Wolf: but if exposed to radiation, one does not die immediately, while chometz immediately destroys a person’s neshama (kares)
A. Enough radiation can kill in a very short time.
B. As I said above, chametz will only kill you if you eat it on purpose. If you eat it accidentally, you will NOT get kares. Radiation, on the other hand, won’t care what your intention was.
C. You can do teshuva regarding kares. Radiation won’t care if you teshuva for being exposed.
The Wolf