Following are excerpts from the Soviet news conference on the Chernobyl nuclear accident, as translated by the Foreign Ministry press center.

Statement by Boris Shcherbina, head of the state committee investigating the accident:

On the 26th of April at 1:23 a.m. at the fourth block of the Chernobyl nuclear plant . . . the accident happened, with particular destruction of the active zone of the reactor and the emission of the structures of fission.

In the area, the local experts did not have a true assessment of the accident. We transferred various kinds of equipment and material and now the consequences have been eliminated and emergency measures are being taken.

The primary results of research into the cause of the accident allow us today to guess that the most probable version is an explosion, a chemical explosion. Taking into account that the existing international practice was being implemented according to safety control measures, the causes could be the breakage of firm, small pieces, the coincidence of several highly improbable and therefore unforeseen failures. And we will also carefully study the actions of the staff on duty.

The accident at Chernobyl has shown that the problem of safety is very important for everyone and speedy conclusions are out of place here and could only confirm the irresponsibility of those who give baseless forecasts.

The commission has not concluded its investigation and has not yet prepared a report. This is natural in such an accident. We need some time to make calculations and it is very dangerous to be mistaken here.

Various kinds of materials have been used, including sand. We have placed more than 4,000 centners one centner is 110.23 pounds over the block. A result of such measures is radioactive circumstances at Chernobyl have normalized.

As to the systematic control of pollution in the Ukraine, Byelorussia and Moldavia, the level of radiation has not overcome the norms of radiation considered safe by the Health Ministry.

Maximum levels of radiation now are 10 to 15 milliroentgens per hour. On the 5th of May, the levels of radiation had been decreased by two- to three-fold. The highest radiation was the 27th of April.

Livestock have been killed. As a result of the accident, two persons were killed and about 100 contaminated, and on the 27th of April they were transported to Moscow and received medical assistance, and a number of them are in a difficult state.

We share, of course, the concerns about consequences of the accident. We are grateful to those who express their sympathy to us in connection with this accident.

Literally, within a few hours our government established a commission. We arrived there and started our job. We had to study to understand what has happened.

Our government has given information to the governments concerned, and after that, information was published almost daily.

Western circles on the one hand would like to show their acuteness, on the other hand they ignore information submitted by the Soviet side. The attempts to use the accident at the Chernobyl nuclear plant for political practices and aims only can serve to undermine the cooperation in this area. Questions From Journalists

Q: What does it mean that the reactor has been covered?

A: Ivan Y. Yemelyanov, deputy director of an energy technology research facility: The reactor is in a sealed state. This means that the chain reaction has been halted. This was achieved at the minimal capacity of the reactor at 200 megawatts. And now there is no kind of decay related to chain reaction.

Q: Can you provide more details of the accident and evacuations?

A: Shcherbina: When the situation became very dangerous from the point of view of radiation , to each house and each apartment -- we had prepared this in advance -- buses were submitted with escorts and from 2 p.m. on the 27th until 4:20 p.m. the same day, during the period of two hours, the entire population was evacuated. A small part of necessary workers were left in order to serve the city, the workers of communications and so forth. When the situation became more dangerous in two days, the security workers of the city were evacuated.

Q: What are the methods of treatment for those exposed to radiation?

A: Yevgeny I. Vorobyev, first deputy health minister: In the western press, various very different figures in regard to the rate of death are provided. These figures amount to thousands. The provided information from television proved that no dangerous fire took place and a separate fire on the power plant itself was extinguished in a matter of a few hours.

I would like to confirm that only two men were killed. One died as a result of very heavy burns, over 80 percent of his skin . . . . The second person died as a result of debris that fell on him.

As for radiation disease, I can say exclusively that 204 people are in hospitals. The rate of exposure is different. Among them 18 have the diagnosis of extreme radioactive exposure. All were transported to the best hospitals in the Soviet Union and every assistance is provided to them.

Q: What are the consequences for adjacent countries?

A: Vorobyev: No imminent danger for the population of a foreign country, in our opinion, exists. Prior to May 1, higher levels of radiation were detected only in the Polish People's Republic. After May 1, some radiation was observed over Romania. In our opinion it was not considerable, that is one one-hundredth of a milliroentgen.

Q: What is the current level of radioactive emissions and what was it at the height of the accident?

A: Yuri S. Sedunov, first deputy chief of the State Committee on Meteorology and Environmental Control: There was no change in radioactive background in Moscow. In Chernobyl, it was raised to 15 milliroentgens per hour and now it has been reduced three times. In Kiev, at the time of the accident, it was at the level of background. Three days later when the weather changed it was slightly above background, at 0.2 milliroentgens per hour.

Q: Why was there a three-day delay in reporting the accident?

A: Androiac M. Petrosyants, head of the Soviet State Committee on the Use of Atomic Energy: It is not true, to put it mildly, because we literally, immediately after we learned about the accident, sent a message to the general director of the IAEA International Atomic Energy Agency , Mr. Hans Blix, and he was grateful for the information.