Nobody knows for sure, but the sole nuclear accident cleanup operations may cost $470 to $660 billion.

https://en.wikipedia.org/wiki/Fukushima_nuclear_accident_cle...

According to https://en.m.wikipedia.org/wiki/Nuclear_power_in_Japan , Japan had about 300 TWh of nuclear for a year at the time of the accident. So $180 billion amount to $0.6/kWh over a year if I'm not mistaken. Not cheap. But if you spread over a few decades then that's reasonable.

Sadly I don't have time to go into it now, but they're massively overpaying due to miscallibrated risk tolerance. (Paying tens of millions per QALY is not a good use of money, 1 milliSv per year is an utterly insane goal)

The actual disaster had noticably bad short term effects on only a small area and long term effects on a tiny area.