title: Calculation of dose rate conversion factors for (238)U, (232)TH and (40)K in concrete structures of various dimensions, with application to Nis, Serbia.
abstract: The absorbed gamma dose rate in indoor air due to natural radionuclides in concrete as a building material was determined in this work. The dose rate conversion factors for (238)U, (232)Th and (40)K, for standard rooms as well as rooms with different sets of dimensions, were evaluated by the point kernel technique, using Harima (geometric progression) build-up factors. The values of the conversion factors, in units (nGy h(-1) (Bq kg(-1))(-1)) calculated for the standard room are: 0.76, 0.91 and 0.070, respectively for (238)U, (232)Th and (40)K. The fitting formula was obtained for dose rate conversion factors, enabling them to be conveniently calculated for a room with arbitrary dimensions. For concrete block samples collected in the area of Niš, Serbia, the measurement of the radionuclide activity concentrations was also carried out. The evaluated absorbed dose rate conversion factors were then applied in the assessment of corresponding indoor gamma dose rates, finding that all the concrete samples fulfilled the usage requirement.
authors.affiliation: Department of Physics,  University of Niš, PO Box 224, 18000 Niš,  Serbia.
authors.forename: Vesna
authors.initials: V
authors.lastname: Manic
authors.forename: Goran
authors.initials: G
authors.lastname: Manic
authors.forename: Dragoslav
authors.initials: D
authors.lastname: Nikezic
authors.forename: Dragana
authors.initials: D
authors.lastname: Krstic
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis*; D003252:Construction Materials / Q000032:analysis*; D011197:Potassium Radioisotopes / Q000032:analysis*; D011829:Radiation Dosage; D011886:Radon / Q000032:analysis*; D055771:Serbia; D014501:Uranium / Q000032:analysis*
chemical_list: D000396:Air Pollutants, Radioactive; D011197:Potassium Radioisotopes; D014501:Uranium; D011886:Radon