Lawnmower blades and molten-salt nuclear reactors have little in common. But for recent PhD graduate William Doniger (PhDMS&E ’22), who currently researches corrosion-resistant materials and electrochemical sensors for next-generation molten salt nuclear reactors at Argonne National Laboratory, one was a direct bridge to the other.
Doniger, a Washington, D.C., native, came to the University of Wisconsin-Madison as an undergraduate in materials science and engineering in 2011. During his studies he developed an interest in molten salt technologies through an internship at Watertown, Wisconsin-based Fisher Barton Inc., one of the world’s largest suppliers of high-wear cutting and plowing components for agriculture. “Molten salts have an enormous variety of industrial applications including aluminum production, heat treatment of materials, and heat transfer fluids for solar and nuclear,” Doniger says.
To stay ahead in the competitive agriculture industry, Fisher Barton is always looking for new techniques and coatings. When Doniger arrived in 2015, he was assigned to an R&D project to develop a steel surface modification process utilizing molten salts that could be integrated into an existing steel heat treatment line.
“The heat treatment process step, which is carried out at 1,500-1,800 degrees Fahrenheit, made for a spectacular and challenging environment to engineer systems for,” he says. “The high temperatures plus serious industrial electronics and automation meant you always had to be on your toes. It was a really cool project because it combined my love of materials science and electronics. So I was having a ball.”
It was an influential internship for Doniger, whose mentor at the company was a former PhD physicist at Sandia National Laboratory. That experience helped Doniger decide that he wanted to pursue a career in research, and also helped him set a goal of working at a National Lab. “I thought I’d like to get a graduate degree in order to continue to do what I saw my mentors doing, which was really cutting-edge research and development,” he says.
Back on campus, Doniger joined the lab of Kumar Sridharan, Grainger Professor in materials science and engineering and engineering physics. Sridharan was working on materials that can withstand the high temperature and aggressive environment of a next generation nuclear power plant design called a molten salt reactor. The molten salt coolant enables the reactor to operate at higher temperatures and at lower pressure than current generation nuclear reactors, leading to improved safety and efficiency of the plant.
After completing his bachelor’s degree, Doniger enrolled in graduate school as a member of Sridharan’s lab. His PhD research focused on a crucial hurdle to commercialization of molten salt reactors, predicting how materials will degrade in the environment over many decades of service. He developed electrochemical techniques for studying molten salt chemistry, which is difficult to analyze with conventional methods. “I really enjoy working through the engineering challenges associated with such an inhospitable environment,” he says. “Molten salts are in some ways more versatile than water-based solvents and could potentially have some really impactful applications in things like energy production and storage, carbon capture, battery recycling and nuclear fuel recycling.”
At Argonne, which he joined in spring 2022, Doniger continues that research, working on several pioneering molten salt technologies, including applications for solar power and for addressing the nuclear fuel cycle.
“I am grateful that my chance encounter with a Wisconsin company willing to try new things, excellent mentorship and opportunities at UW enabled me to accomplish the goal of becoming a researcher at a national lab.” he says. “I am extremely excited about the future of molten salt solar and nuclear technologies. There is so much untapped potential for discovering new industrial processes enabled by molten salts. It really is like exploring a new frontier.”