Would be interesting to see the detailed financials. Reading the already many comments, many important factors need to be assessed.
Regarding the costs, Japan receives the energy output but at what costs and benefits to whom?

CO2 generation, apparently the only ‘by-product’, is of course some sort of dilemma, but only if you believe the pseudo science of the alarmists. It might even be welcome if, as some believe, we are entering a little ice age period. and then, only if atmospheric CO2 actually does make a difference!
Hopefully, this energy production will have less of the subsidization required for solar and wind energies.