
Commonwealth Fusion Systems and MIT’s planned SPARC tokamak, a compact fusion demonstration device intended as a precursor to a fusion pilot plant it hopes to construct by the early 2030s.
(Image credit – T. Henderson, CFS/MIT-PSFC)
Commonwealth Fusion Systems and MIT’s planned SPARC tokamak, a compact fusion demonstration device intended as a precursor to a fusion pilot plant it hopes to construct by the early 2030s.
(Image credit – T. Henderson, CFS/MIT-PSFC)
The House Science Committee recently held a hearing
Leading the hearing, Energy Subcommittee Chair Jamaal Bowman (D-NY) asserted that fusion energy has reached a pivotal moment, pointing to recent breakthroughs and the completion of a long-range plan
“Challenges remain on the path toward realizing this transformative goal. But we now have new reasons for hope, as well as comprehensive roadmaps driven by the research community to guide us on this path,” Bowman said.
The experts appearing at the hearing included UCLA physics professor Troy Carter, who led the long-range planning study, and Bob Mumgaard, CEO of the company Commonwealth Fusion Systems. Also testifying were Steve Cowley, director of Princeton Plasma Physics Laboratory, and Kathy McCarthy, director of the U.S. project office for ITER, the flagship international fusion research facility under construction in France. Rounding out the panel was Tammy Ma, a physicist at Lawrence Livermore National Lab’s National Ignition Facility.
“Now is the time to move aggressively toward the development and deployment of fusion energy,” Carter said in his opening statement, stressing the long-range plan’s recommendations that DOE refocus its fusion science program from research to technology development and recalibrate its relations with the private sector. “We need to look for other mechanisms to do private–public partnership, and that needs to be developed quickly,” he added later.
Mumgaard highlighted that fusion companies have raised around $2.4 billion in private capital to date worldwide, and that a recent Fusion Industry Association survey
“The U.K., Germany, Japan, Italy are building facilities first conceived by the U.S. China is rapidly investing. The U.K. has a government-wide goal
Cowley, who led the U.K. Atomic Energy Authority before becoming PPPL director in 2018, said that although DOE has pioneered much of the fusion science used by other countries, its program has “remained divorced from the idea of actually producing an energy source.”
“That was never true in any of the European programs, and certainly not true in the Chinese program,” he added.
Mumgaard’s company, which was spun out from MIT in 2018, aims to build a compact fusion demonstration device called SPARC that can produce a burning plasma, a key milestone in generating energy from fusion. In his written statement
As a sign of the company’s progress, he pointed to its recent demonstration
The Science Committee has been a driving force behind legislation to expand DOE’s fusion program, including by adding the milestone-based program and other fusion-related provisions to the Energy Act of 2020
The first sector of ITER’s vacuum vessel was transported to the experiment’s assembly hall in April 2021.
(Image credit – ITER)
Although attention has recently turned to private ventures, the U.S. is also committed to providing billions of dollars for ITER. DOE instructed the long-range planning committee to assume the U.S. will remain a partner in the project, and the committee’s report describes U.S. participation as “essential” to fusion energy development.
McCarthy elaborated on this point in her testimony, arguing that pursuing multiple approaches to fusion reduces overall risk and that the practical experience gained through ITER will facilitate the development of a U.S.-based pilot plant. “Domestic supply chains are being developed, fabrication challenges are being resolved, and integration issues are being addressed, all to assemble the world’s first nuclear-certified fusion reactor,” she said.
“For about 9% towards construction costs and 13% towards operation costs, the United States receives 100% of ITER science, technology, and associated intellectual property,” she added. She also pointed out in her written testimony that the bulk of DOE funding for ITER has gone to U.S. institutions, which have been awarded $1.3 billion to date.
Energy Subcommittee Ranking Member Randy Weber (R-TX) echoed these points and added, “Upholding our end of this deal is imperative to the success of U.S. fusion energy and to America’s standing and credibility as a global scientific collaborator.”
According to the Science Committee, DOE’s most recent estimate for the U.S. share of ITER construction costs is roughly $5 billion
Past appropriations have lagged the planned profile and U.S. contributions to the project are now $97 million short of expectations, McCarthy reported. She said that lag has forced the project to prioritize “critical path” activities, though she noted that recent appropriations increases have allowed the project to restart some activities it had put on hold.
The Science Committee has been broadly supportive of ITER. Its DOE Science for the Future Act
A chart of fusion yields from NIF shots over the past decade. The record-breaking shot from August generated 1.35 megajoules of energy, far exceeding the energy absorbed by the experiment’s inner capsule, but fell short of achieving net energy gain.
(Image credit – Livermore Lab)
The hearing also examined prospects for generating energy from inertial fusion in view of a record-breaking experiment the National Ignition Facility conducted in August.
As part of its ongoing experimental program, which uses an array of ultraviolet lasers to compress hydrogen fuel capsules, NIF generated 1.3 megajoules of energy — roughly five times the 250 kilojoules absorbed by the capsule and 70% of the energy used by the lasers. NIF scientist Tammy Ma said the facility has not yet replicated the shot and is working to understand the physics parameters that affected its performance.
“Those repeat shots — the yields were a little bit lower and that is because there were some more imperfections in the target. The laser delivery was not quite as good,” she said.
Ma highlighted the long-range plan’s recommendation for DOE to establish a coordinated inertial fusion energy program. Currently, DOE’s fusion science program focuses on non-inertial methods of energy generation while the DOE National Nuclear Security Administration’s inertial fusion program, which funds NIF, focuses on research to support maintenance of the U.S. nuclear weapons stockpile.
The Energy Act directed the DOE to establish an inertial fusion research program for energy applications, but the department has not yet implemented that guidance. Ma noted that DOE is planning to hold a Basic Research Needs Workshop next year to identify priority research directions for inertial fusion energy.
Rep. Zoe Lofgren (D-CA), a longtime inertial fusion advocate whose district neighbors Livermore Lab, noted there have been tensions between NNSA’s prioritization of its stockpile mission and its support for science activities. “There was a time when NNSA wanted to shut down all of the science projects a few decades ago. Congress rallied around in a day to put a stop to that. So, I’m sure that we will have a bipartisan effort to make sure that the science gets done,” she said.