Analytical characterisation of high level liquid waste for metallic constituents by ICP-AES

The present paper describes a method for the estimation of metallic constituents present in the High Level Liquid Waste (HLLW) of Purex process using Inductively Coupled Plasma Atomic Emission Spectrometric(ICP-AES) technique. As uranium is one of the major constituents in the waste and is a major interfering element, removal of this element is essential to eliminate spectral interferences during ICP-AES analysis. A solvent extraction step is adopted using 2-ethylhexyl hydrogen 2-ethylhexyl phosphonate (KSM-17, equivalent to PCSS-A) as extractant prior to ICP-AES analysis to separate uranium from the diluted waste. The aqueous phase containing metallic constituents was analysed using multichannel and sequential direct-reading spectrometers. This technique has been used to determine 21 metallic constituents viz. Mg, Al, Si, Ca, Cr, Mn, Fe, Ni, Sr, Y, Pd, Cd, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd and Dy in the synthetic as well as in the actual HLLW of Purex origin with a relative standard deviation for various elements in the range of ± 1 to 5 %. (author)