrium of the ²³⁸U series. The effects of the existence of a gap inside some of the walls and the existence of partial walls, windows and doors are also studied. The model is applied through an example that includes all the enrolled factors.