Japan raises nuclear crisis level to 7

NPR : On 12 April the Japanese government raised the rating of the crisis at the Fukushima Daiichi power plant to 7 on the International Nuclear Event Scale (INES). The change in status at Fukushima was prompted by new data on the amount of radiation released rather than by a change in conditions at the plant. The only other nuclear incident to earn that rating to date has been the 1986 Chernobyl accident in Ukraine; the rating indicates a major release of radioactive material with widespread health and environmental effects that require extended countermeasures. The two incidents have significant differences: The amount of radioactive material released by the Fukushima plant to date is one-tenth the amount released at Chernobyl; the reactor cores at Fukushima are still largely protected, albeit with some damage to the containment vessels, whereas the entire reactor at the Soviet plant exploded and was not surrounded by a containment structure. The World Health Organization stated Tuesday that there was very little public health risk outside the 18-mile evacuation zone around the plant.