Originally posted by ZPE StarPilot
A reactor using Helium-3 might be developed, if we had any Helium-3 to try it. We don't have any here on Earth. It's all on the Moon. Having some
might just speed the process up.
Wrongo. There is plenty of helium 3 on earth for research purposes. It can among others be produced by extracting it during natural gas production.
Another important source is decay of tritium in US nuclear weapons, which produces 15 kg per year, more than enough for any research reactor. Further,
there is no need at the time to "speed the process up" as there is not even a research reactor yet that can maintain the tens of millions of degrees
for long enough to have a break even for the lowest temperature fusion reaction, which is deuterium-tritium. Further, you do not need to develop a
commercial reactor using helium 3 with a research reactor using helium 3, p-6Li fusion that requires temperatures of the same magnitude could suffice
to prove the concept. Further, some people present helium 3 as a non polluting fuel, this is not true. The
neutronicity of the reaction is
just around 20 times or so less. This means you'll still have radioactivity and reactor wall damage, but just a lot less. It is hence dubious whether
the enormous costs of developing a fusion reactor using helium 3 that requires temperatures several times higher than for deuterium tritium fusion,
plus the astronomical costs of mining helium 3 on the moon, would offset the rather marginal costs of the higher storage and disposal of nuclear waste
when using the a lot easier to achieve deuterium-tritium fusion.
So in short:
1. There are significant amounts of He3 on earth, just not enough to power several commercial reactors using it IF those were to exist.
2. There is even no immediate need for He3 to develop a nuclear reactor using it.
3. D-He3 fusion requires higher temperatures, which is even more difficult in times of cost to develop.
4. He3 still produces neutrons, just less.
Hence, is the cost of developing D-He3 fusion and mining He3 less than the higher storage of nuclear waste for D-T fusion? I don't think so.