Solvent Performance in THTR Nuclear Fuel Reprocessing. Part II: On the Formation of Dibutyl Phosphoric Acid by Radiolytic and Hydrolytic Degradation of the TBP-n-Paraffin Extractant

Publisher Website
Google Scholar
Abstract
Radiolysis and hydrolysis of tributylphosphate (TBP) in n-paraffin diluent were investigated under conditions simulating several parameters of the THOREX flowsheet for reprocessing thorium containing spent nuclear fuel.The solvent (30 vol% TBP-n-paraffin) was equilibrated with 0.25 to 3 molar nitric acid, and the organic phase was inspected by gas chromatography. As an acid hydrolysis product, only di-n-butylphosphoric acid (HDBP) was detected in the organic phase. Mono-n-butylphosphoric acid (H2MBP), if formed, would have been extracted into the aqueous phase and, thus, escape detection.The HDBP content of the organic phase changes linearly with its acid content and keeps constant after phase separation. Either hydrolysis does not proceed in the organic phase or it is compensated for by amelioration effects.Radiolysis in pure solvents (30 and 5 vol% TBP-n-paraffin) with doses from 0.5 to 13 Wh·ℓ−1 produces HDBP with G values (TBP-based) of ∼2 and ∼6, slightly decreasing with higher doses. No H2MBP was fo...

This publication has 12 references indexed in Scilit: