Trouble in 2nd Soviet Reactor, U.S. Indicates : 1st Unit’s Fire May Rage On for Weeks

The nuclear disaster in the Soviet Union appeared to widen Wednesday as intelligence data indicated that new problems have arisen in a second reactor at the Chernobyl nuclear complex, Reagan Administration sources said.

And, shattered by a violent explosion, the first reactor may keep blazing for weeks because the massive radiation in the plant makes an immediate cleanup impossible, high-ranking U.S. officials said in their first detailed public assessment of the accident.

The radioactive cloud spawned by the explosion covered a large part of Eastern and Northern Europe on Wednesday, extending perhaps as far north as the Arctic basin, and was drifting slowly across the Soviet Union. But no dangerous levels of radioactivity were reported beyond Soviet borders.

“We are not at a point where we would feel there are any health or environmental consequences for the United States,” said Lee M. Thomas, administrator of the Environmental Protection Agency, which will increase its routine testing of air, water and milk for radioactivity. Thomas also heads the inter-agency task force monitoring hazards of the disaster.

An Administration official with access to recent intelligence reports said Wednesday that the burning reactor was “still spewing smoke” and radioactivity.

Officials were uncertain about the nature of the problems in the second reactor, but one said that “there is a possibility of a meltdown under way.”

“From the outset, that has been a concern,” one source said.

‘Might Be Having Problems’

However, while officials raised this possibility, one later said only that the second reactor “might be having problems” because it was “very close” to the first unit.

The two Chernobyl reactors are situated in adjacent buildings and apparently shared a common wall. In addition, officials said, the units shared an electrical generating facility.

Although Administration officials refused to disclose their sources for information about events within the Soviet Union, it is known that spy satellites making regular passes over Soviet territory are able to photograph specific sites and can detect sources of unusual heat. In addition, electronic eavesdropping can provide information.

However, officials said neither of these sources has yet provided indications of casualties caused by the explosion or the release of radiation. But Administration officials have scoffed at a Soviet report that the massive accident caused only two deaths.

President Reagan, in Bali, Indonesia, for a meeting with Southeast Asian foreign ministers, said he had not yet heard a response from Soviet leader Mikhail S. Gorbachev to his offer of U.S. technical and humanitarian assistance in the nuclear disaster. Reagan said it would be helpful if the Soviets would respond.

When Reagan was asked whether the United States knows all it needs to know about the disaster, he said, “Well, they’re usually a little close-mouthed about these things, and this is no exception.”

New intelligence data and fresh analysis of earlier reports gave Administration officials an only slightly better understanding of what happened at the nuclear power plant, which is about 60 miles north of Kiev, the capital of the Ukraine. The paucity of details from the Soviet Union left many questions unanswered and led officials to issue reminders that in many cases they were engaging in speculation.

Yet, piecing together a scenario Wednesday slightly more detailed than those that have been offered, U.S. officials who had said earlier that an explosion and then a meltdown in the core of the reactor occurred Saturday revised their timetable.

During a meltdown, the fuel of a nuclear reactor melts under intense heat, raising the risk of a chemical or steam explosion and extensive radioactive contamination.

In the Administration, meanwhile, nuclear power experts speculated about the chain of events within the reactor itself.

By one account offered by Administration officials who reviewed intelligence data, problems developed Friday at one of four reactors, which are situated in a row at the sprawling Chernobyl complex. The Soviet Union did not acknowledge until Monday--when radiation was detected beyond its borders--that any incident had occurred, an Administration official said, although “some sort of emergency situation” had developed.

“It started out with what may have been a containable problem that wasn’t handled properly,” another Administration official said, speaking on the condition that he not be identified. However, he said, it remains unclear what steps the Soviets took.

On Saturday, a meltdown occurred at one reactor, followed a day later by a chemical explosion, probably involving hydrogen, officials said.

The explosion, which officials believe occurred Sunday, a day after the meltdown, destroyed the building housing the first reactor, they said.

“If there were people working in the building, their chances (of surviving) were probably zero. Whoever was working in there probably didn’t come out,” said one official with access to intelligence reports.

He said that “a big soot footprint” believed to have carried radioactive particles out of the reactor building was detected near the plant and was considered to have been generated by the explosion.

