Japan's Monju reactor was supposed to be a more efficient alternative to conventional nuclear power. The "fast," sodium-cooled prototype plant would produce more plutonium than it ate up, making it relatively easy to recycle fuel. However, that's not how it worked out. A leak and fire led to a 15-year shutdown starting in 1995, and the reactor has been plagued by failures, mismanagement and political fights ever since. And now, the government has had enough: it's planning to close Monju once and for all. It would be slower and more expensive to fully restart the reactor than to shut it down (the equivalent of $4.6 billion versus $3.2 billion), officials claim, and the focus is on developing more practical fast reactors instead.