the fact they contemplated powering it with a nuclear reactor makes it even more intriguing. Just how long could you keep it aloft before crew fatigue issues kick in? It doesn't look big enough to carry any relief crew.
or maybe the reactor was simply to avoid lengthy at-sea refueling: replenishment at see would just mean reloading the bomb bay (did you notice this was done from ABOVE via the rotating carousel?) and exchanging crew