Monitoring Atmospheric Nuclear Explosions

Abstract

A little more than 30 years ago, in October 1980, China conducted its last nuclear test explosion in the atmosphere. This marked the end of atmospheric testing by all countries. The United Kingdom, United States, and Soviet Union, as depositories, had already signed the Partial Test Ban Treaty (PTBT) in 1963, which banned explosions in the atmosphere, in space, and under water. France, the fourth country that conducted atmospheric tests, ended its testing in the atmosphere in 1974. A total of 517 nuclear explosions were carried out in the atmosphere: United Kingdom 21, China 22, France 50, United States 210, and Soviet Union 214. As noted in Chapter 1, the PTBT contains no verification provisions. There might be several reasons for that: explosions in the atmosphere are generally easy to detect, and national monitoring equipment, such as for atmospheric radionuclide surveillance, was already available and operational at the time the treaty was signed. The United States launched its satellite-based Vela project in 1963 to monitor atmospheric nuclear explosions, as discussed under national technical means (NTM) below. The three depositories of the PTBT were also ready to move testing underground to reduce radioactive fall-out and thereby also the information that other states might obtain from analyzing the fall-out.