Radionuclides in Irradiated Graphite of Uranium–Graphite Reactors: Decontamination by Thermochemical Methods
- Autores: Volkova A.1, Zakharova E.1, Rodygina N.1, Pavlyuk A.2, Shiryaev A.1
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Afiliações:
- Frumkin Institute of Physical Chemistry and Electrochemistry
- Experimental and Demonstration Center for Decommissioning of Uranium–Graphite Reactors
- Edição: Volume 60, Nº 6 (2018)
- Páginas: 657-663
- Seção: Article
- URL: https://journals.rcsi.science/1066-3622/article/view/224824
- DOI: https://doi.org/10.1134/S1066362218060152
- ID: 224824
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Resumo
Graphite samples from blocks and sleeves are characterized by extremely heterogeneous spatial distribution of radionuclides on the scale of tens and hundreds of micrometers. The graphite decontamination occurs in three steps: Up to 25% of 14C is removed in the course of low-temperature annealing or treatment of graphite with liquid reagents (total weight loss of graphite ≤10%); up to 70–80% of 14C is removed in the course of 20-h heat treatment under oxidizing conditions; and in the final step the degree of removal of 14C exceeds 90%, with a proportional decrease in the graphite weight. Oxidation of graphite in the first steps of thermochemical treatment mainly occurs along (micro)cracks and other defects, which favors the removal of relatively weakly bound 14C, e.g., from the pore space. The removal of 14C from the crystal lattice of graphite requires its breakdown, e.g., by high-temperature heat treatment.
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Sobre autores
A. Volkova
Frumkin Institute of Physical Chemistry and Electrochemistry
Email: a_shiryaev@mail.ru
Rússia, Leninskii pr. 31, korp. 4, Moscow, 119071
E. Zakharova
Frumkin Institute of Physical Chemistry and Electrochemistry
Email: a_shiryaev@mail.ru
Rússia, Leninskii pr. 31, korp. 4, Moscow, 119071
N. Rodygina
Frumkin Institute of Physical Chemistry and Electrochemistry
Email: a_shiryaev@mail.ru
Rússia, Leninskii pr. 31, korp. 4, Moscow, 119071
A. Pavlyuk
Experimental and Demonstration Center for Decommissioning of Uranium–Graphite Reactors
Email: a_shiryaev@mail.ru
Rússia, Seversk, Tomsk oblast, 636000
A. Shiryaev
Frumkin Institute of Physical Chemistry and Electrochemistry
Autor responsável pela correspondência
Email: a_shiryaev@mail.ru
Rússia, Leninskii pr. 31, korp. 4, Moscow, 119071