Reply To: NIMBY FUD

[Mechanik]

asymmetric_implosion wrote: Li is the only option but you have to worry about the neutron activation and all that goes with it.

In practical terms, Li does not activate. In practice, activated Li should all end up as 4He, 3H, or 9Be.

I’d guess the 9Be content is no big deal, until it comes to recycle the lithium coolant, and in fact the Be-9 and Li-7 reactions will chuck yet more neutrons out (the 9Be is a neutron ‘multiplier’), and the total additional neutron capture reactions should increase the total heating of the blanket (the follow-on heating of a neutron irradiated Li blanket would not be an insignificant fraction of the total heat output of a ‘real’ fusion reactor)

The 4He and T are gases and, presumably, should be readily collectable out of a liquid!?

There is one element that looks like a good neutron-resistant material that might be used as a liquid coolant (though I have never heard anyone else suggest it), and that is tin. For an ‘average’ atom in a given quantity of naturally occurring tin, it can repetitively absorb some 4 neutrons or so before it will become an activated isotope. But, then, why would you bother if liquid Li generates more heat for itself under neutron bombardment, along with some very useful tritium.