Radiation Effects in Actinide-Containing Ceramics

Featuring William J. Weber, Ph.D.
Fundamental and Computational Sciences
Pacific Northwest National Laboratory, Richland, WA

Location:  DBH 1500
Free and open to the public

Abstract:
Self-radiation from the spontaneous fission and alpha decay of actinides in crystalline ceramic host phases for the immobilization of actinides generally leads to track formation, point defect accumulation, amorphization, macroscopic swelling and increases in dissolution rates. The results of computer simulations, new models, and experimental studies in several relevant materials using short-lived actinides and ion-beam irradiation methods, along with comparisons to natural mineral data, will be presented to highlight the fundamental understanding and models of radiation effects in actinide-containing ceramics developed over the past 30 years. Low-energy (~MeV) heavy-ion irradiation techniques have been demonstrated to be very effective in simulating radiation effects from alpha decay over a large range of experimental conditions in order to develop more detailed scientific understanding and predictive models. Swift-heavy ion irradiations (~0.1 to 2 Gev) provide a means to better understand the nature of fission tracks. The integration of computer simulations into these studies have advanced the interpretation of experimental results and led to the development of a comprehensive atomic-level understanding of radiation damage processes and predictive models of the complex evolution of radiation damage in actinide-containing waste forms or inert matrix fuels with time and temperature.

About the Speaker:
William J. Weber, Ph.D., is currently a Laboratory Fellow in the Fundamental and Computational Sciences Directorate at the Pacific Northwest National Laboratory (PNNL) and serves as chair of the PNNL Council of Fellows. He received a B.S. degree in physics (1971, University of Wisconsin-Oshkosh) and both a M.S. degree (1972) and a Ph.D. (1977) in nuclear engineering (University of Wisconsin-Madison). Weber joined the staff of PNNL in 1977 and was appointed Laboratory Fellow in 1997. He has been a visiting scientist at the Institute for Transuranium Elements (Karlsruhe, Germany, 1983) and on special assignment to the Office of Basic Energy Sciences, US Department of Energy (1989-1993). Weber’s research encompasses experimental and theoretical aspects of radiation-solid interactions, evolution of irradiation effects in solids, ion-beam and electron-beam modification of materials, defects and defect/property relationships in ceramics, long-term performance of nuclear waste materials, physics of radiation detectors, and electronic and ionic transport in advanced electroceramics.