Safety Called Prime Design Consideration for New Nuclear Reactor
RENO, Nev. (AP) _ An experimental technology for nuclear power plants has the potential to be safer than today’s technology, and researchers should emphasize that goal in their designs, an expert says.
Producing demonstrably safer reactors using fusion technology should help with public acceptance, regulatory hurdles and perhaps economics, said Steven Piet of EG&G Idaho Inc.
″It’s not enough to be safe in some technical sense. We have to go further than that and demonstrate that safety″ to regulators and the public, Piet told a Wednesday session of the annual meeting of the American Nuclear Society.
In an interview, Piet said that although today’s commercial reactors in the United States and western Europe are very safe, fusion is ″one of the few things that has the potential to be even safer″ than the current technology.
Fusion power harnesses the tremendous amount of energy released when the nucleus of a hydrogen atom fuses with another to form helium. In contrast, current reactors use the energy releasd when atoms of uranium are split, a process called fission.
Fusion requires special forms of hydrogen, called deuterium and tritium. Deuterium, which is not radioactive, is abundant in sea water. Tritium, which is radioactive, is man-made. Current fusion experiments use a mix of the fuels, but future reactors may use just deuterium, a fuel with virtually limitless supply.
The first commercial fusion plant probably won’t be ready until early in the next century, scientists say.
Fusion has several inherent safety advantages over fission, Piet said. A fusion reaction is easier to halt, its tritium fuel has only very mild radioactivity, and in contrast to the inevitable radioactive byproducts of a fission reactor, fusion produces helium and materials whose radioactivity can be limited, he said.
Those materials, initially non-radioactive parts of the reactor, become radioactive from bombardment of tiny particles called neutrons. But proper selection of materials can limit the degree to which they become radioactive, said Piet.
He said it might be possible to keep the total amount of radioactive material in a fusion plant so small that the plant would be inherently safe for the public, no matter what accident happens. But he called that a difficult goal that may not be achievable.
He said he does think a fusion plant could be built such that its design alone would assure public safety despite pipe breaks or other internal troubles. No added-on safety systems would be required.
Other energy technologies probably could not reach that level of safety assurance, Piet said in a paper submitted to the meeting.
Safer designs could lead to greater public acceptance by avoiding a ″catastrophic label″ people attach to fission technology, Piet said. And regulators may license the plants more quickly, allowing an earlier return on a utility’s investment, he said.
The designs might also save money on insurance rates and safety-related features now required that might not be necessary in a well-designed fusion plant, he said.
But researchers have only begun to look at what the kinds of safety approaches he described would cost, and how much they would hinder other aspects of designing a fusion plant, he said.
John P. Holdren, professor of energy and resources at the University of California, Berkeley, agreed that safety should be a key design consideration to make fusion an attractive energy source.
When fusion is ready for commercial application, it probably won’t be cheaper than fission, and other technologies will match its promise of virtually unlimited fuel, leaving safety as a key selling point for fusion, he said.
″Safety has to be designed in from the ground floor, and since we’re on the ground floor now, now is the time to be thinking about how to do it,″ he said in an interview.