Radiolytic degradation of sulphonated BTP and acetohydroxamic acid under EURO-GANEX process conditions

Abstract

In this work, we present a study which tackles the stability of molecules involved in EURO-GANEX aqueous phase, the acetohydroxamic acid (AHA) and the sulphonated BTP (SO3-Ph-BTP), taking into account factors such as the known AHA hydrolysis, acidity of the media, and the radiolysis of AHA and SO3-Ph-BTP. To better understand the system, the radiolysis of AHA and SO3-Ph-BTP in HNO3 has been studied first separately, at low doses (up to 50 kGy) compared with those expected for the recycled organic phase. The concentration after exposure to gamma radiation of AHA and its hydrolysis products, as well as of SO3-Ph-BTP, was measured for the first time by using Quantitative Raman Spectroscopy (QRS), showing that this technique can be used as a reliable tool for assessing the stability of these systems. In addition, the proton concentration and extraction efficiency of each assay were monitored and assessed. Our study extends the knowledge about the resistance to radiation of extractants involved in the EURO-GANEX aqueous phase, showing greater robustness when both molecules are irradiated together, and contributes not only to design reliable simulation strategies of the long-term EUROGANEX process performance, but also to develop analysing tools for further processes implementations.