Japan begins using helicopters to drop water on nuclear plant

March 17, 2011

Japanese military helicopters have begun to drop water on the nuclear power plant in an effort to cool reactors.

The operation began at 0948 local time (0048 UTC) today, after similar efforts were ended early yesterday due to radiation. helicopters dropped four loads of water on reactors three and four, with officials planning up to twelve more drops before crews are forced to leave the area due to radiation.

The water drops are intended to both cool the reactors and add water to pools that hold fuel rods. These pools are believed to be almost empty; if they run out of water the fuel rods can melt and release high levels of radiation. The storage pools have a capacity of about 2,000 tonnes of water, a third of that is needed to keep fuel rods submerged. Each helicopter can carry 7.5 tonnes of water at a time.

TV footage showed helicopters dropping water from about 300 feet above the reactors. Some time after the helicopters began to drop water, military trucks started using a water cannon to spray reactor three.

The crisis at the power plant has led to the evacuation of around 70,000 people who lived within 20 kilometres of the plant, while another 140,000 are under orders to stay inside. The United States has asked its citizens who are within 80 kilometres of the plant to leave.