‘Hotter Than a Pistol’

Referring to the radiation believed to have contaminated the vicinity immediately adjacent to the plant, he said the area was “hotter than a pistol.” Officials have said the fire burning inside the reactor, fed by graphite used in the process of generating nuclear energy in Soviet plants, could reach 4,000 degrees Centigrade.

Harold Denton, director of nuclear reactor regulation at the Nuclear Regulatory Commission, said the control room of the Soviet plant’s second unit was probably evacuated, “but with the equipment left running to keep it cool.”

When asked about whether the accident at the first reactor would result in problems at the other three, he replied, “Assuming the equipment is operable there, I wouldn’t expect it to spread.

“I guess there could be a potential for conventional fires to spread, and that’s probably a concern,” he added. However, he said the plant’s two remaining reactors appeared to be situated far enough from the two troubled facilities to avoid difficulties.

All four reactors at the site were believed to have been shut down, and an Administration official said people were “doing some work around the site, apparently trying to put the fire out.”

Lester Machta, director of the Air Resources Lab at the National Oceanic and Atmospheric Administration, said the radioactive material emitted by the accident should be almost entirely dispersed by the time the remnants of the cloud drift across the Pacific and reach the U.S. West Coast, in a week or more.

Assessing the likely impact of the radioactivity on the Soviet Union, Sheldon Meyers, acting director of the Environmental Protection Agency’s radiation programs, said that most of the particles would be dispersed by rain as the cloud moves across the nation at 15-20 m.p.h. Some of the local milk supply in the Soviet Union might be contaminated if the rain falls on grazing areas for dairy herds, he said.

He said the impact on the crucial wheat-growing region of the Ukraine is unclear. “It would strongly depend upon how it was deposited, whether it rained, whether the growing season was nearly complete. If it’s a kind of setup where the wheat was fully grown, for example, it’s possible the crop might not be damaged,” he said.

The State Department is trying to reach American travelers in Kiev. “All Americans contacted thus far report they are fine and the situation is normal,” department spokesman Charles Redman said, adding that one group of American visitors to Kiev is planning to cut short its tour and others are changing their travel plans to avoid the city.

The State Department has issued a travel advisory warning against trips to Kiev but is not telling Americans to stay away from any other areas of the Soviet Union.

Top-level experts from four U.S. agencies held a crowded joint news conference Wednesday in a State Department auditorium to discuss the causes and consequences of the Chernobyl accident.

The reactor core, a 1,000-ton block of graphite containing 16,000 narrow tubes filled with nuclear fuel, suffered an accidental loss of water coolant, Denton said. He speculated that a pipe may have broken or that the electrical pumping system could have failed.

Normally, the water goes through the bottom of the tubes, where the heat generated by the nuclear reaction turns water into steam to operate a turbine for generating electricity.

Somehow, the water apparently failed to flow properly; the reactor core then began to heat up, Denton said, and the fuel started to melt. The cracking fuel tubes released steam, which combined with the graphite of the reactor core to produce “a violent explosion.”

“A fire followed the explosion,” said Denton, who likened the burning reactor core to glowing charcoal.

“It is probably burning from the top down,” he said. “There is still very high temperature existing in the core. The radiation levels within the plant itself are so very high that I would expect it would be very difficult to take any corrective action there.”

And, he said, the fire, making its way down through 20 feet of graphite, may take weeks to burn itself out.

The building containing the reactor was breached, spewing large volumes of radioactive gases and particles into the air. At the Three Mile Island nuclear plant in Pennsylvania, the radiation released in a 1979 accident was largely trapped within the containment vessel, a massive concrete and reinforced steel structure surrounding the reactor. The Chernobyl reactors lack such structures.

Meanwhile, Sen. John Glenn (D-Ohio), made public an unclassified version of a report completed last September by the General Accounting Office, which indicated that 151 “significant and potentially significant nuclear safety incidents” occurred in 14 countries between 1971 and 1984.

The report did not list the incidents, which were said to have taken place in nations other than those in the Soviet Bloc. However, the study said the incidents involved what were considered significant releases of radiation, safety and design deficiencies and certain equipment failures.

Glenn said such findings show that “the problem of nuclear safety in other countries is becoming increasingly serious . . . and the problem is likely to get worse in the years ahead, since by the year 2000, more than half the countries with nuclear power reactors are expected to be developing countries.”

Times staff writer Karen Tumulty contributed to this story.

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