Radionuclides in Irradiated Graphite of Industrial Uranium–Graphite Reactors: Effect of Irradiation and Thermochemical Treatment on the Graphite Structure
- Authors: Shiryaev A.A.1,2,3, Volkova A.G.1, Zakharova E.V.1, Nikolsky M.S.1,2, Averin A.A.1, Dolgopolova E.A.3, Yapaskurt V.O.4
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Affiliations:
- Frumkin Institute of Physical Chemistry and Electrochemistry
- Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry
- Department of Chemistry
- Department of Geology
- Issue: Vol 60, No 6 (2018)
- Pages: 664-671
- Section: Article
- URL: https://journals.rcsi.science/1066-3622/article/view/224833
- DOI: https://doi.org/10.1134/S1066362218060164
- ID: 224833
Cite item
Abstract
The structure of irradiated graphite from decommissioned industrial uranium–graphite reactors was studied. The extent of disturbance of the graphite structure is closely correlated with temperature and integral neutral fluence. The perfection of the structure of graphite samples (data of X-ray diffraction and Raman spectroscopy) does not correlate with their radioactivity, which is due to low absolute concentration of the radionuclides. Mapping of the samples using Raman spectroscopy reveals spatial heterogeneity of the distribution of graphite lattice damages, which casts doubt on the representativeness of the spectra of individual points. The spatial distribution of domains differing in the crystal lattice perfection was studied for the first time and was compared with the radionuclide distribution. Satisfactory correlation between the radiographic and spectroscopic mapping data is observed for some samples. Irradiated graphite is strongly textured and contains amorphous microvolumes, which are probably radionuclide carriers. Thermochemical treatment (oxidation in O2, thermal shock) leads to degradation of the irradiated graphite structure on the submicron level, accompanied by a drastic decrease in the mechanical strength of the samples.
About the authors
A. A. Shiryaev
Frumkin Institute of Physical Chemistry and Electrochemistry; Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry; Department of Chemistry
Author for correspondence.
Email: a_shiryaev@mail.ru
Russian Federation, Leninskii pr. 31, korp. 4, Moscow, 119071; Staromonetnyi per. 35, Moscow, 119017; Moscow
A. G. Volkova
Frumkin Institute of Physical Chemistry and Electrochemistry
Email: a_shiryaev@mail.ru
Russian Federation, Leninskii pr. 31, korp. 4, Moscow, 119071
E. V. Zakharova
Frumkin Institute of Physical Chemistry and Electrochemistry
Email: a_shiryaev@mail.ru
Russian Federation, Leninskii pr. 31, korp. 4, Moscow, 119071
M. S. Nikolsky
Frumkin Institute of Physical Chemistry and Electrochemistry; Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry
Email: a_shiryaev@mail.ru
Russian Federation, Leninskii pr. 31, korp. 4, Moscow, 119071; Staromonetnyi per. 35, Moscow, 119017
A. A. Averin
Frumkin Institute of Physical Chemistry and Electrochemistry
Email: a_shiryaev@mail.ru
Russian Federation, Leninskii pr. 31, korp. 4, Moscow, 119071
E. A. Dolgopolova
Department of Chemistry
Email: a_shiryaev@mail.ru
Russian Federation, Moscow
V. O. Yapaskurt
Department of Geology
Email: a_shiryaev@mail.ru
Russian Federation, Moscow