Authors:G. Reddy, Pritty Rao, J. Ramana, S. Vikramkumar, V. Raju, and Sanjiv Kumar
The paper describes the determination and depth profiling of oxygen in thin oxide films using 18O(p,α)15N nuclear reaction. The excitation function of 18O(p,α)15N nuclear reaction exhibits a resonance at 629 keV and a plateau at 730 keV with uniform cross-section. The resonance is used
to determine the depth profile of oxygen in films while the plateau, to estimate its overall concentration. The resonance,
characterized by a width of 2.1 keV enables high-depth resolution (~20 nm) measurements and has a probing depth of more than
a micron. The paper presents depth profile measurements of oxygen in several metal oxide films (SiO2, TiO2 and HfO2) using this resonance. Possible interferences arising from 15N(p,α)12C, 19F(p,α)16O and 11B(p,α)2α nuclear reactions are also discussed. It has been shown that it can serve as a suitable alternative to 3.05 MeV 16O(α,α)16O resonant scattering which is generally used for depth profiling oxygen. It is, in fact, more reliable and precise in materials
that witness significant large angle multiple scattering. It can also be advantageously used to monitor 18O, when used as a tracer.
Authors:D. Rao, V. Sudheendran, A. Baburajan, S. Chandramouli, A. Hegde, and U. Mishra
The Environmental Survey Laboratory is responsible for the monitoring of radioactivity due to natural and artificially produced radionuclides in a variety of samples available around the nuclear facilities at Tarapur. Standard methods of radiochemical separation and counting are followed to determine -emitters in various matrices. To make the measurement simple and detect lower levels of contamination in some of the matrices, a method was developed to measure the high energy gross -activity primarily due to 90Y in borehole water and urine samples of occupational workers by Cerenkov counting in a liquid scintillation analyser. Cerenkov counting results of borehole samples were compared with the total gross -activity measured by a low background beta-counter. The combined measurements were used to evaluate 90Sr and 137Cs levels without chemical separation or gamma-spectrometry. Cerenkov counting technique was also utilised to evaluate 40K in drinking water and intercomparison water samples. The paper presents the methodology and results of a few measurements using the technique.
Authors:A. Mahesh, R. Jeyachandran, L. Cindrella, D. Thangadurai, V. Veerapur, and D. Muralidhara Rao
The hepatocurative potential of ethanolic extract (ETO) and sesquiterpene lactones enriched fraction (SL) of
roots was evaluated against carbon tetrachloride (CCl
) induced hepatotoxicity in mice. The diagnostic markers such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bilirubin contents were significantly elevated, whereas significant reduction in the level of reduced glutathione (GSH) and enhanced hepatic lipid peroxidation, liver weight and liver protein were observed in CCl
induced hepatotoxicity in mice. Post-treatment with ETO and SL significantly protected the hepatotoxicity as evident from the lower levels of hepatic enzyme markers, such as serum transaminase (ALT, AST), ALP and total bilirubin. Further, significant reduction in the liver weight and liver protein in drug-treated hepatotoxic mice and also reduced oxidative stress by increasing reduced glutathione content and decreasing lipid peroxidation level has been noticed. The histopathological evaluation of the liver also revealed that ETO and SL reduced the incidence of liver lesions induced by CCl
. The results indicate that sesquiterpene lactones have a protective effect against acute hepatotoxicity induced by the administration of CCl
in mice. Furthermore, observed activity of SL may be due to the synergistic action of two sesquiterpene lactones identified from enriched ethyl acetate fraction by HPLC method.
Authors:A. Kumar, Y. Gautam, V. Kumar, K. Rao, S. Sharma, A. Sharma, and A. Hegde
Knowledge of the dynamics of HTO in leafy plant–soil system is required to verify models, such as the NORMTRI code, which
predict environmental tritium following its release. Tritium concentrations in plants has been evaluated using the code NORMTRI
and experimentally by collection of samples of different plants and their soils samples. In the present study, major seasonal
crop plants i.e. wheat, mustard, sugar cane, coriander, spinach, potato, were collected beyond Narora Atomic Power Station
site boundary and gular, arandi, neem, ashok, amaltas, csuarina leaf samples within NAPS site boundary for analysis of HTO
content. Data analysis indicated that HTO in leaf is strongly influenced by atmospheric relative humidity and type of the
Authors:S. Rao, Biplob Paul, K. Lal, S.V. Narasimhan, and Jaleel Ahmed
Chemical treatment assumes an important role in the management of radioactive wastes as it is a simple technique and offers advantage in terms of handling of wastes thereby reducing the risk of mansievert exposure. Low level wastes (LLW) and intermediate level wastes (ILW) are generated in various facets of nuclear fuel cycle and have various chemical composition. A systematic study was carried out by using copper ferrocyanide and calcium phosphate precipitation methods for the removal of cesium and strontium, respectively. The supernatants were subjected to ultra filtration (UF) using a membrane having a pore size of 0.2 m. The decontamination factors (DF) at 2 and 24-hour intervals with and without UF were estimated. The DF obtained was in the range of 200–300 for cesium and 200 for strontium with LLW solution which has chemical characteristics similar to ground water. Two hours of settling is adequate for strontium before UF. In case of cesium there is no much change in the DF values by UF. However, the UF has helped in the solid — liquid separation as the flocks of copper ferrocyanide precipitate are feathery in nature. The effect of ionic strength and the presence of TBP on the removal efficiency of cesium and strontium have also been studied. DF are observed to be a function of ionic strength and are low in deionized water, in salt solutions containing 1 to 4M sodium nitrate and also in solutions of ILW. However, increasing the chemical dosing to two times of normal plant dosing has yielded a DF of about 200 for sodium nitrate solutions with respect to cesium removal. When the concentration of ammonium nitrate in the waste exceeds 0.1M, the DF reduces. Entrained TBP as well as soluble TBP reduces the removal efficiency of cesium. This paper deals with the experimental data and mechanism of the processes involved in the removal of cesium and strontium.
