For Fukushima that number is circa $800 billion.
If it is as safe as you think it is with a minimum of safety standards then the market will still provide. Sophisticated insurers will be capable of calculating the risk and shouldering all of it for a reasonable fee.
Right?
The act exists, of course, because it definitely isnt safe enough to do that and sophisticated private insurers who are capable of calculating risk better than you or I know this all too well. They won't touch nuclear power without a ludicrously low liability cap.
The ironic thing is that even with this gargantuan implicit subsidy (yes, taxpayer funded insurance that pays out $800 billion in an emergency is a big subsidy), nuclear power still isnt cost competitive with solar and wind.
But, I'm all in favor of letting nuclear plants determine their own safety levels. IF they can get the insurance to cover ALL the costs of dealing with a disaster. Free market, baby.