Posted by: Jonathan Marshall

One of the biggest stories to come out of this week's announcement of the Department of Energy's new budget was its support for nuclear power plant--including $36 billion in new loan guarantees.

But one of the most overlooked stories was DOE's proposed support for small modular reactors in the $195 million "Reactor Concepts Research, Development and Demonstration" program. According to The Energy Daily, Secretary of Energy Steven Chu "appears to have won a tussle with the White House Office of Management and Budget," which "last year had sought to bar DOE work in that area."

In December, a senior DOE official told a Senate committee that small nuclear reactors--typically a tenth the size of most commercial reactors operating today--may prove more cost-effective for many applications and pose fewer proliferation risks. Their modular designs may be suitable for mass production, lowering costs and improving reliability. Some are even designed to be installed underground, reducing the threat of terrorist attack.

A fierce race to develop small commercial reactors is underway globally."Technical and manufacturing innovations make [small reactors] a potential game-changer for the global clean energy market," said Christofer Mowry, president and CEO of Babcock & Wilcox Modular Nuclear Energy, which is developing a 125 MW reactor of its own.

Like their big brethran, most small reactors under development today create heat through uranium fission, which is used to create steam that drives a turbine to generate electricity.

But because of their small size, they should be easier to manufacture and more suitable for remote locations or industrial uses. Many designers claim they are inherently safe as well, incapable of runaway chain reactions and melt-downs. And many proponents project that they could generate clean power for as little as 6 to 9 cents per kilowatt hour, a fraction of the cost of solar power.

One of the centers of research on small reactors is Sandia National Laboratory. Its proposed design will generate between 100 MW and 300 MW of power, and has a relatively simple cooling system based on liquid sodium. It should operate for several decades without refueling, and cost only $250 million per unit.

Meanwhile, design concepts developed at Los Alamos National Laboratory are being commercialized by Santa Fe-based Hyperion Power Generation, Inc. In November, it unveiled its design for a power module, or "fission battery," that generates 25 MW of power, enough to serve about 20,000 typical homes. Hyperion calls it a "safe, self-contained, simple-to-operate" design that is "small enough to be manufactured en masse and transported in its entirety via ship, truck, or rail."

Corvallis-based NuScale Power, commercializing DOE-funded research at Oregon State University, also says it has developed a small nuclear power system that is "safe, modular and scalable." Its 45 MW water-cooled reactors could be combined in clusters to produce as much power as a conventional reactor but with much less construction time. The company hopes to submit a design to the Nuclear Regulatory Commission for certification this year. The company is backed by CMEA Ventures, based in San Francisco.

Posted by: Jonathan Marshall

We've all heard the litany of complaints from opponents of nuclear power: it creates long-lived radioactive waste; the fuel cycle produces plutonium that could be diverted to nuclear weapons; and runaway nuclear reactions might cause reactor meltdowns, endangering the public.

The nuclear industry has good answers to each of these claims, but the best answer may someday be to reinvent nuclear power altogether.

To wit: substitute a relatively abundant, silvery-white element called thorium for uranium and plutonium in commercial reactors.

Thorium-based reactors, like those using uranium or plutonium, work on the principle of nuclear fission. Thorium absorbs neutrons to create uranium 233, whose nuclei are then split to release energy that can be harnessed by steam generators to produce electric power.

Experiments at Oak Ridge National Laboratory in the 1960s and 1970s proved that thorium could work as a fuel, but industry saw no need to introduce new designs when uranium reactors worked well enough.

In principle, say boosters of the rival element,

thorium could solve the nuclear power industry's most intractable problems. After it has been used as fuel for power plants, the element leaves behind minuscule amounts of waste. And that waste needs to be stored for only a few hundred years, not a few hundred thousand like other nuclear byproducts. Because it's so plentiful in nature, it's virtually inexhaustible. It's also one of only a few substances that acts as a thermal breeder, in theory creating enough new fuel as it breaks down to sustain a high-temperature chain reaction indefinitely. And it would be virtually impossible for the byproducts of a thorium reactor to be used by terrorists or anyone else to make nuclear weapons.

In addition, proponents say thorium-based reactors can be designed to regulate their output to eliminate the risk of a meltdown.

Interest in thorium is growing worldwide. India is working on a thorium-based reactor design that may be ready within a couple of years. China also hopes to exploit domestic reserves of thorium to reduce its nuclear industry's dependence on imported uranium. An expert panel formed by the China National Nuclear Corporation has reportedly selected a Canadian reactor design as the most promising way to shift to a thorium fuel cycle. 

A public U.S. company called Lightbridge Corp. is working with nuclear designers in France and Russia to produce thorium-based fuel rods that could replace uranium in some commercial reactors by 2017.

Finally, further research on the prospects of thorium has been championed--so far unsuccessfully--by an unusual pair of bipartisan sponsors in the Senate: Orrin Hatch of Utah and Harry Reid of Nevada.

"With the growing interest in thorium nuclear power in the world and in the U.S.," Hatch said when introducing the Thorium Energy Independence and Security Act of 2008 last fall, "it's time we made sure our government has a regulatory infrastructure in place to accommodate this new generation of nuclear power."