The U.S. should immediately invest in resolving the scientific and technical issues and designing and building a fusion-powered pilot plant to operate in the 2035-2040 time range as a stepping stone to a commercial fusion plant that would fire up by 2050. Calling for the acceleration was a 93-page report put together by a panel of the National Academies of Sciences, Engineering, and Medicine (NASEM) chaired by Richard J. Hawryluk, associate director for fusion at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL).

Fusion, the power that drives the sun and stars, combines light elements in the form of plasma — the hot, charged state of matter composed of free electrons and atomic nuclei that makes up 99 percent of the visible universe — to generate massive amounts of energy. Scientists around the world are seeking to produce and control fusion on Earth for a virtually inexhaustible supply of power to generate safe and clean electricity. In the U.S., fusion could become a major contributor to the transition from fossil fuels to a low-carbon source of electrical generation.

Path to a pilot plant

The DOE-requested report, titled Bringing Fusion to the U.S. Grid, builds upon the 2019 NASEM report on a Strategic Plan for U.S. Burning Plasma Research and a pair of fusion community documents that urge the U.S. to do the research in support of a pilot plant.  “This report outlines the path for U.S. public and private investors to do the necessary scientific and technical innovation and design leading to building a pilot plant,” Hawryluk said. “We’ve identified key goals for a pilot plant that would support a decision to build a commercial fusion power plant and the innovations in research that are needed to get there.” (Click for the initial fusion community report. This initial report informed the Fusion Energy Sciences Advisory Committee to address a recent charge on developing a long-range plan to deliver fusion and advance plasma science.)

The high-level NASEM report abstains from calling for a specific type of fusion device, such as a doughnut-shaped tokamak or a twisty stellarator, as a model for the pilot plant. “The DOE charge requested general criteria that could be applied to different fusion concepts ranging from magnetic, to magneto-inertial to inertial,” Hawryluk said, and noted that “private industry is considering various approaches.”

The first country to generate electricity with a fusion facility will accrue the benefit of defining the future direction of fusion development. The report points out that “China and the United Kingdom are embarking on development to be the first to put fusion on the grid.” However, “The U. S. has played a major role in the development of the fundamental science underlying fusion and has the opportunity to build on its past accomplishments or it can let other countries take the lead on this.”

A key jumping-off point will be 2028, the year the report calls for the completion of a preliminary design for a fusion pilot plant. Meeting that challenge and having a pilot plant in operation in 2035-2040 calls for innovations in fusion confinement concepts and the technology to extract fusion power and close the fusion fuel cycle to be developed in parallel, the report says.

Such innovations should cover “various scientific and technical areas that we haven’t fully resolved yet,” Hawryluk said. “The need is twofold. One is to ensure that the pilot plant meets its technical goals. The second is that it meets its economic goals, so innovations are driven by technical and market considerations.”

Establishing goals

Establishing goals for the pilot plant required exploring marketplace considerations with utilities, electrical grid operators, and other experts. “We looked at the responses and asked ourselves, ‘what does the pilot plant have to accomplish for utility owners to move forward with it?’” Hawryluk said. Agreed-upon goals included operating experience, cost certainty, assured confidence in the regulatory process, and understanding of operation and maintenance costs.

Assembling those goals over a tight three-month period was the Committee on the Key Goals and Innovations Needed for a U.S. Fusion Pilot Plant, the 12-member group that Hawryluk headed. The panel brought together professionals in fields that included fusion energy sciences, electric power systems, licensing, material sciences and participants with experience in public-private partnerships. ‘They’ve all brought their experience to the table and that was extremely valuable,” Hawryluk said.  

To develop the goals, the report calls on the DOE to “move forward now to foster the creation of national teams, including public-private partnerships, that will develop conceptual pilot plant designs and technology roadmaps” that will lead to making fusion commercially viable. The teams should, “Embrace diversity, equity, and inclusion and develop the multidisciplinary workforce required to solve the challenges in fusion and plasma science,” the report said.

Looking back, Hawryluk notes that “this report was done on a very fast timeline. The committee worked very hard to put together the report and to address the DOE questions. It was a pleasure for me to work with and learn from this group. They brought in extensive experience and diverse background, which enabled putting together this report quickly. “

PPPL, on Princeton University's Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit energy.gov/science.