O. S. Lagunenko, V. E. Khan, O. O. Odintsov, O. K. Kalinovskiy, T. A. Kravchuk, V. P. Kovalchuk, P. V. Sabenin, V. O. Kashpur, O. A. Svirid, S. V. Yurchuk
Institute for Safety Problems of Nuclear Power Plants, NAS of Ukraine, 36a, Kirova st., Chornobyl, 07270, Ukraine
DOI: doi.org/10.31717/2311-8253.20.2.7
Abstract
Data on the radionuclide composition, volume activity and dispersity of radioactive aerosols taken in 2017-2018 in room 210/7 of the Chornobyl NPP Shelter, into which the lava-like fuel containing materials (LFCMs) flew after the accident, are presented. Relative air humidity in the room 210/7, depending on a year season, was varying from 40 to 95 %. High humidity (about 90-95 °C) was registered in summer period, when mean daily temperature in the environmental air reached 24-27 °C. In majority of cases, relatively small value of air humidity corresponded to high concentration of radioactive aerosols. High humidity values coincided in time with low values of radioactive aerosol concentrations. Mean daily temperature of room 210/7 air was relatively stable during all survey period. After cold period of year came, it dropped from 17 to 10 °C, and in warm period, when the Shelter was heated, it grew up to 16-17 °C. Such a mode was provided by a huge mass of concrete and metal structures of the Shelter object, and due to the fact that the room 210/7 is located at height elevation +6.00, where air exchange is negligible. It was stated that concentration of beta-radiating aerosol-carriers (90Sr + 90Y and 137Cs) was fluctuating with the range 0.044-16 Bq/m3. Besides, 137Cs share made 62 %. Gamma-spectrometry measurements and radiochemical analyses have demonstrated that average ratios of semi-volatile radionuclide-products of Chornobyl NPP Unit 4 accident in aerosol samples comply with LFCM content in rooms 210/7 of the Shelter. It testifies that LFCM destruction and particular transfer of materials in aerosol state occurs. Their carriers were the aerosols with activity median aerodynamic diameter (AMAD) larger than 5 pm. During 2017-2018, aerosols in room 210/7 were enriched by 137Cs relatively to LFCM located in this place, as it was observed earlier. The sources of additional cesium are 137Cs aerosol-carriers producible, apparently, as result of destruction of surfaces, on which, particles-carriers of condensation cesium were sorbed earlier. Their carriers were the aerosols with AMAD7 pm.
Keywords: Chornobyl accident, Shelter, radioactive aerosols, volume activity, lava-like fuel-containing materials, radionuclide ratios, aerosol dispersity.
References
1. Arutyunyan R. E., Bolshov L. A., Borovoi A. A., Velikhov Ye. P., Klyuchnikov A. A. (2010). Yadernoye toplivo
v obyekte “Ukrytiye” [Nuclear fuel in the Shelter object]. Moscow: Nauka, 240 p. (in Russ.)
2. Bogatov S. A., Borovoy A. A., Kiselev A. N., Obukhova L. A., Checherov K. P. (1991). Otsenka skorosti erozii toplivosoderzhashchikh mass vnutri “Sarkofaga” i kharak-teristiki obrazuyushchikhsya chastits [Estimation of the erosion rate of fuel-containing masses inside the Shelter object and the characteristics of the particles formed]. Moscow: I. V. Kurchatov Institute of Atomic Energy, 21 p. (in Russ.)
3. Bogatov S. A., Borovoy A. A., Yevstratenko A. S., Kheruvi-mov A. N. (1992). Dinamikapovedeniya toplivnykh mass v obyekte “Ukrytiye” [Dynamics of fuel mass behavior in the Shelter object]. Kyiv: V. M. Glushkov Institute of cybernetics, NAS of Ukraine, 20 p. (in Russ.)
4. Kuzmina I. Ye., Tokarevskiy V. V. (1996). Chastitsy dis-persnoy fazy aerozoley obyekta “Ukrytiye” [Particles of the dispersed phase of aerosols of the Shelter object] Prob-lemy Chornobylskoi zony vidchuzhennya [Problems of Chernobyl exclusion zone], vol. 4, pp. 141-150. (in Russ.)
5. Badovskiy V. P., Klyuchnikov A. A., Kravchuk T. A. Me-lenevskiy A. E., Shcherbin V. N. (2009). Issledovani-ye kharakteristik aerozoley v soderzhashchikh toplivo pomeshcheniyakh obyekta “Ukrytiye” [Aerosol characteristic researching in basic fuel-containing premises at object “Ukryttya”] Problemy bezpeky atomnykh elektros-tantsiy i Chornobylia [Problems of Nuclear Power Plants’ Safety and of Chornobyl], vol. 12, pp. 103-112. (in Russ.)
