Nuclear Scientists At Oak Ridge Learn Realities Of Reactor Safety

Temporary shutdown of research reactor turns into three-year hiatus as managers try to understand the world after Chernobyl OAK RIDGE, TENN. -- Though it may be impolite, it's hardly news when a scientist avoids a meeting to carry out an experiment. But for Oak Ridge National Laboratory nuclear physicist George Wignall, showing up late for an interview with a reporter was cause for celebration. "We've been waiting three and a half years for this machine," he explained to a reporter, exulting over the startup of the lab's High Flux Isotope Reactor (HFIR). "We want to get every neutron we can." As he spoke, a voice announced over a loudspeaker that the reactor was being shut down again. In fact, it will be sometime this month before the 85-megawatt reactor is scheduled to resume full-power, around-the-clock operations. But Wignall isn't complaining. "The reactor is actually operating," he said as he collected the last piece of data. "Now we're actually doing research again on the machine. And that's kind of amazing." The largest and most important of the five research reactors at Oak Ridge, HFIR was started up in January after being idle for more than three years. What officials thought would be a brief delay to fix a technical problem snowballed into a comprehensive examination of the 25-year-old reactor. Although the integrity of the reactor itself was never an issue, the process has taught scientists and administrators alike that even the smallest government research reactors must now conform to nationwide industry standards. Wignall came to Oak Ridge in 1980 to help establish its program on small angle neutron scattering. The technique is used to study the molecular structure of polymers and other materials. It's one of many ways that the research reactor is used. For example, the Pentagon uses neutrons generated by HFIR to inspect possible damage to the percussion caps on explosive bolts and to the wings of its airplanes. HFIR is also the nation's only source of californium-252, an isotope used to treat cervical cancer and to inspect the fuel rods in commercial nuclear reactors. Questions about the reactor first arose in November 1986, when a special team of Oak Ridge National Laboratory (ORNL) scientists commissioned by then-director Herman Postmas discovered a metallurgical problem in the carbon-steel pressure vessel. The designers of HFIR had deposited near the beam tubes extra samples of the structural steel used in making the reactor. The samples were supposed to be taken out every few years and, as an extra safety precaution, checked for radiation effects. The team discovered that one sample, taken in 1983, had been tested and found to be surprisingly brittle. The original word was that the reactor would be shut down for a short time while the problem was dealt with. "A couple weeks, that's what we were told," recalls Wignall. But soon questions about brittle steel began to take a back seat to a larger issue: the managerial practices that had allowed the problem to go unreported. It took a long time for the Department of Energy and ORNL to realize that they had to adopt the same operating standards used in the commercial nuclear power field. And it took even longer for them to fully understand the degree to which the system they had been using for more than 20 years would have to be changed. Martin McBride was one of the first people to come on board from industry, having worked as a site representative for the Pilgrim Nuclear Power Plant in Plymouth, Mass. Joe Lenhard, a retired DOE assistant manager formerly in charge of restarting HFIR, remembers the many heated conversations between the two men about what needed to be done. "I can't count the times he would come in and really rattle our chains," says Lenhard. "And our first reaction was always, `My gosh, we can't do that.' " Lenhard adds, "When we made changes, we took little baby steps. Even when we brought in outside experts, and they would tell us everything that had to be done, we simply didn't understand the deep significance of what had to happen." In short, ORNL officials just couldn't believe that they should be held to the same standards of management that were needed for the larger commercial reactors in operation around the country. Until they accepted that need, however, the changes being proposed for HFIR were simply cosmetic ones. Lenhard recalls telling McBride, "Martin, I'm so tired of hearing about the Pilgrim reactor. Let's talk about HFIR." He also recalls McBride's reply: "Joe, I'll tell you what. I won't ever talk again about the Pilgrim reactor if you will stop saying that this is just a little research reactor." In other words, says Lenhard, the culture had to change. Lab managers spent much of the next two years absorbing advice from various review groups, including officials from the nuclear power branch of the U.S. Navy as well as from the nuclear power industry. The process exposed lab officials to the world of nuclear reactors after Chernobyl. "It's the way we do business nowadays," says Hal Glovier, director of ORNL's research reactors division and a former industry consultant. "Today, everything in the nuclear power field operates in a fishbowl. If something happens to someone it puts you in a bad light as well. So even if you were doing it right from the beginning, you have to do it in a more formal manner and be able to document what you've done." For scientists doing work on neutron scattering, the hiatus added the luxury of time to an otherwise hectic pace. It offered them the chance to catch up on data analysis, and they jumped at the opportunity. "At first I thought the shutdown was great," says Wignall. "If we could only get rid of some of our users, I thought, we could finally catch our breath. As it turned out, I've published more in the last three years than in any other time. But after a while I realized it could be a couple of years before we got back on the machine. That's a different kettle of fish." One affected group was graduate students planning to do work on HFIR for their doctoral degrees. "They were hurt badly," says Wignall. "I think that we may have lost a generation of scientists in this field." The delay also meant lost opportunities for researchers already in the field. "The discovery of high-temperature superconducting materials was made just at the time that the HFIR was being shut down," notes Fred Mynatt, an official at Martin Marietta, which has a contract with DOE to operate ORNL. "If it had been operating, a great deal of knowledge could have been developed regarding these types of materials." Wignall and others don't believe that they were left in the dark about the status of HFIR. But the experience was still disheartening, they say. "There was a sense of disbelief and bewilderment," says Ralph Moon, director of the lab's division of solid-state physics. "It was hard to understand why all these managerial changes were necessary in a reactor that had operated safely and successfully for more than 20 years." The shutdown was even felt on the international scale. The Japanese, for example, have a cooperative research program with ORNL scientists in neutron scattering that has been postponed repeatedly. Ironically, a second world-class neutron scattering facility, at the Institute Laue-Langevin in Grenoble, France, was shut down earlier this year when operators discovered that their instruments were registering power levels 10 percent lower than what was actually occurring. "It's supposed to be up again in a few weeks," says Moon about the French facility. "But then, we all thought HFIR would be up in a few weeks." Jennifer Andes is a reporter with the Oak Ridger, a local daily newspaper.

Nuclear Scientists At Oak Ridge Learn Realities Of Reactor Safety

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