The aim of the master's thesis is to present the calculation of the estimated dose from the results of the screening method for determining the gross activities of α and β-ray emitters. The motivation is mainly in the simplicity and speed of this method compared to high-resolution γ-ray spectrometry methods and radiochemical analyzes. The advantage of the method of determining the gross activities of α and β-ray emitters is also the detection of all α and β-ray emitters, and the disadvantage is that we do not have data on the actual activity concentrations of individual radionuclides.
Well calibrated liquid scintillation counters are a must for determining the gross activity of α and β-ray emitters. Therefore, part of the task is to present the preparation of samples with known activities of α and β-ray emitters and different radionuclides for calibration of Quantulus liquid scintillation counters and calculation of PSA values. Calibration is followed by sampling, preparation of tap water for measurements and calculation of gross activities of α and β-ray emitters. Sampling points of water supply systems were distributed over a wide area of Slovenia, a total of 20 locations. The total specific activities of α and β-ray emitters were also calculated from the activity concentrations of individual radionuclides, which were reported from the same samples by the methods of high - resolution γ-ray spectrometry and radiochemical analyzes. The measurements turned out to match well with each other.
Data on the total specific activities of α and β-ray emitters can therefore be used to approximate the indicative dose, using the dose factors for the total specific α or β-ray emitters shown in this work. For a more accurate calculation, we need data on the activity concentrations of individual radionuclides in high-resolution γ-ray spectrometry and radiochemical analyzes.
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