In August of 2021 at Lawrence Livermore National Lab in California, a nuclear fusion milestone was achieved. Researchers at the lab’s National Ignition Facility created a yield of over 1.3 megajoules. It was the first time the researchers had achieved this yield. Three peer-reviewed papers were published about the fusion research one year later.
Typically, people may hear about nuclear power in terms of fission nuclear power plants, including references to its accidents: Fukushima and Chernobyl, for example. Then, there’s the radioactive waste problem. Where does it get buried, is it contained properly, how long is it radioactive, how much does it cost to manage the waste, and so forth. Nuclear fusion does not have these problems, and yet it has not been developed fully yet. Consequently, people generally may not know much about it and confuse it with fission power plants.
To provide some clarity and insights about fusion energy and its potential, it was a privilege to interview Dr. Pravesh Patel, one of the researchers at the National Ignition Facility who worked on the project with the milestone results. He is now the Scientific Director at Focused Energy in Austin, Texas.
What is fusion ignition in a lab, and why is it significant?
Fusion is the energy source that powers the sun and stars. Stars are composed mostly of hydrogen, the lightest element. Under the enormous pressures and temperatures within a star, hydrogen nuclei collide and form helium, releasing a huge amount of energy in the process. Fusion ignition in a lab is essentially trying to replicate those conditions on earth, so we can have an inexhaustible and safe source of clean energy.
What is the measurement 1.3 megajoules and how does it relate to metrics that everyday people are more familiar with such as kilowatts and gigawatts?
1.3 megajoules is the amount of energy that was generated in last summer’s successful ignition experiment on the National Ignition Facility at Lawrence Livermore National Laboratory. This is equal to 0.36 kilowatt-hours.
When you use laser beams and a target, what is the process that allows you to generate a great deal of energy?
The approach Focused Energy is working on is called inertial fusion energy, or IFE. Essentially, it’s a way of using high-power laser beams to compress and heat a tiny amount of deuterium and tritium fuel to the densities and temperatures needed for fusion. First, one set of lasers is aimed at a spherical capsule containing the fuel, compressing it to extremely high density. Then, a second set of lasers is used to produce an intense beam of ions that are focused onto a small part of the fuel, heating it to a high temperature and sparking ignition. The energy released by fusion reactions spreads and heats the remaining fuel, releasing even more energy.
How can that energy be converted to electricity people can use for everyday applications, such as a powerplant?
In a fusion powerplant, the energy released from fusion would convert water into steam to drive turbines that generate electricity. The high temperatures that fusion is capable of can also be used for industrial heat applications.
When you worked at Lawrence Livermore National Laboratory, what were some of your successes in fusion research and what work are you doing at Focused Energy?
I spent more than 20 years at the U.S. Department of Energy’s Lawrence Livermore National Laboratory (LLNL), serving as the Group Leader for High-Intensity Laser-Plasma Physics and Associate Program Leader in the Fusion Energy Sciences Program. About eight years ago, I became Program Element Leader in the Inertial Confinement Fusion (ICF) Program. This involved leading several groups in theory, simulations, and analysis in the campaign to achieve ignition on the National Ignition Facility (NIF), the world’s largest and most energetic laser. Last year, our team succeeded in demonstrating, for the first time, controlled fusion ignition in a laboratory – a breakthrough scientific achievement for fusion energy.
With the controlled fusion ignition experiment under our belts, I am continuing my work on inertial fusion at Focused Energy as Scientific Director, working alongside a team of some of the brightest minds in the field. We’re aiming to demonstrate the feasibility of our process with our own ignition facility by 2030. We’re also building out a laser system at the University of Texas at Austin and experimental test/target facilities in Darmstadt, Germany.
What technologies are you developing at Focused Energy and when might they be available for use?
Looking ahead, we’re aiming to increase the energy output from last year’s experiment many times over using an advanced ignition scheme capable of high energy gain. To achieve this, we’ve developed technologies such as laser amplifiers, target positioning robots, and novel diagnostics for the experiments. The target laboratory in Darmstadt is also already producing targets.
Who will your customers be?
Not only is laser-based fusion a basically inexhaustible clean energy resource – through which our customers will be electrical utilities, or anyone who supplies or uses power – but along the way, there’s potential for our technology to be truly useful in other industries. This involves the development of near-term laser-driven radiation sources (LDRS) to solve critical inspection problems in the national security, maritime, and infrastructure sectors.
In contrast with X-rays, which only view heavy atoms (such as calcium in bones), neutrons generated by Focused Energy’s LDRS have the capacity to see fissures created by hydrogen in steel, carbon atoms in various types of polymers, and nitrogen explosives, all without opening or harming the item. It’s an opportunity to scale up production and reduce costs, as well as help develop analytical, engineering, and materials reliability capabilities
How safe is nuclear fusion power compared with the old fission reactor power plants?
Whilst fission and fusion are both nuclear processes that convert mass into energy, they work on fundamentally different scientific principles. Fission is the splitting of heavy elements, like uranium, whereas fusion is the merging of light elements, like hydrogen. Fission reactions occur rather easily and are amplified through a chain reaction. Fission reactors must actively control this reaction rate to avoid an uncontrolled, runaway chain reaction. In contrast, fusion can only occur in a plasma contained at high temperature and pressure. It is inherently fail-safe to a loss of containment because the reactions would automatically stop.
A further issue with fission is that it produces long-lived radioactive waste that must be safely stored or disposed of. Nuclear fusion has none of these considerations, but still suffers from the reputation of fission – which is what many think of when they hear “nuclear energy.” Even though we aren’t quite there yet with fusion, it must emerge from fission’s shadow in popular opinion as technology advances.
What role do you see nuclear fusion power playing as the world moves away from fossil fuels and toward clean, renewable energy?
Nuclear fusion has long been touted as the “holy grail” of clean energy. Once achieved on a commercial scale, it has the capacity to support renewables such as wind and solar, filling the clean energy gap, and will in fact be able to replace both fossil fuels and fission energy.
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