Gen IV doesn’t mean anything specifically. No individual gen IV designs has every single advantage you see in any of those designs. You need to look at a speci

Gen IV doesn’t mean anything specifically. No individual gen IV designs has every single advantage you see in any of those designs. You need to look at a specific designs in isolation as well as what trade offs are involved in that design. “100-300x energy yield from the same amount of nuclear fuel” That’s one of those things that sounds good in isolation, but ends up being more expensive. It’s just like CANDU reactors don’t need enrichment and can operate on natural uranium, but it turns out fuel costs drop by 20% when they started enriching the fuel. Similarly LWR/HWR could make better use of their fuel if they could operate at higher temperatures, but that causes a world of other problems. Unfortunately nuclear engineers aren’t dumb, they’re doing things for surprisingly solid reasons even if counter intuitive reasons.