Nuclear industry in Canada  Nuclear industry in Canada is an active business and research sector, producing about 15% of its electricity in nuclear power plants of domestic design. Canada is the world's largest exporter of uranium, and has the world's second largest proven reserves. Canada also exports nuclear technology within the terms of the Nuclear Non-proliferation Treaty, to which it is a signatory, and is the world's largest producer of radioactive medical isotopes. The Nuclear industry (as distinct from the uranium industry) in Canada dates back to 1942 when a joint British-Canadian laboratory was set up in Montreal, Quebec, under the administration of the National Research Council of Canada, to develop a design for a heavy-water nuclear reactor. This reactor was called National Research Experimental and would be the most powerful research reactor in the world when completed. In the meantime, in 1944, approval was given to proceed with the construction of the smaller ZEEP (Zero Energy Experimental Pile) test reactor at Chalk River, Ontario and on September 5, 1945 at 3:45 p.m., the 10 Watt ZEEP successfully achieved the first self-sustained nuclear reaction outside the United States. ZEEP operated for 25 years as a key research facility. In 1946, Montreal Laboratory was closed, and the work continued at Chalk River Nuclear Laboratories. Building partly on the experimental data obtained from ZEEP, the National Research Experimental (NRX)—a natural uranium, heavy water moderated research reactor—started up on July 22, 1947. It operated for 43 years, producing radioisotopes, undertaking fuels and materials development work for CANDU reactors, and providing neutrons for physics experiments. It was eventually joined in 1957 by the larger 200 megawatt (MW) National Research Universal reactor (NRU). In 1952, the Canadian Government formed AECL, a Crown corporation with the mandate to develop peaceful uses of nuclear energy. A partnership was formed between AECL, Ontario Hydro and Canadian General Electric to build Canada's first nuclear power plant, called NPD for Nuclear Power Demonstration. The 20 MWe Nuclear Power Demonstration (NPD) started operation in 1962 and successfully demonstrated the unique concepts of on-power refuelling using natural uranium fuel, and heavy wa ter moderator and coolant. These defining features formed the basis of a successful fleet of CANDU power reactors (CANDU is an acronym for CANada Deuterium Uranium) built and operated in Canada and elsewhere. In the late 1960s (1967–1970), Canada also developed an experimental "miniature" nuclear reactor named SLOWPOKE (acronym for Safe Low-Power Kritical Experiment).