The speaker discussed void swelling, considering this phenomenon to cause embrittlement. However, in the days some decades ago when voids were found in fast reactors, the primary talk was of void swelling, not embrittlement. In fact, by pinning dislocations voids could increase material strength. For fusion reactors, if any are built, the embrittlement will come from hydrogen and helium formed via the fast neutron (n,p) and (n,alpha) reactions. No material is immune.
The speaker discussed void swelling, considering this phenomenon to cause embrittlement. However, in the days some decades ago when voids were found in fast reactors, the primary talk was of void swelling, not embrittlement. In fact, by pinning dislocations voids could increase material strength. For fusion reactors, if any are built, the embrittlement will come from hydrogen and helium formed via the fast neutron (n,p) and (n,alpha) reactions. No material is immune.