Our review of worldwide nuclear accident data shows Japan has had more nuclear accidents of greater severity than other countries. Cultural and geological factors likely combined to increase the severity of accidents, while policies designed to incentivize expansion of the reactor fleet likely increased the consequences of accidents. Cost estimates for the Fukushima disaster have doubled to $220 billion, and a literature review indicates total accident costs could exceed $500 billion. Indirect costs could increase that amount even more. To mitigate risk of future accidents, Japan could consider constructing a new fleet of 25 highly advanced reactors and require plant owners to establish set-asides to pay for future accidents in much the same way banks set aside funds to cover loan losses. This would build a profit motive into improving safety protocols and incentivize businesses to foster a stronger safety culture. At the same time, Japan might increase investments in clean fuels, such as hydrogen, to ensure it has feasible alternatives for successfully achieving safe, economically viable, and secure forms of energy.