I guess my point was that the Fukushima reactors themselves were not the primary point of failure, but the on-the-cheap cooling system was the primary point of failure, and that needn’t have happened if they had thought through their design. The end result is however the same.
That is the drive for molten salt reactors, they are inherently safer because runaway overheating can’t occur. If they do start to overheat the molten salt which contains the radioactive material will be forced out of the reactor carrying with it some of the radioactive material thus reducing the reaction and containing the runaway. However, I am not a nuclear physicist so I may not be aware of inherent dangers in these types of reactors that are not in the current ones.
My overall point is that if we are going to move away from burning fossil fuels to produce our energy we need a replacement. Our energy needs are not going to decrease. Right now, renewables simply are not enough.