Modeling of Radiolytic Production of Oxidants Relevant to Corrosion of a Used Fuel Container in Deep Geologic Repository Environments - 17641
- Department of Chemistry, Western University, London, Ontario (Canada)
- Nuclear Waste Management Organization, Toronto (Canada)
The Canadian used nuclear fuel disposal concept involves a deep geological repository using a multi-barrier system. A key barrier is the used fuel container (UFC). It consists of an inner vessel of carbon steel, which provides the structural strength to withstand repository loads, and an outer coating of copper acting as an external corrosion barrier. Relative to other design concepts, coated containers have thinner walls that provide less shielding for γ-radiation, raising the possibility of radiolysis-induced corrosion on the exterior of the container. Also, any trapped aerated water inside the container or in the bentonite clay may condense on the container surface, be exposed to γ-radiation and influence the container corrosion. Understanding the effect of radiation on container corrosion is one key factor to consider in the assessment of the integrity and longevity of the UFC. Humid air radiolysis produces HNO{sub 3} as the dominant oxidizing species. A conservative hemispherical water droplet model was developed to predict the accumulation of HNO{sub 3} and its impact on corrosion. Radiolysis of groundwater in the presence of Cl{sup -} mainly produces H{sub 2}O{sub 2} and HOCl. The concentration of these species is <10 mM and their sum remains almost constant. Radiation exposure tests showed radiation-induced corrosion on carbon steel and Cu. A systematic study of the Cu corrosion and the corrosion rate as a function of [H{sub 2}O{sub 2}], [HOCl], pH and γ-radiation is on-going. (authors)
- Research Organization:
- WM Symposia, Inc., PO Box 27646, 85285-7646 Tempe, AZ (United States)
- OSTI ID:
- 22802534
- Report Number(s):
- INIS-US--19-WM-17641
- Country of Publication:
- United States
- Language:
- English
Similar Records
Radiation Induced Corrosion of Copper in Deep Geological Repositories - 19493
Corrosion of Carbon Steel Inside Used Nuclear Fuel Containers - 19492