Effect of chemical environment on the radiation chemistry of N,N-di-(2-ethylhexyl)butyramide (DEHBA) and plutonium retention

Abstract

Gamma-radiolysis of the ligand DEHBA is accelerated under biphasic acidic conditions and yields one or more plutonium complexing degradation products.

Radiolytic evaluation of acetohydroxamic acid (AHA) under biphasic (HNO3:n-dodecane and TBP/DEHBA/DEHiBA) used nuclear fuel reprocessing conditions

“…(1.56 ± 0.08) × 10 10 , (1.04 ± 0.02) × 10 10 , and (1.52 ± 0.11) × 10 10 M -1 s -1 , respectively. 8,9,10 Radiolytic degradation of the aforementioned extraction ligands leads to the formation of a variety of degradation products, for example, HDBP and H2MBP from TBP, 11 b2EHA and MEHBA from DEHBA, 9 and b2EHA and MEHiBA from DEHiBA. 10 Many of these degradation products are detrimental to process performance as they alter the physical and chemical properties of the system.…”

Impact of lanthanide ion complexation and temperature on the chemical reactivity of N,N,N′,N′-tetraoctyl diglycolamide (TODGA) with the dodecane radical cation

“…The prototypical UNF reprocessing solvent, n -dodecane, is broken down by ionizing radiation () to form several important transient species, including the n -dodecane radical cation (RH˙ + ), which reacts with ligands leading ultimately to their destruction: 16–22 RH e − , H˙, RH˙ + , R˙,Ligand + RH˙ + → [Ligand]˙ + /[Ligand (+H + )] + + RH/R˙.There have been extensive studies on the radiation chemistry of ligands, especially those designed for the separation and recovery of elements from UNF. 23–38 However, most contemporary investigations have focused on the radiolytic behavior of the non-complexed ligand, despite literature precedence for their metal ion complexes exhibiting very different chemical behaviors.…”

“…The prototypical UNF reprocessing solvent, n-dodecane, is broken down by ionizing radiation ( ) to form several important transient species, including the n-dodecane radical cation (RH + ), which reacts with ligands leading ultimately to their destruction: [16][17][18][19][20][21][22] RH e À , H , RH + , R ,…”

Effect off-element complexation on the radiolysis of 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP])

“…The larger fraction of radiation energy is absorbed by the solvent (RH, e.g. , n -dodecane), resulting in a suite of solvent decomposition products which can react with the added ligand leading ultimately to its destruction: 15–21 so-called, indirect radiolytic effects. Multiple studies of the radiation-induced degradation chemistry of ligands such as TODGA have been reported for both single and biphasic solvent systems.…”