Do you mean that the Fukushima nuclear accident dumped locally in a few days 0.45% of all dumped nuclear waste during the last ~80 years?"? If so it seems non-negligible to me.

> 20 years earlier (nothing on tectonic timescales) this wouldn't be up to much discussion

Not sure about this. Maybe ~50 years ago, and even so the accident at Three Mile Island (1979) didn't pollute much but triggered quite a bunch of discussions.

> would you spend it all on this?

Yes, because there is no other realistic way: it is about losing citizens' trust and having to cope with other nations' claims, whatever the real risk. Associations of women were created to periodically measure radioactivity in various areas! In Japan! No government exposed to such distrust can decide to ignore it. A stain was made, it has to be cleaned.