Small Reactors - Are they the answer?

A new type of nuclear reactor—smaller than a rail car and one tenth the cost of a big plant—is emerging as a contender to reshape the nation's resurgent nuclear power industry.


Three big utilities, Tennessee Valley Authority, First Energy Corp. and Oglethorpe Power Corp., on Wednesday signed an agreement with McDermott International Inc.'s Babcock & Wilcox subsidiary, committing to get the new reactor approved for commercial use in the U.S.

The smaller Babcock & Wilcox reactor can generate only 125 to 140 megawatts of power, about a tenth as much as a big one. But the utilities are betting that these smaller, simpler reactors can be manufactured quickly and installed at potentially dozens of existing nuclear sites or replace coal-fired plants that may become obsolete with looming emissions restrictions.

Now, after a two-decade lull in construction, the U.S. is gearing up for a robust revival of nuclear power. Expanding the nuclear sector, which currently produces 20% of the nation's electricity, is considered essential to slashing carbon emissions.

For utilities, a small reactor has several advantages, starting with cost. Small reactors are expected to cost about $5,000 per kilowatt of capacity, or $750 million or so for one of Babcock & Wilcox's units. Large reactors cost $5 billion to $10 billion for reactors that would range from 1,100 to 1,700 megawatts of generating capacity.

While large reactors are built on site, a process that can take five years, the mPower reactors would be manufactured in Babcock & Wilcox's factories in Indiana, Ohio or Virginia and transported by rail or barge. That could cut construction times in half, experts believe.

Because they could be water-cooled or air-cooled, mPower reactors wouldn't have to be located near large sources of water, another problem for big reactors that require millions of gallons of water each day. That could open up parts of the arid West for nuclear development.

The first units likely would be built adjacent to existing nuclear plants, many of which were originally permitted to have two to four units but usually have only one or two.

Down the road, utilities could replace existing coal-fired power plants with small reactors in order to take advantage of sites already served by transmission lines and, in some cases, needed for grid support. Like any other power plants, these small reactors could be easily hooked up to the power grid.

Another advantage: mPower reactors will store all of their waste on each site for the estimated 60-year life of each reactor.

Nuclear development moves at a glacial pace. The next wave of large reactors won't begin coming on line until 2016 or 2017, at the earliest. The first certification request for a small reactor design is expected to be Babcock & Wilcox's request in 2012. The first units could come on line after 2018.

However, some experts believe that if the industry embraces small reactors, nuclear power in the U.S. could become pervasive because more utilities would be able to afford them.