Nuclear waste separation

Ozawa, M., Wakabayashi, T. 1999. Status on nuclear waste separation and transmutation technologies in JNC. Global 1999 Nuclear Technology - Bridging the Millennia, August-September, Jackson Hole, WY. 

Chiarizia, R., Danesi, P. R. (1987). A double liquid membrane for the removal of actinides and lanthanides from acidic nuclear wastes. Separation Science and Technology 22 641-649. 

Thorium, uranium, and plutonium are well known for their role as the basic fuels (or sources of fuel) for the release of nuclear energy (5). The importance of the remainder of the actinide group Hes at present, for the most part, in the realm of pure research, but a number of practical appHcations are also known (6). The actinides present a storage-life problem in nuclear waste disposal and consideration is being given to separation methods for their recovery prior to disposal (see Waste treati nt, hazardous waste Nuclear reactors, waste managet nt). 

Nuclear Waste Management. Separation of radioactive wastes provides a number of relatively small scale but vitally important uses of gas-phase purification appHcations of adsorption. Such appHcations often require extremely high degrees of purification because of the high toxicity of... 

Before leaving ionic liquids it is worth mentioning their potential value in separation processes. Organic solvents are frequently used in multiphase extraction processes and pose the same problems in terms of VOC containment and recovery as they do in syntheses, hence ionic liquids could offer a more benign alternative. Interesting applications along this line which have been studied include separation of spent nuclear fuel from other nuclear waste and extraction of the antibiotic erythromycin-A. 

Horwitz EP, Dietz ML, Fisher DE (1991) Separation and preconcentiation of strontinm from biological, environmental, and nuclear waste samples by extraction chromatography nsing a crown ether. Anal Chem 63 522-525... 

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. 

After the separation of the actinides from the high-level waste, it is desirable to remove certain other fission products from the nuclear wastes. Some Cs and Sr are low-charged cations that react well with macro-cyclic ligands (e.g., crown ethers, calixarenes). Research to synthesize and investigate the properties of macrocyclic ligands for application in nuclear waste treatment has been an active effort internationally. Some of the results obtained are discussed in section 12.7. 

The Met-Tech separation process is a liquid ion exchange process for the ex situ recovery, separation, and concentration of a wide range of heavy metals. The technology is commercially available and, according to the vendor, has been tested at the pilot scale. According to the vendor, future applications will be in soil remediation, acid mine drainage, and the recycling of spent nuclear waste. 

UOP molecular sieves (UOP) has developed the lonsiv family of ion exchange resins for the extraction of radionuclides from wastewater. lonsiv TIE-96 is composed of a titanium-coated zeolite (Ti-zeolite) and is used to separate plutonium, strontium, and cesium from alkaline supernatant and sludge wash solutions. The technology was developed by Pacific Northwest Laboratory (PNL) for use at the West Valley, New York, nuclear waste facility. The technology is commercially available. 

Molecular modelling of transition metal complexes (TMC), reproducing characteristic features of their stereochemistry and electronic structure, is in high demand in relation with studies and development of various processes of complex formation with an accent on ion extraction, ion exchange, isotope separation, neutralization of nuclear waste, and also when studying structure and reactivity of metal-containing enzymes. Solving these techno-... 

Environmental control in respect of determining concentrations and isotope ratios, e.g. of U, Pu and other actinides, is also required in routine measurements near to nuclear power plants, uranium enrichment facilities or nuclear waste recycling companies. Groundwater samples are analyzed after dilution directly by ICP-MS for soils a digestion step before mass spectrometric measurement is necessary. If isobaric interferences are observed a trace matrix separation and/or a careful analyte separation (e.g. of U and Pu) is recommended. 

Kenna, B.T. and Murphy, K.D., "Separation of Cs From Nuclear Waste," Nuclear and Cosmological Chemistry Symposium, ACS Meeting, Anaheim, CA, 1978. Submitted for publication in J. Inorg. Nucl. Chem. 

Nuclear Wastes Technologies for Separations and Transmutation, Committee on Separations Technology and Transmutation Systems, Board on Radioactive Waste Management, Commission on Geosciences, Environment, and Resources, National Research Council, published by National Academy Press, Washington, DC, 1996 by the National Academy of Sciences. 

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. 

Choppin, G.R. 1999. Overview of chemical separation methods and technologies. In Chemical Separation Technologies and Related Methods of Nuclear Waste Management Application, Problems and Research Needs. Choppin, G.R., Khankhasayev, M.Kh. Eds. Kluwer Academic, Netherlands, pp. 1-15. 

Nilsson, M., Ekberg, C., Foreman, M. et al. 2006. Separation of actinides(III) from lanthanides(III) in simulated nuclear waste streams using 6,6 -bis-(5,6-dipentyl-[l,2,4] triazin-3-yl)-[2,2 ]bipyridinyl (C5-BTBP) in cyclohexanone. Solvent Extr. Ion Exch. 

Mohapatra, P.K., Ansari, S.A., Sarkar, A., Bhattacharyya, A., Manchanda, V.K. 2006. Evaluation of calix-crown ionophores for selective separation of radio-esium from acidic nuclear waste solution. Anal. Chim. Acta 571 (2) 308-314. 

Bonnesen, P.V., Haverlock, T.J., Engle, N.L., Sachleben, R.A., Moyer, B.A. 2000. Development of process chemistry for the removal of cesium from acidic nuclear waste by calix[4]arene-crown-6 ethers. In Calixarene Molecules for Separations. Lumetta, G.J., Rogers, R.D., Gopalan, A.S. Eds. ACS Symposium Series Vol. 757, American Chemical Society, Washington, DC, pp. 26-44. 

Moyer, B.A., Birdwell, J.F. Jr., Bonnesen, P.V., Delmau, L.H. 2005. Use of macrocycles in nuclear-waste cleanup A real-world application of a calixcrown in technology for the separation of cesium. In Macrocyclic Chemistry - Current Trends and Future Prospectives. Gloe K. Ed., Springer, Dordrecht, pp. 383-405. 

Romanovsky, V.N. 2002. U.S.-Russian Cooperative Program in Research and Development of Chemical Separation Technologies. In Chemical Separations in Nuclear Waste Management. Choppin, G.R., Khankhasayev, M.K., Plend, H.S. Eds. Battelle Press, Columbus, OH. DOE/EM-0591. 

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