The People's Liberation Army Navy put into service ChangZheng 1, their first nuclear-powered submarine, designed and built in China. Russia had refused to share nuclear propulsion technology with China, so Mao Tse-tung resolved to develop their own nuclear submarine building program. Construction had started by 1968 at Huludao Shipyard, in Liaoning Province. The pressurized-water 90 megawatt reactor provided power for turbo-electric propulsion. The type 091 submarine was launched in 1970, its nuclear reactor was activated in Jul 1971 and it began sea trials the next month. NATO codenamed it a Han class submarine. As China's first-generation design, its performance was generally inferior to American or Russian vessels of the time. It was decommissioned in 2000.