Nuclear's New Ideas Come In A Range Of Sizes

Nuclear power’s proponents are a bit like the Chicago Cubs fans of energy development—steadfastly optimistic, even in the midst of a current-season disaster. Neither the 2011 tragedy at Japan’s Fukushima Dai-ichi nuclear power plant, nor today’s bargain-basement natural gas prices (which are forcing some operators to shut their plants’ doors) stand in the way of today’s new crop of nuclear entrepreneurs. Instead, these intrepid engineers and businesspeople are enthusiastic about their plans to bring emissions-free electricity to new domestic and international markets.

Perhaps the biggest trend among these glass-half-full types is an interest in much smaller-scale installations than past nuclear power plants. While standard model reactors can generate up to 1,200 megawatts (MW), two startup companies are developing plans for small modular reactors (SMRs) that generate as little as 25 MW. And, in an effort to boost their plants’ efficiencies, the backers see opportunities for cogeneration—making use of the 60 percent or more of a nuclear plant’s output that is now considered waste heat.

These smaller plants are intended to be factory-built, delivered and assembled as a sort of very expensive kit. Their reactors are sealed in underground containment vaults, providing isolation from the environment and protection against both tampering and natural disasters. Individual modules can be combined to build larger facilities as needs increase.

Denver-based Gen4 Energy sees its proposed SMR as a direct replacement for diesel generator sets, delivering 70 MW of thermal energy that is used to drive a steam turbine and produce 25 MW of electricity. The remaining 45 MW of thermal energy could be used in steam production for manufacturing or district heating and cooling systems. Target markets for the company include mining and chemical processing and refining facilities; remote communities now depending on oil or diesel fuels; and government installations, such as military bases, which seek grid independence for security reasons. A 10-year supply of fuel would be completely contained within the reactor module. At the end of 10 years, that module would simply be replaced.

Portland, Ore.’s NuScale Power—majority-owned by the engineering behemoth Fluor Corp.—also is thinking modular, with a design about twice the size of Gen4’s that would produce approximately 45 MW of electricity from a 160-MW thermal output. Mike McGough, the company’s chief commercial officer, said this output, along with the kit-like design, has appeal in a range of applications demanding high steam output.

“Because of the way our plant is designed, in 45-MW modules, it’s very easy to take one module and dedicate it to desalination or district heating,” he said. 

While electric utilities might remain primary customers, McGough envisions the possibility of chemical manufacturers, for example, partnering with a utility as a partial owner or lessee. 

“Those are people we’ve spoken to, and they’re encouraging,” McGough said.

Global ambitions

But optimistic nuclear developers aren’t only thinking small. TerraPower—located in Bellevue, Wash., the backyard of its chairman (and major financial backer), Bill Gates—is looking at a new way to generate utility-scale levels of electricity using nuclear energy. The company’s Traveling Wave Reactor (TWR) addresses fears raised by Fukushima with what it claims is an inherently safe approach that relies on the laws of physics—not human operators or backup power systems—to shut the nuclear reaction down in an emergency situation. The design would depend primarily on a fuel we have in abundance—the depleted uranium left over when conventional enriched-uranium fuel is produced. This fuel can’t be used to create weapons, and the slow-burning nature of the TWR’s reaction process means a plant would only need refueling once every 40 years.

CEO John Gilleland said that the idea for the plant came out of discussions former Microsoft boss Gates organized to figure out how to bring more efficient and cleaner electricity to the billions of people who now lack access. Gilleland sees the technology as a way to leverage America’s leadership in nuclear technology to serve a global need for cleaner power. China, among other developing countries, has expressed interest in the approach.

“What we’re trying to accomplish is to do this in a way that uses U.S. know-how [to] participate in what could be an enormous export market,” he said. “For us, that’s good business.”

All three companies face a range of regulatory hurdles to gain the licenses needed to move their plans from drawing board to construction site. A bigger uncertainty, though, is whether they’ll be able to compete with whatever price natural gas is fetching in 2022 or 2023, when all are hoping to begin operations.

“The marketing of our plants depends on the price of natural gas changing,” McGough said. “If they stay where they are now, it will be a very difficult sell for us. But most people don’t believe prices will stay at $4 [per thousand cubic feet] forever. At $6, our plants begin looking a lot more attractive.”

About the Author

Chuck Ross

Freelance Writer
Chuck Ross is a freelance writer and editor who has covered building and energy technologies for a range of industry publications and websites for more than 25 years. He specializes in building and energy technologies, along with electric-utility bus...

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