The University of Kentucky has been selected to lead a project with $2.3 million in funding over four years from the U.S. Department of Energy Advanced Research Projects Agency-Energy (ARPA-E) to develop next-generation materials critical to commercializing fusion power.

The award is part of the Creating Hardened And Durable fusion first Wall Incorporating Centralized Knowledge (CHADWICK) program. The goal is to discover or develop a class of first wall materials — materials that form the inner wall of a fusion reactor and contact the plasma — that will maintain performance over the lifetime of a fusion power plant.

The multi-institutional team, led by UK’s John Balk, Ph.D., director of the Materials Science Research Priority Area, will explore promising alloy design space and manufacturing processes to strengthen that first wall.

This project aims to solve the challenge of containing a plasma at more than 100 million degrees Celsius — essentially a mini-star — in a fusion reactor. Equally important is transferring the technology into practice.

Currently, no materials exist with that level of endurance that would make fusion power plants commercially viable. This project will focus on developing advanced composite materials for use in high-radiation environments.

“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,” said Balk, who also holds the W.T. Bryan Professorship in Materials Engineering in the UK Stanley and Karen Pigman College of Engineering.

Balk is creating materials with tungsten, which has one of the highest melting points of all the elements on Earth; however, it can be brittle. Mixing it with other metals (like chromium or tantalum) creates an alloy with a high melting temperature that can be more durable than tungsten alone.

“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,” explained Balk. “We’re going to backfill them with a high-thermal-conductivity ceramic at a small length scales so that the radiation damage can be shed more easily to the interfaces.”

In addition to working with other researchers at UK, Balk will utilize expertise across the country:

• Remi Dingreville, Ph.D., a technical staff member at Sandia National Labs, will use computational methods to discover optimal materials and microstructures.

• Khalid Hattar, Ph.D., director of the Tennessee Ion Beam Materials Laboratory and associate professor at the University of Tennessee, Knoxville, will conduct ion implantation testing.

• Patrick Hopkins, Ph.D., the Whitney Stone Professor of Engineering at the University of Virginia, will measure the thermal properties of the new materials.

• Eric Lang, Ph.D., assistant professor of nuclear engineering at the University of New Mexico, will examine defect structures in irradiated materials.

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

The project team will also use machine learning technology to optimize the new material for extended exposure to radiation.

UK’s Beth Guiton, Ph.D., Frank J. Derbyshire Professor of Materials Science and professor of chemistry in the College of Arts and Sciences, is an expert materials chemist. She is on the federal Fusion Energy Sciences Advisory Committee and is a member of the leadership team for the Materials Science RPA.

Guiton underscored the significance of this research.

“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 said. “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. Balk’s work is important for Kentucky science; it’s important for fusion energy and for advancing U.S. energy technology.

“If a commercial fusion power plant is successfully created, you’ve solved cheap, clean, safe and abundant energy production,” Guiton said.

UK’s project is one of 13 selected by ARPA-E for nearly $30 million in combined funding.

“ARPA-E is a leader in supporting technologies that could make commercial fusion a reality on a much shorter timescale,” said ARPA-E Director Evelyn Wang. “CHADWICK expands our focus to making fusion power plants operationally and economically viable by developing a high performance and durable first wall.”

Learn more about the other projects supported through CHADWICK online here.

This material is based upon work supported by the Department of Energy under Award Number DE-AR0001998. This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.