Progress towards the Full Recovery of Neptunium in an Advanced PUREX Process

Development and Validation of a Flowsheet Simulation Model for Neptunium Extraction in an Advanced PUREX Process

“…For example, most existing models predefine the phase holdup volumes, while holdup volumes in the separation unit of a centrifugal contactor depend on the weir diameters of the contactor and change with fluid flow rates. To address these shortcomings, this paper proposes a new centrifugal contactor model for neptunium extraction and presents the application of the model to investigate neptunium extraction in an advanced PUREX process (for which experimental data have been published [13] ). Further to previous work [20] , our main contributions are to include in the model mass transfer kinetics and hydraulic calculations under a centrifugal force field on extraction.…”

“…Current reprocessing plants, for example, only extract 60-80% of neptunium in the primary extraction section, with the remainder being lost to the fission product raffinate stream. [13][14][15] Therefore, a simulation model is needed to predict neptunium extraction behavior in the PUREX process and to guide design of flowsheet modifications that better control neptunium in the process.…”

Challenges to deployment of twenty-first century nuclear reactor systems

“…TRansUranic in high-level waste are dominated by Np, Am, Cm) are sent to the vitrified high-level waste (VHLW) stream for interim storage and eventual geological disposal. Partitioning and transmutation involves the separation of MA species, usually Np, Am and Cm for recycle [32]. The MAs can be recycled homogeneously as a minor component of nuclear fuel or heterogeneously in the form of target fuels.…”

Solvent Extraction and Fluorescence Spectroscopic Investigation of the Selective Am(III) Complexation with TS-BTPhen

“…[1] Therefore, the MA content in the disposed waste is a decisive factor in determining the size of a final geological repository for high active wastes. Neptunium can be separated in a modified PUREX process, [2] leaving americium and curium as the principal contributors to the long-term radiotoxicity of the remaining waste. The partitioning and transmutation (P&T) concept strives for the multi-recycling of long lived MA in generation IV reactor systems by fast neutron irradiation.…”

“…An americium(III) selective separation procedure was developed based on the co-extraction of trivalent actinides (An(III)) and lanthanides (Ln(III)) by TODGA (N,N,N',N'-tetraoctyldiglycolamide), followed by Am(III) selective stripping using the hydrophilic complexing agent 3',3'',2,5,6,tetrayl]tetrabenzenesulfonic acid). Distribution ratios were found at an acidity of 0.65 mol L -1 nitric acid that allowed for the separation of Am(III) from Cm(III) (D Cm > 1, D Am < 1), giving a separation factor between curium and americium of SF Cm/Am = 3.6 within the stripping step.…”