8:45 AM EDT
Tokyo Electric Power Company is battling to cool a reactor to prevent another explosion at its nuclear power plant in quake-hit Fukushima Prefecture.
The utility firm said on Monday afternoon that fuel rods are exposed at the Number Two reactor of its Fukushima Number One plant after the level of coolant water dropped. At around 6pm, the power company began pumping in seawater. But it says all fuel rods in the reactor could be exposed. The firm says a core meltdown might have occurred.
The Nuclear and Industrial Safety Agency says that pumping seawater into the reactor is working now to cool the reactor.
Earlier in the day, the firm told the government that the reactor had lost all cooling capability due to a failure of the emergency power system.
Since then, the company has tried to circulate the coolant by steam instead of electricity. But attempts to lower the temperature inside the reactor chamber have not worked well.
The company is also considering opening a hole in the reactor housing building to release hydrogen generated by the exposed fuel rods.
Accumulated hydrogen has caused blasts at two other reactors at the plant.