Minor actinides separation

It should be noted, however, that a simplified version of the DIAMEX-SANEX/ HDEHP process was also successfully implemented on a genuine highly active DIAMEX product (An(III) + Ln(III) fraction) in 2005, as the second step of an An(III)/Ln(III) partitioning scheme, in the scope of the technical feasibility validation of minor-actinide separation proposed by the CEA to address the issues of the 1991 French radioactive waste management act (154). 

Geist, A., Weigl, M., Gompper, K. 2004. Hydrometallurgical minor actinide separation in Hollow Fibre Modules. ATALANTE 2004 Advances for Future Nuclear Cycles, June, Nimes, France. 

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. 

Transuraniums generated hy fuel huming include fissile material (e.g., Pu and Pu) and fertile material (e.g., Pu, Pu, and minor actinides), separated and recovered in a fuel cycle facdity, and then recycled as fuel materials. Basically, transuraniums are assumed to he transmuted into fissUe materials in a reactor at some stage and eventually to undergo fission reactions. 

Ansari, S.A., Pathak, P.N., Mohapatra, P.K. Manchanda, V.K. (2011a) Aqueous partitioning of minor actinides. Separation Purification Reviews, 40,43-76. 

The elucidation of actinide chemistry in solution is important for understanding actinide separation and for predicting actinide transport in the environment, particularly with respect to the safety of nuclear waste disposal.72,73 The uranyl CO + ion, for example, has received considerable interest because of its importance for environmental issues and its role as a computational benchmark system for higher actinides. Direct structural information on the coordination of uranyl in aqueous solution has been obtained mainly by extended X-ray absorption fine structure (EXAFS) measurements,74-76 whereas X-ray scattering studies of uranium and actinide solutions are more rare.77 Various ab initio studies of uranyl and related molecules, with a polarizable continuum model to mimic the solvent environment and/or a number of explicit water molecules, have been performed.78-82 We have performed a structural investigation of the carbonate system of dioxouranyl (VI) and (V), [U02(C03)3]4- and [U02(C03)3]5- in water.83 This study showed that only minor geometrical rearrangements occur upon the one-electron reduction of [U02(C03)3]4- to [U02(C03)3]5-, which supports the reversibility of this reduction. 

Madic, C., Lecomte, M., Dozol, J.F., Boussier, H. 2004. Advanced chemical separations of minor actinides from high active nuclear wastes. EURADWASTE 04, Luxembourg, Belgium, March 24 to April 1. 

Due to the ease of formation of third phase with CMPO, many literature reports are based on the use of the mixture of 0.2 M CMPO + 1.2 M TBP as the solvent (63). This mixture has also been used in the TRUEX process recommended for the partitioning of minor actinides from HLW. Some applications of CMPO for the separation of Pu include its recovery from assorted laboratory wastes and oxalate supernatant (64, 65). 

Mathur, J.N. Murali, M.S. Iyer, R.H. Ramanujam, A. Dhami, P.S. Gopalkrishnan, V. Rao, M.K. Badheka, L.P. Baneiji, A. Extraction chromatographic separation of minor actinides from purex high-level wastes using CMPO, Nucl. Technol. 109 (1995) 216-225. 

Naik, P.W. Dhami, P.S. Misra, S.K. Jambunathan, U. Mathur, J.N. Use of organo-phosphorus extractants impregnated on silica gel for the extraction chromatographic separation of minor actinides from high level waste solutions, J. Radioanal. Nucl. Chem. 257 (2003) 327-332. 

As no technology can selectively transmute minor actinides to a degree meaningful for waste management while they are contained in the spent nuclear fuel, these elements must be separated from the neutron-absorbing elements before being properly transmuted. In the case of trivalent minor actinides, this preliminary step is further necessary because of the following reasons ... 

Baron, P., Heres, X., Lecomte, M., Masson, M. 2001. Separation of the minor actinides The DIAMEX-SANEX concept. Global 2001 Back-end of the Fuel Cycle From Research to Solutions, September, Paris, France. 

Modolo, G., Seekamp, S. 2002. Hydrolysis and radiation stability of the alina solvent for actinides(III)/lanthanide(III) separation during the partitioning of minor actinides. Solvent Extr. Ion Exch. 20(2) 195-210. 

Geist, A., Weigh M., and Gompper, K., Minor actinide partitioning hy hquid-hquid extraction using a synergistic mixture of his (chlorophenyl)dithiophosphinic acid and TOPO in a hollow fibre module for americium(III) and lanthanide(ni) separation. Sep. Sci. Tech., 2002, 37 3369-3390. 

Nuclear fuel reprocessing and partitioning allow recycling of useful fissionable materials such as uranium and plutonium, and remove harmful long-lived minor actinides (americium and curium). It is necessary also for safety storage of high-level liquid wastes(l). In order to improve efficiency of mutual separation between lanthanide and actinide elements, design of useful extractants are requisite. 

The interest in phosphate minerals is largely based on their ability to incorporate actinides (Ewing et al. 1995a). In addition to the Pu that results from dismantling nuclear weapons and the plutonium separated during the reprocessing of spent nuclear fuel from nuclear power plants, substantial quantities of the minor actinides are generated annually Np (3.4 tons/yr), " Am (2.7 tons/yr), and (335 kg/yr). 

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