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A novel type of reactor could cut the cost of nuclear power by as much as 40 percent, making it far more competitive with fossil-fuel power plants. Designed by General Atomics, a San Diego–based company, the reactor could also be safer than existing reactors and reduce nuclear waste by 80 percent.

General Atomics has been working on the reactor for five years. Now it is trying to win several hundred million dollars in funding from the U.S. Department of Energy, which the company says would be crucial to commercializing the technology. At least one other new design aims to substantially reduce the cost of nuclear power, but it’s from a startup with limited funding (see “Safer Nuclear Power, at Half the Price”).

In the United States, where natural gas is cheap, the main thing keeping utilities from building nuclear plants is their expense. While some other new reactor designs lower the up-front cost of nuclear power, they don’t necessarily lower electricity costs (see “Can Small Reactors Ignite a Nuclear Renaissance?”). Estimates from the Energy Information Administration suggest that if the General Atomics design cuts the cost of electricity by 40 percent as the company claims, new nuclear power plants would be economically competitive with natural-gas plants.

John Parmentola, senior vice president of the Energy Group at General Atomics, says the new reactor will be safer than many conventional ones. In the case of a power failure, it is designed to shut down and cool off without the need to continuously pump in coolant. This is accomplished in part by using ceramics that can withstand very high temperatures without melting.

To reduce costs, General Atomics is making the reactor smaller than conventional ones. Several other manufacturers are taking the same approach, but this design goes further by substantially increasing the efficiency of the power plant. Using helium as a coolant instead of water allows the plant to operate at higher temperatures, and the reactor also incorporates a new gas turbine for producing electricity. Thanks to these changes, the technology can generate more power from a given amount of heat produced in the reactor core. While conventional reactors convert 32 percent of the energy in heat to electricity, this one is expected to convert 53 percent.

Although the biggest cost savings will come from the reduction in size, the reactor will also save money by burning less fuel. That’s in part because it is more efficient and in part because it’s designed to burn up elements that are normally tossed away as nuclear waste.

Some experts are skeptical about General Atomics’ claims. Mujid Kazimi, a professor of nuclear and mechanical engineering at MIT, says that while the new design is likely to be more efficient and produce electricity at a lower cost than conventional reactors, “I doubt that the cost reduction would reach 40 percent.”

Licensing the design could also be difficult, since it’s very different from most nuclear reactors. Helium-cooled reactors have been built before—two operated in the U.S. in the 1980s—but they’re rare and had technical issues. “There were several problems in the U.S. reactors, which led to shutting them down after only a few years of operation,” Kazimi says. “I think that led the power companies to avoid them.”

Yet newer helium-cooled reactors designs have proved attractive—at least in China. The country recently built and started operating a small 10-megawatt helium-cooled reactor, and it is building a commercial version now that’s scheduled to be ready by 2017. If General Atomics gets the DOE award, it says it plans to have a commercial reactor operating within 12 years.

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Tagged: Energy, natural gas, nuclear power, small modular reactors

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