6 (34) 6. REGARDING THE USE OF BENTONITE CLAYS FROM THE CHERKASY DEPOSIT FOR SAFE RADIOACTIVE WASTE DISPOSAL IN NEAR-SURFACE LOW LEVEL WASTE STORAGE FACILTIES: RESEARCHES ON SORPTION PROPERTIES OF BENTONITES

B. Shabalin, K. Yaroshenko, O. Marinich, I. Koliabina, N. Mitsiuk, S. Buhera

Shabalin B.G., D.Sc. (Geol.), Head of Department, State Institution “The Institute of Environmental Geochemistry of National Academy of Sciences of Ukraine”, ORCID: 0000-0002-6425-5999, b_shabalin@ukr.net

Yaroshenko K.K., Ph.D. (Engin.), Researcher, State Institution “The Institute of Environmental Geochemistry of National Academy of Sciences of Ukraine”, ORCID: 0000-0002-7180-4642: igns.yaroshenko@gmail.com

Marinich O.V., Ph.D. (Geol.), Head of group, State Specialized Enterprise “Central Enterprise for Management of Radioactive Waste”, ORCID: 0000-0002-2389-9341, olhamarinich@gmail.com

Koliabina I.L., Ph.D. (Geol.), Senior Researcher, Institute of Geological Sciences of National Academy of Sciences of Ukraine, ORCID: 0000-0002-6120-4491, kolira_igns@i.ua

Mitsiuk N.B., Junior Researcher, State Institution “The Institute of Environmental Geochemistry of National Academy of Sciences of Ukraine”, ORCID: 0000-0003-3875-007X, nmitsiuk@gmail.com

Buhera S.P., Researcher, State Institution “Institute of Environmental Geochemistry, National Academy of Sciences of Ukraine”, ORCID: 0000-0001-9968-7591: sergii.bugera@gmail.com

 

Abstract

The article is devoted to the study of the barrier properties of bentonite clays from the Cherkasy deposit (Ukraine) as the most promising material for engineered barriers in near-surface disposal facilities for low-level radioactive waste.
The work presents a description of the Cherkasy bentonite deposit, in particular, of the most promising II layer of the Dashukivka site, and the composition and properties of the natural and soda-modified (PBA20) bentonites which can be used for safe long-term storage and disposal of radioactive waste. The scanning electron microscope (SEM) images of the samples were made and the chemical and mineral composition of the samples was determined. Based on the obtained data, the Dashukivka bentonite was classified as Al-Fe-montmorillonit. The main rock-forming minerals of the bentonite are montmorillonite (75 ± 3 wt. %) and quartz (20 – 25 wt. %). Infrared spectra of the bentonites in the range of 4000 – 400 cm-1 are typical for dioctahedral Al-smectites and are almost identical both for the natural and modified samples. The derivatographic analysis (DTA) of the bentonite samples allows us to conclude that the modified bentonite PBA-20 has greater thermal stability than the natural bentonite. The total weight loss of the samples is about 10.3% and 17.8%, respectively. From the experimental study of 137Cs adsorption from a simulated ChEZ water solution (mineralization – 0.2 g/dm3), it was found that the equilibrium in the sorbent-solution system is established within 12 to 14 h, and the degree of adsorption on the modified bentonite PBA-20 reaches 93%. The degree of adsorption on the natural bentonite is 7 – 10% lower. Analysis of the partition coefficients (Kd) also indicates a higher efficiency of the Na-modified bentonite compared to the natural, and that ion exchange is the main mechanism of caesium adsorption. Increasing of the pH of the initial solution results only in a slight increase of the degree of adsorption. The degree of 137Cs adsorption on Na-modified bentonite is practically independent of the initial concentration of Ca2+ (from 16 to 160 mg/dm3) and Na+ (from 6 to 60 mg/dm3) in the solution. However, 137Cs adsorption on natural bentonite decreases with the increase in Na+ concentration. Thus, the bentonite clays from the Cherkasy deposit (Dashukivka site, II layer) having good barrier properties can be recommend as anti-migration engineered barriers for radioactive waste repositories, in particular, near-surface storage facilities I and II line of Vector complex.

Key words: Chornobyl Catastrophe, overcoming strategy, “Shelter” Object, radioactive contamination, lava-like fuel-containing materials, radioecological issues, radiohydrogeoecological monitoring, radioactive waste disposal and temporary storage facilities, Americium-241.

