The story was first published in Astounding Science Fiction in 1940, before any nuclear reactors had ever been built, and for its appearance in the 1946 anthology The Best of Science Fiction, Heinlein made some modifications to reflect how a reactor actually worked.
It Could Happen to You (film) | It Could Happen to You | It Should Happen to You | It Couldn't Happen Here | I Know It's Gonna Happen Someday | Strange Things Happen at Sundown | Something Tells Me (Something's Gonna Happen Tonight) | Let's Make It Happen | It Shouldn't Happen to a Vet (film) | It Shouldn't Happen to a Vet | It Couldn't Happen Here (film) | Dude, What Would Happen |