Assessment of indoor absorbed gamma dose rate from natural radionuclides in concrete by the method of build-up factors

Abstract

© The Author 2014. Published by Oxford University Press. All rights reserved. The specific absorbed gamma dose rates, originating from natural radionuclides in concrete, were calculated at different positions of a detection point inside the standard room, as well as inside an example room. The specific absorbed dose rates corresponding to a wall with arbitrary dimensions and thickness were also evaluated, and appropriate fitting functions were developed, enabling dose rate calculation for most realistic rooms. In order to make calculation simpler, the expressions fitting the exposure build-up factors for whole 238U and 232Th radionuclide series and 40K were derived in this work, as well as the specific absorbed dose rates from a point source in concrete. Calculated values of the specific absorbed dose rates at the centre point of the standard room for 238U, 232Th and 40K are in the ranges of previously obtained data.