A prominent Russian writer recently produced a tattered old Bible and with a practiced hand turned to Revelations. ''Listen,'' he said, ''this is incredible: 'And the third angel sounded, and there fell a great star from heaven, burning as it were a lamp, and it fell upon the third part of the rivers, and upon the fountains of waters; and the name of the star is called wormwood: and the third part of the waters became wormwood; and many men died of the waters, because they were made bitter.' ''

In a dictionary, he showed the Ukrainian word for wormwood, a bitter wild herb used as a tonic in rural Russia: chernobyl.

The writer, an atheist, was hardly alone in pointing out the apocalyptic reference to the star called chernobyl. With the uncanny speed common to rumor in the Soviet Union, the discovery had spread across the Soviet land, contributing to the swelling body of lore that has shaped the public consciousness of the disaster at the Chernobyl atomic power plant in the Ukraine.

In the three months since an explosion ripped open the fourth reactor at the plant, Chernobyl has become an indelible part of Soviet life, whether as an inevitable topic in kitchen conversation, as a daily subject in the national press, as a source of rumor, sensation and threat, or as a direct influence on daily life.