About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
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Symposium
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Synergistic Irradiation, Corrosion, and Microstructural Evolution in Nuclear Materials
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Presentation Title |
Ni Oxidation by CO2 and Its Impact on D2 Ingress: A Nanoscale Study by In-Situ Atom Probe Tomography |
Author(s) |
Sten Lambeets, Elizabeth J Kautz, Karen Kruska, David Senor, Daniel E Perea, Arun Devaraj |
On-Site Speaker (Planned) |
Sten Lambeets |
Abstract Scope |
Tritium production depends on the proper functioning of the dedicated Tritium-Producing Burnable Absorber Rods (TPBARs) which are sensitive to degradation. Under the operating conditions, the zirconium alloy (zircaloy) getter acts to absorb and store tritium. However, zircaloy is susceptible to contamination. Contaminants, such as CO2, can promote unwanted oxidation. Hence, the zircaloy is protected with a Ni coating that prevents oxygen atoms migration while remaining open to tritium diffusion. Oxidation of the Ni coating may lead to structural and chemical changes that compromise tritium diffusion. Using an in-situ atom probe tomography (APT) approach, we track composition evolution of Ni when exposed to 50mbar of deuterium (as tritium surrogate) and CO2 at 350oC. Data reveal how CO2 dissociative adsorption leads to Ni oxide layer formation, but also how the simultaneous presence of CO2+D2 may prevent the oxide formation but lead to a carbon-rich layer formation. Both layers negatively impact deuterium diffusion. |
Proceedings Inclusion? |
Planned: |
Keywords |
Nuclear Materials, Copper / Nickel / Cobalt, Environmental Effects |