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I wasn't aware of any radioactive waste from these fusion processes. I was also under the impression that fusion fuel is quite abundant (Deuterium and Lithium a

I wasn't aware of any radioactive waste from these fusion processes. I was also under the impression that fusion fuel is quite abundant (Deuterium and Lithium as an example discussed in one of the videos linked in the comments).

yholio 6y ago
There are no fission waste products but the reactor deals with massive neutron fluxes that activate all internal components, coolants and the internal fuel fluxes that need to be processed in order to keep the reaction going. The Deutherium-Lithium route is not direct, you need to breed Tritium, a hazardous radioactive gas. There is poor neutron economy and you need neutron multiplicators that also become activated. While I agree the quantity of waste is low, that doesn't really matter for the general public. We had for decades the technology to put fission waste in deep geological storage, what held it up were political concerns - the same for fast breeders that could burn the waste. So I cannot for the life of me understand how NIMBY-ism, the major cost driver of fission plants (via political challenges, court actions, schedule slips etc.), is allayed, when the plant will regularly ship out tons of hazardous materials through the communities they serve. As for the fuel cost issue, you cannot use natural Lithium due to low cross section, but blankets made up of tons of enriched Lithium that has a large Li6 content, that are continually circulated and need to be topped off as H3 is bred. No estimate of cost for this feed-stock exists, but it is likely more expensive than natural uranium that can be burnt in a heavy water reactor, for example. (that reactor design has it's own issues with heavy water inventory costs, but this material is most probably easier to produce than enriched Li6, and is not consumed as a fuel) When you draw the line, the best prospects of ITER derived fusion plants (not existing experiments, mind you, but the theoretical future, practical designs) is at best comparable to existing fusion plants. Why should we waste money on them, if they cannot improve on the current state of the art?

yholio 6y ago

There are no fission waste products but the reactor deals with massive neutron fluxes that activate all internal components, coolants and the internal fuel fluxes that need to be processed in order to keep the reaction going. The Deutherium-Lithium route is not direct, you need to breed Tritium, a hazardous radioactive gas. There is poor neutron economy and you need neutron multiplicators that also become activated. While I agree the quantity of waste is low, that doesn't really matter for the general public. We had for decades the technology to put fission waste in deep geological storage, what held it up were political concerns - the same for fast breeders that could burn the waste. So I cannot for the life of me understand how NIMBY-ism, the major cost driver of fission plants (via political challenges, court actions, schedule slips etc.), is allayed, when the plant will regularly ship out tons of hazardous materials through the communities they serve. As for the fuel cost issue, you cannot use natural Lithium due to low cross section, but blankets made up of tons of enriched Lithium that has a large Li6 content, that are continually circulated and need to be topped off as H3 is bred. No estimate of cost for this feed-stock exists, but it is likely more expensive than natural uranium that can be burnt in a heavy water reactor, for example. (that reactor design has it's own issues with heavy water inventory costs, but this material is most probably easier to produce than enriched Li6, and is not consumed as a fuel) When you draw the line, the best prospects of ITER derived fusion plants (not existing experiments, mind you, but the theoretical future, practical designs) is at best comparable to existing fusion plants. Why should we waste money on them, if they cannot improve on the current state of the art?