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
Russian military intervention in Ukraine (2014–present) sphere of interest. Iulian Chifu and his co-authors claim that in regard to Ukraine, Russia pursues a modernized version of the Brezhnev Doctrine on "limited sovereignty", which dictates that the sovereignty of Ukraine cannot be larger than that of the Warsaw Pact prior to the demise of the Soviet sphere of influence. This claim is based on statements of Russian leaders that possible integration of Ukraine into NATO would jeopardize Russia's national security. After the collapse of the Soviet Union, both nations retained very close ties. At the same time, there were several sticking points, most importantly Ukraine's significant nuclear