“…−1 , cps = net counts per second, E = photo-peak efficiency I = gamma intensity and W = samples weight (in kg). The relative combined standard uncertainty (CSU) of the activity concentration was calculated (considering all known uncertainty components at coverage factor k = 1) by using equation given below [ 31 , 32 ] where, N, T, Iγ, m and E are the sample counts, counting time, gamma-ray emission probability, sample weight, and counting efficiency, respectively and u(N), u(T), u(Iγ), u(m) and u(E) are their respective uncertainties. In this study, the minimum detectable activity (MDA) of the gamma-ray measurement system was calculated by the following equation [ 33 – 35 ] where, B, is the background counts over the region of interest for each radionuclide and T , is the measurement time in seconds.…”