The utilization of nuclear power in Kazakhstan began with Kazakhstan's first nuclear power plant, the BN-350 fast-neutron reactor in Aktau, operating from 1973 to 1999, a Soviet era prototype investment preceding the BN-600 reactor. Since 1999, it has only operated four smaller research reactors and did not have nuclear electricity production capabilities. Kazakhstan is the number one country in the world for uranium production volumes, which is used for nuclear fuel. Current plans, reaching back to 1997, foresee the construction of two new nuclear power plants near the towns of Ülken and Kurchatov. The plans were last backed by the 2024 Kazakh nuclear power referendum.