[en] Short communication

[en] An indigenous Fluoride Ion Selective Electrode has been used for the determination of thorium in aqueous solutions. The method involves the addition of known excess of fluoride followed by the determination of uncomplexed fluoride. The performance with respect to stability and sensitivity of the electrode has been studied. The useful working range has also been determined. An accuracy of about 5 % has been achieved for the determination of Th in the range of 30 to 60 μg. (author)

[en] Determination of plutonium in nuclear fuel materials is routinely carried out by a potentiometric method based on the oxidation of Pu to the hexavalent state by AgO, destruction of the excess AgO by sulphamic acid, reduction of Pu(VI) to Pu(IV) using a known excess of Fe(II) and titration of the excess Fe(II) with standard K₂Cr₂O₇

[en] A method has been developed for the determination of lithium (Li) present in organic matrix containing hexa methylene tetramine (HMTA) and urea used in the sol-gel process for preparing lithium titanate microspheres, using fluoride ion selective electrode and potentiometric end point. Lithium is present in the wash solutions of the Sol-Gel process employed for the preparation of lithium titanate microspheres, proposed to be used in TBM (Test Blanket Module) of International Thermonuclear Experimental Reactor (ITER) project. Methods such as ICP-AES, AAS etc. used in aqueous solutions cannot be employed directly for lithium determination in organic matrix containing hexa methylene tetramine (HMTA), urea, NH₄NO₃, NH₄Cl etc. A potentiometric method using a combination fluoride ion selective electrode for end point detection was developed and has been employed for lithium determination in the process streams from sol-gel process. The method is simple and rapid and an accuracy of about 0.5 % was achieved for the determination of Li in the range of 1 to 20 mg. The method is based on the complexation of Li by adding a known excess of NH₄F solution, followed by potentiometric end point detection using fluoride ISE

[en] This paper reports the results of the experiments carried out for the determination of Th and Zr in aqueous solutions using an indigenous fluoride ion selective electrode

[en] Determination of La and Nd by TIMS is required for accurate determination of burn-up of nuclear fuels. During their thermal ionization mass spectrometric (TIMS) analysis, ¹³⁸Ce and ¹⁴²Ce show spectroscopic isobaric interferences at ¹³⁸La and ¹⁴²Nd, respectively. Hence, it is essential to remove Ce from La and Nd for their accurate isotopic composition determination. Reversed phase high performance liquid chromatography (HPLC) is a promising technique for rapid and effective separation

[en] A correlation has been developed for the determination of ²³⁴U/²³⁸U atom ratio in Nuclear Fuel Samples using the atom ratios ²³⁴U/²³⁸U and ²³⁵U/²³⁸U determined by Thermal Ionization Mass Spectrometry. The relation is linear over the range of atom ratios of ²³⁴U/²³⁸U that would be encountered in the nuclear fuel samples. This correlation is extremely useful for the determination of ²³⁵U/²³⁸U in fuel samples using the cheaper alternative method such as alpha spectrometry for ²³⁴U/²³⁸U without resorting to the capital intensive Thermal Ionization Mass Spectrometric measurements. (author)

[en] This study shows that there is a possibility of the isotopic analysis of Sr as SrF⁺ if proper sample preparation steps are followed. Since, rubidium does not form RbF⁺, interference free analysis of Sr using TIMS is also possible. Since the mass numbers of the ions used for analysis is slightly higher, the isotopic fractionation in TIMS analysis would also be less. The intensity of SrF⁺ is less in comparison to Sr⁺ which necessitates the use of larger amount of sample for analysis (∼ 20 times or more) which can pose difficulties, when the sample amount available is less

[en] Studies were performed on the formation of atomic and molecular ions of Uranium under the different conditions of loading in TIMS. Aqueous solutions of natural uranium samples were treated with organic reagents such as benzene, toluene and xylene. The intensity ratio of metal to oxide ion was obtained in each analysis, under identical conditions of analysis. The intensity ratio of metal to oxide ion in the organic treated samples was found to increase by around three orders of magnitude in comparison to that obtained by the conventional nitric acid treated samples. (author)

[en] A simple sample preparation and simultaneous analysis method to determine uranium and plutonium from dissolver solution, employing the technique of Isotope Dilution Mass spectrometry has been demonstrated. The method used, co-elusion of Uranium and Plutonium from anion exchanger column after initial elution of major part of uranium in 1:5 HNO₃ in order to reduce the initial U/Pu ratio from 1000 to about 100-200 in the co-eluted fraction. Due to the availability of variable multi-collector system, different Faraday cups were adjusted to collect the different ion intensities corresponding to the different masses, during the simultaneous analysis of Uranium and Plutonium, loaded on Re double filament assembly. ²³³U and PR grade Plutonium were used as spikes to determine Uranium and Plutonium from dissolver solution of irradiated fuel from research reactor. The possibility of getting the isotopic composition of uranium from the simultaneous analysis of co-eluted purified fraction of U and Pu from spiked aliquots is also explained. (author)