Yu. A. Olkhovik1, Yu. G. Fedorenko1, A. N. Rozko2, S. Yu. Saenko3,
V. A. Shkuropatenko3
1SI “The Institute of Environmental Geochemistry of the National Academy of Sciences of Ukraine”, 34 a, Palladin ave., Kyiv, 03142, Ukraine
2M. P. Semenenko Institute of Geochemistry, Mineralogy and Ore Formation of the National Academy of Sciences of Ukraine, 34, Palladin ave., Kyiv, 03142, Ukraine
3Institute of Solid-State Physics, Materials Science and Technology of the National Science Center “Kharkov Institute of Physics and Technology”, 1, Akademichna st., Kharkiv, 61108, Ukraine
The features of cementation of borate-containing concentrated salt solutions, which, in their composition simulate liquid radioactive solutions of atomic power plants with WWER reactors, are considered. The addition of salts of imitate of crystallization centers in the form of bentonite powder and portland cement in an over-saturated solution (800 g/dm3) promotes the formation of a large number of small crystals of salts, including sodium metaborate, in the compounds.
The purpose of the work was to investigate the effect of temperature and the bentonite during cementation of borate liquid radionuclide radwaste imitation on the normalized indexes of compounds. Tests for compression of samples of compounds were carried out on the electromechanical press of the brand ZD 10/90 (production – Germany), the maximum load – 10 t. Imitation of irradiation was carried out on an electron accelerator LU-10 with energy of 10 MeV, the rate ofleach-ing of stable cesium was determined by an atomic absorption spectrophotometer AA 8500F «Jarrel-H», annealing of samples of compounds – using the device Vick.
The samples of cement compounds that have been synthesized under these conditions have a compressive strength of more than 4.9 MPa, and the satisfactory strength of the samples is preserved after y-irradiation with a dose of 10 kGy and after 30 cycles of freezing-thawing. The visual inspection of irradiated samples of mechanical fracture marks in the form of chips and cracks and color changes did not reveal. The normalized leaching rate of 10-3g/(cm2·d) is achieved on 107-M46 days.
The equations that associate the masses of imitate, water, cement and bentonite salts with the term of the beginning of gripping, the limit of compressive strength and the time of reaching the normalized value during leaching are obtained. The equations allow taking into account the change in the values of the parameters when optimizing the relations between the components.
Keywords: radioactivity, radiation firmness, speed of lixiviating, speed of consolidation, mechanical durability.
1. Kozlov P. V, Slyunchev O. M., Kiryanov K. V. (2011) [Cementing of bottoms of nuclear power plants with the placement of the compound in bulk storages], Atomnaya energiya [Atomic energy], vol. Ill, no. 3, pp. 148-154. (in Russ.)
2. Kozlov P. V, Slyunchev O. M , Smooth S. I. (2009) [Cementation as a method of solidifying liquid radioactive waste], Tsement i yego primeneniye [Cement and its application], vol. 6, pp. 67-72. (in Russ.)
3. Ershov B. G., Yurik T. K. (2008) [Immobilization of medium and high level waste in the cement matrix: the effect of irradiation on the formation of gases and leaching of radionuclides], Voprosy radiatsionnoy bezopasnosti [Radiation Safety Issues], no. 1, pp. 3-15. (in Russ.)
4. Maslov M. V, Gupalo B. C., Chistyakov V. N. (2012) [Investigation of schemes for the management of accumulated radioactive waste in order to prepare them for final isolation], Gornyi informatsionno analiticheskiy byulleten [Mining Information Analytical Bulletin], no. 1, pp. 160— 164. (in Russ.)
5. [Rostov NPP operates an installation for liquid radioactive waste cementation] (17.05.2013) EnergyLand. info. Available at: http://www.energyland.info/analit-ic-show-104136. (in Russ.)
6. RD 306.4.098-2004. Recommendations on the establishment of criteria for the acceptance of conditioned radioactive waste for disposal in near-surface storage facilities. Approved by order of the State Nuclear Regulatory Committee of Ukraine from the no. 160, dated 25.10.2004. (in Ukr.)
7. Criteria for the acceptance of radioactive waste for disposal in a specially equipped near-surface storage facility for solid radioactive waste (SOPSTRV). The first stage of operation of SOPSTRV. Acceptance of radioactive waste from ZPPRW and ZPTRW ofChNPPfor disposal in two symmetric compartments of SOPSTRV. Chornobyl, 2009, 38 p. (in Russ.)
8. GOST R 51883-2002. Waste radioactive cemented. General technical requirements. Moscow, IPK Publishing house of standards, 2002, 7 p. (in Russ.)
9. Novik F. S., Arsov Ya. B. (1980) Optimizatsiya protsessov tekhnologii metallov metodami planirovaniya eksperimen-tov [Optimization of metal technology processes using experimental planning methods], Moscow: Mechanical Engineering; Sofia: Technique, 304 p. (in Russ.)
10. ASTM C293/C293M-10. Standard Test Method for Flexural Strength of Concrete (Using Simple Beam With Center-Point Loading). ASTM International, West Conshohocken, PA, 2010. doi: 10.1520/C0293_C0293M-10.
11. SOU YaEK 1.037: 2013. Short-lived low- and intermediate-level waste of NPPs. Requirements for the final processing product. Approved by the order of the Ministry of Energy and Coal Industry of Ukraine dated October 28, 2013, no. 790. Kyiv, 2013. (in Ukr.)
If the article is accepted for publication in the journal «Industrial Heat Engineering» the author must sign an agreement on transfer of copyright. The agreement is sent to the postal (original) or e-mail address (scanned copy) of the journal editions.
Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License International CC-BY that allows others to share the work with an acknowledgement of the work’s authorship and initial publication in this journal.