US team to build nuclear wall to withstand 180 Million°F artificial star power

A team of scientists has just landed a massive grant to build materials strong enough to withstand the blistering heat and radiation inside a fusion reactor, where temperatures soar beyond 180 million degrees Fahrenheit (100 million degrees Celsius).

The U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E) allocated USD 2.3 million to the University of Kentucky to lead the development of next-generation materials that could make commercial fusion power a reality.

The project, which tackles one of the biggest hurdles in the quest for limitless clean energy, will be managed by John Balk, PhD, director of the Materials Science Research Priority Area and W.T. Bryan Professor of Materials Engineering in the University of Kentucky’s Stanley and Karen Pigman College of Engineering.

“This is a great opportunity for the expertise of our team behind the Materials Science Research Priority Area to solve one of the key challenges in radiation-heavy industries: how to enhance thermal conductivity without sacrificing material strength,” Balk says.

Exploring raw materials

By trapping a mini star inside a fusion reactor, and transferring the technology into practice, the team aims to make fusion power commercially viable.

To achieve this, their goal is to discover or develop a class of first wall materials that form the inner wall of a fusion reactor and contact the plasma, which will maintain performance over the lifetime of a fusion power plant.

They will then explore promising alloy designs and manufacturing processes to enhance the strength and resilience of this critical barrier.

With no existing materials capable of enduring the extreme conditions required for commercial fusion power, the project will focus on developing advanced composites for high-radiation environments.

Balk emphasizes the challenge of working with tungsten (W), a metal with one of the highest melting points on Earth but prone to brittleness. By combining it with other metals like chromium (Cr) or tantalum (Ta), he aims to create a high-melting alloy that is significantly more durable and better suited for fusion reactor conditions.

“We’re going to make materials that are based on porous tungsten-based alloys, but they’re optimized for the mechanical and thermal properties we want,” Balk reveals. “We’re going to backfill them with a high-thermal-conductivity ceramic at small length scales so that the radiation damage can be shed more easily to the interfaces.”

“Materials research is critically important and underpins many other science and engineering efforts, and this project is a good example of that impact,” Balk adds.

Making fusion power a reality

Beth Guiton, PhD, Frank J. Derbyshire Professor of Materials Science and professor of chemistry in the College of Arts and Sciences, emphasizes the importance of the research and how the team aims to use machine learning to improve the material’s strength and radiation resistance.

“Keeping the plasma contained without accidentally stopping the fusion reaction or damaging your reactor materials is a challenge and a huge roadblock in this work,” Guiton explains.

“The temperatures involved are sufficient to vaporize the structure should they come into contact with it, yet we need to be able to extract the enormous amount of energy evolved so that it can be useful,” he adds.

“Balk’s work is important for Kentucky science; it’s important for fusion energy and for advancing U.S. energy technology,” the chemistry expert says in a news release. “If a commercial fusion power plant is successfully created, you’ve solved cheap, clean, safe and abundant energy production.”

“ARPA-E is a leader in supporting technologies that could make commercial fusion a reality on a much shorter timescale,” ARPA-E Director Evelyn Wang states, adding that the project is one of 13 selected by the agency for nearly USD 30 million in combined funding.

“CHADWICK expands our focus to making fusion power plants operationally and economically viable by developing a high performance and durable first wall,” Wang concludes.