Radionuclides released by nuclear test are still widely abundant in the environment and biosphere. Most releases were caused by the nuclear atmospheric test. The last one was conducted by the People’s Republic of China on October 16, 1980. It was the last known atmospheric detonation before the Comprehensive Nuclear-Test-Ban Treaty (CTBT) was negotiated in from 1993 to 1996. With regard to limiting the environmental releases of radioactivity, the major landmark was the Partial Test Ban Treaty (PTBT) of 1963. which bans tests in the atmosphere, outer space, and underwater. On August 5, 1963, the PTBT was signed by the three original Depositary Governments, the Union of Soviet Socialist Republics (USSR),…