Prior to Fukushima Japan operated 54 nuclear plants that provided about 30% of the nation's electricity. Today 38 are shutdown and just 16 are running. The 38 shut nukes represent about 20% of the total electric generation of the third largest economy in the world.
Both the New York Times and the Wall Street Journal had front page stories about how the lights have stayed on in Japan, despite 38 nuclear plants not operating. Massive conservation that has become a near compulsory religion plus utilities scrambling to bring on line some gas and coal plants have maintained reliability.
Conservation has been so successful that most of the time Japan has substantial excess capacity and so successful that a serious debate has begun about closing all 54 nuclear plants, possibly as soon as 2012.
While Japan has kept the grid reliable and is using much less electricity, the decline of nuclear power has led to higher carbon emissions, since part of the nuclear loss has been filled with more coal and gas generation. This fact reminds once again that saying "no" to one power source means saying "yes" to something else. And sometimes it means taking steps forward and backward environmentally. Energy realities are messy and complex.
The Black Swan of Fukushima has triggered previously unthinkable changes in the powering of Japan, a big deal in energy and environment policy.