MTd2 wrote:
…
So, we would have, at the very best, 20 years to finish all boron.

I hope I am wrong…

The researcher’s figures are somewhat different… 🙂

https://focusfusion.org/index.php/forums/viewreply/229/

Boron is not in short supply. About 500,000 tons are produce per year for a price of about $700/ton. Since each GW of focus fusion power takes a ton per year of boron, the entire current world production of energy would only consume about 10,000 tons per year. If, in the far future, we ran short, we can get boron from seawater. Total resources would last billions of years at current rates.