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
South Ukraine Nuclear Power Plant following major upgrade work, unit 1 was given a 10-year license extension, which will take it beyond its original 30-year design lifetime. Similar extensions are planned for units 2 and 3, licensed until 2015 and 2019, respectively. The main supplier of fuel for nuclear power plants in Ukraine has been TVEL, with whom NNEGC signed a contract for the supply of nuclear fuel for Ukrainian WMR in 1997 until 2010. Under a US-Ukrainian initiative to reduce Ukraine's dependency on Russia for fuel, tied to the dismantling of its nuclear weapon arsenal, Energoatom had been using reactor core of unit 3