Journals →  Tsvetnye Metally →  2021 →  #8 →  Back

ArticleName Thermochemical treatment of a cladding fuel simulator based on UO2 with an oxidizing mixture NxOy + O2 + CO2 + H2O(steam)
DOI 10.17580/tsm.2021.08.06
ArticleAuthor Aksyutin P. V., Dyachenko A. S., Zhabin A. Yu., Zherin I. I.

FSUE Mining and Chemical Combine, Zheleznogorsk, Russia:

P. V. Aksyutin, Radiochemist Engineer, e-mail:
A. S. Dyachenko, Leading Engineer
A. Yu. Zhabin, Head of Laboratory


National Research Tomsk Polytechnic University, Tomsk, Russia:
I. I. Zherin, Professor, Doctor of Chemistry


Thermochemical treatment of irradiated fuel simulator containing UO2 of ceramic properties by NxOy + O2 + CO2 + H2O(steam) oxidizing mixture was tested in the range of 588 to 663 K. Fragments of new fuel elements were used as a feed material containing uranium-235 within 0.72 wt. % and 50 mm in length while jam of ends cutoff was 30% or less. Ability in principle to convert ceramic fuel in zirconium cladding into powder-like material during 3 hours was proven under NxOy + O2 + CO2 + H2O(steam) atmosphere at temperatures of 623–643 K. Thermochemical treatment was carried out in a furnace based reactor equipped with horizontal axis of rotation. Following thermochemical treatment of ceramic fuel simulator by NxOy + O2 + CO2 + H2O(steam) oxidizing mixture at temperature of 623 and 643 K, we made black powders separated from zirconium claddings completely. Fuel coming out of cladding was 99.9%. These powder s are in agreement with molecular formula U3O8 based on gravimetric analysis. Powder-like material was proven to be triuranium octoxide (X-ray peaks for 20; 21.5; 26; 34; 44; 46; 47;52) in accordance with X-ray phase analysis and typical reflections of XRD patterns. Particle sizes of powder in its basic fraction were 2–6 microns (95% of derived product or more).
This research was supported by TPU development program.

keywords Uranium dioxide, fragment of ceramic fuel simulator, oxidizing mixture, catalyst, temperature, powder-like material, triuranium octoxide, XRD pattern

1. Khaperskaya А. V. Russian approaches to advanced nuclear cycles. Atom-Eko-2017. Available at: (accessed: 21.06.2021).
2. Gromov B. V. Introduction to uranium chemical technology. Moscow : Atomizdat, 1978. 336 p.
3. Kulyukhin S. А., Nevolin Yu. М., Mizina L. V., Konovalova N. А., Gordeev А. V. Gas-phase conversion of U, Sr, Mo and Zr oxides into watersoluble compounds in NOx – H2O (steam) – air atmosphere. Radiokhimiya. 2016. Vol. 58. No. 1. pp. 15–29.
4. Johnson J. A. Studies of reaction process for voloxidation methods: diss. PhD. Knoxville, 2013. 121 p.
5. GOST 4461–77. Reagents. Nitric acid. Specifications. Introduced: 01.01.1979.
6. GOST 22180–76. Reagents. Oxalic acid. Specifications. Introduced: 01.01.1977.
7. Matyukha V. А., Matyukha S. V. Oxalates of rare earth elements and actinides. Moscow : IzdAT, 2008. 607 p.
8. Gavrilov P. M., Merkulov I. A., Aksyutin P. V. et. al. Method of oxidating treatment (voloxidation) of irradiated nuclear fuel. Patent RF, No. 2654536. Applied: 15.08.2017. Published: 21.05.2018. Bulletin No. 15.
9. Ananyev А. V., Tananaev I. G., Shilov V. P. Heterogeneous catalytic redox reactions in chemistry and technology of the nuclear fuel cycle. Uspekhi khimii. 2005. No. 11. pp. 1132–1155.
10. Kozhakhina А. V. Catalysts for the redox interaction of nitrogen and carbon (II) oxides: thesis of inauguration of Dissertation … of Candidate in Chemistry. Saratov, 2008.
11. Leonov V. Т. Scientific and technological basis for utilization and processing of nitrogen oxides from waste gases: Dissertation … of Doctor of Technical Sciences. Мoscow, 2009.
12. Apalkov G. A., Smirnov S. I., Zhabin A. Yu. Method for catalytic denitration of liquid radioactive waste. Patent RF, No. 2593163. Applied: 14.05.2015. Published: 27.07.2016. Bulletin No. 21.
13. Merkulov I. A., Tikhomirov D. V., Aksyutin P. V. et. al. Method for oxidative treatment (voloxidation) of irradiated nuclear fuel. Patent RF, No. 2619583. Applied: 01.09.2016. Published: 17.05.2017. Bulletin No. 14.
14. Stromberg А. G., Semchenko D. P. Physical chemistry. Textbook for universities. Мoscow : Vysshaya shkola, 1973. 480 p.
15. Dyachenko А. N., Shagalov V. V. Chemical kinetics of heterogeneous processes: tutorial. Tomsk : Izdatelstvo Tomskogo politekhnicheskogo universiteta. 2014. 95 p.
16. OST 95175–2003. Uranium and its compounds. Method for gravimetric peroxide deposition measurement of uranium content. Accepted: 01.01.2003.
17. Schwartz D. S., Tandon L., Martinez P. Morphological Comparison of U3O8 Ore Concentrates from Canada Key Lake and Namibia Sources. Report of Los Alamos national laboratory. 2016.
18. Kang K. H., Na S. H., Song K. C. Oxidation behavior of the simulated fuel with dissolved fission product in air at 573–873 K. Thermochimica Acta. 2007. Vol. 455, Iss. 1-2. pp. 129–133.
19. Rui L. The study of pre-oxidation and low temperature sintering mechanism to UO2+x pellets. Adv. Mat. Res. 2014. Vol. 1053. pp. 80–86.
20. Lee J.-W., Yun Y.-W., Kim Y.-H. Thermal granulation of U3O8 powder using rotary voloxidizer. Ceramics International. 2015. Vol. 41, Iss. 9. Part A. pp. 10810–10817.

Language of full-text russian
Full content Buy