K 0-RNAA used in determination of 129I in a mixed resin sample

Abstract

A k 0-RNAA procedure was developed to determine 129I in a mixed resin sample. CH4 extraction and (NH4)2SO3 back-extraction were used to separate 129I in ashed samples. The 129I target sample for irradiation in the reactor was prepared by heating the (NH4)2SO3 back-extraction solution to reduce its volume and then to dry it in a quartz ampoule. No MgO and LiOH were needed during the target sample preparation. After irradiation, the nuclide 130I was purified by combining hydrated antimony pentoxide column and CH4 extraction separations. A k-factor was determined for the reaction of 127I (n, 2n) 126I and used for iodine chemical yield determination. The apparent 129I concentrations of five nuclear reaction interferences were calculated. The relative standard deviation of three 129I determinations was found to be 3.5 %. The 129I content in the analyzed resin was found to be 1.36 × 10−9 g/g (8.63 × 10−3 Bq/g) with a relative uncertainty of 9.1 %. The detection limit of 129I was calculated to be 7.4 × 10−13 g (4.7 × 10−6 Bq) in a k 0-RNAA of a blank sample.