Moscow Rated Damaged Plant Among Safest

The accident at a Soviet nuclear power plant struck a facility that the Soviets believed to be much safer than nuclear plants elsewhere, according to scientists in the United States familiar with the Soviet nuclear industry.

In fact, the Soviets have been so confident of the safety of their nuclear power plants that they only recently began taking precautionary steps to contain radiation in the event of an accident.

Decision Too Late

It was an accident in the United States--at Three Mile Island in Pennsylvania, in March, 1979--that persuaded the Soviets to enclose their new plants in containment structures like the massive steel and concrete domes that house U.S. reactors. But that decision came too late to protect the Chernobyl plant, on the Dneiper River 60 miles north of the industrial city of Kiev, which spewed radioactive materials into the air over the weekend.

The sketchy description of the incident released by the Soviets suggests that the accident involved “some kind of rupture” of the main reactor vessel, which is one of the most serious mishaps that can befall a nuclear power plant, said Julius Goodman, a Soviet emigre and a nuclear physicist who worked for many years on reactor safety in the Soviet Union.

“There would definitely be some fatalities for people who work there,” said Goodman, who is now doing research at California State University, Long Beach. Goodman was a professor of theoretical physics at Odessa Polytechnic University in the Soviet Union.

The Soviet accident occurred at one of that country’s largest nuclear installations. Four 1,000 megawatt reactors have been completed there, and two more are under construction for a total capacity of 6,000 megawatts. By contrast, the San Onofre nuclear power plant in San Diego County, California’s largest, has a total of 2,650 megawatts.

Soviet reactors are significantly different in design from Western reactors. U.S. reactors are cooled by a single, primary cooling loop and have numerous backup cooling systems.

But at the Chernobyl plant, fuel is dispersed in a rectangular pile of graphite blocks, though which water flows at low pressure through hundreds of slender tubes, drawing off heat. As recently as June, 1983, the Bulletin of the International Atomic Energy Agency said that “a serious loss of coolant accident is practically impossible” with that design.

But speculation Monday centered on the possibility of a graphite fire that could have destroyed the reactor and released radioactive fission products. And since there is no containment building, there would be nothing to keep the deadly radiation from being released into the air.

Goodman said that only a rupture of the reactor vessel itself could account for the widespread radiation detected in Finland and Scandinavian countries.

Radioactive materials were carried by prevailing winds 750 miles across Finland, Sweden, Denmark and Norway, but U.S. officials said Monday that they doubted whether any radioactivity would be detected in this country.

Goodman said the radioactivity from the plant would most likely have been carried away quickly by the wind, although anyone within 10 to 15 miles could have been exposed to significant radiation. He said it is less likely that people in Kiev, the nearest major population center, would receive significant doses, but even at that distance the long-term effect could be significant. Some radioactive elements are known to cause cancer.

“The Soviet Union did not build containment (buildings) before Three Mile Island,” said Goodman in reference to the most serious nuclear incident in the history of the United States. “They weren’t as concerned about safety. But after TMI they came up with the conclusion that this would be a major disaster” if a similar accident occurred at a Soviet plant.

Beginning in 1980, the Soviets started building plants with containment structures, although older facilities, such as the Chernobyl plant, are not believed to have been retrofitted.

Although Soviet officials said Monday that the accident was the first at a nuclear power plant in that nation, Western intelligence sources in 1976 said there was little doubt that a Soviet reactor went out of control in late 1957 or early 1958 several hundred miles northeast of the Caspian Sea, near the southernmost Ural Mountains.

At the time, Soviet dissident Zhores Medvedev, a scientist living in exile in England, said the 1958 accident had killed hundreds of people.

Nuclear power accounts for 10% of all electricity generated in the Soviet Union, based on estimates by foreign diplomats in that nation, compared to 15.5% in the United States, 64.8% in France, 31.2% in West Germany and 19.3% in Great Britain.

Soviet officials did not reveal the extent of damages or injuries resulting from the weekend accident, but a statement by Tass, the official news agency, said that “aid is being given to those affected.”

The medical treatment of less-than-lethal doses of radiation consists mainly of administering fluids and pain killers, treating the burns and giving emotional support, according to Dr. Joseph F. Ross, a UCLA expert on nuclear radiation.

“There is nothing special,” he said.

Times staff writers Robert Gillette in Warsaw and Harry Nelson in Los Angeles contributed to this story.