Corrosion Behavior and Control of SS316H in Impure NaCl-MgCl₂ Molten Salts: Experimental Study and Long-Term Predictions

with Haiyan Zhao, Associate Professor & Program Director
Chemical & Biological Engineering Department,
Affiliated faculty in Nuclear Engineering Program and Environmental Science Program,
University of Idaho, Idaho Falls

Friday, Sep 20th, 2024, 10:10am - 11:00am
Arlington - 6-051 VTRC
Blacksburg - Goodwin 440

Molten salts are widely used in nuclear energy applications as coolants and fuel salts for advanced molten salt reactors, as well as electrolytes in pyroprocessing spent nuclear fuels. The composition of these salts, including impurities, plays a crucial role in determining their corrosive effects on structural materials. In this study, we performed static corrosion tests on SS316H in impure NaCl-MgCl₂ salts prepared directly from commercial-grade salts without pretreatment. The impurity-driven corrosion process was modeled using a combination of Nernst−Planck and Butler−Volmer equations within a level-set framework, predicting long-term corrosion rates over a decade. Additionally, we experimentally demonstrated the effectiveness of corrosion control for SS316H in impure NaCl-MgCl₂ salts using H₂/Ar gas.

Dr. Haiyan Zhao is an associate professor in the Chemical and Biological Engineering Department and an affiliated faculty member in the Nuclear Engineering Program at the University of Idaho, Idaho Falls. Before joining the University of Idaho in 2014, Dr. Zhao worked as a postdoctoral research associate and later as an assistant chemist at the Advanced Photon Source, Argonne National Laboratory, where she specialized in using Synchrotron X-ray probes for advanced materials characterization.

At the University of Idaho, Dr. Zhao collaborates closely with Idaho National Laboratory, focusing on pyroprocessing of spent nuclear fuels and molten salt chemistry. Her current research includes investigating the oxidation kinetics and mechanisms of TRISO fuel particles for high-temperature gas reactors, exploring nickel alloy corrosion in fluoride salts, studying the fundamental properties of multicomponent chloride salts, and developing corrosion control strategies for chloride salt systems. These projects are supported by the DOE-NEUP and LDRD programs through Idaho National Laboratory.