The Atomic Energy Council (AEC) was founded in 1955 at the ministerial level under the Executive Yuan. Its original mission was to foster peaceful applications of atomic energy, and to coordinate international cooperation on nuclear energy. In 1961, an open-pool reactor built by the National Tsing Hua University, THOR, reached its first criticality. Then, the Atomic Energy Law was enacted in 1968 and the Institute of Nuclear Energy Research (INER) was founded in the same year. In 1974, the Taiwan Radiation Monitoring Station (TRMS) was established under AEC. Four years later, the state-owned power utility Taiwan Power Company (TPC) connected its first nuclear power plant (NPP) to the grid and started its commercial operation. In 1981, Radwaste Administration (RWA) was formed under AEC aimed to regulate radioactive waste management. TRMS and RWA were then renamed as the Radiation Monitoring Center (RMC) and the Fuel Cycle and Materials Administration (FCMA), respectively, in 1996. In 1999, AEC issued a construction permit to TPC for its fourth nuclear power (Lungmen) project. Now with six NPP units in operation, two advanced boiling water reactor units under construction, and other peaceful applications of nuclear and radiation technology expanding in great pace, AEC's most important mission has long been shifted to reactor safety regulation, radiation protection, radwaste administration, environmental monitoring and R&D for technology development and other civilian nuclear applications.