Keep in mind that one mistake made in the Fukushima design, and which might be happening here, is whether these estimates are based only on past historical data

Keep in mind that one mistake made in the Fukushima design, and which might be happening here, is whether these estimates are based only on past historical data or not. If they're based on historical data, on the worst known past earthquake/s in the region, then they may be effectively black-swan blind. Eg, they may be failing to take into account that the worst past events always exceeded the prior worst event before it, and therefore prior worst events were not, and are not, a reliable measure for future ones. Building earthquake-proof nuclear reactors requires, at minimum, taking the worst past earthquake nearby, and assuming the next will be worse yet, and building for that one (or the one after, etc). Or better yet, just don't build nuclear plants on top of fault lines, regardless of what historical data shows about it.