Ядерна фізика та енергетика Nuclear Physics and Atomic Energy   ISSN: 1818-331X (Print), 2074-0565 (Online)   Publisher: Institute for Nuclear Research of the National Academy of Sciences of Ukraine   Languages: Ukrainian, English   Periodicity: 4 times per year   Open access peer reviewed journal

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O. O. Odintsov^*, L. A. Palamar, L. B. Chikur

Institute for Safety Problems of Nuclear Power Plants, National Academy of Sciences of Ukraine, Chornobyl, Ukraine

^*Corresponding author. E-mail address: ooodin@ukr.net

Abstract: The results of experimental determination of the forms of uranium and radionuclides ⁹⁰Sr, ¹³⁷Cs, ¹⁵⁴Eu, ²³⁸Pu, ^239+240Pu, ²⁴¹Am, and ²⁴⁴Cm in the bottom sediments of the premises 001/3 of the "Shelter" object are presented. By the sequential extraction procedure, the following amounts are determined: water-soluble, exchange, carbonate, and acid-soluble forms of uranium, fission products (⁹⁰Sr, ¹³⁷Cs, ¹⁵⁴Eu), and transuranium elements (²³⁸Pu, ^239+240Pu, ²⁴¹Am, ²⁴⁴Cm) in the bottom sediments in the premises 001/3 on a mark of -2.60 m of auxiliary systems of the reactor compartment of the "Shelter" object. The concentration of uranium in the bottom sediments of room 001/3 is 3.1 ± 0.5 g/kg. Specific activity of ⁹⁰Sr, ¹³⁷Cs in the bottom sediments is within the range of 6·10⁸ - 1·10⁹ Bq/kg, and ^239+240Pu and ²⁴¹Am within the range of 6·10⁵ - 8·10⁶ Bq/kg. Radionuclides ⁹⁰Sr, ¹³⁷Cs, ¹⁵⁴Eu, ²³⁸Pu, ^239+240Pu, ²⁴¹Am, ²⁴⁴Сm in the bottom sediments are in different chemical forms that will define their different potential mobility. Uranium and ¹³⁷Cs in the bottom sediments of premises 001/3 mainly are in exchange forms. The amount of water-soluble forms of uranium and cesium is 1.5 - 3 %. The basic amount of ⁹⁰Sr, more than 60 %, is carbonate soluble in a weak acid at рН 4.8. More than 65 % of ²³⁸Pu and ^239+240Pu in the bottom sediments are in acid-soluble forms. The mobility of ¹⁵⁴Eu, ²⁴¹Am and ²⁴⁴Cm in the bottom sediments is much higher than that of plutonium; at pH 4.8 more than 40 % of ²⁴¹Am go to soluble state. The ratio between the activities of ¹³⁷Cs/⁹⁰Sr, ⁹⁰Sr/^239+240Pu, ²⁴¹Am/^239+240Pu, and ²⁴⁴Cm/^239+240Pu in the bottom sediments considerably differ from the analogical relations of radionuclides in a fuel containing materials of the "Shelter" object.

Keywords: uranium, ¹³⁷Cs, ⁹⁰Sr, plutonium, americium, sequential extraction, speciation of radionuclides, bottom sediments, "Shelter" object.

1. A.A. Korneev et al. Liquid radioactive waste inside the "Shelter" object. Radiokhimiya 44(6) (2002) 545. (Rus)

2. A.P. Krinitsyn, O.L. Strikhar, V.N. Shcherbin. The problem of handling liquid radioactive waste from the "Shelter" object. Radiokhimiya 45(5) (2003) 461. (Rus) https://doi.org/10.1023/A:1026276329238

3. A.A. Odintsov et al. Transuranium elements in liquid radioactive waste from the "Shelter" object. Radiokhimiya 51(4) (2009) 337. (Rus) https://doi.org/10.1134/S1066362209040109

4. A.A. Borovoy. Nuclear safety of water accumulations in the "Shelter" object. Atomnaya Energiya 107(2) (2009) 91. (Rus) https://doi.org/10.1007/s10512-009-9205-3

