An explosion at a crippled nuclear power plant in northern Japan on Saturday blew the roof off one building and caused a radiation leak of unspecified proportions, escalating the emergency confronting Japan’s government a day after an earthquake and tsunami devastated parts of the country’s northeastern coast.
Government officials said that the explosion, caused by a build-up of pressure in the reactor after the cooling system failed, destroyed the concrete structure surrounding the reactor but did not collapse the critical steel container inside. They said that raised the chances that they could prevent the release of large amounts of radioactive material and could avoid a core meltdown at the plant.
