CONTROL OF THE REMEDIATION STATE OF THE REMEDIATED MECSEK URANIUM MINE WITH BIOMONITORING PhD Theses MÁTÉ BORBÁLA Doctoral School in Chemical Engineering and Materials Sciences Supervisor: DR. KOVÁCS TIBOR Associate professor University of Pannonia Institute of Radiochemistry and Radioecology Veszprém, 2012.
ABSTRACT The risk of the contamination originated by the industrial waste or by-products continues existing even after the origination and remediation. The special type of the waste and byproducts is called NORM, which contains radionuclides with elevated concentration. The measurement and the follow-up tracking of certain radionuclides are not viable with traditional chemical methods. In case of these circumstances the parallel chemical properties cannot be applied. The remediated uranium mine in Mecsek Mountains (Hungary) is also a NORM site. The result of the uranium ore processing, the originated rock-refuse had been deposited in waste dumps and tailing ponds. Very near to the objects two water resources and agricultural sites can be found which in case of incidental radionuclide migration would risk the elevation of radiation dose. On the basis of the obtained results of the last ten years it can be stated that the isotopic equilibrium among the U-238, Ra-226 and Pb-210 is broken demonstrating Pb-210 activity concentration surplus. 1
THESES 1. On the basis of the ordained annual soil control surveys of the remediated site and the chemical and physical behaviour of the radio nuclides it can be stated that among the examined U-238, Ra-226 and Pb-210 isotopes the Pb-210 isotope provides the most significant information for the follow-up tracking of the after-remediation migration processes. a. On the basis of 350 samples taken from the tailing ponds, waste rock piles and their vicinities (examined with gamma-spectrometry) it can be stated that the isotopic equilibrium among the U-238, Ra-226 and Pb-210 is broken with Pb-210 activity concentration surplus in horizontal and vertical direction as well. The reason of disequilibrium can be explained by the Rn-222 emanation and migration. b. According to 200 not selected, homogenised plant community and soil samples (measured by gamma-spectrometry), explicit correlation cannot be observed. Since the homogenised plant sample consists of numerous species the activity concentration of the examined isotope is quite stable in the sample. Therefore the author suggests on species as bio indicator. Furthermore the gamma-spectrometric method has high detection limit therefore the author proposes a more sensitive measurement technique. 2. Owing to the biodiversity of the cover vegetation considerable deviation can be observed in the case of the Pb-210 concentration. Due to that fact the examination of a single selected plant species is effective. In the light of the circumstances the tobacco plant is recommended as bioindicator species by the author. On the one hand the tobacco plant has optimal physiological features which are supported by the examination of 53 tobacco plants. The analysis of the different parts of the tobacco has proved that saturation curve shape correlation can be found between the lower leaves and the soil. The correlation can be defined with the following empirical equitation: Where: A l 99 (1 e 0,01 (A A l : the Pb-210 activity concentration of the lower leaves (mbq/g) A t : the Pb-210 activity concentration of the soil (mbq/g) t 21) ) 3. In the case of freshly collected samples of two years the Pb-210 was in equilibrium state with the Po-210. Therefore the determination of Pb-210 with gamma-spectrometry can be substituted with the Po-210 isotope determination via alpha spectrometry. However the sample preparation method for alpha-spectrometry is relatively difficult, but to get an adequate routine it can be applied with low detection limit and uncertainty. Above all, this method requires a small sample amount. 2
4. On the basis of afore-mentioned equitation it can be stated that quasi-linear relationship can be found in low range (20-100 mbq/g) of the surveyed lower leaves. Due to the radiological features of the surveyed site the quasi-linear range is the indication range with which it could be indicated the trace impurities from the tailing ponds and waste rocks. 3
