Fukushima itself revealed numerous lapses in safety procedures, including the fact that they built it at that site at all, that they didn’t have adequate emergency generators, that they never tested the isolation condensers (which would have prevented the meltdown and hydrogen explosion at Unit 1) etc. Contrast that to Nine Mile Point here in upstate NY where they test the isolation condensers every chance they get and the operators know exactly how it works.
Many of the Japanese ideas that lead to quality, efficiency and a seemingly harmonious society lead to death in nuclear work. Critical tasks are treated as 無駄 (waste).
And speaking of 無駄, there is a real tension between a heavier process and faster feedback. That missing header takes 30 minutes to fix but if the process to avoid that mistake adds 30 minutes of time you don’t come out ahead. For superficial problems like that the answer is to speed up your cycle and try to get that 30 minutes down to 20.
A better example of a “a stitch in time saves nine” is where people get the data structures behind the application wrong and fixing it is more like 30 weeks.
I have experienced the bit of "Japanese working folk being willing (or perhaps expected) to commit their lives fully to their jobs", and I wonder if putting your own health on the line comes as a byproduct of that? Definitely not an aspect of the culture I'd try to encourage.
(2) As someone whose obsession with anime even annoys people at anime conventions, my take is that irony has a special place in Japanese culture. For instance they say they have filial piety but they have high rates of elder abuse. Allegedly they have a pacifist constitution but they have a large “Japan Self Defense Force”. There is always an outsider and insider view of a situation which is fertile ground for “normalization of deviance”, see
https://en.wikipedia.org/wiki/Uchi–soto
https://en.wikipedia.org/wiki/Honne_and_tatemae
(3) “Continuous improvement” optimizes the happy path at the expense of resilience to exceptional events. For instance just in time production was crippled by the supply chain shocks of the pandemic. At Tokaimura they were mixing nuclear fuel and were (a) making a higher enrichment than they ever did before and (b) had modified their tools to speed production up. (b) is a competitive advantage in most places but in nuclear fuel processing you have to always avoid forming a critical mass and that is done through applying rules to the process. They got away with it… Until they didn’t.