A new idea for nuclear power

Energy: A University of Maryland scientist has faith in his novel approach but finds $2 million for testing difficult to come by.

Medicine & Science

September 13, 2004|By Dennis O'Brien | Dennis O'Brien,SUN STAFF

Claudio Filippone is convinced that the jury-rigged gadget in his College Park lab can help solve the world's energy problems - even if it does look like it was designed by Rube Goldberg.

The University of Maryland researcher bought wiring and other parts from hardware stores to build a "heat cavity," a sandwich of six-foot steel sheets with a razor-thin space between them.

Bolted together, sealed on each side with silicone putty and connected by wires to a portable generator that can heat up the sheets like burners on a stove, the device is designed to simulate what happens in a nuclear reactor - minus the radioactive material.

FOR THE RECORD - An article about nuclear reactor designs in Monday's editions incorrectly reported the type of coolant used in breeder reactors overseas and the type of reactors U.S. universities use for research. Breeder reactors use liquid metals as coolants, and universities conduct research with thermal reactors.
The Sun regrets the errors.

Filippone says his ultimate goal is a nuclear power plant that minimizes radioactive waste. He says he can test his theory for $2 million - possibly by using a nuclear lab in the Czech Republic. The problem is finding someone willing to take a chance on what looks like a long shot at a time when the government and power industry are ready to move on with other designs.

Steam as a coolant

When Filippone flicks a switch to heat the steel sheets in his lab and then hoses water between them, the cavity generates steam through a valve. He hopes he can use the same kind of steam to cool down a reactor.

Currently, the nation's 103 commercial nuclear plants, which generate about 20 percent of its electricity, operate on a slightly different principle. They split, or fission, uranium atoms in a containment vessel, heating water into steam that is used to generate electricity.

Known as light water reactors, they use water to cool off the enriched uranium that heats up in the fission process. Filippone says his tests show that steam can be used to cool the fuel, a key factor in his experimental reactor design.

"It shows steam is an effective heat-transfer mechanism," he said. "Now, I need to go to the next step."

Filippone's work, and that of other scientists, comes at a critical time for the nation's power industry.

Memories of the nuclear accident at Three Mile Island in Pennsylvania in 1979 and the Soviet Union disaster at Chernobyl in 1986 remain etched in many minds. After TMI, about 50 nuclear reactors with prior approvals were completed, but plans for others were scrapped.

In 1992, the nuclear industry was dealt a major setback when the $5.5 billion Shoreham nuclear power plant on Long Island closed before it began operating because of public opposition.

But with oil prices rising and the future of coal uncertain, sentiment for new reactors is growing. Up to three U.S. nuclear plants could be built in the next decade - at sites near existing nuclear plants, according to the Department of Energy. The Bush administration wants at least one new reactor by 2010.

DOE is working with three utilities - Dominion Resources, Entergy and Exelon - to explore the feasibility of building reactors in Virginia, Mississippi and Illinois. The Tennessee Valley Authority is considering reopening a closed nuclear plant in Alabama.

Critics of this nuclear expansion say nuclear waste remains a major concern. About 44,000 metric tons of highly radioactive, spent nuclear fuel are stored at power plant sites around the country, awaiting shipment to a proposed Nevada storage facility that faces a court fight years from resolution.

The light water reactors used in commercial power plants and the breeder reactors used in university labs produce plutonium as a byproduct - the same material the United States is trying to restrict overseas because it is highly poisonous and can be used to make nuclear weapons.

Dual-reactor system

Filippone says his proposal offers a solution: a closed-cycle nuclear plant with two reactor systems. One would be a fast reactor that uses uranium to produce plutonium, the other a thermal reactor that uses plutonium as a fuel source. Either reactor system could be used to produce power, allowing power companies to switch between them. And the byproduct of the fast reactor would become fuel for the thermal reactor. That would cut down considerably on nuclear waste.

"It would be an excellent solution, in terms of proliferation issues," Filippone said.

Filippone's system relies on testing his hypothesis that steam can be used as a coolant in the two-reactor system. Using steam instead of helium and other gases now used in breeder reactors would make the system safer, he said.

But his solution isn't on DOE's radar screen. The federal agency plans to spend $97 million this year on research for new designs and fuel systems for so-called Generation IV nuclear power plants. It worked with experts in a dozen countries, reviewing more than 100 nuclear energy concepts for two years, before its engineers came up with six prototype designs for new reactors in 2002.

"The process was very thorough," said William Magwood, director of the DOE's Office of Nuclear Energy, Science and Technology.

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