Even Fukushima was a human problem, they had the warnings, the designs, the technology, the reviews, and the equipment to prevent a meltdown. But newer safety features were never implemented due to political problems and concerns. They knew Tsunamis bigger than the plant was designed for could happen, they knew earthquakes bigger than the plant could handle could happen, they had the technology and knowledge to reduce or eliminate those problems so it wouldn't melt down, they just didn't bother doing any of the work to accomplish it.