I-131 can be only a consequence of recent nuclear reaction taking place. Sudden criticality and explosion of an old submaride won't produce enough of that - whi

I-131 can be only a consequence of recent nuclear reaction taking place. Sudden criticality and explosion of an old submaride won't produce enough of that - while will release whole lot of other isotopes, so no one would mention iodine. It can be little but a reactor meltdown or a nuclear explosion (while that must have seismic signature hard to not mention)