Interfacial degradation of ceramic and metallic materials under corrosion and irradiation conditions
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Authors
Wang, Yachun
Issue Date
2020-08
Type
Electronic thesis
Thesis
Thesis
Language
ENG
Keywords
Nuclear engineering
Alternative Title
Abstract
The corrosion interactions between a metallic canister material, stainless steel 316, and IAPT ceramic in a chloride solution was explored. Crevice corrosion of the SS in close proximity to the IAPT resulted in the development of an aggressive environment at the interface of the two materials, which was acidic and enriched in Cl− anions. The enrichment of Cl− anions within the occluded crevice space as the result of SS crevice corrosion drastically enhanced the corrosion of IAPT. The release of radioactive iodine from this apatite waste form could be accelerated owing to this mechanism. This is evidenced by a substantial depletion of iodine from the I-APT matrix and a large amount of Cl-bearing precipitates on the surfaces of both SS and I-APT. On the other hand, the corrosion of IAPT leads to the precipitation of a V- and Pb-rich layer, which inhibits the localized corrosion of SS to an extent. This study reveals a new near-field corrosion mechanism for ceramic waste forms when they are exposed to aggressive local conditions created by the electrochemical reactions of nearby metals. This study advances the understanding of the near-field corrosion interactions between metallic canisters and ceramic waste forms and could be beneficial for a more accurate prediction of waste form degradation.
Description
August 2020
School of Engineering
School of Engineering
Full Citation
Publisher
Rensselaer Polytechnic Institute, Troy, NY