Actinide, separation from reprocessing

Acetic acid, removal using emulsion liquid membranes, 215 Acrylic acid, use in plasma graft polymerization, 254-268 Acrylic acid grafted membranes, use in facilitated transport, 250-264 Actinide, separation from reprocessing wastes with liquid membranes, 391-406 Acyclic ligands, 167,168/... 

Magnusson, D., Christiansen, B., Glatz, J.P., Malmbeck, R., Modolo, G., Serrano Purroy, D., Sorel, C. 2008. Demonstration of minor actinide separation from a genuine PUREX raffinate by TODGA/TBP and SANEX reprocessing. ATALANTE 2008 Nuclear Fuel Cycles for a Sustainable Future, May, Montpellier, France. 

The counting techniques described in this paper are also readily applicable to studies of "hot radioactive waste (z.e.j radioactive waste from reprocessed nuclear fuel). With this type of material, the cesium can be analyzed as 30-y (662-keV y), the RE as 13-y Eu (964-keV and 1408-keV y), strontium as 28-y Sr (after chemical separation and beta counting), and the actinides by group separation and alpha counting. 

The CTH actinide separation process was developed as a possible means to reduce the expected long term dose to man from a geologic repository containing solidified radioactive waste from the reprocessing of spent nuclear fuel The distribution data for the elements present in significant amounts in the high level liquid waste (HLLW) from a Purex plant, the general principles and the flowsheet have been described in detail elsewhere A... 

Shukla, J.P. et al., Separation of radiotoxic actinides from reprocessing wastes with liquid membranes, ACS Symposium Series in Chemical Separation with Liquid Membranes, Bartsch, R.A. and Wey, J.D. (Eds.), American Chemical Society, Washington DC, 1996, chapter 27. 

Actinide separation techniques and methods play a very important role in analysis and production of nuclear materials, reprocessing of nuclear fuels, nuclear waste management, and other aspects of the nuclear fuel cycle. Professionals from several disciplines—analytical chemists, chemical engineers, process chemists, etc.—make much use of this technology. 

This Symposium has been organized about new concepts, new systems, and new developments in actinide separations methodology. Much of the work reported here is based on fundamental actinide chemistry developed since the Manhattan Project days. The chapters in this volume describe ion exchange, solvent extraction, precipitation, pyrochemical, photochemical, and other methods of actinide separations as well as application of these separation methods to power reactor fuel reprocessing and recovery of actinides from waste solutions. 

The separation of actinides has been studied for various purposes in Japan Atomic Energy Research Institute (JAERI). The works which have been carried out so far, are classified into four categories preparation studies of actinides nuclides, separation chemistry for chemical analysis, separation of actinides from radioactive waste, and studies on reprocessing of spent nuclear fuels. The present work is to review studies of actinide separation performed in JAERI, emphasizing the need of the separation for the main purpose of individual. Concern is focussed on the separation of transuranium elements and studies on thorium and uranium are put aside. 

The removal of actinides from reprocessing acidic waste solutions is advantageous in terms of minimizing the radioactive discharge to the natural environment. The separation of plutonium using supported liquid membranes was extensively studied, as well as U(V1) and Pu(lV) selective transport over fission products and minor actinide contaminants (Lakshmi et al. 2004 Sriram et al. 2000 Kedari et al. 1999). 

Chemistry used in the recovery of plutonium from irradiated fuel must provide a separation from all these elements, other fission and activation products, and the actinides (including a large amount of unburned uranium), and still provide a complete recovery of plutonium. The same issues apply to the recovery of uranium from spent thorium fuel. Most of the processes must be performed remotely due to the intense radiation field associated with the spent fuel. As in the enrichment of uranium, the batch size in the later steps of the reprocessing procedure, where the fissile product has become more concentrated, is limited by the constraints of criticality safety. There is a balance between maximizing the yield of the precious fissile product and minimizing the concentrations of contaminant species left in the final product These residual contaminants, which can be detected at very small concentrations using standard radiochemical techniques, provide a fingerprint of the industrial process used to recover the material. 

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