MSE Colloquium: Grace Burke, Developing a Mechanistic Understanding of Irradiation Embrittlement of RPV Steels and Welds

Professor and Director, Materials Performance Centre, School of Materials University of Manchester (UK)

Abstract

As the lifetimes for nuclear power plants are extended to beyond 60 years, the need for ensured conservative predictions of materials performance becomes increasingly important in order to guarantee continued safe plant operations.  The reactor pressure vessel represents a major, non-replaceable, primary boundary in light water reactor plants and the changes in materials properties have been studied for many years.  In pressurized water reactor vessels, the degradation has been demonstrated to be related to both material composition and irradiation exposure.  Although empirical equations have been developed to follow these irradiation embrittlement trends for proper safety assurance as well as extended life predictions, it is important to develop an understanding of the microstructural changes that cause the changes in the properties.  This knowledge can not only be employed to underpin extended life predictions but can also be applied to develop better materials for new build and future reactor systems.

This presentation will provide an overview of the investigations of the underlying irradiation-induced microstructural damage development in low alloy steels and welds.    Emphasis will be placed on the detailed physical characterization of the materials using a broad range of complementary analytical techniques.  In particular, it will be shown that key combinations of advanced techniques are required to properly indentify the microstructural changes that really govern performance.  It will be shown that detailed characterization can isolate the key materials chemistry and microstructural features that control material properties and their degradation, which impacts service-critical mechanical properties.

Bio

Grace Burke joined the University of Manchester as Director of the Materials Performance Centre in September 2011.  Prior to this, she had been a Consultant in Materials Technology in the Bettis Atomic Power Laboratory.  Prior to transferring to (Westinghouse) Bettis in 1994, Grace was a Fellow Engineer at the Westinghouse Science and Technology Center, where she was very active in nuclear materials research.  She received her BS in Metallurgical Engineering from the University of Pittsburgh, and her PhD in Metallurgy from Imperial College of Science and Technology (London).  Her interests include the application of advanced microstructural analysis techniques, in particular, analytical electron microscopy and atom probe microanalysis, to the study of environment-sensitive behavior of materials, including stress corrosion cracking and irradiation damage.  She has authored or co-authored over 100 publications, is a Fellow of ASM International, the Microscopy Society of America, and the Royal Microscopical Society, and is a member of the International Group on Radiation Damage Mechanisms, the International Cooperative Group on Environmentally-Assisted Cracking, IOM3 and TMS.