TVA's closed Bull Run plant could get second life harnessing fuel hotter than the sun

The Tennessee Valley Authority's retired Bull Run Fossil Plant may be out of a job, but a leading fusion company wants to use the site for research that could one day replace coal with the power of the sun.

In the same building where crews once burned millions of tons of coal, Type One Energy Group plans to build Infinity One, a prototype of its fusion device. In the push toward cleaner energy sources, no technology is as promising yet elusive as fusion, which exceeds the heat of the sun by fusing atoms together rather than splitting them apart.

Infinity One is set to be the world's most advanced stellarator, and engineers will use it to run tests as a crucial step toward opening a full-scale fusion power plant. Stellarators are devices formed in a twisted doughnut shape that use powerful magnetic fields to contain plasma heated to temperatures several times hotter than the core of the sun.

The company also announced Feb. 21 it would establish its headquarters in East Tennessee, creating more than 300 jobs over the next five years with an average salary of $130,000. Though its headquarters will likely be in the Knoxville area, the company has not selected a location. It plans to invest $223 million in the region over the next five years.

Type One Energy opened an Oak Ridge office last August and signed an agreement with TVA and Oak Ridge National Laboratory to expand its fusion projects in the region with their help.

Type One Energy's announcement comes as scientific breakthroughs across the globe make a future with fusion power more tangible.

"This is incredibly symbolic," Type One Energy CEO Christofer Mowry told Knox News. "It is the first time that a fusion company is actually partnering with an electric utility, like TVA, and also, frankly, a national laboratory in this way. This is really linking the technology to the end market and I think that in this sense, it really is a watershed moment for fusion."

The company has a series of permits and licenses it must secure before it can begin construction. If it receives those permits, Type One Energy expects to begin construction on Infinity One in 2025 and to begin operating the prototype in 2028.

TVA has not given a permit or operating license to Type One Energy, though spokesperson Scott Brooks told Knox News that Bull Run's infrastructure makes it an "ideal location for assembly and operation" of the prototype.

Infinity One will not generate electricity for homes or businesses, though retired coal sites could be a good fit for the fusion power plants of the future, Mowry said. Type One Energy has a goal to build a pilot fusion power plant in the next decade and its Bull Run prototype would verify that its stellarator technology can work at a larger scale.

The size of the prototype may depend on whether the Department of Energy plans to use it for research once Type One Energy is finished working with it, a company spokesperson said. For now, the design could be up to about 20 feet wide.

Bull Run, a 750-acre site in the Claxton community of Anderson County, opened in 1967 as the largest single-generator coal plant in the world by volume of steam produced. TVA closed the plant in December 2023 as it forged ahead with its goal to fully phase out coal by 2035 and reach net-zero carbon emissions by 2050.

Separately, TVA plans to use portions of the plant for condensers that will support the stability of its grid.

Type One rises at exciting time for fusion

The announcement adds momentum to a fast-paced few years for fusion.

Fusion has many advantages over nuclear fission, the reaction that powers all nuclear power plants today, including a lack of radioactive waste and fewer costly regulations. The most common fuel needed for fusion, an isotope of hydrogen called deuterium, is also abundant in nature.

U.S. scientists ignited a fusion reaction that released more energy than it absorbed at the Department of Energy's Lawrence Livermore National Laboratory in California in 2022. The facility has repeated the landmark ignition process several times since.

Scientists at the Joint European Torus in England set a world fusion energy record last year when they sustained a six-second reaction that released nearly 70 megajoules of heat using just 0.21 milligrams of fuel. Workers at Bull Run would have had to burn about 10 million times more coal to release the same amount of heat.

When Type One Energy was founded in 2019, it formed a team of leading U.S. experts to strive for commercial fusion. The company hopes to capitalize on enthusiasm from private investors and federal and local governments.

Its Infinity One prototype is the first grant recipient of Tennessee's state nuclear fund, created by Gov. Bill Lee last year to accelerate nuclear innovation. The company also was included in the Department of Energy’s $46 million Milestone-Based Fusion Development program.

Type One Energy bases its work in regions with strong fusion talent. Its other offices are in Boston, Vancouver, and Madison, Wisconsin. Fusion experts at ORNL hope the announcement could attract other companies to come to Oak Ridge.

"This is an emerging industry. I think it's really good for us to be at the epicenter," said Mickey Wade, associate laboratory director for the fusion and fission energy and science directorate at ORNL. "It matters a lot to Oak Ridge because it sort of gives us an avalanche effect. We have the capabilities, companies come and we get more capabilities, so more companies come. I think it will build on itself."

If Type One Energy can achieve its mission, Mowry said fusion power plants could be built quickly and in place of coal plants, one day rivaling natural gas as well.

Challenges of fusion innovation

Stellarators are unique for their shape and their promise. In a stellarator, the shape of the magnetic containment structure is the "secret sauce" to sustaining a fusion reaction, Mowry said.

Though stellarators were first developed in the U.S. in the 1950s, they have become more advanced in the last two decades using supercomputers to calculate their precise shape. Part of Type One Energy's partnership with ORNL may include using its supercomputer Summit to run complex models.

Once a fusion reaction is started within the twisted doughnut shape, the reaction is steady rather than pulsed, and it will sustain itself as long as it has fuel. In a future fusion power plant, the devices would be blanketed in a material that could absorb their heat to create steam and spin a turbine.

Wade, who leads fusion research at ORNL, said there are a few key technology challenges for stellarators.

Scientists must find materials that can survive in temperatures unlike anything on earth for extended periods of time. The plasma inside stellarators is heated to at least 40 million degrees Fahrenheit. They must also develop ways to use the fusion reaction to create tritium, a hydrogen isotope that does not occur in nature but is necessary to keep the deuterium reaction going.

Correction: A previous version misstated the year Type One Energy Group was founded. The group was founded in 2019 and launched as a venture-backed company last year.

Daniel Dassow is a growth and development reporter focused on technology and energy. Phone 423-637-0878. Email daniel.dassow@knoxnews.com.

Support strong local journalism by subscribing at knoxnews.com/subscribe.   

This article originally appeared on Knoxville News Sentinel: Type One Energy picks TVA Bull Run coal plant for nuclear fusion tests