This is a close-up view of an X-ray photoelectron spectroscopy system used at the Idaho National Laboratory to measure surface chemistry on potential candidate material to be used for synthesis.
Masashi Shimada has been studying fusion since 2000, when he joined the master’s program at the University of California, San Diego. He is currently a lead scientist at the Applied Safety and Tritium Research (STAR) facility at the National Laboratory of Idaho, one of the federal government’s leading research laboratories.
The sphere has changed a lot.
In the beginning of his career, fusion was often the subject of jokes, if at all. “Fusion is the energy of the future and always will be” was the crack Shimada heard all along.
But that is changing. Dozens of startups have raised nearly $ 4 billion in private funding, according to the Fusion Industry Association, an industrial trade group.
Investors and Secretary of Energy Jennifer Granholm called thermonuclear energy the “holy grail” of clean energy, with the potential to provide almost unlimited energy without emitting any greenhouse gases and without the same kind of long-lived radioactive waste as nuclear fission. there is.
There is a whole great harvest of new young scientists working in fusion, and they are inspired.
“If you talk to young people, they believe in synthesis. They will succeed. They have very positive, optimistic thinking,” Shimada said.
For his part, Shimada and his team are now researching the management of tritium, a popular fuel that many fusion startups are pursuing in hopes of making the United States a bold new fusion industry.
“As part of the government’s new ‘bold vision’ for the commercialization of fusion, tritium processing and production will be a key part of their research,” Andrew Holland, chief executive of the Fusion Industry Association, told CNBC.
Masashi Shimada
Photo courtesy of Idaho National Laboratory
Study the tritium supply chain
A fusion is a nuclear reaction in which two lighter atomic nuclei are pushed together to form a heavier nucleus, releasing “huge amounts of energy.” This is how the sun is fed. But controlling the reactions of the Earth’s fusion is a complex and delicate process.
In many cases, the fuels for the fusion reaction are deuterium and tritium, which are both forms of hydrogen, the most abundant element in the universe.
Deuterium is very common and can be found in seawater. If fusion is achieved on an Earth-wide scale, one gallon of seawater will have enough deuterium to produce as much energy as 300 gallons of gasoline, according to the Department of Energy.
However, tritium is not common on Earth and must be produced. Shimada and his team of researchers at the National Laboratory in Idaho have a small tritium laboratory 55 miles west of Idaho Falls, Idaho, where they are studying how to produce the isotope.
“Since tritium is not available in nature, we have to create it,” Shimada told CNBC.
Currently, most of the tritium used by the United States comes from Canada’s national nuclear laboratory, Shimada said. “But we really can’t count on these supplies. Because once you use it, if you don’t recycle, you’re basically wasting all the tritium,” Shimada said. “So we have to create tritium while working with a fusion reactor.”
There is enough tritium to support pilot projects for synthesis and research, but its commercialization will require hundreds of reactors, Shimada said.
“That’s why we need to invest in tritium fuel cycle technologies right now to create and recycle tritium.
Chase Taylor, a scientist at the National Laboratory of Idaho, measured the chemistry of the surface of a potential material for use in synthesis by X-ray photoelectron spectroscopy.
Photo courtesy of Idaho National Laboratory
Security protocols
Tritium is radioactive, but not in the same way as fuel for nuclear fission reactors.
“The radioactive decay of tritium takes the form of a weak beta emitter. This type of radiation can be blocked by a few inches of water,” Jonathan Cobb, a spokesman for the World Nuclear Association, told CNBC.
The half-life, or the time it takes for half of the radioactive material to decay, is about 12 years for the tritum, and when it decays, the released product is helium, which is not radioactive, Cobb explained.
By comparison, the fission reaction divides uranium into products such as iodine, cesium, strontium, xenon and barium, which are themselves radioactive and have a half-life ranging from days to tens of thousands of years.
However, it is still necessary to study the behavior of tritium, as it is radioactive. In particular, the Idaho National Laboratory is studying how tritium interacts with the material used to build a synthesis machine. In many cases, this is a donut-shaped machine called a tokamak.
In order for a fusion reaction to occur, the fuel sources must be heated to plasma, the fourth state of matter. These reactions occur at extremely high temperatures of up to 100 million degrees, which could potentially affect how much and how quickly tritium can enter the plasma-holding material, Shimada said.
Most fusion reaction containers are made of special stainless steel with a thin layer of tungsten on the inside. “Tungsten was chosen because it has the lowest solubility of tritium in all elements in the periodic table,” Shimada said.
But high-energy neutrons generated by the fusion reaction can cause radiation damage even in tungsten.
Here at the National Laboratory in Idaho, Rob Kolasinski, an associate at Sandia National Laboratories, works with a frog on the tritium plasma experiment.
Photo courtesy of Idaho National Laboratory
The team’s research aims to give fusion companies a set of data to understand when this could happen, so they can identify and measure the safety of their programs.
“We can do a fusion reaction in 5, 10 seconds, probably without much worry,” about the material that will be used to contain the fusion reaction, Shimada told CNBC. But for energy production on a commercial scale, the fusion reaction will have to be maintained at high temperatures for years.
“The purpose of our study is to help designers of thermonuclear reactors predict when the accumulation of tritium in materials and the penetration of tritium through the vessel reaches unacceptable levels,” Shimada told CNBC. “In this way, we can set protocols for heating the materials (ie firing) and removing tritium from the vessel to reduce the risk of potential tritium release in the event of an accident.”
While the Idaho National Laboratory investigates the behavior of tritium to set safety standards for a thriving industry, its waste is far less problematic than today’s fission-powered nuclear facilities. The federal government has been researching how to set up a permanent repository for fission-based waste for more than 40 years and has yet to find a solution.
“Fusion does not generate long-term radioactive nuclear waste. This is one of the advantages of fusion reactors over fission reactors,” Shimada told CNBC.