Speaker: Dr. Stephen Raiman, Oak Ridge National Laboratory

Speaker: Dr. Stephen Raiman

Affiliation: Oak Ridge National Laboratory, Materials Science and Technology Division

Abstract:

As energy system designers challenge the limits of material performance, corrosion scientists work on controlling material and environmental properties to meet these challenges and ensure long economic service times. This 2-part talk will discuss current research showing how corrosion science is used to support clean energy, by addressing challenges with current nuclear reactors, and by enabling next generation molten salt systems for heat transfer and thermal energy storage.

Nuclear power is our world’s most abundant source of clean, scalable baseload energy, but high-profile accidents have eroded public confidence. It may be surprising to learn the Fukushima accident in 2011 was a corrosion problem, involving runaway oxidation of a zirconium alloy used as a core structural material. Since the accident, the nuclear industry together with the Department of Energy has sought to replace zirconium-based fuel cladding with a material that will better withstand a beyond-design-basis accident. Part 1 of this talk will present results and analysis of experiments investigating corrosion of FeCrAl alloys and SiC/SiC composite materials for use as a new generation of accident-tolerant fuel cladding.

Molten salts possess many attractive properties for use as a coolant and storage medium in concentrated solar power systems, thermal batteries, and advanced nuclear reactors. Among the challenges presented by the use of molten salts is the aggressive environment imposed upon salt-facing structural components. Part 2 of this talk will discuss efforts aimed at fundamentally understanding degradation of alloys in molten salts. Results of a combined experimental and computational strategy in which traditional experimentation is coupled with x-ray spectroscopy and thermodynamic modeling are used to identify relevant reactions and to develop a thermodynamic description of the alloy-salt system. Flowing experiments are used to more accurately recreate the in-service environment and qualify materials for service in molten salt systems.

Biography:

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