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.
Alvin C. Graves
Graves became dismissive of the radiation risks from nuclear testing while serving as test director for the Nevada Test Site shots during the 1950s. He announced that the risks from fallout were "concocted in the minds of weak malingerers." As a spokesman for the Nevada Test Site, he spoke in local areas around Nevada assuring the population of no danger from the activities there. As the head of the Los Alamos Laboratory's J (Test) Division, he was the scientific director or deputy director of most of the nuclear tests from 1948 through the 1950s, including the Desert Rock exercises which exposed military personnel to radiation, and the Castle Bravo test that irradiated many native islanders and test personnel. Asked to testify before the Joint Committee on Atomic Energy on the danger of radiation causing cancer, Graves replied: