Is a Nuclear Fusion Power Grid in America’s Future?
In a move toward carbon-free energy generation in the next decade, the Department of Energy is investing $46 million in designs for nuclear fusion. But can fusion energy live up to expectations?
Nuclear fusion. It’s the process that powers the sun and other stars. It is a reaction caused by combining two light atomic nuclei that join together to create one heavier nucleus. In the process, significant energy is released.
Researchers at Lawrence Livermore National Laboratory used laser technology to ignite fusion. Image used courtesy of LLNL
Nuclear fusion doesn't create radioactive waste, unlike the nuclear reactions in a uranium fission reactor. Nuclear fusion could replace traditional energy sources from fossil fuels. But, according to all the best estimates, researchers are still decades away from creating fusion technology to produce enough emissions-free energy to supply power for homes and businesses.
Funding a Fusion Roadmap
To help reach that goal more quickly, the U.S. government plans to build a commercial nuclear fusion facility within ten years. In 2023, the Department of Energy (DOE) provided $46 million to eight fusion companies to develop designs and roadmaps for fusion pilot plants. The administration has also proposed major increases in the Fusion Energy Sciences (FES) program within the Office of Science. These investments will accelerate fusion development and bring the day fusion is a source of zero-carbon energy closer.
In December 2022, scientists at Lawrence Livermore National Laboratory (LLNL) announced they had achieved scientific energy breakeven with nuclear fusion. Energy breakeven means the fusion reaction uses less energy than it produces. The announcement came after decades of fusion research by laboratories and research institutes worldwide.
Video used courtesy of LLNL
In the LLNL research, the researchers achieved fusion by making a plasma consisting of hydrogen isotopes called deuterium and tritium and exposing it to a temperature of 100 million degrees Kelvin. When the two light atomic hydrogen nuclei combine to form a single heavier helium nucleus, a tremendous amount of energy is released because the resulting nucleus mass is slightly less than the two original nuclei masses. The leftover mass is converted into energy, according to Einstein's famous equation E=mc2.
The fusion reaction uses deuterium (D) and tritium (T), isotopes of hydrogen, and produces a helium nucleus and a neutron. Image used courtesy of the Department of Energy
One of the biggest challenges nuclear fusion presents is it needs immensely high temperatures and pressures. The hydrogen plasma must be heated to a temperature six times hotter than the temperature at the sun's core to initiate a fusion reaction. The high-temperature hydrogen plasma must be confined long enough for fusion to occur, which is difficult to do because the plasma is so hot and energetic.
The energy created from nuclear fusion can generate steam to power turbines and generators to produce electricity to run the grid without the carbon dioxide emissions from fossil fuels like coal, oil, or natural gas or the highly radioactive waste created from uranium fission nuclear reactors.
Working Here and Worldwide
The Department of Energy's Office of Science Fusion Energy Sciences (FES) program aims to develop a practical fusion energy source. To do so, FES collaborates with other Office of Science programs, such as the Advanced Scientific Computing Research program, to use scientific computing to advance fusion science and the Nuclear Physics program to develop nuclear reaction databases, generate nuclear isotopes, and conduct nucleosynthesis research.
In addition to DOE’s $46 million Fusion Development MIlestone program, 90 awards totaling $19.3 million have been made since 2019 under the Innovation Network for Fusion Energy (INFUSE) program. This funding has enabled ten DOE national labs and ten universities to collaborate with 26 individual private fusion companies. For 2024, the Presidential Budget Request has proposed major increases in the Fusion Energy Sciences program within the Office of Science.
One of the world's most ambitious fusion research projects is ITER, an international collaboration building a tokamak fusion reactor in France. ITER is expected to begin operation in 2025 and will demonstrate whether fusion energy can become a feasible source of electricity.
ITER’s tokamak experimental fusion machine. Image used courtesy of ITER
In addition to ITER, private companies are developing fusion reactor technologies and making significant progress in recent years.
It is too early to say when and if nuclear fusion will become a viable energy source for the future. However, recent advances in fusion research are encouraging. In working with private companies to create a commercial nuclear fusion facility within ten years, DOE has made its hopes clear that nuclear fusion will be an important breakthrough in the fight against climate change.