There are two out of print books written about the history of nuclear regulation in the US.
They are called CONTROLLING THE ATOM and CONTAINING THE ATOM.
The first typically goes for a few dollars on Amazon. The second is much rarer, evidently, because its Amazon asking price is currently over $2,000.
To see that for your own eyes, click this link:
The NRC mentions both books on their history page:
There, they say they have been reprinted as NUREGs, and that you can get new copies through the GPO. I searched the GPO website, but I guess you have to call.
Thanks to Google, you can read both online for free. Google Books makes them available here:
CONTROLLING THE ATOM (Google Books link)
CONTAINING THE ATOM (Google Books link)
The books’ original publisher (University of California Press) makes them available online, too. Test out the different viewers and see which works best for you:
CONTROLLING THE ATOM (UC Press link)
CONTAINING THE ATOM (UC Press link)