The Incredible Shrinking Reactor


Small is beautiful for nuclear developers.

Small is beautiful for nuclear developers.

Fortnightly Magazine - May 2010

Small modular reactors (SMRs) are nuclear generating units that are about the size of railroad cars and provide about one-tenth to one-fourth the power of full-size reactors. As a result, they cost a fraction of what full-size reactors cost. The reactors are designed to provide between 40 MW and 300 MW of electric power, compared with the 1,100 to 1,700 MW output of larger reactors. In addition, most are expected to cost under $1 billion, compared with the $5 billion to $10 billion price tags of the larger units.

Over the past decade, a number of companies have begun work on SMRs, including Westinghouse, Toshiba, GE Hitachi Nuclear, Babcock & Wilcox, NuScale Power, PBMR, Hyperion Power, Areva and General Atomics.

Westinghouse was one of the earliest to develop the technology. “We have been working on SMRs since 1999,” reports Michael Anness, manager, advanced reactors, for Westinghouse in Pittsburgh, Pa. Initially, these were in the range of about 200 MW. However, the designs have evolved over the years, with multiple power levels. “The more we learn about them, the more we learn how to streamline the design,” he explains. “We are now working on the optimum configuration for SMRs, and we are currently in the conceptual design phase.” Anness says one such design, the International Reactor Innovative and Secure (IRIS), is about 10 years from its first actual deployment.

Utilities are beginning to express interest in the potential for SMR technology. In February 2010, Tennessee Valley Authority, FirstEnergy and Oglethorpe Power signed an agreement with Babcock & Wilcox (B&W), a subsidiary of McDermott International, creating a consortium that’s committed to getting B&W’s SMR, called mPower, approved for commercial use in the United States. “Some other utilities have expressed interest, and some are getting ready to sign up with the consortium,” says Christofer Mowry, president of Modular Nuclear Energy, the small reactor division of B&W. “However, at this point, they want to keep a low profile.”

Interest is growing beyond just a few vendors and utilities, though. Microsoft founder Bill Gates, for example, is negotiating with Toshiba to develop plants based on the company’s Traveling-Wave Reactor technology. As envisioned, such a reactor would use depleted uranium and would operate for 100 years without refueling.

“There have been a lot of conferences recently on small modular reactors, and they have been well attended by vendors and utilities,” says Michael Mayfield, director of the advanced reactor program at the Nuclear Regulatory Commission.

Moreover, the U.S. government is responding to this rising interest in SMRs. “The Department of Energy is working on this, as is the Nuclear Energy Institute,” Mayfield says. “In addition, the NRC created the Advanced Reactor Program to provide an organization within the office of new reactors to focus on this technology in order to provide appropriate attention, while at the same time not distract resources or attention from the large light-water reactors.”

The Technology

According to Mayfield, there are at least three different technologies in