On José Marcial’s desk sits a 2,000-year-old piece of glass from Israel.
Created incidentally by ancient people as they were copper smelting, the glass holds clues that could help researchers solve some of the biggest long-term environmental challenges in nuclear waste cleanup.
“It’s an astounding combination of archeology and materials science that allows us to observe the rate of glass corrosion,” said Marcial, a scientist at Pacific Northwest National Laboratory (PNNL) and Washington State University (WSU) alumnus (MSE BS ’13, PhD ’17). “This gives us an opportunity to understand how glass corrodes under real conditions over time, whereas in the lab we have to speed the process up.”
Marcial was the first in what has become a long list of students in a decade-long collaboration between WSU and the U.S. Department of Energy’s (DOE) Office of River Protection (ORP), envisioned and made possible by Albert Kruger at DOE-ORP, to train a generation of students to solve critical environmental challenges in nuclear waste clean-up.
At the Hanford nuclear site in eastern Washington, DOE is building the world’s largest treatment plant to clean up 56 million gallons of radioactive and chemical waste that is held historically in 177 underground storage tanks. As much as 70% of the periodic table is contained within the highly heterogenous waste, a mixture of liquid, sludge, and crystallized salts, making it one of the most complex of any nuclear waste cleanup challenges.
The treatment plant will convert the waste into durable glass that can be safely stored for thousands of years. WSU researchers are involved in investigations to better understand how glass corrodes, performs, and alters over time. The work aims to optimize the rate of nuclear waste melting to speed its cleanup while ensuring that the final glass product meets safe storage requirements for radioactive components.
“This project is not a 10-year problem,” said John McCloy, director of WSU’s School of Mechanical and Materials Engineering who has led the collaboration. “It is going to be here 50 to 100 years from now — long after you and I are gone. We need well-trained people for the future workforce.”
The WSU and Office of River Protection relationship began more than a decade ago as leaders in the nuclear waste cleanup effort realized that better basic understanding of glass formulations, and an engagement intensive training as provided by universities, could improve and possibly eliminate some complicated pretreatment processes. The WSU researchers, joined later by a team at Rutgers University, were able to offer small-scale, fundamental science that is traditionally done at universities to address the challenges. This program is a complement to the ongoing focus at PNNL in Richland, Washington, where McCloy was a senior scientist until 2013, and retains an affiliation as a joint appointee.
Marcial was the first student through the program that has brought a 10-year history of extraordinary student success. Two of the program’s students in the past two years have received the American Ceramic Society’s top award for undergraduate research in the glass community, and current undergraduate student John Bussey received a prestigious Goldwater Scholarship, which supports high-achieving undergraduates in science, technology, engineering, and mathematics (STEM) fields. Six graduate students from the WSU group have received the Roy G. Post Foundation graduate fellowships, which support students who are working on careers in the safe management of nuclear materials. Ten students have received either outstanding departmental or college awards at WSU since 2014.
Meanwhile, the relationship with WSU in the last 10 years has led to many successful research collaborations, over $3 million of direct funding, millions more in leveraged funding, and over 30 WSU students working on the project, including 6 completed PhDs, 8 senior undergraduate theses, and over 60 peer-reviewed publications. Among other things, McCloy’s team measures properties of glass and tries to understand the interaction of different components in the system – both as the glass melts and its end performance and long-term stability.
The researchers have been studying how to prevent crystallization and to understand salt phase separation, which is a problem as some of the waste glass melts. They have also studied some radioactive isotopes, called radionuclides, in the waste, including technetium and iodine. The group has also performed international collaborations looking at degradation of an archaeological site in Sweden where pre-Viking people made the walls of their hillforts by melting rocks into glass. During the past decade, McCloy has received a Fulbright fellowship and was named a fellow of the American Ceramic Society for his work.
“I have no other project like this,” said McCloy. “I just worry about solving the problems, doing science, and bringing up the students. It’s a partnership between WSU, PNNL, and the Department of Energy in support of an issue that’s important for our state.”
Many of the students have come to understand the scope of the technical issues, providing important training for a future workforce, he said.
Bussey, a senior in materials science and engineering and an avid hiker, began working for McCloy as a freshman. He has worked on a variety of problems, such as using new x-ray techniques to characterize glass and studying how elements, such as sulfur, chlorine, or chromium, interact in glass. While the work is complex and presents interesting academic questions, he also cares about it because of its importance in addressing sustainability and environmental challenges.
“It’s the biggest environmental challenge facing Washington State,” Bussey said. “It’s also right in our backyard.”
Marcial’s work, meanwhile, has brought him full circle back to the Tri-Cities area where he grew up. As a high school student, he started working at PNNL. There, he first learned about glass, materials characterization and science, and about how to pursue higher education.
“I had so many questions about what college looked like and what one needed to do to pursue fields of study like materials science and engineering,” Marcial said. “Having that internship was very valuable because it gave me the chance to interact with professionals and ask them.”
During his time at WSU as an undergraduate and graduate student, Marcial continued working as an intern at PNNL. At WSU, he got valuable hands-on training in using scanning electron microscopy or x-ray diffraction that many other graduate students do not necessarily get. He was also able to perform experiments to a particle accelerator laboratory at a national lab user facility and make high-energy, x-ray scattering measurements. Now, he has returned to PNNL, where he works with scientists to answer some of the biggest questions that society is facing in nuclear waste and sustainability.
“I gained amazing opportunities that have guided me in my future,” he said. “WSU was a huge part of that.”