N. I. Pavliuchenko, D. O. Muliar, A. O. Doroshenko
Institute for Safety Problems of Nuclear Power Plants, NAS of Ukraine,
36a, Kirova st., Chornobyl, 07270, Ukraine
Measures of dust suppression are considered, in particular, in the under-roof space of the Shelter object (SO). Methods for assessing the state of the protective polymer coating on the surfaces of the «collapse» of the 4th ChNPP unit and the intercontrophoric surfaces of the under-roofing space are described. The results of a mathematical and statistical analysis of monitoring the activity of radioactive emissions from the SO, the concentration of radioactive aerosols in the surface air layer at the industrial site of the SO are presented, as well as the dynamics of emissions of radioactive aerosols are analyzed. The evaluation of the protective properties of the area and depth of destruction of the coating was carried out and the thickness of the coating on the selected samples (in laboratory conditions) was determined.
According to the results of the research, conclusions were formulated, namely, the polymer coating firmly fixed radioactive dust on the coated surfaces, the growth over time of some of the monitored parameters is not associated with film destruction, there are minor secondary pollution processes, and the existing processes of coating destruction are slow. With the current operation of the Shelter object and without changes in its state, dust suppression measures are not recommended in the short term, as the coverage condition is satisfactory and it performs its protective functions, and the values of the monitored parameters do not exceed the operational limits.
Research contributes to optimizing the schedule of dust suppression sessions, their economic feasibility, because the amount of expensive localizing materials is reduced, the inflow and formation of radioactively polluted water to the New Safe Confinement (NSC) of the SO is reduced, which has a significant economic effect without environmental damage. In the future, it is necessary to continue monitoring the parameters of SO radioactive aerosols, and to assess the state of the protective coating in the sub-roofing and inter-control spaces of the NSC-SO.
The monitoring results should be used when taking decisions on the timing of irrigation with a protective coating, when detecting destruction processes, which result in an increase in the activity of SO radioactive aerosols.
Keywords: dust suppression measures, localizing of the polymeric coverage, standard of enterprise, estimation of the coverage state, radioactive aerosol.
1. Technological regulation of the Shelter object of the reactor unit no. 4 of the Chornobyl NPP: 1R-OU (with changes from 06.07.2016). Slavutych: SSE «Chornobyl NPP», 2011, 71 p. (in Ukr.)
2. Minutes of the working meeting on the issue of dust suppression at the Shelter object of the Chornobyl NPP dated 12.23.2014. Kyiv, 2014. (in Ukr.)
3. STP 3.031-2015. Assessment of the state of protective polymer coating in the under-roof space of the Shelter object. Enterprise standard. Effective from 05.25.2015. Slavutych: SSE «Chornobyl NPP», lip. (in Ukr.)
4. Assessment of the protective polymer coating in the under-roof space of the Shelter object as of 2018. Report on research and development work. ISP NPP, NAS Ukraine. Chornobyl, 2018, 77 p. (in Ukr.)
5. Samoylenko Yu. N., Chernouchenko V. M. (1989). [The use of polymer coatings to improve the radiation situation in the aftermath of the Chernobyl accident]. Proceedings of the Reports of the 1st All-Union Scientific and Technical Meeting on the Results of the Chornobyl Nuclear Power Plant Accident Consequences Elimination (Chornobyl, 1989), vol. 7, part 2, pp. 152-184. (in Russ.)
6. Mamaev L. A., Galkin G. A., Khrabrov S. L. (1989). [Localization of radionuclides in ChNPP], Proceedings of the Reports of the 1st All-Union Scientific and Technical Meeting on the Results of the the Chornobyl Nuclear Power Plant Accident Consequences Elimination. (Chornobyl, 1989), ed. E. I. Ignatenko. Vol. 7, part 1, pp. 226-235. (in Russ.)
7. SIP AOS210 4 SMT 0001 Material for assessing the safety ofMSDS. Contract report SIP05-4-011. Chornobyl, 2006. (in Russ.)
8. Bogatov S. A., Evstratenko A. S., Simanovskaya I. Ya. (2001). [Enhance the safety of the Shelter by expanding the dust suppression system], Problemy Chornobylia [Problems of Chornobyl], vol. 8, pp. 35-38. (in Russ.)
9. Assessment of the effectiveness of the upgraded dust suppres-
sion system and its impact on the radiation environment inside the Shelter and the environment at the commissioning stage. Report of the ISTC «Shelter» of the NAS of Ukraine. Chornobyl, 2003, 34 p. (in Russ.)
10. SIP 09-2-001 N103 RPT 005 02. Characterization of samples of the protective film coating of the Shelter object under-roofing space. Contract report SIP09-2-001-HOSR-005. Chornobyl, 2010, 136 p. (in Russ.)
11. Conducting research localizing polymer coating in the Shelter object roofing space to assess its physical, mechanical and protective properties. Report of the ISP NPP NAS of Ukraine no. 0112U005383. Chornobyl, 2012, 173 p. (in Russ.)
12. SIP AOS1 080 MR0001 of 17.11.2004. Results of the first test cycle MSDS. Contract report SIP05-4-011. Chornobyl, 2004. (in Russ.)
13. SIP AOS2024 SMT 00 01 of 26.06.2005. Test results of the MSDS during the spring period. Contract report SIP05-4-011. Chornobyl, 2005. (in Russ.)
14. SIP AOS2 03 4 SMT 00 01 of 03.11.2005. Test results of the MSDS during the summer period. Contract report SIP05-4-011. Chornobyl, 2005. (in Russ.)
15. TU U24.6-25661375-001-2004 (TU95 2850-2004). Dust suppression polymer compositions. Technical conditions, (in Russ.)
17. Ovchinnikov A. K. (1974). Instruktsiya po gamma-karo-tazhu pri poiskakh і razvedke uranovykh mestorozhdeniy [Instructions for gamma logging when searching and prospecting for uranium deposits], Moscow: Ministry of Geology of the USSR, 108 p. (in Russ.)
19. ISP NPP NAS of Ukraine (2017). Control of fugitive emissions from the Shelter and aerosol conditions during the construction of the NSC. Final report on contract no 372/17. Chornobyl, 186 p. (in Russ.)
20. ISP NPP NAS of Ukraine (2018). Scientific and technical support at the stages of commissioning and operation of the NSC-SO (aspects of nuclear and radiation safety). Final report on contract no 372/18. Chornobyl, 175 p. (in Russ.)
21. Ogorodnikov В. I., Pazukhin E. M., Klyuchnikov A. A. (2008). Radioaktivnye aerozoli objekta «Ukrytie»: 1986-2006 gg [Radioactive aerosols of the Shelter object: 1986-2006.]. Chornobyl: ISP NPP NAS of Ukraine, 456 p. (in Russ.)
22. About the state of safety of the Shelter object. Report of SSE «Chornobyl NPP». Slavutych, 1998-2018. (in Ukr.)
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