5. O.O. Odintsov, V.E. Khan, B.I. Ogorodnikov. Control of factors of radiation danger of apartment 001/3 object "Ukryttya". Problemy Bezpeky Atomnyh Elektrostantsiy i Chornobylya (Problems of Nuclear Power Plants and of Chornobyl) 15 (2011) 96. (Rus) http://www.ispnpp.kiev.ua/wp-content/uploads/2017/2011_15/c96.pdf

6. O.O. Odintsov et al. Long-term monitoring of the unorganized accumulations liquid radioactive wastes of object "Ukryttya". Problemy Bezpeky Atomnyh Elektrostantsiy i Chornobylya (Problems of Nuclear Power Plants and of Chornobyl) 27 (2016) 43. (Rus) http://www.ispnpp.kiev.ua/wp-content/uploads/2017/2016_27/c43.pdf

7. L.I. Rudenko, V.Ya. Sklyar, V.E. Khan. Purification of liquid radioactive waste from the "Shelter" object from transuranium elements, Sr and γ-emitters. Radiokhimiya 46(2) (2004) 184. (Rus) https://doi.org/10.1023/B:RACH.0000024951.07434.47

8. L.I. Rudenko et al. The mechanism of purification of liquid radioactive waste from transuranium elements and uranium by complex formation and ultrafiltration. Dopovidi NAN Ukrayiny 11 (2009) 145. (Rus)

9. O.O. Odintsov, V.E. Khan. Radioactive water in object "Ukryttya" after pulling down of "Arch" of NEV safe confinement in project statute. Problemy Bezpeky Atomnyh Elektrostantsiy i Chornobylya (Problems of Nuclear Power Plants and of Chornobyl) 30 (2018) 67. (Rus) https://doi.org//10.31717/1813-3584.18.30.8

10. F.I. Pavlotskaya. Migration of Radioactive Products of Global Fallout in Soils (Moskva: Atomizdat, 1974) 216 p. (Rus)

11. А. Tessieer, P.G.C. Campbell, M. Bisson. Sequential extraction procedure for the speciation of particulate trace metals. Anal. Chem. 51(7) (1979) 844. https://doi.org/10.1021/ac50043a017

12. O.O. Odintsov, A.D. Sazhenyuk, V.A. Satsyuk. Association of ⁹⁰Sr, ¹³⁷Cs, ^239+240Pu, ²⁴¹Am, and ²⁴⁴Cm with Soil Adsorbing Complex in Soil Typical of the Vicinity of the Chernobyl NPP. Radiochemistry 46(1) (2004) 95. https://doi.org/10.1023/B:RACH.0000024644.05926.da

13. V.P. Protsak, O.O. Odintsov. Estimation of the forms of Chornobyl radionuclides in the bottom sediments of the Chornobyl cooling reservoir. Yaderna Fizyka ta Energetyka (Nucl. Phys. At. Energy) 15(3) (2014) 259. (Ukr) https://jnpae.kinr.kyiv.ua/15.3/Articles_PDF/jnpae-2014-15-0259-Protsak.pdf

14. A.A. Odintsov, E.M. Pazukhin, V.E. Khan. Method for simultaneous determination of the content of uranium and transuranium elements in groundwater and liquid radioactive waste of the "Shelter" object. Radiokhimiya 47(5) (2005) 467. (Rus) https://doi.org/10.1007/s11137-005-0130-6

15. A.A. Borovoy et al. Determination of the nuclear-physical characteristics of the fuel of the 4th power unit of the Chernobyl Nuclear Power Plant. Report of the Nuclear Safety Institute of the Russian Academy of Sciences, Inv. No. 52/11-20 (Moskva, 1991). (Rus)

16. V.A. Rabinovich, Z.Ya. Khavin. Brief Chemical Guide (Leningrad: Khimiya, 1978) 392 p. (Rus)

17. A.N. Nesmeyanov. Radiochemistry (Moskva: Khimiya, 1978) 560 p. (Rus)