In the six decades since the Shippingport Atomic Power Station near Pittsburgh began operating as the nation’s first commercial nuclear reactor, the industry has built ever larger plants to improve the economies of scale. A typical commercial reactor now produces about 20 times as much electricity as the first Shippingport unit in 1958.
So it may seem counterintuitive that the industry sees the future not in building gargantuan plants, but in small modular reactors, or SMRs — factory-built units with fewer parts, designed to be installed underground with passive cooling systems that the industry says are “inherently safe.”
Unlike large nuclear units, which are designed to operate full-tilt all year, SMR designers say the small units are flexible enough to be cranked up as needed to fill gaps in production from wind and solar-powered plants — a critical role as some see nuclear power as a carbon-free bridge between fossil fuels and renewable energy. The worldwide market for such reactors is expected to reach $100 billion by 2035, according to the Nuclear Energy Agency, an intergovernmental organization based in Paris.
Among U.S. developers, NuScale Power of Corvallis, Ore., has surpassed its competitors — including Holtec International of Camden — to advance its design closer to the finish line. Supported with $275 million in U.S. Energy Department grants, NuScale has invested about $800 million to design a 75-foot-tall cylindrical reactor that the Nuclear Regulatory Commission is expected to approve next year. NuScale aims to begin producing power at its first plant in 2026.
“There’s a good case for SMRs in a lot of markets, both in the U.S. and throughout the world,” said John Kotek, vice president of policy development and public affairs for the Nuclear Energy Institute, an industry trade group.
But not everyone is sold on their promise.
“SMRs seem to be a fad, as far as I can tell," said Edwin Lyman, a senior scientist with the Union of Concerned Scientists, who wrote a widely cited paper questioning the economics of small reactors. “There’s very really little substance to its motivation, other than the private sector can’t afford ordinary sized reactors.”
Each NuScale reactor would produce 60 megawatts of power — the same as the original Shippingport reactor, which was decommissioned in 1989. The company says its units can be installed individually, or in groups. The initial plant at the Department of Energy’s Idaho National Laboratory would contain 12 reactors. Utah Associated Municipal Power Systems is the primary customer.
The smaller reactors will be cost-effective because they can be mass-produced at existing U.S. manufacturing facilities, dramatically reducing onsite construction costs and times, said Tom Mundy, NuScale’s chief commercial officer.