That Japanese government’s decision will seems to cost 100 trillion yen. Can you believe it? That amount of money is easily over Japanese national budget.
Why this kind of things happen is easy, people can’t trust invisible things. Obviously we can’t see radioactive materials because it’s too small to see. It also doesn’t have any smell, color and taste.
Currently scientific consensus is saying that difference of dangerousness between 20mSv/year and 1mSv/year doesn’t have statistical significance. If it had, 20mSv/year risk of cancer would be 1.0128times as much as normal, 1mSv/year risk of cancer would be 1.00064times as much as normal. It means the most dangerous point of nuclear decontamination is to threaten people’s peace of mind.