PUBLICATIONS IN CONNECTION WITH THESIS Kovács Tibor, Somlai János, Máté Borbála: Növény- és gombaminták 210 Po- és 210 Pbkoncentrációjának meghatározása alfa-spektrometriai módszerrel. MAGYAR TUDOMÁNY 2: pp. 146-151. (2012) Borbála Máté, Mária Horváth, János Somlai, László Kovács, Tibor Kovács: 210 Po activity concentration of blood samples after the radon inhalatoric therapy. RADIATION EMERGENCY MEDICINE 1:(1-2) pp. 121-126. (2012) B Mate, A Csordas, M Horvath, J Somlai, T Kovacs: Pb(Po)-210 concentration of tobacco samples grown in the vicinity of a remedied uranium mine. RADIOPROTECTION 46:(6) pp. S161-S165. (2011) IF: 0.862 V Jobbagy, N Kavasi, J Somlai, B Mate, T Kovacs: Radiochemical characterization of spring waters in Balaton Upland, Hungary, estimation of radiation dose to members of public. MICROCHEMICAL JOURNAL 94:(2) pp. 159-165. (2010) IF: 2.480 B. Máté, M. Horváth, J. Somlai, T. Kovács: Using tobacco plant as bioindicator of the contaminated NORM areas. In. Miroslaw Janik, Masahiro Hososa, Atsuyuki Sorimachi, Shinji Tokonami (szerk.) International Symposium on Natural Radiation Exposures and Low Dose Radiation Epidemiological Studies. Hirosaki, Japán, 2012.03.01-2012.03.03.Hirosaki University, 2012. p. 113. Borbala Mate, Maria Horvath, Anita Csordas, Janos Somlai, Tibor Kovacs: Pb(Po)-210 levels of tobacco and soil samples at remedied uranium mine. In: Dumitru Ristoiu, Melinda-Haydee Kovacs, Adrian Piticar, Andreea Dragus (szerk.) International Conference Environment & Progress: Environment - Research, Protection and Management. Cluj-Napoca, Románia, 2011.11.11-2011.11.12.Cluj-Napoca: p. 79.(ISBN:1584-6733) Mate Borbala, Csordas Anita, Horvath Maria, Somlai Janos, Kovacs Tibor: Pb(Po)-210 concentration of tobacco samples grown in the vicinities of a remedied uranium mine. ICRER2011, Hamilton, Canada, 19-24. 06. 2011. (2011) Máté B, Csordás A, Horváth M, Somlai J, Kovács T: Remediált uránbánya környékén termesztett dohányminták Po-210 koncentrációja. In: Szentmiklósi L (szerk.) Őszi Radiokémiai Napok 2010. Keszthely, Magyarország, 2010.10.20-2010.10.22.Keszthely: Magyar Kémikusok Egyesülete, p. 69.(ISBN:978-963-9970-07-6) FURTHER PUBLICATIONS Kovács Tibor, Máté Borbála, Csordás Anita, Somlai János: Development a low level radon measurement system based on pulse shape discriminating NDI detector. In: Kovács Tibor, Somlai János, Szabó Csaba (szerk.) VI. Magyar Radon Fórum: A Radon a Környezetben Nemzetközi Workshop. Veszprém, Magyarország, 2011.05.16-2011.05.17. Veszprém: Pannon Egyetemi Kiadó, pp. 255-259.(ISBN:978-615-5044-51-9) Borbála Máté, Mária Horváth, János Somlai, László Kovács, Tibor Kovács: 210 Po activity concentration of blood samples after the radon inhalatoric therapy. In: Prof Dr Goran Ristic (szerk.) Conference Environment & Progress: Environment - Research, Protection and Management. Cluj-Napoca, Románia, 2011.11.11-2011.11.12. Cluj-Napoca: p. 78.(ISBN:1584-6733) 4
Somlai János, Vincze Miklós, Máté Borbála, Kovács Tibor: Jelalak elválasztáson alapuló alacsony hátterű radon mérőműszer fejlesztése. In: Kovács Tibor, Somlai János (szerk.) II. Földkérgi radioizotópok a környezetünkben: Környezetvédelmi Konferencia Kiadványa. Veszprém, Magyarország, 2010.05.12-2010.05.13. Veszprém: Pannon Egyetemi Kiadó, pp. 105-113.(ISBN:978 615 5044 05 2) Máté B, Kovács T, Jobbágy V: Determination of Uranium Isotopic Ratio in Surface and Mineral Waters around Different Mining Sites in Carpathian Region. In: Kovács Tibor, Somlai János (szerk.) II. Földkérgi radioizotópok a környezetünkben: Környezetvédelmi Konferencia Kiadványa. Veszprém, Magyarország, 2010.05.12-2010.05.13. Veszprém: Pannon Egyetemi Kiadó, pp. 31-38.(ISBN:978 615 5044 05 2) Csordás Anita, Horváth Mária, Máté Borbála, Somlai János, Kovács Tibor: A déli-bakonyból származó ehető gombafajok Po-210 koncentrációjának meghatározása. In: Kovács Tibor, Somlai János (szerk.) II. Földkérgi radioizotópok a környezetünkben: Környezetvédelmi Konferencia Kiadványa. Veszprém, Magyarország, 2010.05.12-2010.05.13. Veszprém: Pannon Egyetemi Kiadó, pp. 115-123.(ISBN:978 615 5044 05 2) Borbala Mate, Miklos Vincze, Anita Csordas, Janos Somlai, Tibor Kovacs: Development a low level radon measuring system based on pulse shape discrimination. In: Dumitru Ristoiu, Melinda-Haydee Kovacs, Adrian Piticar, Andreea Dragus (szerk.) International Conference Environment & Progress: Environment - Research, Protection and Management. Cluj- Napoca, Románia, 2011.11.11-2011.11.12. Cluj-Napoca: p. 78.(ISBN:1584-6733) J Somlai, Cs Földesi, G Szeiler, B Máté, T Kovács: Seasonal Changes of Radon Concentration Where Building Materials of High Radon Concentration were Used. In: Devasagayam TPA (szerk.) 7th International Conference on High Levels of Natural Radiation and Radon Areas: 7HLNRRA. Mumbai, India, 2010.11.24-2010.11.26. Mumbai: p. 71. Horváth E, Szeiler G, Máté B, Jobbágy V, Somlai J, Kovács T: Balaton-felvidéki forrásvizek összes alfa-béta és Ra-226 koncentrációja és a fogyasztásból származó sugárterhelés becslése. In: Kovács T, Somlai J (szerk.) I. Földkérgi Radioizotópok a Környezetünkben: Környezetvédelmi Konferencia. Veszprém, Magyarország, 2008.05.14 Veszprém: Pannon Egyetemi Kiadó, pp. 119-124. (I.)(ISBN:978 963 9696 48 8) Máté B, Kávási N, Mesterházy D, Somlai J, Kovács T, Szeiler G, Cosma C, Horváth Z: Romániai forrás- és bányavizek rádium és radonkoncentrációjának vizsgálata. In: Szabó Tibor, Bártfai Imre, Somlai János (szerk.) XVII. Környezeti ártalmak és a légzőrendszer. Hévíz, Magyarország, 2007.10.17-2007.10.18. Hévíz: Levegőszennyezés Által Veszélyeztetettekért Alapítvány, pp. 70-79.(ISBN:978 963 87327 1 2) 5