Enormous Soviet Economic Toll Likely

In addition to the undisclosed numbers of deaths and injuries, the Chernobyl accident’s long-term financial toll on the Soviet Union, which relies heavily on civilian nuclear power, is expected to be enormous.

Replacing the destroyed plant is only the first cost. “You’re talking about a facility of billions of dollars,” one Reagan Administration official said.

Beyond that, other plants of similar design may require modifications if the accident is determined to have been caused by a design flaw. If other nuclear plants must be shut even temporarily, Administration officials predicted, the reduction of electrical-generating capacity could damage overall Soviet economic production.

‘A Lot of Rubles’

“It’s going to run into a lot of rubles,” a Reagan Administration official said.

The United States has formally offered technical and humanitarian aid to the Soviet Union to help deal with the accident, but the Soviets made no response to the offer, State Department officials said Tuesday.

The offer of assistance, announced by a spokesman for President Reagan during his visit to Bali, was formally given to Soviet charge d’affaires Oleg M. Sokolov by Assistant Secretary of State Rozanne L. Ridgway.

Ridgway told Sokolov that Reagan and the United States feel “deep regret” over the accident, State Department spokesman Charles Redman said.

“We hope the Soviet Union will provide information about the accident in a timely manner,” he added.

State Department officials said that the United States offered five specific types of assistance, the Associated Press reported. These include:

--Technical advice on predicting radioactive-material dispersion based on geography, weather and the type of radioactive material released.

--An aerial measuring system that can map the spread of radioactive contamination.

--Radiological assistance teams to measure radioactivity in water, air and soil, and technical assistance in assessing environmental effects of the radioactive materials released.

--Medical personnel experienced in diagnosing and treating radioactive exposure.

--Technical assistance in radiological decontamination, in recovery from nuclear reactor accidents, and in minimization of environmental effects.

State Department officials said they have no reports that any Americans were injured in the disaster.

One official said that neither the U.S. Embassy in Moscow nor the State Department was aware that at least two American tour groups from New York State were in Kiev. Members of those tours called relatives and friends in the United States to assure them that they were unhurt.

The State Department issued a formal travel advisory for “Kiev and adjacent areas,” urging Americans not to go to the area.

An official said that the advisory does not include the Soviet Baltic Sea coast, Finland or Sweden, where radiation from the accident has been detected.

Times staff writers Doyle McManus and Karen Tumulty contributed to this story.