Small Is Beautiful is the title of a book often cited by environmentalists, but it could the concept also be applied to nuclear power plants?
A study by the University of Chicago’s Energy Policy Institute says that small, modular reactors may be the future of the nuclear power industry in the United States.
Small, modular reactors (SMRs in industry parlance) are designed to generate 600 megawatts or less; by contrast the smallest current designs from nuclear power plant builders start in the 1100-megawatt range.
Nuclear plants generally require a huge up-front financial investment, which is one reason that only regulated utilities or government-owned monopolies have built them. The big costs involved incentivize owners to build big plants in order to get a better return on investment. More power equals more revenue.
However, the EPI study says it might be worth rethinking that assumption, and looking at what would happen if nuclear plants could be built smaller, with standardized parts that would be mass-produced. The report claims that the costs of electricity per kilowatt-hour from the SMRs compare favorably to those of wind and solar, coming in at about 9 cents per kilowatt-hour. That's about half the cost of solar photovoltaic (18 cents) and 36 percent that of solar thermal (25 cents). Wind energy would cost about the same, and biomass ranges from 9 to 18 cents.
The cost savings would be from the efficiencies gained by standardizing the manufacturing of parts (something similar to this was done in France, which generates 76 percent of its electricity with nuclear).
Another big advantage would be the lead time. A new nuclear power plant can take a decade to come on-line, between the construction and regulatory approvals. A smaller-scale facility with simpler parts could be built much more quickly, on the order of a few years.
Smaller reactors could also be built to be safer. Robert Rosner, the EPI’s director and one of the report’s authors, said in a statement that many of the new designs allow the reactor to be passively air-cooled, via convection, rather than with pumping water. That simplifies the design. Some, he said, could even go through an accident with no human intervention because they would be able to throw off their heat load before melting down.
The nuclear accident at Fukushima, as well as that at Three Mile Island in 1979 and the 1986 disaster at Chernobyl were all caused by failures of the cooling systems, which allowed the nuclear fuel in the reactor cores to overheat. In the case of Fukushima the result was water with radioactive contamination being released into the ocean.
Building a whole lot of small reactors will still run into challenges. Besides the safety concerns with new designs, there are the economics. The report admits that for a full-on program of building nuclear plants to replace coal, for example, government subsidies would likely be needed. Probably the government would end up being an early customer. There is also the waste disposal, which remains a hot-button issue.
A copy of the study is available here.
Image: Felix König / Wikimedia Commons