Woodruff School of Mechanical Engineering

NRE/MP Seminar

Nuclear & Radiological Engineering and Medical Physics Programs


Corrosion Studies of Coated Silicon-Carbide for use as Next-Generation LWR Fuel Cladding


Dr. Stephen Raiman


R&D Associate in the Corrosion Science and Technology Group at Oak Ridge National Laboratory


Thursday, January 18, 2018 at 11:00:00 AM


Boggs Building, Room 3-47


Dr. Farzad Rahnema


Since the Fukushima incident in 2011, the nuclear industry has sought to replace Zircaloy fuel cladding with a material which that better withstand a beyond-design-basis incident. A suitable material must possess superior oxidation resistance in high temperature steam (1200-1700°) to withstand a loss of coolant accident, while maintaining good hydrothermal corrosion properties for environmental compatibility during normal operating conditions (288-320°C water). In addition to corrosion issues, a suitable material must also demonstrate sufficient mechanical strength, creep resistance, radiation tolerance, and favorable neutronics. Researchers at Oak Ridge National Laboratory are engaged in testing of two leading candidates for accident tolerant fuel cladding: iron-chomium-aluminum (FeCrAl) alloys, and silicon carbide ceramic matrix composites (SiC/SiC). FeCrAl alloys have shown excellent oxidation resistance due to the formation of a passive alumina film in high temperature steam, and a protective Fe-Cr spinel layer in water. SiC/SiC has shown excellent corrosive properties in high temperature steam, but a tendency to dissolve in LWR water. To improve the performance of SiC/SiC during normal operating conditions, several protective coatings are under investigation. This talk will present results and analysis of experiments investigating corrosion of SiC materials and FeCrAl alloys with and without mitigation coatings during normal operating conditions, and during accident scenarios. Emphasis will be placed on hydrothermal corrosion experiments with coated SiC in BWR-HWC and BWR-NWC (288°C with 150 ppb H2 or 2 ppm O2 respectively) conditions. Coating development efforts will be discussed, along with results of corrosion experiments in high-temperature steam. Development and validation of FeCrAl alloys will also be discussed and compared to development of SiC/SiC


Dr. Stephen Raiman is an R&D Associate in the Corrosion Science and Technology Group at Oak Ridge National Laboratory. He is interested in understanding corrosion and degradation of materials in nuclear power plants and other extreme environments. His recent work has focused on evaluating materials for accident tolerant fuel cladding in light water reactors, and on materials compatibility in molten salts for use in molten salt reactors and concentrated solar power. Prior to joining ORNL, he graduated from The University of Michigan in 2016 with a Ph.D. in Nuclear Engineering and Radiological Sciences.


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