Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-17T21:31:12.716Z Has data issue: false hasContentIssue false

Variation in the uranium isotopic ratios 234U/238U,238U/total-U and 234U/total-U in Indian soil samples:Application to environmental monitoring

Published online by Cambridge University Press:  18 December 2012

S.K. Srivastava*
Affiliation:
Health Physics Unit, NFC, Environmental Assessment Division, Bhabha Atomic Research Center, P.O. ECIL, Hyderabad-500062, India
A.Y. Balbudhe
Affiliation:
Health Physics Unit, NFC, Environmental Assessment Division, Bhabha Atomic Research Center, P.O. ECIL, Hyderabad-500062, India
K. Vishwa Prasad
Affiliation:
Health Physics Unit, NFC, Environmental Assessment Division, Bhabha Atomic Research Center, P.O. ECIL, Hyderabad-500062, India
P. Padma Savithri
Affiliation:
Health Physics Unit, NFC, Environmental Assessment Division, Bhabha Atomic Research Center, P.O. ECIL, Hyderabad-500062, India
R.M. Tripathi
Affiliation:
Environmental Assessment Division, Bhabha Atomic Research Centre, Bhabha Atomic Research Center, Trombay, Mumbai-400085, India
V.D. Puranik
Affiliation:
Environmental Assessment Division, Bhabha Atomic Research Centre, Bhabha Atomic Research Center, Trombay, Mumbai-400085, India
Get access

Abstract

The uranium isotopes 238U, 235U and 234U are foundnaturally in the environment. 238U and 235U are parent nuclides of twoindependent decay series of isotopes, while 234U is a member of the238U decay chain. When decay series occur in a closed system the series tendsto reach, with time, the state of secular equilibrium in which the activities of all seriesmembers are equal to the activity of its first nuclide. The activity ratio234U/238U in natural uranium may vary as a consequence of decaychain disequilibrium due to alpha recoil and biogeochemical processes. A study based onmeasurement of uranium concentration and 234U/238U activity ratios insoil samples collected from Nalgonda district, Andhra Pradesh, India, a proposed miningsite, was carried out to find the spatial distribution of uranium and the state of secularequilibrium of 234U/238U to examine the possibility of applyinguranium concentration and uranium isotopic activity ratios to detect any hydrogeochemicalchanges in the environment during/post-operation. Soil samples were collected and analyzedfor uranium concentration using the conventional UV fluorimetric method, showing a uraniumconcentration in the range of 0.7 ± 0.2 ppm to 7.9 ± 0.4 ppm with an average of 3.4 ppm, and234U/238U activity ratios were estimated using the alphaspectrometry technique, showing an activity ratio in the range of 0.92 ± 0.11 to1.02 ± 0.11. The 234U/ 238U activity ratio obtained indicated thatthese two uranium isotopes are in the state of secular radioactive equilibrium. The percentactivity ratio of 238U/total U and 234U /total U is observed to varyfrom 47.94 ± 4.83 to 50.76 ± 4.87 and 45.80 ± 3.83 to 49.14 ± 3.99, respectively.

