The U.S. has two components—and Mr. McCauley may wish to add to this response. There is a limit on the liability of an operator in a range of $310 million. If damages exceed that amount, there can then be a call on the other reactors in the United States, up to an amount of $120 million per reactor. It's almost a self-insured pool. Given the large number of reactors in the U.S., this approach is more readily feasible than it would be in Canada, given the smaller pool of reactors here.
So that's how you get to a higher threshold. They don't need to buy the equivalent of the higher limit in the insurance market. It is basically a “tax” on the other reactors in the event of an incident.