National Geographic: Chris Carroll - March 2010

ART: Splashlight

8,000 - Approximate number of households that could be powered bt a 10-megawatt mini-reactor

They'd be carbon free, relatively cheap, and according to the industry, inherently safe. An underground mini-nuke could power a village.
Most nuclear power plants are behemoths, big enough to power a medium-size city. They are also behemoth investments, costing upwards of several billion dollars each to construct. Small wonder then that dozens of small-reactor prototypes are vying for attention in an industry newly energized by nuclear power's advantages as a low-emission alternative to fossil fuels.

"Small reactors can't address all the problems standing in the way of more nuclear investment, but they can address the biggest barriers—the economic ones," says Richard Lester, head of nuclear science and engineering at MIT. Building giant reactors, he points out, isn't the only way to achieve economies of scale; another way is to mass produce inexpensive mini-nukes. If they're designed as modules, a single unit might power a remote town or mine, while a dozen used in tandem could match the output of a traditional nuclear plant. In the developing world, small reactors would place less strain on fragile electrical grids. And the ability to start small and gradually add power modules could appeal to cash-strapped utilities everywhere.

ART: Hiram Henriques

None of the new small reactors have been deployed yet. Some, like the one designed by NuScale Power, are light-water reactors that resemble ones long used on warships. Others are more novel. Toshiba and the Japanese Central Research Institute of Electric Power Industry are working on a liquid-sodium-cooled "nuclear battery." Delivered partially assembled and installed underground, the reactor would generate ten megawatts for 30 years until it needed refueling. The isolated Alaska village of Galena is in discussions with Toshiba to become its first customer.

Besides costing less to build, some small reactors could be inherently safer, says Vladimir Kuznetsov of the International Atomic Energy Agency. NuScale's design requires no reactor cooling pumps, while Toshiba's pumps are electromagnetic, without moving parts; either approach diminishes the possibility of a disastrous failure. Chinese researchers, meanwhile, are developing a small reactor in which the nuclear reaction itself is self-limiting. In a dramatic 2004 demonstration, they turned off the cooling system; the reaction just burned itself out. With any of the new reactors, of course, there will still be radioactive waste to contend with.

There are 56 reactors under construction in the world today, 19 in China alone. But with energy demand soaring—and the threat of climate change looming—even that much construction will not greatly increase nuclear's share of the global electricity supply. Small reactors could help, Lester says. "The point is to scale up low-carbon energy sources rapidly. Nuclear has great potential to do this." If regulators go along, that is. In the U.S., officials say some designs may win certification within five years. More innovative ones may take longer.


Bill Gates, Toshiba in early talks on nuclear reactor March 23, 2010

TOKYO (AFP) – A company backed by Microsoft founder Bill Gates and Toshiba are in early talks to jointly develop a small nuclear reactor, the Japanese electronics giant said Tuesday.

The Nikkei business daily earlier reported that the two sides would team up to develop a compact next-generation reactor that can operate for up to 100 years without refueling to provide emission-free energy.

The daily said the joint development would focus on the Traveling-Wave Reactor (TWR), which consumes depleted uranium as fuel. Current light-water reactors require refueling every few years.

"Toshiba has entered into preliminary talks with TerraPower," said Toshiba spokesman Keisuke Ohmori. "We are looking into the possibility of working together."

Gates is the principal owner of TerraPower, an expert team based in the US state of Washington that is investigating ways to improve emission-free energy supplies using small nuclear reactors.

Unlike the current reactors at mega power plants, the smaller types could be introduced by cities or states or in developing countries more easily.

Ohmori said Gates, together with other TerraPower executives, had visited a Toshiba laboratory for nuclear power research near Tokyo last year.

"TerraPower is developing a small nuclear reactor and Toshiba is developing a different kind of small reactor. They were interested in Toshiba's technology and aiming at practical realisation" of small reactors, he said.

Ohmori said the two sides had just begun to "exchange information" but stressed that "nothing concrete has been decided on development or investment."

Gates is expected to use his personal wealth to back the development of TWRs and his investment could reach several billion dollars, the Nikkei said.

The news boosted Toshiba's share price by around four percent Tuesday.

The Nikkei said TerraPower had decided to join hands with Toshiba as it lacks the know-how to manufacture nuclear power equipment.
Toshiba, which owns US nuclear plant maker Westinghouse, has developed a design for an ultracompact reactor that can operate continuously for 30 years.

The company is preparing to apply for US approval to start constructing the first such reactor as early as 2014 and put it into practical use by the end of the decade, Ohmori said.