Authors:X. Liang, K. Tsukada, A. Toyoshima, Z. Li, M. Asai, T. Sato, N. Sato, and Y. Nagame
Adsorption of carrier-free radiotracers 181W and 93mMo produced in the 181Ta(p, n) and natNb(p, n) reactions, respectively, on anion-exchange resin was studied in mixed solution of HF and HNO3 in a concentration range of 10−4–10−1 M HF/0.1 M HNO3. Distribution coefficients (Kd) of 181W and 93mMo at 70 °C showed the V-shaped variation with the minimum at around 10−1 M HF/0.1 M HNO3, although variation of the Kd values for 93mMo was quite small compared with that for 181W. Formation of oxofluoro complexes for W and Mo is briefly discussed.
Authors:A. Toyoshima, K. Tsukada, H. Haba, M. Asai, S. Goto, K. Akiyama, I. Nishinaka, S. Ichikawa, Y. Nagame, and A. Shinohara
The anion exchange behavior of 255No produced by the 248Cm(12C,5n) reaction has been investigated in 11.5M HCl, 4M HCl and 8M HNO3 to deduce the behavior of 'primordial 257No' produced via 248Cm(18O,5n)261Rf
257No before anion exchange separation in the 261Rf experiment. It was found that 255No is mostly eluted from the anion exchange column with these solutions. The contribution of 'primordial 257No' to the -decay events of 261Rf in the 261Rf experiment was evaluated based on the present results.
The diffusion of chlorocomplexes of some corrosion and fission products in anion exchange beads has been studied in mixed
solvent media. The effects of variables on the kinetics of the exchange process by the batch and flow technique were examined.
The strongly basic anion exchanger Dowex 2X8 in its Cl− form was used in organic solvent—water—hydrochloric acid solutions. The dependence of the exchange rate on temperature, the
viscosity of the solution, the mean resin particle diameter and the composition of the solution was studied. Film and particle
diffusion coefficients were calculated from the experimental data. The results provide valuable data for the design of separation
The diffusion of cobalt chloro complexes in anion-exchange beads has been studied in mixed solvent media. The effects of variables
on the kinetics of the exchange process by the batch technique were examined. The strongly basic anion-exchanger Dowex 2X8
in its Cl− form was used in ethyl alcohol-water-hydrochloric acid solutions. The rate laws were verified experimentally. The dependence
of the exchange rate on the temperature, the viscosity of the solution, the mean resin particle diameter and the composition
of the solution was studied.
A quantitative separation scheme for 15 radionuclides is presented. The scheme is based on group separation by means of anion-exchange
resins using mixed solvent systems and subsequent separation of the groups into individual components by means of change of
both eluting agent and resin type. The optimum working conditions for separation are established. Separation procedures are
of good reproducibility and practically quantitative.
Authors:S. Marsh, G. Jarvinen, R. Bartsch, J. Nam, and M. Barr
Additional1 bifunctional anion-exchange resins have been designed, synthesized and evaluated for their ability to take up Pu(IV) from
nitric acid solutions. Bifunctionality is achieved by adding a second anion-exchange site to the pyridine nitrogen (also an
anion-exchange site) of the base poly(4-vinylpyridine) resin. Previous work focused on the effect of varying the chemical
properties of the added site along with the length of an alkylene ‘spacer’ between the two sites. Here we examine four new
3- and 4-picolyl derivatives which maintain more rigidly defined geometries between the two nitrogen cationic sites. These
materials, which have the two anion-exchange sites separated by three and four carbons, respectively, exhibit lower overall
Pu(IV) distribution coefficients than the corresponding N-alkylenepyridium derivatieves with more flexible spacers. Methylation
of the second pyridium site results in a ca. 20% increase in the Pu(IV) distribution coefficients.
Pyrolysis-gas chromatography was used in the study of the thermal behaviour of some acrylic anion-exchangers for identification of the thermal decomposition products and their percentage estimation. The acrylic anion-exchangers were prepared by aminolysis of cross-linked acrylic ester copolymer with difunctional amines. The pyrolysis-gas chromatography studies, coupled with data obtained by thermogravimetry, showed that the acrylic anion-exchangers first lose the water easily absorbed from the air, and the decomposition starts at temperatures above 100°. The great number of decomposition products identified in the pyrograms on the thermal degradation of acrylic anion-exchangers indicated a complex degradation mechanism, with important variations in the contents of the evolved amine compounds.
The separation of strontium and yttrium from calcium on the anion exchanger column with alcohol solution of nitric acid as eluent may be described by Glueckauf's model of elution chromatography. Experimental and theoretical results have shown that this separation is characterized by a small number of theoretical plates of the separation column. This model may also be applied for the simulation of the separation of strontium and yttrium from calcium in the strontium isolation from natural samples. The model parameters may be used for the assessment of the optimum column dimension and the optimum working conditions for the isolation of radioactive strontium and yttrium from natural samples.
Organic anion exchange resins, loaded with99Tc pertechnate were incorporated into polymer modified cements and BFS/OPC(9∶1) cements. The composites formed were tested
for initial compressive strenghts, underwater and radiation stabilities and leach rates. IAEA standard leach testing was with
simulated sea and ground waters. Ground water leaching was also carried out on composites subjected to 1.1 MGy (γ). Polymer
modified composites performed better than the BFS/OPC mix under all the conditions studied and, in most cases, were able to
encapsulate high resin loading.
Authors:E. Tereshatov, H. Bruchertseifer, M. Voronyuk, G. Starodub, O. Petrushkin, and S. Dmitriev
Isocratic anion exchange separations of Group V elements from solutions containing HF have been considered for the development
of Db aqueous phase chemistry experiments. Separation of Nb/Ta from an HF/NH4F system has been demonstrated but has limited utility due to interferences with alpha and spontaneous fission (SF) source
preparation. The physical parameters associated with ion exchange chromatography have been optimized for the separation and
sequential isolation of Pa, Nb and Ta from mixed HF/HNO3 solutions. A suitable procedure incorporating a series of successive chemical separation techniques, i.e. precipitation and
ion exchange chromatography, has been suggested for off-line Db characterization studies.