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In this study, the practical methodologies are described for the determination of the factors for the selfabsorption effect(F_s), spectral interferences(F_(csi)), and true coincidence summing effects(F_(coi)), which are used in direct gamma-spectrometric measurement of radionuclides such as ~(210)Pb, ~(238)U, ~(234)Th, ~(226)Ra,~(214)Pb, ~(228)Ac,~(208)Tl, ~(214)Bi,~(137)Cs and ~(40)K in samples. To validate the applied methods, certified reference materials(CRMs) of lake and stream sediments were measured with an n-type Germanium(Ge)detector-calibrated using a multinuclide reference source. The highest self-absorption correction factors ranged from F_s = 1.44-2.10 for 46.5 keV peak(210 Pb) and F_s = 1.25-1.60 for 63.3 keV peak(~(234)Th) lying in the low energy region of the spectrum. The systematic influence was observed for 186.2 keV(226 Ra)peak due to spectral interferences with the 235 U contribution. For this peak, F_(csi) is changed from 0.921 to0.955. Additionally, the present study suggests that true coincidence summing(TCS) effects are not dominant, except for 208 T1 and 214 Bi for which F_(coi) ranged from 1.179 to 1.192 an ranged from 1.140 to1.151, respectively.
In this study, the practical methodologies are described for the factors for the selfabsorption effect (F_s), spectral interferences (F_ (csi)), and true coincidence summing effects (F_ (coi)), which are used in direct gamma -spectrometric measurement of radionuclides such as ~ 210 Pb, 238 U, 234 Th, 226 Ra, ~ 214 Pb, 228 228 Ac, 208 Tl ~ To validate the applied methods, certified reference materials (CRMs) of lake and stream sediments were measured with an n-type Germanium (Ge) detector-calibrated using a multinuclide reference source. The highest self-absorption correction factors ranged from F_s = 1.44-2.10 for 46.5 keV peak (210 Pb) and F_s = 1.25-1.60 for 63.3 keV peak (~ (234) Th) lying in the low energy The systematic influence was observed for 186.2 keV (226 Ra) peak due to spectral interferences with the 235 U contribution. For this peak, F_ (csi) was changed from 0.921 to 0.955. Additionally, the present s tudy suggests that true coincidence summing (TCS) effects are not dominant, except for 208 T1 and 214 Bi for which F_ (coi) ranged from 1.179 to 1.192 an ranged from 1.140 to 1.1.1, respectively.