596, originally named by western intelligence agencies Chic-1, is the codename of the People's Republic of China's first nuclear weapons test, detonated on October 16, 1964 at the Lop Nur test site. It was a uranium-235 implosion fission device and had a yield of 22 kilotons. With the test, China became the fifth nuclear power. Project 596 was named after the month of June 1959 in which it was initiated, immediately after Nikita Khrushchev decided to stop helping the Chinese with their nuclear program 20 June 1959.