MOSCOW, April 29, 1986 (UPI) - Word of mouth and two brief media announcements about a nuclear disaster in the Ukraine were all it took to alarm the Soviet people, who are accustomed to reading between the lines of brief government statements.
''Now it seems we're sitting on a nuclear time bomb,'' said a young Muscovite.
''Listen, when they (the official press) say there has been an accident, and then say it is a disaster, you know it is serious, very serious,'' said a middle-aged Moscow man. ''The problem is there is so much we don't know, and it worries us.''
According to Western diplomats and scientists, it worries the Soviet government too.
With an ambitious program to double the Soviet Union's nuclear capacity in the next five years and triple it by the year 2000, the Kremlin has much to lose if word of a major accident involving thousands of deaths reaches the Soviet populace.
''The Soviets are underplaying this whole thing so as not to arouse fear in the people and create objections to the nuclear energy program,'' a Western diplomat said.
Western diplomats in Moscow and the city's natives have been shocked by the announcements on Soviet television acknowledging the nuclear accident. They attribute the new -- yet limited -- government openness to recent calls by Soviet leader Mikhail Gorbachev for more honesty.
The afternoon newspaper Izvestia reported the accident in a brief front-page announcement bordered by two thick black lines used rarely and only for major accidents such as airplane crashes and for the deaths of Soviet leaders.
The announcement said only that there had been an accident, but to Soviets the black lines meant only one thing: death.
The accident at the Chernobyl atomic power station near Kiev in the Ukraine likely affected many people. The nightly news program Vremya told millions of Soviet viewers that three populated areas around the plant had been evacuated.
The somber announcer also told viewers that two people died ''during the accident.'' Diplomats and Soviets took ''during'' to mean more probably died later.
A Kiev resident said she didn't have to read between the lines: ''It's a fact and anyone who knows anyone involved in the rescue knows that thousands died. The Oktyabrsky (October) Hospital is packed with injured.''
''What a nightmare, what unhappiness. There are no words,'' said a young Moscow writer.
Another Muscovite outside a train station expressed confusion, saying, ''Nuclear energy is modern and clean. This could not happen.''
Tass has reported many times that ''the whole Soviet experience of operation of nuclear power stations ... indicates that they are reliable and safe.''
But the official Soviet news agency stunned the nation by reporting for the first time, ''This accident and others at nuclear power stations in the West show that nuclear power, even when used for peaceful purposes, can be dangerous.''
''I can't believe it,'' said a young woman. ''We've never heard this before.''