Type
Research Article
Copyright
© EDP Sciences, 2013

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Asmeron, Y., Edwards, R.L. (1995) U-series isotope evidence for the origin of continental basalts, Earth Planet. Sci. Lett. 134, 1-7.Google Scholar
Bleise, A., Dansei, P.R., Burkart, W. (2003) Properties, use and health effects of depleted uranium (DU): a general overview, J. Environ. Radioactivity 64, 93-112.Google ScholarPubMed
Brindha, K., Elango, L., Nair, R.N. (2011) Spatial and temporal variation of uranium in a shallow weathered rock aquifer in southern India, J. Earth Syst. Sci. 120, 911-920.Google Scholar
Burnett W.C., Veeh H.H. (1992) Uranium-series studies of marine phosphates and carbonates (M. Ivanovich and R.S. Harmon, Eds.), Uranium Series Disequilibrium: Applications to Earth, Marine and Environmental Sciences, 2nd edn, pp. 487-512. Science Publications, Oxford University Press, Oxford.
Chabaux, F., Allegre, C.J. (1994) 238U–230Th– 226Ra disequilibria in volcanics: a new insight into melting conditions, Earth Planet. Sci. Lett. 126, 61-74.Google Scholar
Condomines, M., Hemond, Ch., Allegre, C.J. (1988) U–Th–Ra radioactive disequilibria and magmatic processes, Earth Planet. Sci. Lett. 90, 243-262.Google Scholar
Condomines, M., Tanguy, J.C., Michaud, V. (1995) Magma dynamics at Etna: constraints from U–Th–Ra–Pb radioactive disequilibria and Sr isotopes in historical lavas, Earth Planet. Sci. Lett. 132, 25-41.Google Scholar
Fisenne, I.M. (1996) USDOE remediation site case study, Environ. Int. 22, S243-S249. Google Scholar
Gilkeson R.H., Cowart J.B. (1987) Radium, Radon and Uranium Isotopes in Groundwater from Cambrian-Ordovician Sandstone Aquifers in Illinois. In: Radon, Radium and Other Radioactivity in Ground Water, Proc. NWWA Conf., April 7-9, Lewis, Chelsea.
Goldstein, S.J., Rodriguez, J.M., Lujan, N. (1997) Measurement and Application of Uranium Isotopes for Human and Environmental Monitoring, Health Phys. 72 (1), 10-18.Google ScholarPubMed
Hansen, R.O., Stout, P.R. (1968) Isotopic Distributions of Uranium and Thorium in Soils, Soil Sci. 105, 44-50.Google Scholar
Heath, E., Turner, S.P., Macdonald, R., Hawkesworth, C.J., Calsteren, P. (1998) Long magma residence times at an island volcano (Soufriere, St. Vincent) in the Lesser Antilles: evidence from 238U–230Th isochron dating, Earth Planet. Sci. Lett. 160, 49-63.Google Scholar
IAEA (1989) Methods for determining gamma emitters. Technical Report Series No. 295 (C. Klusek, O. Paakkola, T. Scott, Eds.), Measurement of Radionuclide in Food and the Environment, a Guidebook. IAEA, pp. 58-60.
Ivanovich, M., Frohlich, K., Hendry, M.J. (1991) Uranium series radionuclides in fluids and solids from the Milk River aquifer, Alberta, Canada, Appl. Geochem. 6, 405-418.Google Scholar
Ivanovich M., Latham A.G., Ku L. (1992) Uranium-series disequilibrium applications in geochronology (M. Ivanovich, R.S. Harmon, Eds.), Uranium series disequilibrium: Applications to Earth, marine and environmental sciences, 2nd edn., pp. 62-95. Oxford University Press, Oxford.
Jia Guogang,Torri, G., Innocenzi, P. (2004) An improved method for determination of uranium isotopes in environmental samples by alpha-spectrometry, J. Radioanal. Nucl. Chem. 262 (2), 433-441.Google Scholar
Legeleux, F., Reyss, J.L., Schmidt, S. (1994) Particle mixing rates in sediments of the northeast tropical Atlantic: evidence from 210Pbxs 137Cs 228Thxs and 234Thxs downcore distributions, Earth Planet. Sci. Lett. 128, 545-562.Google Scholar
Lievert, C., Short, S.A., von Gunten, H.R. (1994) Uranium infiltration from a river to shallow groundwater, Geochim. Cosmochim. Acta 58 (24), 5455-5463.Google Scholar
Lowson, R.T., Short, S.A., Davey, B.G., Gray, D.J. (1986) 234U/238U and 230Th/234U Activity Ratios in Mineral Phases of a Lateritic Weathered Zone, Geochim. Cosmochim. Acta 50, 1697-1702.Google Scholar
Lowson, R.T., Short, S.A. (1988) 238U Decay Series Disequilibria in Clay/Quartz Mineral Phase, Uranium 4, 275-278.Google Scholar
Macdougall, J.D. (1995) Using short-lived U and Th series isotopes to investigate volcanic processes, Annu. Rev. Earth Planet. Sci. 23, 143-167.Google Scholar
Mathieu, D., Bernat, M., Nahon, D. (1995) Short-lived U and Th isotope distribution in a tropical laterite derived from granite (Pitinga river basin, Amazonia, Brazil): application to assessment of weathering rate, Earth Planet. Sci. Lett. 136, 703-714.Google Scholar
Osmond, J.K., Cowart, J.B. (1976) The Theory and Uses of Uranium Isotopic Variations in Hydrology, Atomic Energy Rev. 14, 621-679.Google Scholar
Plater, A.J., Ivanovich, M., Dugdale, R.E. (1992) Uranium Disequilibrium in River Sediments and Waters: The Significance of Anomalous Activity Ratios, Applied Geochem. 7, 101-110.Google Scholar
Richter, S., Alonso, A., De Bolle, W., Wellum, R., Taylor,, P.D.P (1999) Isotopic “Fingerprints” for Natural Uranium Ore Samples, Int. J. Mass Spectrom. 193, 9-14. Google Scholar
Riotte, J., Chabaux, F. (1999) (234U/238U) Activity Ratios in Freshwaters as Tracers of Hydrological Processes: The Strengbach Watershed (Vosges, France), Geochim. Cosmochim. Acta 63 (9), 1263-1275.Google Scholar
Rosholt, J.N., Doe, B.R., Tatsumoto, M. (1966) Evolution of the Isotopic Composition of Uranium and Thorium in Soil Profiles, Geol. Soc. Am. Bull. 77, 987-1004.Google Scholar
Stuckless, J.S., Bunker, C.M., Bush, C.A., Doernar, W.P., Scott, J.H. (1977) Geochemical and Petrological Studies of a Uraniferous Granite from the Granite Mountains, Wyoming, US, Geol. Survey Jour. Res. 5, 61-81.Google Scholar
Vera Tome, F., Vargas, M.J., Sanchez, A.M. (1994) Yields and losses at each step in preparing uranium and thorium samples for alpha spectrometry, Appl. Radiat. Isot. 45, 449-452. Google Scholar
Yamamoto, M., Kawabata, Y., Murata, Y., Komura, K. (2002) Variation of uranium isotopic composition in soil within the JCO grounds from the 30 September 1999 criticality accident at JCO, Tokai-mura, Japan, Health Phys. 83, 197-203.Google ScholarPubMed