Semi-quantitative and quantitative studies on the gamma radiolysis of C5-BTBP

Journal article, 2011

An industrial liquid liquid extraction process for reprocessing of spent nuclear fuel will inevitably lead to radiolysis of the phases, since the process streams contain highly radioactive species. Solvents containing one of the BTBP (6,6'-bis(5,6-dialkyl-[1,2,4]-triazin-3-yl)-2,2'-bipyridine) molecules intended for the separation of trivalent actinides (An) from lanthanides (Ln), the so called C5-BTBP, have shown a dramatic decrease in both distribution ratios and An/Ln separation factor when irradiated; hence, the molecule is highly unstable towards radiolysis. HPLC-, APCI(+)-MS and LC-MS analyses were performed on irradiated solvents containing initially 0.005 M C5-BTBP dissolved in either hexanol or cyclohexanone. The decrease in concentration of starting molecule as well as the increase in concentration of various degradation products were studied with quantitative and semi-quantitative measurements. Structures were suggested for the degradation products produced in highest yields and these were compared to previously proposed structures for the same products.