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90Sr (T1/2 = 28 y) is always in equilibrium with 90Y in High Level Liquid waste (HLLW) and hence 90Sr is a suitable long lasting source of 90Y, if it is purified suitably for therapeutic applications. A combination of CMPO & TBP was found to be the most suitable solvent system for alpha activity removal. CMPO has high selectivity for alpha contaminants (Pu/Am) w.r.t. 90Sr. For regeneration of spent organic, 3 M Phosphoric acid was most suitable with the ability to strip back more than 98% of gross alpha activity in single contact and thus solvent system was qualified for recycling. [ABSTRACT FROM AUTHOR]

90Y, a beta emitting radionuclide (T1/2 ~ 64 h, Emax= 2.3 MeV), the daughter product of 90Sr is used for radio therapeutic applications. Non dispersive solvent extraction in hollow fibre membrane contactor (HFMC) with CMPO solvent studies were done to achieve the desired purification of 90Sr nitrate solution with respect to gross alpha activity. This purified solution is promising feed for 90Sr–90Y generator to achieve the clinical grade product of 90Y. In HFMC recirculations, around 99.97% alpha impurities were extracted in two recirculations from the feed solution with 0.2 M CMPO while only two recirculations were required with 0.4 M CMPO. A simplified mathematical model has also been developed to model the extraction of alpha impurities through the HFMC using CMPO as a solvent. [ABSTRACT FROM AUTHOR]

Fission product yield studies in the reaction of 73,4 and 84.2 MeV12C with209Bi have been carried out using gamma-ray spectrometry. The cross sections for the production of fission products have been determined. The yield distribution of fission products is found to be symmetric and broad with FWHM around 25 mass units and peak near mass 107.7 and 107.0. The average number of neutrons emitted per fission have been found to be around 5.5 at 73.4 MeV and 7.1 at 84.2 MeV, respectively. [ABSTRACT FROM AUTHOR]

A chemical neutron activation analysis method to determine trace amounts of palladium present in the uranium ores has been developed. Palladium was concentrated on an anionic exchanger to purify from large amounts of uranium, iron and copper that were present in the ore. The resin in which Pd was adsorbed was neutron irradiated and the activation product109Pd was assayed through its daughter109mAg by low energy photon spectrometry to estimate palladium. Both the 88 keV gamma-line and the 22 keV X-ray line (arising out of the internal transition of109mAg) were used to arrive at the concentration values by a standard comparison technique. A thin window Si(Li) detector and an HPGe detector were used for the radioactive assay. Detection limits and the advantage of using the X-ray line of Ag over that of the gamma-line were discussed. An absolute detection limit of 0.12·10−9 g could be arrived at by the use of the 22.10 keV X-ray line in an interference-free condition. [ABSTRACT FROM AUTHOR]

Three ferromanganese crusts from different locations of the Indian Ocean were analysed by neutron activation analysis using the k0 method ( k0 NAA method) for studying the distribution of some trace elements along with Fe and Mn. Another crust from the Lau basin of the Pacific Ocean was investigated for comparison of the influence of different oceanic conditions on the trace element distributions in ferromanganese crusts. Variation in Co concentration along with the Mn/Fe ratio were discussed in terms of the hydrogenous/hydrothermal nature of the crusts. The normalised REE content was used to identify possible anomalies. The observed Ce anomaly is discussed in the light of the depositional environment. The precision and accuracy of the method were confirmed by measuring the elemental concentrations in a USGS nodule standard NOD A-1. [ABSTRACT FROM AUTHOR]

Multielement analysis was carried out in two samples of natural rubies obtained from Kenya and Tanzania and a synthetic ruby obtained locally. The trace element profile was used to characterise the ruby samples. Instrumental Neutron Activation Analysis (INAA) by the single comparator ( K0 method) was used to determine the concentrations of 22 elements with gold as the comparator. High resolution γ-ray spectrometry was employed for radiometric assay of the activation products. The accuracy and precision were evaluated by analysing standard reference materials such as USGS-W-1 and AGV-1 and were found to be satisfactory. [ABSTRACT FROM AUTHOR]

A simple technique based on the measurement of the ratio of alpha-decay constant to neutron induced fission cross section for pure actinides using solid state nuclear track detectors (SSNTDs) is developed for the identification of the actinides in trace levels in pure solutions. The alpha-decay constant to fission cross section ratios for depleted U,238Pu and240Pu have been measured for the epicadmium neutron induced fission of these actinides. The measured values are (6.19±0.34)·106, (6.95±0.26)·1012, (2.12±0.95)·109 and (2.18±1.58)·1011 sec−1·cm−2, respectively. These ratios can be used for the trace level identification of pure actinides. [ABSTRACT FROM AUTHOR]