There are two ways to make a nuclear reaction - fission and fusion. Fission is when an atom in the high end of the periodic table splits into two. The and more powerful fusion is when two low end atoms combine. Th sun is powered by fusion
If I remember right. 2 hydrogen atoms bonding together is normal in nature and we don't see that type of spontaneous atomic explosion every day, right?
Fuu.... Sion... HA!