Steam explosion major cause of human fatalities in volcanic eruptions. The 1986 Chernobyl nuclear disaster in Soviet Union was feared to cause major steam explosion (and resulting Europe-wide fallout) upon melting the lava-like nuclear fuel through the reactor's basement towards contact with residue fire-fighting water and groundwater. The threat was averted by frantic tunneling underneath the reactor in order to pump out water and reinforce underlying soil with concrete. When a pressurized container such as the waterside of a steam boiler ruptures, it is always followed by some degree of steam explosion. A common operating temperature and pressure for a marine boiler
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