The Department of Energy will select industry partners to build two next-generation reactors, such as the molten salt cooled reactor being designed by Terrestrial Energy USA.

Terrestrial Energy USA

In the latest effort to revive the United States’s flagging nuclear industry, the Department of Energy (DOE) aims to select and help build two new prototype nuclear reactors within 7 years, the agency announced last week. The reactors would be the centerpiece of DOE’s new Advanced Reactor Demonstration Program, which will receive $230 million this fiscal year. Each would be built as a 50-50 collaboration with an industrial partner and ultimately could receive up to $4 billion in funding from DOE.

“This can be a game changer,” says Jacopo Buongiorno, a nuclear engineer at the Massachusetts Institute of Technology. “It’s time for the community to go from designing paper reactors to building demonstrations.”

But even some proponents of nuclear power doubt the program will spur construction of new commercial reactors as long as natural gas and renewable energy remain relatively cheap. “New builds can’t compete with renewables,” says Robert Rosner, a physicist at the University of Chicago. “Certainly not now.”

Commercial nuclear reactors supply 20% of the United States’s electrical power and 50% of its carbon-free energy. However, the U.S. nuclear industry has struggled for decades. Its fleet now comprises 96 reactors, down from 113 in the early 1990s. More reactors are slated to close and the nuclear industry’s share of the electricity supply is expected to start to fall. In spite of that dreary picture, engineers have continued to develop designs for advance reactors they say would be safer and more efficient.

The Trump administration wants to breathe new life into the nuclear industry. In April, DOE announced plans to increase domestic uranium mining and establish a national uranium reserve. And it will put $160 million of the $230 million Congress provided for the reactor demonstration program toward selecting two designs to be built posthaste, most likely at DOE’s Idaho National Laboratory (INL).

The program aims to incubate ideas that aren’t already well along in development, says Ashley Finan, a nuclear engineer and director of the National Reactor Innovation Center at INL. For example, DOE is already working with NuScale Power to develop the company’s factory-built small modular reactors, which means it isn’t eligible for the new program. The money also won’t go to the development of a reactor called the Versatile Fast Neutron Source, which DOE has already begun to prepare to build at INL and which will serve as a facility for materials science research.

Otherwise, “This is an open call,” Finan says. “I think we’ll see a lot of interest and a lot of great applications for a variety of different reactor types,” she says. Buongiorno says recent designs tend to focus on reactors that are smaller than the standard gigawatt power reactor. A standard commercial reactor burns fuel that’s between 3% and 5% fissile uranium-235 to heat water and drive steam turbines. New designs could circulate coolants such as molten salt and burn fuels containing up to 20% uranium-235, which could make them more efficient.

Some observers say the initiative is unrealistic. DOE officials may struggle to identify the most promising of the many disparate designs, predicts M. V. Ramana, a physicist at the University of British Columbia, Vancouver. “You’re be comparing apples, oranges, grapes, plums, everything,” he says. The 7-year time frame also strains credulity, Ramana says, especially as DOE wants the reactors to pass licensing reviews at the Nuclear Regulatory Commission, which typically takes several years. “It’s absurd to think they can do it.”

However, Buongiorno notes, the prototypes could be licensed for commercial use and constructed at the same time if they were sited at a DOE facility such as INL, which has built 52 different experimental reactors since its birth in 1949 as the National Reactor Testing Station. Finan says the time frame is “aggressive,” but is meant to spur developers in their work. “This is a goal that’s difficult but achievable,” she says, “and that’s the right place to be.”

Ramana questions whether the U.S. nuclear industry can be saved. Although issues of dealing with waste and the public’s apprehension about radioactivity remain, the biggest issue confronting the nuclear industry is the high capital cost of new reactors, which can be $7 billion or more. In deregulated markets, utility companies cannot afford such capital expenses, which is why cheaper renewables may ultimately replace nuclear energy, he says. “This is a sunset industry,” he says, “and the sooner you recognize that the better.”

But the cost of wind and solar will climb, Rosner argues. Electricity from renewables waxes and wanes uncontrollably, and when they expand to 20% or 30% of the market such intermittency will make them significantly more expensive, he says. Nuclear will then become economically competitive and complementary to renewables as a steady source of carbon-free energy, he predicts. “By 2030, if the United States has a bunch of designs that are well advanced, that’s a good investment because ultimately we’re going to need those plants,” Rosner says.

But to build reactors in the future, the United States needs to maintain its capabilities now, Buongiorno says. “If we let the entire fleet go down the toilet and expect that 20 years from now we can turn on our nuclear expertise like a switch, we’re delusional,” he says. “You need to maintain that capability.”

That’s what the new DOE program aims to do. Letters of intent are due in June, and DOE aims to select the winning designs by the end of the fiscal year, 30 September.

source: sciencemag.org

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