In the years following the major accidents at Three Mile Island in 1979 and Chernobyl in 1986, nuclear power fell out of favor, and some countries applied the brakes to their nuclear programs. In the last decade, however, it began experiencing something of a renaissance. Concerns about climate change and air pollution, as well as growing demand for electricity, led many governments to reconsider their aversion to nuclear power, which emits little carbon dioxide and had built up an impressive safety and reliability record. Some countries reversed their phaseouts of nuclear power, some extended the lifetimes of existing reactors, and many developed plans for new ones. Today, roughly 60 nuclear plants are under construction worldwide, which will add about 60,000 megawatts of generating capacity -- equivalent to a sixth of the world's current nuclear power capacity.
But the movement lost momentum in March, when a 9.0-magnitude earthquake and the massive tsunami it triggered devastated Japan's Fukushima nuclear power plant. Three reactors were severely damaged, suffering at least partial fuel meltdowns and releasing radiation at a level only a few times less than Chernobyl. The event caused widespread public doubts about the safety of nuclear power to resurface. Germany announced an accelerated shutdown of its nuclear reactors, with broad public support, and Japan made a similar declaration, perhaps with less conviction. Their decisions were made easier thanks to the fact that electricity demand has flagged during the worldwide economic slowdown and the fact that global regulation to limit climate change seems less imminent now than it did a decade ago. In the United States, an already slow approach to new nuclear plants slowed even further in the face of an unanticipated abundance of natural gas.
It would be a mistake, however, to let Fukushima cause governments to abandon nuclear power and its benefits. Electricity generation emits more carbon dioxide in the United States than does transportation or industry, and nuclear power is the largest source of carbon-free electricity in the country. Nuclear power generation is also