Czechs in Ukraine Mostly, they were women with ethnic Ukrainian husbands. Some others stayed of their own choice. During the Soviet era, they were one of the most affected groups by the Chernobyl nuclear power plant disaster in 1986. At the end of the 1980s, ten thousand Czechs lived in Ukraine. At the beginning of the 90s Czechoslovakia invited these remaining Czechs to return to the Czech Republic, which in 1993 almost 2,000 people did, and other people came to the Czech Republic in later years. As of today, Volhynian Czechs are still migrating. In 2014, after the revolution in Ukraine and the
Ryanggang explosion popular speculation that the explosion was nuclear in origin. United States Secretary of State Colin Powell said there was "no indication" that it was nuclear, and South Korea similarly said that it did not appear to be nuclear. It would be some days before the effects of a nuclear explosion would be unequivocally visible to apolitical authorities. It would not be possible to hide the nuclear nature of such an explosion for long, as the radioactive isotopes created by a nuclear explosion would be detectable to outside observers around the world. North Korea initially denied that the explosion was nuclear.