Wasn't there a graduate student who wrote thesis about building an atomic bomb from readily available resources. I don't remember if his work was ever published

Wasn't there a graduate student who wrote thesis about building an atomic bomb from readily available resources. I don't remember if his work was ever published, but I certainly remember reading about this. Update: https://en.m.wikipedia.org/wiki/John_Aristotle_Phillips https://en.m.wikipedia.org/wiki/John_Aristotle_Phillips