International Nuclear Safety Group the Kyshtym disaster, which occurred at Mayak, a Nuclear fuel reprocessing plant in the Soviet Union. Since then, there have been hundreds of nuclear accidents, some considered minor while others were horrendous, with one of the worst accidents being the Chernobyl disaster of April 26, 1986. Involving a nuclear power plant at Chernobyl, now in Ukraine, a combination of nuclear volatility and the disregard of several safety procedures caused an explosion of its fourth reactor, ending in the worldwide environmental and human catastrophe. Following the Chernobyl accident, the IAEA was forced to create a new branch of their organisation to
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