Authors:K. Venugopal Chetty, A. G. Godbole, R. Swarup, V. N. Vaidya, V. Venugopal, and P. R. Vasudeva Rao
The sorption of Pu from nitric acid solutions containing oxalate/fluoride was studied using an indigenously available macroporous
bifunctional phosphinic acid (MPBPA) resin. Batch experiments were carried out to obtain the distribution data of Pu(IV) with
a view to optimize conditions for its recovery from nitric acid waste solutions containing oxalate or fluoride ions. The measurements
showed high distribution ratio (D) values even in the presence of strong complexing ions, like oxalate and fluoride, indicating the possibility of recovery
of Pu from these types of waste solution. Column studies were carried out using this resin to recover Pu from the oxalate
supernatant waste solution, which showed that up to 99% of Pu could be adsorbed on the resin. Elution of Pu loaded on the
resin was studied using different eluting agents.
Authors:S. Abdul Sattar, B. Seetharami Reddy, V. Koteswara Rao, A. Pradeep, G. Naga Raju, K. Ramanarayana, P. Madhusudana Rao, and S. Bhuloka Reddy
Trace elemental analysis was carried out in various parts of 10 anti-epileptic medicinal plants using PIXE technique. A 3 MeV
proton beam was used to excite the samples and spectra were recorded using a Si(Li) detector. Data analysis was done using
Gupix Software. The elements Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Br and Sr were identified and their concentrations estimated.
The presence of some of these trace elements is correlated with the anti-epileptic curative property of these plants.
Authors:Y. Gautam, A. Sharma, S. Sharma, K. Rao, J. Kumar, V. Kumar, B. Singh, A. Kumar, and A. Hedge
Atmospheric tritium activity is measured regularly around Narora Atomic Power Station (NAPS) since gaseous waste, which contains
tritium, is being released through a 145 m high stack at NAPS site. Atmospheric data collected during 2004–2008 shows a large
variation of 3H concentration in air, fluctuating in the range of ≤0.2–91.6 Bq m−3. Significantly, higher tritium levels were measured in samples near the site boundary (1.6 km) of NAPS compared to off-site
locations. The atmospheric dilution factor was found to be in the range of 1.1 × 10−7–7.3 × 10−7 s m−3. The scavenging ratio of NAPS site was found to be varying from 0.2 × 104 to 14.1 × 104 (Bq m−3 rain water per Bq m−3 air). The inhalation dose to a member of general public at different distances (1.6–30 km) from NAPS site was found to be
ranged from 0.08–0.21 μSv year−1.
Authors:Pritty Rao, G. Reddy, S. Vikram Kumar, J. Ramana, N. Chattopadhyay, A. Basu, Seema Srivastava, R. Sarin, V. Raju, and Sanjiv Kumar
The paper describes the simultaneous determination of 14N and 15N isotopes in opium by proton induced γ-ray emission (PIGE) technique. The isotopic ratio of 14N and 15N is a useful parameter for assigning provenance of (seized) illicit drugs. The measurement, non-destructive in nature, is
performed on pellets made up of opium powders and is based on the prompt detection of 2.313 and 4.4 MeV γ-rays emanating from
14N(p,p′γ)14N and 15N(p,αγ)12C nuclear reactions respectively, induced simultaneously by 3.6–3.8 MeV proton beam. Positive as well as negative deviations
from the natural isotopic abundance (99.63:0.37) were observed in the samples. The precision of the measurements is about
4%. The methodology provides an easy and rapid approach to determine the isotopic ratio of 14N and 15N and has been used for the first time in the analysis of opium.