Comment by rnhmjoj
6 hours ago
The breeding blanket is entirely contained inside a vacuum vessel, so there isn't any oxygen to react with. Also, the are many blanket designs, but the lithium is never present in its elemental form (precisely because it would be very reactive), but in a stable chemical bond with some neutron multiplier (like lithium-lead alloys or beryllium ceramics). In some design the lithium is even immersed in the coolant itself, which is high pressure helium, so it's not going to ignite in any reasonable way.
> breeding blanket is entirely contained inside a vacuum vessel, so there isn't any oxygen to react with
When the vessel works. If the vessel breaches, that lithium could ignite. Note a showstopper. But I suppose a risk to be thought about by the engineers (probably not by policymakers).
Commonwealth Fusion Systems plan to use lithium in salt form FLiBe, a molten salt made from a mixture of lithium fluoride (LiF) and beryllium fluoride (BeF2). It does not violently react with air or water.
https://en.wikipedia.org/wiki/FLiBe