There has not been a major (or minor) nuclear explosion since the 1960s. This is almost entirely because the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) was opened for signature on July 1 ...

In 1952, the United States detonated the first full-scale thermonuclear bomb, unleashing an explosion unlike anything the world had ever seen. The blast released more than 10 megatons of energy, ...