A mock-up of the ITER fusion reactor.

A mock-up of the ITER fusion reactor.

IAEA Imagebank/Flickr

U.S. fusion plan draws blistering critique

Many U.S. fusion scientists are blasting a report that seeks to map out a 10-year strategic plan for their field, calling it “flawed,” “unsatisfactory,” and the product of a rushed process rife with potential conflicts of interest. One result: Last week, most members of a 23-person government advisory panel had to recuse themselves from voting on the report as a result of potential conflicts.

“The whole process was unsatisfactory,” says Martin Greenwald of the Massachusetts Institute of Technology’s (MIT’s) Plasma Science and Fusion Center in Cambridge.

Achieving fusion—nuclear reactions that have the potential to produce copious, clean energy—requires heating hydrogen fuel to more than 100 million degrees Celsius, causing it to become an ionized gas or plasma. Huge and expensive reactors are needed to contain the superhot plasma long enough for reactions to start. The largest current fusion effort is the ITER tokamak, a machine under construction in France with support from the United States and international partners. But no fusion reactor has yet produced more energy than it consumes.

This past spring, the U.S. Department of Energy (DOE) commissioned its Fusion Energy Sciences Advisory Committee (FESAC) to produce a report examining potential paths forward. The request came as the U.S. program was struggling to maintain a viable research program amid stagnant budgets and the growing financial commitment to ITER, which is consuming an increasingly large share of U.S. fusion funding. FESAC set up a subcommittee that, at DOE’s request, did not include any members from the major existing U.S. fusion labs. The subcommittee had only a few months to consult the community and draft a report. In addition, its recommendations had to fit within four 10-year budget scenarios that called for relatively little or no growth in spending.

The report proposes reshuffling U.S. plasma research, in particular doing less basic plasma physics and more technology development for future power reactors. That would mean a new emphasis on controlling unruly plasma, understanding plasma’s interactions with the solid surfaces of the reactor, and improved modeling and simulation. The report proposes creating a new facility on the site of an existing spallation neutron source to test neutron-resistant materials for future reactors. At the end of the 10-year period, it recommends that the United States be ready to build a new reactor: the Fusion Nuclear Science Facility (FNSF).

Such plans will require sacrifices elsewhere. The United States now has three medium-sized fusion reactors. One of those, Alcator C-Mod at MIT, was marked for closure by the president’s 2013 budget request but later saved by Congress following extensive lobbying from Massachusetts politicians and scientists. The new report proposes closing C-Mod immediately and running the other two—the NSTX-U in Princeton, New Jersey, and the DIII-D in San Diego, California—for 5 years. Then, depending on funding, the report recommends possibly closing one of them as well.

FESAC met on 22 and 23 September to consider the draft report and vote on submitting it to DOE. But the subcommittee publicly released the draft just 1 day before the meeting, leading to complaints that people did not have enough time to read its 70+ pages and digest its conclusions. As a result, FESAC postponed a vote on the report to 10 October.

During the 2.5 weeks between the two FESAC meetings, some fusion researchers launched blistering attacks on the report. One letter, signed by 50 senior researchers, concluded that “[t]he underlying strategic vision that guides this report is flawed.” The letter argues that there is no design for the proposed FNSF or scientific consensus on what the goals for the machine should be. The letter acknowledges that fusion technology development will be needed, but argues that the report does not demonstrate “that progress in fusion and plasma science is sufficiently mature” to warrant reducing basic research.

Other researchers criticized the panel that wrote the report for not getting enough input from the fusion community. It held just one open meeting to collect opinions, they note, and presentations were limited to 10 minutes each; there were more than 100. “It was uplifting to hear all those ideas, but there was not adequate time [after] to sift through it all,” says Stewart Prager, director of the Princeton Plasma Physics Laboratory (PPPL) in New Jersey, who was not on the report panel or FESAC.

Some researchers complain that there was not a proper competition for the proposed facilities included in the report, or peer review. And Greenwald points out that by barring staff from the major fusion labs from the report subcommittee, “it lacked a whole class of expertise.” But the subcommittee did include members with potential conflicts of interest, he adds, such as links to DOE laboratories that would host new facilities proposed by the report.

DOE moved to address such potential conflicts when the report finally came to a vote during the 10 October FESAC teleconference. Department officials asked the 23 FESAC members to recuse themselves if they had connections to a lab with a major fusion facility, or a lab that might benefit from the report’s recommendations. That left just nine eligible voters, who voted 6 to 3 to approve the report.

That’s “not exactly a ringing endorsement of the report,” wrote Stephen Dean, director of the educational foundation Fusion Power Associates, based in Gaithersburg, Maryland, in a 10 October letter to FESAC.

One researcher, Charles Skinner of PPPL, tried to dramatize his feelings about the lackluster appeal of the proposed plan in a 6 October letter to FESAC. In it, he imagined a fictional dialogue at an energy fair between “Joe Everyman” and a gray-haired scientists representing FESAC. Joe recalls the excitement that greeted a fusion breakthrough 20 years ago. “How much fusion power are you up to now?” he asks. “Er … well, actually we haven’t generated any fusion power since then. But we have been studying fusion science,” the scientist responds. But when the scientist tries to explain the U.S. plan for future research, Joe just loses interest and ushers his kids off to see something more interesting.

MIT’s Greenwald echoes the concern that the proposed plan will generate little enthusiasm. He says: “We need a road map to something attractive.” And Prager believes that “with more time, a more complete job would have been done.”

DOE is now considering its next move and should have plenty input from fusion researchers as it mulls the options.

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