A new fire broke out Wednesday in an already fire-damaged reactor(反应堆) at a crippled nuclear power plant in Fukushima, Japan.
Tokyo Electric Power Co. spokesman Hajimi Motujuku says the blaze erupted(爆发，喷发) early Wednesday in the outer housing of the reactor's containment vessel. Firefighters are trying to put out the flames. Japan's nuclear safety agency also confirmed the fire, whose cause was not immediately known.
It's the second fire to break out at the plant's reactor No. 4 in as many days. The first occurred Tuesday morning near a pool where spent fuel rods are left to cool. That fire and an apparent explosion damaged the reactor's roof, and there are concerns that the spent fuel rods are overheating.
About three hours after the blaze erupted Wednesday, Japan's nuclear safety agency said fire and smoke could no longer be seen at Unit 4, but that it was unable to confirm that the blaze had been put out.
Also Wednesday, the agency said 70 percent of the nuclear fuel rods may have been damaged at another Fukushima Daiichi reactor that was first stricken last week, triggering the crisis.
"But we don't know the nature of the damage, and it could be either melting, or there might be some holes in them," said an agency spokesman, Minoru Ohgoda.
Desperate plant operators considered dramatic plans to stave off(避开，挡开) a meltdown in the reactor, including dumping water on it by helicopter. But plant operators worried that the water wouldn't reach the fuel rods. 
