Hammered by a tremendously powerful earthquake and then bludgeoned by a gigantic tsunami, Japan really had enough trouble on its hands. But as fate would have it, the only nation ever to witness the full horrors of nuclear war is, in addition to its other woes, face to face with a nuclear power nightmare. Problems with cooling three reactors at Fukushima Daiichi have already led to the venting of radioactive steam and two explosions. There are similar concerns about another reactor at the nearby Fukushima Daini plant. A desperate struggle is on to prevent the worst from happening — a complete meltdown of the nuclear core that could lead to large releases of radioactivity into the environment. With few natural resources of its own, Japan opted for nuclear power to supply a third of its energy needs. It has today more than 50 commercially operating nuclear reactors. These reactors were built taking into account the fact that they would be operating in a seismically dangerous environment. Unfortunately, Friday's earthquake, which was the worst recorded in the country, and the huge tsunami it unleashed set off a cascade of problems at the two nuclear power plants.

Safely shutting down a nuclear power plant is not simple. Stopping the chain reaction that keeps fission going, thereby producing vast amounts of energy, is just the first step. But even after that is achieved, the core of a nuclear reactor is still very hot. In addition, radioactive processes continue in the nuclear fuel, which too produce heat. The plant at Fukushima Daiichi relied on pumps powered by electricity to keep cooling water circulating. Friday's quake and tsunami knocked out electric supply from the grid. Standby generators kept at the plant for such contingencies could not be used because of the flooding and damage caused by the tsunami. Batteries, which were intended only to keep the cooling going until the generators came on, were soon depleted. The lack of cooling led to what Japanese officials say is only a partial meltdown of the nuclear cores in two reactors. Even if a total meltdown is avoided, it is believed that for many months to come the plant's operator will have to continue pumping in seawater to cool the two reactors and periodically release radioactive steam. People who have been evacuated from the area may not be able to return home any time soon. Understandably, these events in Japan have set off waves of concern in countries that have nuclear plants of their own, with worries about some unforeseen chain of events producing serious safety issues. In India, the country's nuclear agencies have promised a revisit of safety issues at all atomic plants. Such a safety audit must be carried out with a transparency that engenders public trust, without which nuclear power will not flourish.