re: #1 Destro

The draw of coal and gas and oil is the price. But we don’t calculate the damage to the ecosphere, or the fact that it’s all finite resources. What the most expensive option of all is continuing with fossil fuels. The price? The deaths of millions in climate changes.
I looked up the French design, very interesting.
The Hyperion reactor looks interesting as does many of the later generation designs. Thorium is one possibility but it may not work out. Fission power is a natural bridge to fusion power. One technology teaches the lessons needed for the next. Just as wood and coal taught us about how to advance metallurgy to construct steam engines that led to combustion engines that led to electric motors. Each builds a foundation for the next.