The International Atomic Energy Agency said today that Japan has declared a state of emergency at a second earthquake-ravaged nuclear plant after measuring higher-than-permitted levels of radiation. The IAEA says the source is being investigated, but all three reactors at the Onagawa plant are currently under control. Japan also said earlier attempts to cool the No. 3 reactor at the Fukushima Dai-ichi plant had failed. At least 22 people around the Fukushima Dai-ichi have been contaminated by radiation.
Chief Cabinet Secretary Yukio Edano also said today that a hydrogen explosion could occur at Unit 3 of the Fukushima Dai-ichi nuclear complex, the latest reactor to face a possible meltdown. "At the risk of raising further public concern, we cannot rule out the possibility of an explosion," Edano said. "If there is an explosion, however, there would be no significant impact on human health." (Read more Japan earthquake stories.)