Determination of 94Nb in radioactive wastes using extraction chromatography and gamma spectrometry

Abstract

A radiochemical methodology for the determination of 94nb in low-level radioactive wastes from nuclear power plant was proposed. Although 94Nb is a strong gamma emitter, its concentration in radioactive waste samples is usually several orders of magnitude lower than that of other β–γ emitters, whose emissions interferes in the detection of the emission lines of 94Nb. The procedure involves acid digestion, precipitation, cation exchange chromatography by using Amberlite IRA120 resin, extraction chromatography by using TEVA resin to isolate the Nb and the gamma spectrometry to its measurement. The chemical yield was 70% in average. Samples of evaporator concentrate and spent resin were analyzed. For the samples of the evaporator concentrate, the results obtained were below L D = 9.59 × 10−4 Bq g−1. For the spent resin an average result of 1.54 × 102 Bq g−1 was obtained.