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Is The Future Of Nuclear Power In Minireactors?

Instead of building costly, huge nuclear power plants like the Exelon Byron station in Byron, Ill., engineers are scaling down — aiming for garage-sized reactors that produce just one-tenth the amount of electricity of a conventional facility.
Jeff Haynes
AFP/Getty Images
Instead of building costly, huge nuclear power plants like the Exelon Byron station in Byron, Ill., engineers are scaling down — aiming for garage-sized reactors that produce just one-tenth the amount of electricity of a conventional facility.

Almost 60 years ago, engineers in Idaho switched on the world's first nuclear power plant. It was only able to illuminate four light bulbs. The reactor vessel in Idaho stood about 8 feet high, and eventually it made enough electricity to power a building.

A nuclear plant today can produce 10,000 times as much electricity. But for the past 20 years, new nuclear plants have been too expensive to build. Now engineers are trying to revive the industry by thinking small again.

They're designing what they call "modular" or "mini"reactors. Instead of occupying a city block of buildings, the smallest could fit in a two-car garage. And it won't break the bank.


"We've been calling it the economy of small," says Jose Reyes, who runs a company called NuScale Power. Reyes has designed a reactor about one-tenth the size of current reactors. It looks very different, though, kind of like a 50-foot-plus thermos.

"The concept is that you can't take a large reactor with all of its pumps and valves and piping and just shrink it down and expect to see an economic advantage there," he says.

In a standard reactor, there are pipes running everywhere, and pumps and valves to circulate water to the reactor core. The hot fuel creates steam that is piped out of the reactor vessel to run a turbine. If pumps or valves fail to keep the water moving, you can get a Fukushima-style meltdown.

In the NuScale reactor, there are no pumps. Water circulates naturally as it gets heated and then cools off. The whole reactor sits underground in a tank of water that will flood everything in case of an accident.

Economies Of (Small) Scale?


Nuclear engineers say this so-called "passive" cooling design is safer than existing plants. Reyes says it's cheaper, too. Because his reactors are small, a utility company can order, say, have a dozen, then add more as needed.

"If you built a six-pack plant," says Reyes, "you're looking at a cost of around $1 billion, $1.2 billion. And if you are looking at filling it out with the remainder, it's about a $2 billion plant. So we're not asking the utilities to put out 5, 6, 7 billion dollars upfront to build a large facility. "

A large traditional plant also takes a decade to build. During that time, a builder pays interest on borrowed money and jumps through numerous regulatory hoops. But the minireactor people say, "Just tell us how many you want, and we'll ship them from the factory along with the ignition key."

There are doubters, of course, like Ernest Moniz, a physicist and energy expert at the Massachusetts Institute of Technology.

"To really test that proposition, you've got to produce a whole bunch of the same modular reactor on a cookie cutter line, because that's where the cost reduction is supposed to come from," he says. That requires a lot of start-up money and lots of orders for an unproven technology.

Another problem: If a minireactor puts out, say, one-tenth the electricity of one of its giant brethren, it will have to cost about one-tenth as much to build and operate to be competitive.

Energy consultant Kevin Book, with ClearView Energy Partners, says that's not likely. Some costs are pretty well fixed, no matter how small you are — getting permits, for example, or paying interest on loans.

"If you only have a very small plant bearing a very large regulatory or capital cost from delay," he says, "you don't have an economic resource at all."

Looking To The Future

Nonetheless, mininukes are popular. Enthusiasts include Microsoft's Bill Gates, who's backing a company called TerraPower.

At the industry's Nuclear Energy Institute, policy head Paul Genoa says minireactors might appeal to smaller utilities or foreign buyers who can't afford $5 billion for a big power plant. And cheaper kinds of power — coal and natural gas, for example — may not look so good as more governments tax or limit climate-warming carbon from power plants. Nuclear reactors don't emit carbon.

"The price that we're trying to compete with is not the price of a big nuclear plant today, or natural gas today," says Genoa, "but it's what it will be in 2020, and it's what it will be in different parts of the world."

Reyes' company, NuScale, and reactor builder Babcock & Wilcox have asked the Nuclear Regulatory Commission to approve their mininuke designs. Babcock & Wilcox is, in fact, already making small reactors — but they don't make commercial electricity. They power Navy submarines.

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