Re:Major breakthrough on nuclear fusion energy
by Filligree on Wednesday February 09, 2022 @01:10PM
(#30275951)
Activation of the reactor walls. The neutrons don't disappear; they're absorbed, and some fraction of the atoms that absorb them become radioactive themselves. I've seen lifetime estimates ranging from five to ten years for the walls, after which they'll be high-level waste.
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Re:Major breakthrough on nuclear fusion energy
by ClumsyPilot on Wednesday February 09, 2022 @01:32PM
(#30276363)
Isn't the breeding blanket suppose to prevent that?
Re:Major breakthrough on nuclear fusion energy
by willis936 on Wednesday February 09, 2022 @02:07PM
(#30276955)
The breeding blanket does slow the neutrons, but there needs to be a first wall material that does not ablate into the plasma. You need very little of non-hydrogen material in the vacuum to cause a density collapse. If you made the wall out of liquid lithium then there would be a lot of lithium in the plasma.
Tungsten is a good choice for a first wall material because of its uniquely high melting point, low rate of embrittlement in high neutron flux, and short-lived radioisotopes.