Abstract:
The objective of this work is to determine the uncertainty budget and sensitivity of the
measurements of the INAA laboratory of the ETRR-2. Concentrations of 9 elements, Ca, Co, Cr, Cs, Fe, K, Mn, Na, and Rb, were measured against a certified test sample. Relative, absolute, and K0-IAEA standardization were employed. Measurements of samples were carried out at 7 cm from the top of HPGe detector. Detector resolution FWHM is 2.1keV for the Co-60 line at 1332.4 keV. The detector is coupled to a computer controlled gamma ray spectrometric system through a chain of associated linear electronics which contain a multi-channel analyzer, and adapted nuclear data software (Gamma Vision) for neutron activation analysis employed for online spectral evaluation. The uncertainty budget in the relative, the K0-IAEA, and the absolute standardization methods ranged from 2-11%, 3-15%, and 6-27%, respectively. Despite that the relative method is the most accurate among the three methods tested, the K0 method is more handy and easier to employ when large amount of data must be processed. The minimum detectable concentration was the lowest for Cs ranging between 0.36 and 0.59 ppb and the highest being for the K in the range of 0.32 to 8.64 ppb.