Is fusion energy, for some the holy grail of electric generation, just around the corner at a rural Virginia site? Boston-based startup Commonwealth Fusion Systems is making that claim and drawing a lot of favorable attention. The company’s claims may be hyperbolic.
The young company’s announcement, highly optimistic in tone, got considerable buzz, mostly uncritical. The company said it “will build the world’s first grid-scale commercial fusion power plant at the James River Industrial Park in Chesterfield County, Virginia.
“As part of this effort, CFS has reached an agreement with Dominion Energy Virginia to provide non-financial collaboration, including development and technical expertise as well as leasing rights for the proposed site. Dominion Energy Virginia currently owns the proposed site.”
Despite over 50 years of failed fusion predictions from multiple directions – endless, cheap, clean energy — CFS says it will have a smaller-scale prototype reactor under construction at its Devens, Mass., headquarters up and running in 2006. Then a 400-MW (e) machine will follow in Virginia “in the early 2030s.”
The guts of the CFS fusion machine is a magnetic confinement tokamak. Originally a Russian concept, a tokamak is a donut shaped reactor designed to control the enormous temperatures necessary cause hydrogen atoms to fuse together to produce helium, releasing energy in excess of the energy input. This is known as “break even.”
The CFS design for a much smaller tokamak than previous attempts — including the troubled International Thermonuclear Experimental Reactor in France — is based on research done over several years at MIT’s Plasma Science and Fusion Center. The MIT center in 2014 came up with a theoretical tokamak using superconducting magnets to increase the magnetic fields inside the reactor, powered by the conventional deuterium-tritium (D-T) fuel. They called the machine the “affordable, robust, compact” or ARC reactor.
A team of former MIT researchers in 2018 founded CFS, with Robert “Bob” Mumgaard as CEO. Their task was to create a working prototype of the ARC machine, with the moniker of “Smallest Possible ARC” or SPARK. This machine is designed to exceed breakeven, possibly 140 MW(t) in 10-second bursts. Construction began in 2021. A key to the technology, according to IEEE Spectrum magazine, is the “use of high-temperature superconducting tape, which is layered and stacked to create extremely strong electromagnets.”
CFS has raised over $2 billion over the years, according to the FusionX website that tracks developments in fusion technology and funding. The largest investment was $1.8 billion in December 2021 from a consortium of well-known investors including Tiger Global Management, Khosla Ventures, Soros Fund Management, Google, Bill Gates, and John Doerr. The U.S. Department of Energy awarded the company $15 million.
There is some inconclusive evidence that CFS may be considering an initial public stock offering. Forge, a website that describes itself as “a gateway to pre-IPO investment opportunities, delivering exposure to private company shares and creating a more accessible and transparent private market,” has a posting highlighting CFS, with the caveat, “These comments should not be interpreted to mean that the company is formally pursuing or foregoing an IPO.” Forge also notes that there are other ways of going public, including the popular Special Purpose Acquisition Companies (SPACs), which shortcut the Securities and Exchange Commission’s intensive regulatory scrutiny of conventional IPOs.
While the general reaction to the CFS announcement of its Virginia ambitions was uncritical, particularly in the trade press, there is significant informed skepticism about the company’s plans. The Quad Report reached out to CFS with a series of questions about its technology and business strategy. The company did not respond.
Fusion pioneer Robert L. Hirsch, co-inventor of the legendary Farnsworth-Hirsch fusor and long-time leader of the federal government’s fusion R&D programs over multiple agencies, has doubts. In an email exchange, Hirsh, a mechanical engineer and nuclear physicist, told The Quad Report, “From what I know, I don’t understand how they believe they can overcome the significant problems that regular tokamaks have, since higher fields and smaller sizes will aggravate some of the important physics and materials problems.
“I have not seen and have not heard of any truly independent engineering studies that honestly indicate the potential commercial viability of their concept. Often, one sees home grown engineering studies done by people whose employment depends on getting ‘the right answer.’”
Hirsch added a general caveat about safety concerns that will confront all tokamak fusion reactors. CFS will need a license from the U.S. Nuclear Regulatory Commission before it can build its Virginia project. While the NRC has issued a controversial and fairly lax policy statement about regulating fusion machines, reality may intrude, notes Hirsch: “Active feedback to control instabilities can work fine in many situations. In fusion when a feedback system might fail, the result could be catastrophic, leading to radioactive material release to the public. Regulators don’t like that so they would tend to require expensive extra containment like with fission reactor domes, which can be hellishly expensive for inherently large tokamak power plants. Physicists don’t think that way.”
Scientific American also shed a skeptical light on SPARC and ARC. Veteran science reporter Ben Guarino wrote, “But let’s hold our nuclear horses for just a moment: there are several steps that must be completed before this fusion plant, named ARC (for “affordable, robust, compact”), could be plugged into Virginia’s power grid. For one, CFS has not finished its demonstration machine, SPARC (“smallest possible ARC”). The company says it expects the completed SPARC to show net energy production in 2027. That alone would be a feat.”
Guarino added, “Failed promises litter the path to workable fusion.” He cited Lockheed Martine, which “began working on a small fusion reactor in 2010. In 2014 it said it would develop a reactor compact enough to fit on a truck before 2019. But by 2021, Lockheed Martin had quietly shelved the project.”
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