[en] The Fifth Symposium on Nuclear Analytical Chemistry (NAC-V) was organized at BARC, Mumbai during January 20-24, 2014 with more than 300 participants. It was sponsored by the Board of Research in Nuclear Sciences, Department of Atomic Energy (DAE), India and organized in cooperation with the IAEA and coorganized by the IANCAS. A total of 240 contributed abstracts along with 27 invited talks and 10 invited short talks were presented in 15 technical sessions. Selected 54 full papers of NAC-V have been accepted after review for publication in special issue of JRNC. (author)

[en] The progress of research and development work and various activities of the Radiochemistry Division of the Bhabha Atomic Research Centre, Bombay, during 1974, are reported. The Division developed : (1) coulometric methods of determination of plutonium and uranium (2) titrimetric method of determination of uranium (3) analytical techniques for determination of metallic and non-metallic impurities in plutonium fuel for its quality control and (4) magnesium tracer techniques MAGTRAP based on isotope dilution and mass spectrometry for accounting of plutonium in a fuel reprocessing plant. An alpha tight 10,000 Ci hot cell has been commissioned and used for separating fission-produced ⁹⁹Mo required for preparation of ⁹⁹Tc generators for medical application. The Division fabricated: (1) a controlled potential coulometer for plutonium estimation (2) an assembly for fluorescence lifetime studies (3) an I.C. based coincidence/anticoincidence unit for use with low background β-counter and (4) photo-multiplier pre-amplifier for long distance applications. The work is continuing in the following areas: (1) process chemistry of neptunium (2) X-ray fluorescence analysis for uranium determination (3) in-line analytical technique for fuel reprocessing stream (4) antinide chemistry and (5) fission phenomena. (M.G.B.)

[en] Concentrations of five rare earth elements (REE) were measured in clay samples of a deep bore hole comprising major aquifers of Pondicherry region, south India in order to investigate the geochemical variations among various litho-units. Clay samples from Cretaceous formation show distinct gray to black color whereas Tertiary deposits have clays with color varying from pale yellow to brown to gray. All measured REEs exhibit lower concentrations than Upper Continental Crust (UCC) average values. Large variations in REEs contents were observed in different sedimentary formations (Tertiary and Cretaceous). Chondrite normalized ratio of La/Lu and Eu/Eu* indicate that the clays are derived from weathering of felsic rock and possibly under humid climate. All the samples showed positive Eu anomaly in North American Shale Composite (NASC) normalized plot which shows plagioclase feldspar as the major contributor to these clays. Positive Eu anomaly is also an indication of reduced condition of the formation. (author)

[en] The highlights of the research and development (R and D) activities of the Neutron Physics Division of the Bhabha Atomic Research Centre, Bombay, during January - December 1980 are summarised. The R and D activities are in the fields of critical and subcritical fission systems, the plasma focus device, applied neutron physics, neutron and X-ray crystallography, materials physics and seismology. (M.G.B.)

[en] In order to understand the mobility of uranium it is very important to know about its sorption kinetics and the thermodynamics behind the sorption process on soil. In the present study the sorption kinetics of uranium was studied in soil and the influence parameters to the sorption process, such as initial uranium concentration, pH, contact time and temperature were investigated. Distribution coefficient of uranium on soil was measured by laboratory batch method. Experimental isotherms evaluated from the distribution coefficients were fit to Langmuir, Freundlich and Dubinin-Raushkevich (D-R) models. The sorption energy for uranium from the D-R adsorption isotherm was calculated to be 7.07 kJ mol^-1. The values of ΔH and ΔS were calculated to be 37.33 kJ mol^-1 and 162 J K^-1 mol^-1, respectively. ΔG at 30 deg C was estimated to be -11.76 kJ mol^-1. From sorption kinetics of uranium the reaction rate was calculated to be 1.6 x 10^-3 min^-1. (author)

[en] The wild plant species occurring in the campus of the Bhabha Atomic Research Centre, Bombay, have been put on record. The plants collected and identified are maintained in a herbarium. The species collected are enumerated and the species under each family are arranged in the alphabetical order. The classification of Bentham and Hooker is followed with some modifications in the names of families which are adopted from recent works. (M.G.B.)

[en] Research and development activities of the Analytical Chemistry Division of the Bhabha Atomic Research Centre, Bombay (India), for the year 1973 are reported. From the point of view of nuclear science and technology, the following are worth mentioning: (1) radiochemical analysis of mercury in marine products (2) rapid anion exchange separation and spectrophotometric determination of gadolinium in uranium dioxide-gadolinium oxide blend and (3) neutron activation analysis for forensic purpose. (M.G.B.)

[en] A radiotracer study was carried out in a trickle bed reactor (TBR) independently filled with two different types of packing i.e., hydrophobic and hydrophilic. The study was aimed at to estimate liquid holdup and investigate the dispersion characteristics of liquid phase with both types of packing at different operating conditions. Water and H2 gas were used as aqueous and gas phase, respectively. The liquid and gas flow rates used ranged from 0.83 x 10^-7-16.67 x 10^-7 m³/s and 0-3.33 x 10^-4 m³ (std)/s, respectively. Residence time distribution (RTD) of liquid phase was measured using ⁸²Br as radiotracer and about 10 MBq activity was used in each run. Mean residence time (MRT) and holdup of liquid phase were estimated from the measured RTD data. An axial dispersion with exchange model was used to simulate the measured RTD curves and model parameters (Peclet number and MRT) were obtained. At higher liquid flow rates, the TBR behaves as a plug flow reactor, whereas at lower liquid flow rates, the flow was found to be highly dispersed. The results of investigation indicated that the dispersion of liquid phase is higher in case of hydrophobic packing, whereas holdup is higher in case of hydrophilic packing. (author)

[en] Bhabha Atomic Research Centre was established in 1950 and is engaged in: 1. Setting up research facilities. 2. Process development for various chemical and metallurgical needs of nuclear industry. 3. Production of nuclear instrumentation and more particularly high vacuum equipment. The first nuclear power station was built on turnkey-type by Americans and the second in collaboration with Canada, with the most responsibility handled by India. For the third, responsibility for design, construction and commissioning has been handled by Indians. Construction of heavy-water plants and a nuclear fuel complex for production of nuclear fuel has also proceeded. Transfer of technology from research and technology and development groups to manufacturing operation and project sites has taken place successfully

[en] An account of the work done in the Metallurgy Division of the Bhabha Atomic Research Centre, Bombay, during the calendar year 1976 is given. Some of the major achievements are: (1) production of boron carbide and boral sheet for the Trombay R-5 reactor under construction, (2) production of niobium metal for the manufacture of Zr-Nb-Cu alloy garter springs, (3) development of a process for graphite coating on zircaloy, (4) studies on structural and metal physics aspects of zirconium alloys and steels, (5) studies on the corrosion behaviour of zircaloy-2 as affected by the replacement of helium and stress corrosion cracking of zircaloy fuel tubes in iodine atmosphere and (6) production of high density UO₂ pellets with stable microstructures and sinterable magnesium oxide for MHD application. (M.G.B.)