The deadly earthquake and tsunami   that struck Japan on March 11 damaged two nuclear power stations. Officials are now working to prevent dangerous radiation from poisoning the air in the area surrounding the Fukushima Daiichi plant. The Japanese government has ordered people living within 12 and a half miles of the plant to , and asked those living 12 and a half to 20 miles away to stay indoors. Nuclear power plants create energy using a chemical reaction that produces large amounts of heat. Reactors in Japan have many long, thin rods, called fuel rods , which must be kept cool. If the reactor's fuel rods aren't cooled, the reaction can burn out of control. That's what happened at the two Japanese plants after the quake caused a power failure and the cooling systems malfunctioned . This overheating could cause radiation to escape and sicken many people. Japan's 54 nuclear reactors are built to withstand the many small or moderate earthquakes the country faces each year. But Friday's earthquake was one of the most severe earthquakes ever recorded. People exposed to unsafe levels of radiation have a higher than normal risk of getting cancer. The Japanese government has been distributing potassium iodide pills to people in the surrounding areas to protect those who may have come in contact with radiation from the power plant. The pills flood the body with healthy potassium iodide. The potassium iodide works to crowd out "bad" iodine in the body that may have been poisoned by radiation. On Tuesday morning, 750 workers left the Fukushima Daiichi plant. However, 50 workers stayed behind to use sweater to cool the fuel rods. These dedicated employees are risking their own lives to save many others. On Thursday, officials used helicopters, fire trucks, and water cannons to spray water on the reactors to cool the fuel rods. But it's not clear whether these efforts were successful. Officials are now working on a power line to restore electricity to the plant. They hope this will help restart the plant's cooling system and stop the fuel rods from leaking radiation. This text is most probably taken from    _    .
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