From what I found on that site, the design principally is a "What If", but is said to be based on an
actual design, shown in a document from the "Conference on Peaceful Uses of Atomic Energy"
(short "Atoms for Peace" ?). No year given, maybe 1955 or 1958 ? The ship shown above that
sub on that site somehow reminds me of the NS Savannah and has the same "source", perhaps
this limits the timeframe ?