6. Melenevskiy A. E., Badovskiy V. P., Klyuchnikov A. A., Morozov Yu. V., Ushakov I. A., Shcherbin V. N. (2011). Otsenka sostoyaniya poverkhnosti LTSM v realnykh usloviyakh obyekta “Ukrytiye” [Assessment of the surface condition of the LFCM in the real conditions of the Shelter]. Proceedings of the Int. scient. conf. “Twenty-five Years after Chernobyl Accident. Safety for the Future” (April 20-22, 2011, Kyiv, Ukraine), pp. 46-50. (in Russ.)
7. Melenevskiy A. E., Ushakov Y. A., Badovskyy V. P. (2012) Doslidzhennya pyloheneruyuchoi zdatnosti PVM obyekta “Ukryttya” [Investigation of the dust-generating capacity of the Shelter Object FCM]. Problemy bezpeky atomnykh elek-trostantsiy i Chornobylya. [Problems of Nuclear Power Plants’ Safety and of Chornobyl], vol. 18, pp. 119-120. (in Ukr.)
8. Badovskiy V. P., Klyuchnikov A. A., Melenevskiy, A. E. Morozov YU. V., Ushakov I. A., Shcherbin V. N. (2013). Generatsiya toplivosoderzhashchey pyli lavoobraznymi materialami obyekta “Ukrytiye” [Fuel containing dust generation by Shelter object lava materials]. Problemy bezpeky atomnykh elektrostantsiy i Chornobylya. [Problems of nuclear power plants and of Chornobyl], vol. 20, pp. 68-76. (in Russ.)
9. Badovskiy V. P., Melenevskiy A. E., Morozov Yu. V., Ushakov I. A., Shcherbin V. N. (2014). Generatsiya radioaktivnoy pyli lavoobraznymi toplivosoderzhashchimi materialami obyekta “Ukrytiye” Chernobylskoy AES [Generation of radioactive dust by lava-like fuel-containing materials at the Shelter Object of Chernobyl NPP]. Radiokhimiya [Radiochemistry], vol. 56, no. 3, pp. 264-270. (in Russ.)
10. Ogorodnikov B. I., Khan V. Ye., Kovalchuk V. P. (2013). Aerozoli — svideteli razrusheniya lavoobraznykh topli-vosoderzhashchikh materialov v obyekte “Ukrytiye” [Aerosols as evidences of destruction in the Shelter object] Problemy bezpeky atomnykh elektrostantsiy i Chornobylya [Problems of Nuclear Power Plants’ Safety and of Chor-nobyl], vol. 20, pp. 94-106. (in Russ.)
11. Ogorodnikov B. I., Khan V. Ye., Kovalchuk V. P. (2015). Kharakteristiki radioaktivnykh aerozoley bliz skopleniya LTSM v pomeshchenii 012/15 obyekta “Ukrytiye” [Characteristics of radioactive aerosols in 2014 near lavaliked fuel contained materials in premise 012/15 of the Shelter object]. Problemy bezpeky atomnykh elektrostantsiy i Chornobylya [Problems of Nuclear Power Plants’ Safety and of Chornobyl], vol. 25, pp. 125-138. (in Russ.)
12. Ogorodnikov B. I., Khan V. Ye., Kovalchuk V. P., La-gunenko A. S., Dovydkov S. A. (2015). Sostav i kont-sentratsii radioaktivnykh aerozoley v 2013 g. okolo sko-pleniya LTSM v pomeshchenii 210/7 obyekta “Ukrytiye”
[Composition and concentration of radioactive aerosols near lava-like fuel containing materials in premise 210/7 of the Shelter object]. Problemy bezpeky atomnykh elektrostantsiy i Chornobylya [Problems of Nuclear Power Plants’ Safety and of Chornobyl], vol. 24, pp. 70-84. (in Russ.)
13. Pazukhin E. M. (1994). Lavoobraznyye toplivosoderzhash-chiye massy 4-go bloka Chernobyl’skoy AES: topografiya, fiziko-khimicheskiye svoystva, stsenariy obrazovaniya [Lava-like fuel-containing masses of the 4th unit of the Chernobyl nuclear power plant: topography, physicochemical properties, formation scenario]. Radiokhimiya [Radiochemistry], vol. 36, no. 2, pp. 97-142. (in Russ.)
14. Ogorodnikov B. I., Pazukhin E. M., Klyuchnikov A. A. (2008). Radioaktivnyye aerozoli obyekta “Ukrytiye”: 1986-2006 gg. [Radioactive aerosols of the Shelter object: 1986-2006]. Chornobyl: ISP NPP, NAS of Ukraine, 456 p. (in Russ.)
15. Odintsov A. A., Khan V. Ye. (2018). Radioaktivno zagry-aznennaya voda v obyekte «Ukrytiye» posle nadvizhki “Arki” novogo bezopasnogo konfaynmenta v proyektnoye polozheniye [Radioactive water in the Shelter object after pulling down of “Arka” of New safe confinement in design position] Problemy bezpeky elektrostantsiy i Chornobylya [Problems of Nuclear Power Plants’ Safety and of Chornobyl], vol. 30, pp. 67-77. (in Russ.)
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