Dynamics of Changing of Volumes and Radiation Properties of Radioactive Contaminate Water in the Shelter Object in the Condition of New Safety Confinement

O. O. Odintsov, V. Е. Khan, L. А. Palamar,
P. V. Sabenin, L. B. Chikur

Institute for Safety Problems of Nuclear Power Plants,
NAS of Ukraine, 36a, Kirova st., Chornobyl, 07270, Ukraine

DOI: doi.org/10.31717/2311-8253.21.2.10

Abstract

In November 2016 the “Arch” of the New Safe Confinement (NSC) was installed into design position over the Shelter object (SO). Installation of the NSC in design position stipulated the changes of the mode of water inflow into underroof space of the SO. The conditions of the SO rooms ventilation as well as temperature-humidity conditions have changed inside the SO. It resulted in the considerable changes of formations conditions of the radioactively contaminated water (RCW) unorganized accumulations in the complex NSC–SO rooms. Aim of the work is to study the dynamics of changes of RCW volumes, concentration of uranium, macrocomponets, as well as radionuclides activity concentration in the RCW unorganized accumulations in rooms at the bottom marks of the SO under conditions of the NSC operation for 2017−2020. Experimental data on the determination of the volumes and radiation characteristics of radioactively contaminated water in unorganized accumulations of liquid radioactive waste at the bottom marks of the SO after the NSC installation into the design position are presented. The biggest accumulations of RCW are in the room 001/3 at the mark −2.60 m. Volume of the accumulation is approximately 270 m³. During the last decade a water level at the control point is about 1.1 m and does not change practically. During December 2016 – June 2020 the volume of radioactively contaminated water in rooms 017/2, 012/5–8 and 012/13–16 decreased by more than 10 times. In rooms 009/4, 013/2, 014/2 and 210/5–7, the water has dried completely. A decrease of radioactively contaminated water volume occurs due to the evaporation of water during the autumn-winter seasons and is not compensated by the formation of condensation moisture in the summer. Due to the water evaporation, concentrations of macrocomponents and uranium, as well as the activity concentration of radionuclides ⁹⁰Sr, ¹³⁷Cs, ^154,155Eu, ^238,239,240Pu, ²⁴¹Am and ²⁴⁴Cm in the radioactively contaminated water increased significantly. The activity concentrations of radionuclides are ⁹⁰Sr — n ∙ 10⁹, ¹³⁷Cs — n ∙ 10¹⁰, ¹⁵⁴Eu – n ∙ 10⁶, ^{239 + 240}Pu – n ∙ 10⁶, ²⁴¹Am — n ∙ 10⁷, ²⁴⁴Cm — n ∙ 10⁵ Bq/m³. As a result of drying out of radioactively contaminated water accumulations, highly active deposits are formed, which are a source of radioactive aerosols in the rooms of the SO. During water evaporation there is an increase of RCW alkaline, рН increases to the values of 9.5–10.2. It is due to the increase of concentration of carbonates of CO₃ ²– and hydro carbonates of HCO₃ – in water.

Keywords: Shelter object, radionuclides, uranium, liquid radioactive waste, New Safe Confinement.

References

1. Bogatov S. A., Korneev A. A., Krynitsyn A. P., Strikhar O. L., Shherbin V. N. (2000). [Researches of water streams inside the Shelter object]. Radiokhimiya [Radiochemistry], vol. 42, no. 3, pp. 276–280. (in Russ.)

2. Koreneev A. A., Krinitsyn A. P., Strikhar O. L., Shcherbin V. N. (2002). [Liquid radioactive waste inside the Shelter object]. Radiokhimiya [Radiochemistry], vol. 44, no. 6, pp. 545–552. (in Russ.)

3. Krinitsyn A. P., Strikhar O. L., Shcherbin V. N. (2003). [The problem of handling the liquid radioactive waste of the Shelter object]. Radiokhimiya [Radiochemistry], vol. 45, no. 5, pp. 461–465. (in Russ.)

