Day 4: Fresh explosion at nuclear plant in Japan

A third explosion in four days rocked the earthquake-damaged Fukushima Daiichi nuclear plant in northeast Japan early Tuesday, the country's nuclear safety agency said. The blast at Daiichi Unit 2 followed two hydrogen explosions at the plant -- the latest on Monday -- as authorities struggle to prevent the catastrophic release of radiation in the area devastated by a tsunami. The troubles at the Daiichi complex began when Friday's massive quake and tsunami in Japan's northeast knocked out power, crippling cooling systems needed to keep nuclear fuel from melting down.
The latest explosion was heard at 6:10 am on Tuesday (2110 GMT Monday), a spokesman for the Nuclear Safety Agency said at a news conference. The plant's owner, Tokyo Electric Power Co, said the explosion occurred near the suppression pool in the reactor's containment vessel. The pool was later found to have a defect. Radiation levels spiked Tuesday after a blast at a reactor in a quake-damaged nuclear power plant in northeastern Japan. The plant's operator said it feared the reactor containment vessel had been damaged. The explosion happened in reactor number 2 at a plant in Fukushima that is home to six nuclear reactors. Earlier blasts had occurred in reactors 1 and 3 there, and a fire was also reported Tuesday in reactor number 4. It was put out, the Kyodo News agency reported, citing the operator, the Tokyo Electric Power Co (TEPCO).