Large sample NAA work at BARC: Methodology and applications

Large sample neutron activation analysis (LSNAA) was carried out using thermal column facility of Apsara reactor at Bhabha Atomic Research Centre, Mumbai, India. The k0-based internal monostandard NAA (IM-NAA) using in situ detection efficiency was used to analyze large and non-standard geometry samples of clay pottery, uranium ore and stainless steel. Elemental concentration ratios with respect to Na as a monostandard were used in the study of pottery and ore samples. For stainless steel sample of SS 304L, the absolute concentrations were calculated from concentration ratios by mass balance approach since all the major elements (Fe, Cr, Ni and Mn) were amenable to NAA. Applications of LSNAA in the above-mentioned three different areas are described in this paper.