On the other hand, the radioactive fallout at the plant keeps mounting.
Shifting from big nuclear devices that burst at the earth's surface to smaller ones that detonate below ground could indeed reduce the radioactive fallout released by a factor of about 20—but it would by no means make the smaller munitions “clean.
The radioactive fallout might be a bigger problem, although crop failures from even temporary cooling could result in famine in some parts of the world.