CORVALLIS, Ore. - A costly and disturbing accident that two decades ago seemed like the death knell for the nuclear power industry may in fact have set the stage for its rebirth, experts say.

On March 28, the United States will observe the 20th anniversary of its worst nuclear power accident at Three Mile Island in Pennsylvania - an incident that to this day has cast a pall of suspicion and doubt over the future of the nation's nuclear energy industry.

But that same event set into motion technological research and other changes that some experts believe will soon lead to a revitalization of the industry not only in other nations around the world - where the active development of nuclear power never really stopped - but also in the U.S.

And the key, they say, may lie in such events as the 80 or more nuclear "accidents" that have happened at Oregon State University during the past six years, as engineers used simulations in an $8.5 million test facility, which contains no actual radioactive materials, to fine tune the "next generation" of passively-safe nuclear reactors.

"In various tests we have caused loss of coolant, broken pipes, failed pumps, and loss of all electricity for our systems," said Jose Reyes, a professor of nuclear engineering at OSU and former Nuclear Regulatory Commission official who helped review the Three Mile Island incident after it happened. "In some of these scenarios we basically caused everything imaginable to go wrong. And this new reactor design proved to be outstanding."

The result is that based on these and other tests Westinghouse Corp. recently received final design approval for its "AP600" reactor design, bringing it a major step closer to legal certification, commercial sale, and status as the world's first design licensed as a "passively-safe" nuclear reactor.

Those mechanisms - gravity, natural circulation, condensation, evaporation - are based on little more than the natural laws of physics. But researchers say they will produce nuclear reactor technology that could push this form of energy back onto the front burner, especially as demand heats up for a form of energy that, unlike fossil fuels, does not exacerbate the greenhouse effect and global warming.

The accident at Three Mile Island - in which a valve failed, reactor operators misdiagnosed the problem and the reactor core was eventually destroyed - caused the initial impetus for simpler, less complex reactor technology, Reyes said.

It also prompted more focus on the type of smaller, non-catastrophic accidents that posed the most realistic obstacle to the use of nuclear power. After 20 years of research that vision is nearing a reality.

The AP600 design, for instance, has 50 percent fewer valves and 35 percent fewer pumps than a conventional nuclear reactor, Reyes said. In the event of problems or a malfunction, it's designed to protect the nuclear core with basic, natural mechanisms instead of complicated technology.

"This design is very dependable," Reyes said. "It and other passively-safe designs that are under development should go a long way towards resolving any realistic concerns people may have about nuclear safety. About all we have to depend upon is the force of gravity."

The last nuclear power plant in the United States was completed in the 1980s, Reyes said. No new plants have been ordered in the U.S. since then, although the 109 operating nuclear power plants still provide 20 percent of the nation's electricity. But the need for a form of energy that is readily available, can be produced close to where it is needed, is cost competitive and doesn't cause greenhouse gas emissions should force a closer look at expanding the nuclear energy role, he said.

"Other nations such as Japan and France make heavy use of nuclear energy, and in fact are now moving ahead of us in the development of the newest technology," Reyes said. "And the United States is committed to reducing greenhouse gas emissions. Frankly I don't know how we can do that without further expansion of our nuclear energy industry."

OSU has been instrumental in helping to bring new reactor technology from the drawing board to reality, Reyes said. Its elaborate testing facilities have been used in years of testing by private industry and the Nuclear Regulatory Commission, and that agency has just given OSU a new five-year contract to explore basic technological questions related to advanced reactor concepts.

One of the few remaining obstacles to a renewed push for nuclear energy - the lack of a permanent repository for high level radioactive waste - has basically been solved on a technical level, Reyes said, and is just waiting for final designation of a site by the U.S. Department of Energy.

"We've come a long way since the incident at Three Mile Island," Reyes said. "It seemed like nothing but a tragedy at the time, but in fact it helped motivate this industry towards simpler reactor designs, more sophisticated inspections, improved maintenance, incident response management and risk assessment studies. And people sometimes forget that even in that accident, no one was ever injured.

"It's time now for people to take another look at nuclear energy and the safe, dependable new technologies that have been developed," Reyes said. "Around the world they are already doing that. With the environmental issues we're concerned about, it's clear that nuclear power is one of the solutions."

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Jose Reyes, 541-737-7065