The Economist’s Graphic Detail blog post earlier this week highlighted their nuclear energy interactive guide, which shows the nuclear electricity production, number of operational reactors, and the metric tons of uranium required for nuclear production of 30 countries currently using nuclear power. According to the map, the US produces by far the largest amount of nuclear power at about 800 terawatt hours (TWh), with France following at a little over 400 TWh and Japan at 280 TWh. (It is important to note that this data was produced before the Fukushima Daiichi nuclear disaster in March 2011, which has led to a shutdown of almost all of Japan's nuclear reactors.)
However, the map showing nuclear electricity as a percentage of total production shows the U.S. produces a relatively small proportion of their electricity through nuclear power (just under 20%). France’s nuclear power makes up the largest percentage of their total electricity at 74.1%, followed by Slovakia at 51.8% and Belgium at 51.2%.