Fusion reaction is not possible at room temperature because: 1) nuclei only moves at high temperatures 2) nuclei move too slowly at room temp I'm not sure about this. but i think that 2 is right. Can someone verify this? Another question that I am also wondering is that when comparing the fission of a uranius nuclear to fusion of deuterius. Which one releases more envery. or is the amount of energy dependent on how much reactants are involved?