
Castle Bravo was in 1954. He began to push for for Plowshare in the late 50s. Here he is in 1965 advocating for it.[2]
Read "The Firecracker Boys" if you are interested in a lot more detail.[3]
[1] - https://en.wikipedia.org/wiki/Castle_Bravo#High_levels_of_fa...
[2] - https://www.youtube.com/watch?v=Oa-IqOHDr_k
[3] - https://books.google.com/books/about/The_Firecracker_Boys.ht...
