A report released earlier this month outlines steps that the United States can take to become closer to obtaining a commercially-feasible source of fusion power. The report, authored by 300 researchers, hopes to align the fusion community to realize this goal. The question that remains – is fusion the answer to our globe’s energy needs?

The Report

The nearly 200-page report hopes to align the fusion research community so that obtaining a commercial fusion energy source within the United States might become a reality.

“It’s the whole community, coming together in a very transparent grassroots effort to answer questions about what we’re doing, what needs to be done, and what we’re willing to not do,” says Bob Mumgaard, the chief executive of Commonwealth Fusion Systems (CFS). “It wasn’t done in a back room but by scientists themselves, and they came out with a plan and priorities — it’s kind of cool.”

The report targets several goals:

  • Beefing up plasma research in fields from astrophysics to nanotechnology.
  • Creating a fusion pilot plant that produces net energy. Such a plant would be a proof of concept showing that commercial fusion energy is indeed possible.
  • Understand how neutrons, a product of fusion reactions, will affect the facility.
  • Having the US maintain a constant presence in the international ITER project, an international project to produce energy from fusion reactions, in which the US has been an intermittent partner.

Getting Energy From Fusion Reactions

Fusion is the most prevalent energy source in the universe. Stars sustain nuclear fusion within their cores, combining atomic nuclei to form heavier elements, releasing huge amounts of energy.

In the lab, however, fusion is incredibly difficult. In order for nuclei to fuse, the electrostatic forces that push two positively charged nuclei apart must be overcome. If two nuclei are hot enough or dense enough, they can come close enough together so that the strong nuclear force will attract them together, fusing them into one nucleus. This releases a huge amount of energy.

This happens in stars, where their cores are extremely hot and dense. In order to happen in the lab, plasma must be heated even hotter than the core of the sun – perhaps six to seven times as hot as the sun’s core, a whopping 100 million Kelvin. The hydrogen plasma must then be confined so that protons will collide. To do this, reactors use magnetic fields to contain the plasma (using tokamaks, which confine the plasma into a donut-shaped torus, or stellarators, complex, twisty structures that are incredibly hard to build but that may eventually outpace tokamaks).

Fusion – All It’s Hyped To Be?

Some remain skeptical that fusion is the silver bullet in solving our energy needs. One main reason is that fusion in the lab utilizes isotopes of hydrogen with neutrons. This creates a bi-product neutron stream, which could be very dangerous, both to the health, structures and because of the production of radioactive waste. Many times fusion also utilizes tritium, an isotope of hydrogen that is actually quite scarce in nature. Yet, this may be overcome by the ability to “breed” tritium.

And one fact remains – fusion is incredibly difficult. Overcoming the nuclear strong force to combine two nuclei is far, far more challenging than splitting nuclei apart.

Yet, here we stand in the midst of a global energy crisis. Resources like fossil fuels are diminishing and contributing to climate change. Renewable resources like wind power and hydroelectric dams have their own problems. Obtaining a commercial source of energy via fusion reactions could have the potential of revolutionizing how energy is obtained. Unlike fission, fusion does not produce long-lived radioactive waste and there is no chance of a runaway reaction. Since fusion energy has zero carbon emission, if successful, it could also be an important tool for meeting our energy needs while combating climate change.

Every source of energy will have difficulties and drawbacks. It’s up to us to decide where the benefit is the greatest while doing the least amount of harm.