Experimental and Modeling of Extraction of Lanthanides in System HNO3-TEDGA-{DMDOHEMA-HDEHP}

AbstractThis paper presents the development of a model which calculates the composition of the organic phase for a system used to remove selectively americium from a PUREX raffinate. A phenomenological approach is performed to aggregate step by step the specificities of this complex extraction system. Modeling of the influence of TEDGA is complex because experiments have shown that the water-soluble ligand TEDGA is extracted by the diamide and that its extraction is enhanced in presence of lanthanides. The formation of mixed solvates lanthanides-TEDGA-DMDOHEMA is thus taken into account

Development of a selective americium separation process using TPAEN as a water-soluble stripping agent

International audienceRecycling americium from spent fuels is an important option considered for the future nuclear cycle. The PUREX solvent extraction process can be used to separate U and Pu from a dissolution solution of spent fuel in nitric acid. Then in a second step americium should be separated from fission products and especially lanthanides but also from curium. For this purpose, a new liquid-liquid extraction process is under development using TODGA as an extractant in the organic phase and TPAEN as a selective Am stripping agent in the aqueous phase. With this promising system it is possible to co-extract Am, Cm and lanthanides at high acidity and then selectively strip americium from the loaded organic phase at pH around 1 with TPAEN. Batch data were acquired to evaluate best conditions to develop a liquid-liquid extraction flowsheet and the effect of several parameters on Am/Cm was evaluated like concentration of ligand, cations, temperature, etc

Development of a selective americium separation process using TPAEN as a water-soluble stripping agent

International audienc

Development of a Selective Americium Separation Process using H4TPAEN as Water-Soluble Stripping Agent

Recycling americium from spent nuclear fuel is considered as an important option for a future sustainable nuclear fuel cycle. The PUREX solvent extraction process allows to separate uranium and plutonium from a solution of spent fuel dissolved in nitric acid. In a second step, it would be desirable to separate americium from fission products, and especially lanthanides, but also from curium in order to further transmute americium in future fast neutron reactors. For this purpose, we report the investigation of a new solvent extraction process based on the use of TODGA as an extractant in the organic phase and H4TPAEN as a selective Am(III) stripping agent in the aqueous phase. With this promising system it is possible to co-extract Am, Cm and lanthanides at high acidity and then selectively strip americium from the loaded organic phase at pH around 1 with H4TPAEN. Batch extraction data were acquired to evaluate best conditions to develop a liquid-liquid extraction flow sheet. The influence of several parameters like concentration of ligand, cations and temperature on Am(III)/Cm(III) and Am/lanthanides separation was evaluated. Especially, the ability of H4TPAEN complexing agent to strip macro-concentrations of Am was demonstrated

Selective separation of Am(III) from PUREX Raffinate with a TODGA-based solvent using innovative hydrophilic complexing agents

Americium is the main contributor to the longtermradiotoxicity and to the heat generation of glassesused for HLW conditioning. To decrease these impactsand to avoid the difficult recycling of curium, the selectiveseparation and recovery of a pure americium productdirectly from PUREX raffinate is envisaged in this study.The new approach is based on the co-extraction oflanthanide(III) and actinide(III) cations from a PUREXraffinate into an organic phase containing N,N,N’,N’-tetraoctyl-diglycolamide (TODGA) as extractant,followed by the subsequent selective stripping of Am(III)and separation from Cm(III) and lanthanides. Threewater-soluble selective ligands were studied: H4TPAENdeveloped at the CEA Marcoule, TS-BTPhen developed atthe University of Reading, and SO3-Ph-BTBP developedat KIT. Very promising results were achieved for allsystems with a quite high Cm(III)/Am(III) selectivitybetween 3-4 to carry out the difficult separation atreasonably high process relevant nitric acid acidities.Numerous batch experimental data were acquired for thedevelopment of the extraction model. Finally, tests onsingle centrifugal contactors were conducted to getinformation on the kinetic and hydraulic performance ofthe system. Finally, tests on single centrifugal contactorswere conducted to get information on the kinetic andhydraulic performance of the system

Self-reported injection practices among people who use drugs in French prisons: Public health implications (ANRS-Coquelicot survey 2011–2013)

International audienceIntroduction and Aims:The Aims:of this study were to describe the prevalences of injection practices and needle/syringe sharing in people who use drugs in French prisons, and to investigate associated factors. Design and Methods: Using the ANRS-Coquelicot survey (2011−2013), a random sample of 1718 people who used drugs in free society was included. Information regarding a history of incarceration, drug-injection practices inside prison and needle/syringe sharing was collected during interviews. Results: In our sample, 65.5% reported a history of injection and 57.4% had been incarcerated at least once. Among those who reported both of these conditions, 14% reported injection practices inside prison, 40.5% of whom had shared needles/syringes. In the multivariable model, the following variables were associated with injection practices inside prison: being a Russian-speaking detainee, having spent more time in prison, and having started to inject before 1996 and especially before 1987. Being Russian speaking was also associated with needle/syringe sharing in prison. Discussion and Conclusions: The prevalences of injection practices and needle/syringe sharing in prisons are alarmingly high. Effective interventions to prevent the transmission of infectious diseases among people who use drugs in the prison setting are essential. The implementation of international recommendations on the principle of equivalence between prisons and the community is still very limited in most countries, and should be complemented with tailored interventions for the most vulnerable prison populations, especially Russian-speaking detainees