Simulation of the shielding properties of environmental components against the external radioactive radiation from the Ordovician Dictyonema shale

Authors

  • Sergey V. Lebedev St. Petersburg State University, 7–9, Universitetskaya nab., St. Petersburg, 199034, Russian Federation
  • Stanislav V. Dubrova Russian State Pedagogical University named after Herzen, 48, nab. r. Moiki, St. Petersburg, 191186, Russian Federation
  • Petr V. Fedorov St. Petersburg State University, 7–9, Universitetskaya nab., St. Petersburg, 199034, Russian Federation
  • Willington Siabato Universidad Nacional de Colombia, Department of Geography, Carrera 30, No. 45–03, 212, Bogota D. C., 111321. Colombia
  • Vitalij V. Kurilenko St. Petersburg State University, 7–9, Universitetskaya nab., St. Petersburg, 199034, Russian Federation

DOI:

https://doi.org/10.21638/spbu07.2020.101

Abstract

This paper presents the results of simulating the conditions of absorption of natural radionuclides (uranium-238, thorium-232, potassium-40) in different environment media (water and quartz sand) to assess the effect of the shielding properties of environmental components on the intensity of external radiation exposure to the benthic biota. The source of radiation was the lower Tremadocian Dictyonema shale, which formed the bottom of the Baltic Paleobasin. Water and quartz sand, which was gradually deposited on the roof of the Dictyonema shale, were used in the simulation as media (materials) absorbing the primary radiation. The manuscript shows an experiment conducted in full-scale conditions considering a single exposure of a section of Ordovician rocks that includes highly radioactive Dictyonema shale. This is a small area, but the simulation results are also valid for larger areas as the Baltic Paleobasin. During the late Tremadocian — Floian, along with transgression, benthic biota began to emerge. The experiment shows quantitatively what dosage this biota could have experienced over tens and hundreds of thousands of years, until the Dictyonema shale was covered with a sufficiently thick layer of water-flooded sediments. Experimental data show that the presence of a 10 cm thick layer of water reaches absorption of 40 % of the integral flux of all gamma lines of natural radionuclides (NRN), and in a moist quartz sand layer of the same thickness the absorption value does not exceed 50 %. Thus, despite the screening effect of the environment, the benthic biota of Baltoscandia in the Early Ordovician could have been under significant radiation exposure for millennia. The main value of the experiment is that it was performed in situ, and exclusively natural media were used as modelling elements. 

Keywords:

Dictyonema shale, natural radionuclides, gamma radiation, absorption coefficient, radiation shielding properties, benthic biota

Downloads

Download data is not yet available.
 

References

Литература

Galy, J., Magill, J. (2001). y-DOSE: A Dosimetry and Shielding Module for Nuclides 2000. [report] European Commission, Joint Research Centre, Institute for Transuranium Elements, Karlsruhe.

Gilmore, G. R. (2008). Practical Gamma-ray Spectrometry. 2nd ed. John Wiley & Sons, Chichester. https://doi.org/10.1002/9780470861981

Harrell, J. A., Belsito, M. E., Kumar, A. R. (1991). Hazards Associated with Outcrops of Ohio Shale in Ohio. Environ. Geol. Water Sci., 18(1), 17–26. https://doi.org/10.1007/BF01704574

International Commission on Radiation Units and Measurements, (1994). ICRU. Gamma-ray Spectrometry in the Environment (Report 53). Bethesda-Maryland.

Lebedev, S. V. (2012). Radioactivity of sedimentary rocks and ecological situation in the Sablinsky nature monument. Vestnik of Saint Petersburg University. Ser. 7. Geology, Geography. (2), 22–32. (In Russian)

Lebedev, S. V., Dubrova, S. V., Fedorov, P. V., Kurilenko, V. V., Siabato, W. (2018). Environmental assessment of risks associated with the Ordovician Dictyonema shale in the eastern part of the Baltic Klint. Vestnik of Saint Petersburg University. Earth Sciences, 63(2), 147–159. https://doi.org/10.21638/11701/spbu07.2018.202

Lee, J. S., Chon, H. T., Kim, J. S., Kim, K. W., Moon, H. S. (1998). Enrichment of potentially toxic elements in areas underlain by black shales and slates in Korea. Environ. Geochem. Health, 20, 135–147.https://doi.org/10.1023/A:1006571223295

Männil, R. M. (1966). History of the evolution of the Baltic basin in the Ordovician. Valgus Publishers, Tallinn. (In Russian)

Ogendi, G. M., Hannigan, R. E., Farris, J. (2007). Toxicity of metal-enriched black shale-draining surface waters to Ceriodaphnia dubia, and Pimephales promelas. J. Agric. Food. Environ. Sci., 1(1), 1–14.

Ogendi, G. M., Hannigan, R. E., Farris, J. L., Smith, D. (2004). The impact of black shale weathering on sediment quality. J. Ark. Acad. Sci., (58), 84–90.

Ragheb, M. (2006a). Radiation Protection and Shielding. Attenuation of gamma radiation. Principles of Radiation Protection. NPR 441 Lecture Notes University of Illinois at Urbana-Champaign. [online]. Available at: http://mragheb.com/NPRE%20441%20Principles%20of%20Radiation%20Protection/Attenuation%20of%20Gamma%20Radiation.pdf (accessed: 03.04.2020).

Ragheb, M. (2006b). Radiation Protection and Shielding. Gamma rays interaction with matter. Principles of Radiation Protection. NPR 441 Lecture Notes University of Illinois at Urbana-Champaign. [online]. Available at: http://mragheb.com/NPRE%20441%20Principles%20of%20Radiation%20Protection/Gamma%20Rays%20Interactions%20with%20Matter.pdf (accessed: 03.04.2020).

Saito, K., Jacob, P. (1995). Gamma ray fields in the air due to sources in the ground. Radiat. Prot. Dosimetry, 58(1), 29–45. https://doi.org/10.1093/oxfordjournals.rpd.a082594

Soesoo, A., Hade, S. (2012). Metalliferous organic-rich shales of Baltoscandia — a future resource or environmental/ecological problem. Archiv EuroEco, 2(1), 11–14.

Sokolova, T. N. (1971). Geological map of the Pre-Quaternary deposits of Leningrad, Pskov, and Novgorod regions. Scale: 1:1000000. In: V. A. Selivanova, ed. Geology of USSR. I. Leningrad, Pskov, and Novgorod regions: Appendix 1. Moscow: Nedra Publ.

United Nations Scientific Committee on the Effects of Atomic Radiation, (2000). UNSCEAR 2000 Report Vol. 1. Sources and effects of ionizing radiation. Annex В: Exposures from natural radiation sources [report]. New York: United Nation

Downloads

Published

2020-05-29

How to Cite

Lebedev, S. V. . (2020) “Simulation of the shielding properties of environmental components against the external radioactive radiation from the Ordovician Dictyonema shale”, Vestnik of Saint Petersburg University. Earth Sciences, 65(1). doi: 10.21638/spbu07.2020.101.

Issue

Vol. 65 No. 1 (2020)

Section

Articles

License

Articles of "Vestnik of Saint Petersburg University. Earth Sciences" are open access distributed under the terms of the License Agreement with Saint Petersburg State University, which permits to the authors unrestricted distribution and self-archiving free of charge.