The Krško Nuclear Power Plant is located in Vrbina in the Municipality of Krško, Slovenia. The plant was connected to the power grid on October 2, 1981 and went into commercial operation on January 15, 1983. It was built as a joint venture by Slovenia and Croatia which were at the time both part of Yugoslavia.The plant is a 2-loop Westinghouse pressurized water reactor, with a rated thermal capacity of 1,994 thermal megawatts and 696 megawatts-electric . It runs on enriched uranium, fuel mass 48.7 t, with 121 fuel elements, demineralized water as the moderator, and 36 bundles of 20 control rods each made of silver, indium and cadmium alloys to regulate power. Its sister power plant is Angra I in Brazil.The operating company Nuklearna elektrarna Krško is co-owned by the Slovenian state-owned company Gen-Energija and the Croatian state-owned company Hrvatska elektroprivreda . The power plant provides more than one-quarter of Slovenia's and 15 percent of Croatia's power.HistoryThe reason why the plant is co-owned by two countries was that these then-constituent republics of Yugoslavia planned to build two plants, one in each republic, according to the original 1970 agreement and its revised version from 1982. However, that plan was abandoned in 1987 by Slovenia due to a referendum held in 1986. From that point on, there arose an issue with nuclear waste storage, because the only existing waste storage site was in Slovenia.