O. S. Lagunenko, V. Ye. Khan, O. K. Kalynovskyi, V. O. Kashpur,
V. P. Kovalchuk, P. V. Sabenin, O. A. Svirid, A. V. Tkach, S. V. Yurchuk
Institute for Safety Problems of Nuclear Power Plants, NAS of Ukraine,
36a, Kirova st., Chornobyl, 07270, Ukraine
DOI: doi.org/10.31717/2311-8253.20.3.9
Abstract
The results of monitoring of radioactive aerosols emissions from the Shelter object in 2018 are given. The maximum value of «unorganized» release rate was observed in November and was 4.6 kBq/(m2 ∙ day). The completion of construction and sealing of the enclosing contours of the New safe confinement (NSC) in 2018 completely limited the influence of meteorological environmental conditions: precipitation, temperature and wind on the Shelter object. As a result of changes in the temperature and humidity conditions inside the facility, water accumulations of radioactively contaminated water in rooms gradually dry up, air humidity decreases, which in turn helps to increase the secondary dust lift, including from the surfaces of fuel-containing masses. In 2018, the average daily density of radioactive particles precipitation on the light roofing totalled 2.2 kBq/(m2 ∙ day), which was higher than in the previous years. Increase in release of radioactive particles intensity on the Shelter object’s light roofing is provided by implementation of building and assembly works under the NSC Arch. The concentration of sum of long-lived beta-emitting aerosols-carriers (90Sr + 90Y and 137Cs) entering the atmosphere through the Bypass system was within the range of 0.1-2.6 Bq/m3. Besides, 137Cs share was 30%. The particles with 4.3-10 μm active median aerodynamic diameter acted as their carriers. Stable trend is observed in reducing the sum of long-lived beta-emitting aerosols in unorganized releases through «Bypass» system. Airflow movement within «Bypass» system has unstable character. In 2018, airflow direction inside the Shelter object was prevailing. The data on the contamination by radioactive aerosols of the atmosphere surface layer under the NSC Arch are represented.
Keywords: New safe confinement, Shelter object, aerosols, volume activity, activity median aerodynamic diameter.
References
1. Ogorodnikov B. I., Pazukhin E. M., Klyuchnikov A. A. (2008). Radioactivnye aerozoli ob’yekta “Ukrytie”: 1986−2006 gg. [Radioactive aerosols of the Shelter object: 1986−2006]. Chornobyl: ISP NPP, NAS of Ukraine, 456 p. (in Russ.)
2. Lagunenko A. S., Khan V. E., Kalinovskiy A. K., Krasnov V. A., Kashpur V. O., Kovalchuk V. P. (2017). [Monitoring of radioactive aerosol releases from Shelter object within conditions of New Safe Confinement in 2017]. Problemy bezpeky atomnykh elektrostantsiy i Chornobylya [Problems of nuclear power plants’ safety and of Chornobyl], vol. 31, pp. 68−75. (in Russ.)
3. Borovoi A. A., Dovbenko А. А., Markushev V. M. et al. (1989). Radiatsionno-phizitcheskiye kharakteristiki topliva 4-go bloka ChAES i otsenka ikh pogreshnosti [Radiationphysical characteristics of the fuel of 4th power unit of the Chornobyl NPP and estimation of their error]. Chоrnobyl: CE at I. V. Kurchatov Institute of Atomic Energy; inv. no. 11.07-06/172, 115 p. (in Russ.)
4. Research investigation report “Determination of the nuclear-physical characteristics of the fuel of the 4th power unit of the ChNPP”; inv. no. 52/11-20). Moscow IBRAE, NAS of USSR, 1991. (in Russ.)
5. Lagunenko A. S., Khan V. E., Kalinovskiy A. K., Krasnov V. A., Kashpur V. O., Dovyd’kov. S. A. (2017). [Monitoring of releases of radioactive aerosols from Shelter object in 2015−2016]. Problemy bezpeky atomnykh elektrostantsiy i Chornobylya [Problems of nuclear power plants’ safety and of Chornobyl], vol. 29, pp. 69−77. (in Russ.)
6. Garger Ye. K., Kashpur V. A., Korneyev A. A., Kurochkin A. A. (2001). [Experimental estimation of the amount of emission of radioactive aerosols from the openings of the Shelter object]. Proceedings of the Int. conf. “Fifteen years of the Chornobyl accident. Overcoming Experience”. Kyiv, p. 11. (in Russ.)
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