 

Article

Reference

  1. Verkhovna Rada of Ukraine (2019), Decree 208-IX of 17.10.2019: Pro vnesennia zmin do deiakykh zakonodavchykh orhaniv Ukrainy shchodo vdoskonalennia zakonodavstva z pytanʹ povodzhennia z radioaktyvnymy vidkhodamy. Kyiv, UA.
  2. Ministry of Health of Ukraine, Decree No. 54 of 02.02.2005: Pro zatverdzhennya derzhavnykh sanitarnykh pravyl “Osnovni sanitarni pravyla zabezpechennya radiatsiynoyi bezpeky Ukrayiny “. Kyiv, UA. 167 p.
  3. On nuclear and radiation safety in ukraine for 2019(2020).  SNRIU. Kyiv, UA. 71 p. URL:https://snriu.gov.ua/storage/app/sites/1/docs/Annual%20Reports/Annual%20reports%20SNRIU/Annnual_Report_2019_EN.pdf
  1. Monitoring of geological disposal facilities. Technical and societal Aspects. NEA Report № NEA/RWM/R(2014)2. Paris, France. 72 р. URL: https://one.oecd.org/document/NEA/RWM/R(2014)2/en/pdf (дата звернення 23.07.2021 р.)
  2. Shabalin, B.G., Lavrynenko, O.M., Kosorukov, P.O., Buhera, S.P. (2018), Zhurnal, Kyiv, UA,Vol. 40 No. 4, pp. 65–78.
  3. Shabalin, B.G. (2019), Ekolohichna bezpeka ta tekhnolohii zakhystu dovkillia, Kyiv, UA, No. 1, pp. 60–69.
  4. Yaroshenko K.K., Shabalin B.G., Koliabina I.L., Bondarenko G.M. (2019), Proceedings of the XVth International Scientific and Practical Conference “Environmental safety and solutions”, Kharkiv, UA, pp. 309–314.
  5. Grim, R. (1967), Mineralogiya i prakticheskoye ispolzovaniye glin. Mir, Moscow, RF, 512 p.
  6. Drits V.A., Kossovskaya A.G. (1980), Litologiya i poleznyye iskopayemyye, Kyiv, UA, 10, pp. 3–23.
  7. PDF-2. Powder diffraction file, 2003, Database.
  8. Tarasevych, Yu.I. (1968), Chim.Zhurn., Kyiv, UA, Vol. 34 No. 5, pp. 439–446.
  9. Okumura, M., Kerisitb, S., Bourgc, I. C. et al. (2018), Radiocesium interaction with clay minerals: Theory and simulation advances Post–Fukushima, Journal of Environmental Radioactivity, 189, pp. 135–145.
  10. Essington, E.(2004), Soil and Water Chemistry. CRC Press, New York, USA, 534 p.
  11. Osipov, V.I., Sokolov, V.N. (2013), Gliny i ikh strukturniye svoistva. Sostav, stroyeniye i formirovaniye svoystv. GEOS, Moscow, RF, 576 p.
  12. Konopliev, A.V., Konoplieva, I.V. (1999), Geokhimiya, Moscow, RF, 2, pp. 207–214.
  13. Krupskaya V.V., Zakusin S.V., Tyupina Ye.A, Chernov M.S. (2016), Gornyy zhurnal, Petersburg, RF, No. 2, pp. 81–87.
  14. Sanzharova, N.I., Sysoyeva, A.A., Isamov, N.N. et. al. (2005), Rossiyskiy khimicheskiy zhurnal, Moscow, RF, Vol. 49 3, pp. 26–34.
  15. Tarasevych, Yu.I. (1988), Stroyeniye i khimiya poverkhnosti sloistykh silikatov. Dumka, Kyiv, UA, 248 p.
  16. Erdeyi-Gruz, T. (1976), Yavleniya perenosa v vodnykh rastvorakh. Mir, Moscow, RF, 592 p.
  17. Davydov, Yu.P., Voronik, N.I., Shatylo, N.N., Davydov, D.Yu. (2002), Radiokhimiya, Petersburg, RF,Vol. 44 No. 3, pp. 285–288.
  18. Sabodina, M.N. (2008), The thesis of dissertation for a Candidate’s degree in Radiochemistry. Moscow, RF, 27 p.
  19. Kriterii priyemki radioaktivnykh otkhodov na zakhoroneniye v spetsial’no oborudovannom pripoverkhnostnom khranilishche tverdykh radioaktivnykh otkhodov (SOPKHTRO). Pervyy etap ekspluatatsii SOPKHTRO. Priyem RAO ot ZPZHRO i ZPTRO GSP CHAES dlya zakhoroneniya v dva simmetrichnykh otseka SOPKHTRO. 2009.
  20. Laine, H. and Karttunen, P. (2010), Long-term stability of bentonite – a literature review. Working Report 2010-53, Posiva Oy, Eurajoki, Finland, 132 р.Available from https://inis.iaea.org/collection/NCLCollectionStore/_Public/43/066/43066643.pdf
  21. Neff, D., Elisabeth, M.V., Hostis, V. et al. (2008), Preservation of historical buildings: understanding of corrosion mechanisms of metallic rebars in concrete. Proceedings of “Metal 2007” ICOM-CC Conference, Vol. 4, pp. 30–35.Available from https://hal.archives-ouvertes.fr/hal-02119980/document
  22. 14th Natural Analogue Working Group Workshop (NAWG14) (2015), Abstract Book, Geological Survey of Finland, Olkiluoto, Finland, 169 p. Available from https://tupa.gtk.fi/julkaisu/opas/op_061.pdf