Lithium hydride
Before the Castle Bravo nuclear weapons test in 1954, it was thought that only the less common isotope lithium-6 would breed tritium when struck with fast neutrons. The Castle Bravo test showed (accidentally) that the more plentiful lithium-7 also does so under extreme conditions, albeit by an endothermic reaction.
Castle Bravo
The detonation took place at 06:45 on March 1, 1954, local time (18:45 on February 28 GMT).
When Bravo was detonated, within one second it formed a fireball almost across. This fireball was visible on Kwajalein atoll over away. The explosion left a crater in diameter and in depth. The mushroom cloud reached a height of and a diameter of in about a minute, a height of and in diameter in less than 10 minutes and was expanding at more than . As a result of the blast, the cloud contaminated more than of the surrounding Pacific Ocean, including some of the surrounding small islands like Rongerik, Rongelap, and Utirik.