Synthesis characterization of nitrogen heterocyclic ligands for the separation of minor actinides from lanthanides

Abstract

Nuclear energy is one of the alternative energy sources to satisfy the newlineenormous energy demand of society. Major nuclear fuels used in nuclear reactors newlineare uranium and plutonium-based compounds. Nuclear energy production newlinegenerates extremely radiotoxic waste. The solution left after the removal of newlineunreacted uranium and plutonium by PUREX process is called high-level liquid newlinewaste (HLLW). The HLLW contains several stable and unstable fission products, newlinelanthanides, and minor actinides (Np, Cm and Am) in small concentrations. The newlinehalf-life period of minor actinides is between a few hundred years to millions of newlineyears. These minor actinides are long-lived and#945;-emitters and significant contributors newlineto the long-term radioactivity of the HLLW. Actinide partitioning involves the newlinecomplete elimination of minor actinides from the HLLW accompanied by neutron newlinebombardment in accelerators or fast breeder reactors to transmute the separated newlineactinides to other stable or short half-life nuclides. This process is regarded as an newlineessential method for nuclear waste management. The partitioning of trivalent newlineminor actinides (An(III)) from HLLW is an arduous task due to trivalent newlinelanthanides (Ln(III)) having similar chemical properties. The minor actinide newlinepartitioning has two steps based on solvent extraction. Usually, the first step is the newlineco-extraction of Ln(III) and An(III). The product obtained in the first step serves newlineas the feed solution for the separation of An(III) from Ln(III) in the second step. newlineThis work aim to synthesize aqueous soluble complexing agents based on newlinebis-1,2,4-triazines such as SO3-Ph-BTP, SO3-Ph-BTBP, and SO3-Ph-BTPhen for newlinethe selective stripping of An(III) and to propose a suitable modifier free organic newlinesolvent to be used along with these aqueous complexants for the separation of newlineAn(III) from Ln(III) with a high separation factors of Eu(III) over Am(III) newline(SFEu(III)/Am(III)). newline newline