The Japanese government and Tepco colluded to cover it up and did insane things like burning debris that was coated with radioactive isotopes. Or since they had insufficient fresh water flow, sending salt water in which accelerated corrosion.

Meanwhile scientists leaked that radioactive isotopes that were clearly linked to Fukushima were being found in filters in the USA as the fallout spread. And then the USA just astronomically raised the allowable amount of contamination to hide this fallout.