@spcputtur.ac.in
Associate Professsor, Physics
St.Philomena College
Environmental Radioactivity, Astrophysics
Scopus Publications
K. Chandrashekara, H. M. Somashekarappa, and A. P. Radhakrishna
Springer Science and Business Media LLC
H.M. Somashekarappa, Y. Narayana, A.P. Radhakrishna, K. Siddappa, V.B. Joshi, R.V. Kholekar, and A.M. Bhagwat
Elsevier BV
H.M. Somashekarappa, Y. Narayana, A.P. Radhakrishna, N. Karunakara, K.M. Balakrishna, and K. Siddappa
Elsevier BV
A.P. Radhakrishna, H.M. Somashekarappa, Y. Narayana, and K. Siddappa
Elsevier BV
Y. Narayana, A.P Radhakrishna, H.M. Somashekarappa, N. Karunakara, K.M. Balakrishna, and K. Siddappa
Oxford University Press (OUP)
Systematic studies on radiation levels and radionuclide distribution in the environment of coastal Kamataka, located on the south west coast of India, was initiated to provide baseline data on background radiation levels for the future assessment of the impact of the nuclear and thermal power stations that are being set up in the region. The paper presents the concentration of the prominent natural and artificial radionuclides in vegetarian and non-vegetarian composite diet samples of the region. The internal exposures to the population of the region were estimated from the concentration of prominent radionuclides in total diet. The results are discussed in the light of literature values reported for other environments.
Y. Narayana, A. P. Radhakrishna, H. A. Somashekarappa, N. Karunakara, K. M. Balak, K. M. Balakrishna, and K. Siddappa
Ovid Technologies (Wolters Kluwer Health)
In order to understand the distribution of radionuclides in the newly discovered high background area in Ullal near Mangalore, soil and sand samples collected from different depths were analyzed for the concentration of primordial radionuclides by gamma spectrometry. The activity of 232Th and 238U in soil and sand was observed to be maximum in the 0-10 cm layer. The activity of primordial radionuclides was determined for the different size fractions of soil and sand to study the enrichment pattern. The highest activity was found in the 250-125 mu fraction in both soil and sand. The concentration of primordial radionuclides in riverine and marine sediments in the vicinity of the high background area was measured to understand the transportation of radionuclides in riverine and marine environments and to throw light on the formation of the new patches of monazite deposit. The results of these systematic investigations are discussed in this paper.
Y. Narayana, A.P. Radhakrishna, H.M. Somashekarappa, N. Karunakara, K.M. Balakrishna, and K. Siddappa
Elsevier BV
Y Narayana, H M Somaskekarappa, A P Radhakrishna, K M Balakrishna, and K Siddappa
IOP Publishing
External gamma-ray dose rates in air have been measured using a sensitive plastic scintillometer in the environment of coastal Karnataka, on the south west coast of India, where intensive industrial activities including a nuclear power plant, a super thermal power station and a petrochemical complex are envisaged. The gamma dose rates in air range from 26 to 174 nGy h-1 with a geometric mean of 74 nGy h-1 and geometric standard deviation of 1.4. The activity of primordial radionuclides in soil samples of the region were measured using an HPGe gamma ray spectrometer and the resulting doses in air were calculated. The mean absorbed dose rate due to primordial radionuclides was 41.4 nGy h-1 with a geometric standard deviation of 1.4. A correlation was found between doses measured using scintillometer and doses estimated from the measured activity of primordial radionuclides when the cosmic ray component is taken into account. The concentration of primordial radionuclides in soil and sand show considerable variation in their vertical depth distribution in the high background area of the region.
A. P. Radhakrishna, H. M. Somashekarappa, Y. Narayana, and K. Siddappa
Ovid Technologies (Wolters Kluwer Health)
The systematic study of background radiation and the distribution of radionuclides in the environment of coastal Karnataka, South India, has been initiated with an objective of establishing reliable baseline data on the background radiation level of the region for future assessment of the impact of nuclear and thermal power stations that are being set up in the region. The ambient gamma radiation survey in the environment of Mangalore, a major industrial city of coastal Karnataka, revealed significantly high gamma dose in air in certain locations of the Mangalore beach area. Thermoluminescent dosimetric studies indicated conspicuously high gamma dose in air in these places. Gamma spectrometric analyses of the soil and sand samples of this high background area have been carried out. The measured gamma dose in air in high background area is in the range 44-2102 nGy h-1. The average activity of 232Th, 238U, and 40K in soil samples is 2,971 Bq kg-1, 546 Bq kg-1, and 268 Bq kg-1, respectively. In sand samples, the respective activities are 1,842 Bq kg-1, 374 Bq kg-1, and 158 Bq kg-1. Results of these systematic investigations which establish the existence of new patches of monazite in the Mangalore beach area, on the southwest coast of India, are presented in this paper.