From 1940 onward, Kurchatov worked on and contributed to the advancement of the nuclear weapons program, and later advocated for the peaceful development of nuclear technology. In 1950, Kurchatov contributed in the development of the hydrogen bomb with Sakharov, who originated this development as "Sakharov's Third Idea". Other projects completed under Kurchatov included the installation and the development of Soviet Union's first particle accelerator, the Cyclotron; inauguration and establishment in Obninsk of the Obninsk Nuclear Power Plant, the world's first nuclear power plant; and the completion and launching of the "Lenin", the first nuclear-powered surface vessel under his leadership in 1959.