And unto Adam he said, Because thou hast hearkened unto the voice of thy wife, and hast eaten of the tree, of which I commanded thee, saying, Thou shalt not eat of it: cursed is the ground for thy sake; in sorrow shalt thou eat of it all the days of thy life;
(Genesis 3:17) KJV
Nuclear decay began when God cursed the Earth. God’s presence is the power which maintains matter in a stable state. God can’t tolerate sin, so when sin entered the world he withdrew his presence.
Since God was no longer maintaining creation it began deteriorating. Adam began aging and dying, biological senescence began. For the Earth it began as nuclear decay.
So why didn’t the surface of the Earth turn into an ocean of lava? This is because of the process of creation that we have come to understand. On the second day of creation God created gravity and a spherical Earth formed around it. This process, the core accretion model, caused the vast majority of heavy metal elements, the ones that we now call unstable, to be concentrated at the core. When nuclear decay began Earth’s core began to melt. Hell began.
However, there was enough radiation at the surface to cause crops to suffer. All of a sudden there wasn’t a bountiful harvest of fruit available for easy picking. It took a lot of hard work to get the Earth to bring forth crops, and once an area had been used is was no longer any good. The land began to wear out.
Matty's Paradigm 