By Kevin Bullis
Small, modular nuclear reactor designs could be relatively cheap to build and safe to operate, and there’s plenty of corporate and government momentum behind a push to develop and license them. But will they be able to offer power cheap enough to compete with natural gas? And will they really help revive the moribund nuclear industry in the United States?…
…Nuclear reactors that generate over 1,000 megawatts each can cost more than $10 billion to build, an investment that’s extremely risky for a company whose total assets are only $23 billion. Power plants based on small modular reactors, which produce roughly 200 to 300 megawatts, are expected to cost only a few billion dollars, a more manageable investment. “They’re simply more affordable,” says Robert Rosner, coauthor of a University of Chicago study of potential costs that the DOE has drawn on in evaluating the potential of small reactors.
The smaller size has other potential advantages. Siting a large nuclear power plant can be difficult—it requires, for example, an emergency planning zone extending 10 miles around the plant, Cryderman says. That zone could be as small as half a mile for a small modular reactor—in part because of its size and in part because the reactors have added design features. For example, while the newest reactors—such as the Westinghouse AP1000—are designed to keep the fuel cool for three days without power, small modular reactors can be designed to go without any power for weeks. He says that if the Nuclear Regulatory Commission approves a smaller emergency planning zone, that could allow Ameren to build nuclear power plants at old coal plant sites, simplifying grid connections and other siting issues.
The smaller size is also an advantage in the United States, where power demand is growing slowly and many utilities don’t want to add multiple gigawatts at a time. The modular reactors are expected to take much less time to build as well, so utilities need to forecast demand only a few years out rather than more than a decade, Cryderman says.
Yet questions remain about the viability of small nuclear reactors. While their up-front cost is lower than that of larger reactors, they might prove to cost more per kilowatt of capacity—and per kilowatt-hour of power generated.
Nuclear power plants are built large to achieve economies of scale. “Designers could make the reactors put out more power, but they didn’t have to increase the capital costs proportionally,” says John Kelly, deputy assistant secretary for nuclear reactor technologies at the Department of Energy. The hope, he says, is that building the reactors in factories will provide an alternative way to reduce costs—through mass production. The small reactors are also simpler in some ways, which can also reduce costs.
But whether those savings will be realized is uncertain. It’s not clear how many reactors need to be built before the potential savings from factory production kick in, and whether there will be enough orders for reactors to hit those numbers. For that to happen, Rosner suggests, the government may have to be the first customer, buying the reactors for military bases or government labs…
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