Indeed. It was originally a prototype for an aircraft carrier engine, but the Navy was waffling on whether or not it needed such things. So Rickover led its development as a commercial demo instead, and it worked better than most of the other more exotic reactor types being tried at the time, and so now we have mostly this kind of reactor in the world (the PWR), and its close relative (the BWR).

Later the Navy decided that they did indeed want nuclear powered aircraft carriers, and so now they have them.