I wasn't speaking of nukes at that point, but rather ordinary chemical explosivebombs, which you also wanted to ban as "indiscriminate".
However there are some very low yield nukes that could be contained in a thousand acres, just a modest Kansas wheat farm. In fact a really small nuke, say .1 KT, would have the thermal and blast effects contained within that 200 acres. Even a 1 KT weapon, detonated at ground level would produce blast (out to moderate damage levels) and thermal effects, covering no more than a 1/2 mile radius. That would mean it would fit inside a single section (square mile), which is 640 acres. (Numbers for the 1 KT weapon obtained from the anti-nuke Federation of American Scientists Besides I might want the thing(s) for underground excavation, freeing oil and gas deposits, or other situations where release of radioactivity would not be a problem. Of course those "civil engineering" uses would not be protected by the second amendment, because such a device would not really be an arm, just a tool.
More seriously though. I'm OK with banning individual ownership of nukes, if you amend the Constitution to provide for it, but the amendment would have to be very carefully worded, lest some future Court interpret "Weapon of Mass Destruction" to mean a .22 rifle other than a single shot. (whose "effect" actually extends a bit farther from the point of origin than that 1 KT nuke, albeit over a very tiny area).
The DC Circuit court in _Parker_ described cannons as WMDs.