While the demand for new large nuclear reactors may have fallen in the United States in response to the recession, interest in smaller, cheaper, scalable nuclear reactors is on the rise.

B&W, mPower nuclear reactor, TVA, Clinch River
Image: Babcock & Wilcox Nuclear Power
B&W’s modular mPower unit. Six are under consideration for installation at TVA’s Clinch River site.

About a half-dozen companies have notified the Nuclear Regulatory Commission that they will apply for design certification and eventually licenses for smaller reactors that range in size from 25 megawatts to about 300MW.

“It’s a challenging time to justify putting on 1,500 MW of nuclear power onto the grid. Some of it [the nuclear renaissance] is going to be reprogrammed into the small nuclear reactor market,” says Christofer Mowry, president and CEO of Babcock & Modular Nuclear Energy, LLC . “I think that some places are much better suited for the SMR.”

B&W, along with Bechtel, is developing a 125-megawatt nuclear reactor, called mPower. The companies believe the first such units could be deployed by 2020. Those units might be at the Tennessee Valley Authority’s Clinch River Site in Roane County, Tenn. In November, TVA notified the NRC that it is considering installing six mPower reactors at Clinch River.

And in September, Savannah River Nuclear Solutions also announced that it had signed an agreement with Hyperion Power Generation Inc., Los Alamos, N.M., to pursue the development of a nuclear mini-reactor that could produce 25 MW of power. Both SRNS and TVA say they are pursuing the modular nuclear units as a way to demonstrate such units are feasible.

“We are taking the lead at this point in time to try to help get the units licensed,” says Jack Bailey, vice president of nuclear generation development for TVA. “We want to bring it all the way to commercialization.”

Proponents argue modular reactors can be built primarily in factories, shipped by rail or truck and installed, at the site of a mothballed coal plant, for instance. The modular units are scalable, meaning one module might be enough for one site, while another site might choose to install two or three modules. Some, like Hyperion’s design, are permanently sealed.

“One of the drivers to he SMR value proposition is that it changes that traditional paradigm that 70% of your cost and effort and risk is at site,” Mowry says. “70% of this thing is in the factory, 30% is in the field.”

The mPower’s entire nuclear steam supply system would be built offsite. B&W says that a unit can be built within three years. Under the agreement with Bechtel, B&W will focus on designing and testing the nuclear steam supply system, the nuclear island, including design certification and Bechtel will assist with integrated engineering and project management leadership.

Mowry won’t yet discuss the estimated cost to build the units, but has said that they will be cost-competitive. Hyperion has been reported as saying that the unit at SRS could cost as little as $50 million.

Hyperion’s reactor would be about the size of a refrigerator and buried below grade. The complete plant, including the electrical generation system, would take up less than an acre, the company says.

The mPower unit would also be underground, would have passive safety systems, and would have the ability to operate for four years between refuelings, according to B&W.

Greenpeace has criticized the small modular units as being potential targets for terrorism, and points out that the issues of nuclear waste still haven’t been resolved. The units also take as many people, with nuclear expertise, to operate as larger plants.

The U.S. isn’t the only country considering the small reactors. Many developing countries have plans for such reactors, with China and South Africa the farthest along with their plans. The International Atomic Energy Agency, in a 2009 study, concluded that there could be 43 to 96 of the smaller nuclear units in operation worldwide by 2030.

“Internationally, there are grids that can NOT sustain a large new build on the grid,” says Carl Rau, president of San Francisco-based Bechtel's nuclear power division. “We�re excited about it and so is DOE.”

Dept. of Energy Secretary Steven Chu supported the development of the small reactors in a opinion piece in the Wall Street Journal. The Obama administration has requested $39 million in the 2011 budget to support the development of small nuclear reactors. Chu touted the units as being “plug and play,” and a good solution for many sites.

“If we can develop this technology in the U.S. and build these reactors with American workers, we will have a key competitive edge,” Chu wrote.