The Diffusion of Tc-99 in Beishan Granite-Temperature Effect

C. Li, Z. Zheng, X. Y. Liu, T. Chen, W. Y. Tian, L. H. Wang, C. L. Wang, C. L. Liu

Beijing National Laboratory for Molecular Science, Radiochemistry & Radiation Chemistry Key Laboratory for Fundamental Science, College of Chemistry and Molecular Engineering, Peking University, Beijing, China.
Beijing National Laboratory for Molecular Science, Radiochemistry & Radiation Chemistry Key Laboratory for Fundamental Science, College of Chemistry and Molecular Engineering, Peking University, Beijing, China; North China Electric Power University, Beijing, China.

DOI: 10.4236/wjnst.2013.31006                

Abstract

In the safety assessment of a potential site for high-level radioactive wastes (HLW) disposal, the investigation on the geochemical behaviors of key radionuclides with the possibility for releasing from the potential repository is an important aspect. Due to the high mobility of technetium under most repository conditions, lots of research works were performed to investigate the diffusion of technetium in different potential rocks. In spite of these studies, there remains a lack of data addressing temperature effects. In this paper, the diffusion of ⁹⁹Tc in Beishan granite at temperatures from 25℃ to 55℃ was studied with laboratory small scale diffusion devices. The experimental data were fitted with a finite difference scheme to get the effective diffusion coefficient (De) of . The results indicated that the relationship of De with temperatures could be described as the modified Stokes-Einstein equation, and the formation factor of Beishan granite was constant in the temperature range of 25℃ - 55℃ with the value of (3.91 ± 1.77) × 10^-4.

Keywords

Diffusion; Technetium; Beishan Granite; Temperature Effect

Conflicts of Interest

The authors declare no conflicts of interest.

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