4. Odintsov A. A., Khan V. E., Krasnov V. A., Pazukhin E. M., Shcherbin V. N. (2009). [Transuranium elements in liquid radioactive waste of the Shelter object]. Radiokhimiya [Radiochemistry], vol. 51, no. 4, pp. 337–343. (in Russ.)

5. Odintsov A. A., Khan V. E., Krasnov V. A., Shcherbin V. N. (2016). [Long-term monitoring of unorganized accumulations of liquid radioactive waste at the Shelter object]. Problemy bezpeky atomnykh elektrostantsiy i Chornobylya [Problems of Nuclear Power Plants’ Safety and of Chornobyl], vol. 27, pp. 43–58. (in Russ.)

6. Odintsov A. A., Khan V. E. (2018). [Radioactive water in the Shelter object after installing the “Arch” of the New Safe Confinement into design position]. Problemy bezpeky atomnykh elektrostantsiy i Chornobylya [Problems of Nuclear Power Plants’ Safety and of Chornobyl], vol. 30, pp. 67–77. (in Russ.)

7. Borovoy A. A. (2009). [Nuclear safety of water accumulations in the Shelter object]. Atomnaya energiya [Atomic Energy], vol. 107, no. 2, pp. 91–95. (in Russ.)

8. Odintsov O. O., Khan V. E., Ogorodnikov B. I. (2011). [Control of radiation hazard factors in room 001/3 of the Shelter object]. Problemy bezpeky atomnykh elektrostantsiy i Chornobylya [Problems of Nuclear Power Plants’ Safety and of Chornobyl], vol. 15, pp. 96–102. (in Russ.)

9. Rudenko L. I., Gumennaya O. A., Khan V. E., Dzhuzha О. V. (2009). [The mechanism of purification of liquid radioactive waste from transuranium elements and uranium by the method of complexation and ultrafiltration]. Dopovidi NANU [Reports of NАSU], vol. 11, pp. 145–148. (in Russ.)

10. Lagunenko A. S., Khan V. Ye., Odintsov O. O., Kovalchuk V. P., Kravchuk T. A., Kalinovskiy A. K., Kashpur V. O., Svirid O. A., Tkach A. V., Yurchuk S. V. (2019). [Radioactive aerosols in 2017–2018 near lava-like fuel containning materials in premise 012/7 of the Shelter object]. Yaderna energetyka ta dovkillia [Nuclear Power and the Environment], vol. 13, no. 1, pp. 83–90. doi: 10.31717/2311–8253.19.1.10. (in Russ.)

11. Lagunenko А. S., Khan V. Е., Odintsov O. O., Kalinovskiy А. К., Kovalchuk V. P., Kravchuk Т. А., Filipov O. В., Popov M. M.. (2019). Radioactive aerosols near lava-like fuel contained materials in premise 012/15 of Shelter object in 2017–2018 гг. Yaderna energetyka ta dovkillia [Nuclear Power and the Environment], vol. 14, no. 2, pp. 31–38. (in Russ.)

12. Ageyev V. A., Odintsov O. O., Sajeniouk A. D. (2005). Routine radiochemical method for the determination of ⁹⁰Sr, ²³⁸Pu, ^239+240Pu, ²⁴¹Am and ²⁴⁴Cm in environmental samples. J. Radioanal. Nucl. Chem., vol. 264, no. 2, pp. 337–342.

13. Odintsov O. O., Pazukhin E. M., Khan V. E. (2005). [Method for the simultaneous determination of the content of uranium and transuranic elements in groundwater and liquid radioactive waste of the Shelter object]. Radiokhimiya [Radiochemistry], vol. 47, no. 5, pp. 467–471. (in Russ.)

14. Garrels R. M., Christ C. L. (1965). Solutions, Minerals, and Equilibria. San Francisco: Freeman, Cooper & Co., 450 p.

15. Rudenko L. I., Dzhuzha O. V., Khan V. E. (2007). [Transuranium elements in liquid radioactive waste of the Shelter object]. Dopovidi NANU [Reports of NАSU], vol. 10, pp. 142–146. (in Russ.)

Full Text(PDF)