Fusion vs Fission

Energy Ratios

As shown below (to the right), the energy released by fusion is three to four times greater than the energy released by fission. This is because the amount of mass transformed into energy is that much greater in a fusion reaction than in a fission reaction.

In addition, because the species used in fusion are so much smaller than those used in fission (by a factor of ca 200!), the energy density of the fuel is even higher than depicted in the chart below.

Courtesy of Richard McCray (Link)

Radioactivity

The sources of radioactive waste in the fission energy cycle are numerous: From low-level mine-tailings to the high level waste from the burnt out fuel rods, the problem of waste disposal in in the fission cycle is grave and has yet to be solved. The fusion fuel cycle has none of these problems, as the source of fuel doen't require mining. D is found to a small percentage in sea water and can be separated and T is bred on-site in a reaction with Lithium. The waste product is an intert gas, Helium, which is completely harmless.

As for the dangers of a nuclear accident, this a real concern with fission reactors, meltdowns and runaway reactors are a reality for which Tschernobyl serves as an example. This danger is not present in fusion reactions, as fuel is only inserted as needed, in other words, should the reaction become uncontrolled, all it does is go out with no other negative impact than a loss of power.

So, if fusion is such a great source of power, why isn't is our main source of energy today? To find out about the problems facing fusion today, please go to the next page.