Indeed. What insurer could have covered the estimated 137 billion dollar hit [1] from the Fukushima disaster? The Japanese government has had to step in, to the very real financial detriment of its people and their nation.
(Nuclear reactors have the same "too big to fail" problem as the banking system: the expected value is positive, but the worst-case is a huge open ended liability and toxic asset)
[1] http://www.bloomberg.com/news/articles/2012-11-07/fukushima-...