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.
Daigo Fukuryū Maru
The "Lucky Dragon No. 5" took five ocean voyages, the last of which began on January 22, 1954, and ended on March 14 of that year. The crew set off to go fishing in the Midway Sea near Midway Atoll, but when they lost most of their trawl nets to the sea, they altered their course southward near the Marshall Islands and encountered fallout from the Castle Bravo nuclear test at Bikini Atoll on March 1.