A third explosion damaged the nuclear core of one of the reactors at the Fukushima Daiichi nuclear plant Tuesday morning Tokyo time. Japanese officials also reported a fire in a pool of spent reactor fuel that sent large amounts of radioactive material into the air. In the wake of the explosion, plant operators said radiation levels surrounding the plant are now at "levels that can impact human health," urging people within a 30-kilometer radius — a population of 140,000 — to remain indoors. As low levels of radiation float toward Tokyo, some citizens are fleeing, while others are stripping stores bare of daily essentials. In a brief address, Prime Minister Naoto Kan asked his people to remain calm but warned that there was a "very high risk" of further leakage from crippled reactors. Three explosions in four days have already made Fukushima Daiichi the worst nuclear accident since Chernobyl, which rated a maximum level 7 on the INES scale. France's nuclear agency just declared Fukushima a level 6. And that's before the matter of the pools of water containing spent fuel rods, which could pose an even greater danger.
The pools sit on the top level of the reactor building, with spent fuel rods submerged in water. But like the reactors, the pools have lost power to their cooling systems after the earthquake. If any of the spent fuel rods were to catch fire, high heat would "loft the radiation in clouds that would spread the radioactivity," says the New York Times.
“It’s worse than a meltdown,” said David A. Lochbaum, a nuclear engineer at the Union of Concerned Scientists who worked as an instructor on the kinds of General Electric reactors used in Japan. “The reactor is inside thick walls, and the spent fuel of Reactors 1 and 3 is out in the open.”
Most of the plant's 800 workers have been withdrawn. The 50 or so that remain, at tremendous personal risk, continue to pump in seawater to cool the second reactor, but the pools, which have reached a boiling point, are unapproachable.
Prime Minister Kan faced a public backlash yesterday for leaving the bulk of the communication about the disaster to his right-hand man, Yukio Edano. But Reuters reports Kan himself may be left out of the loop. He was furious with executives at the Tokyo Electric Power Co., which has been at the center of this disaster, for taking so long to inform his office about the explosion, prompting him to ask, "What the hell is going on?" TEPCO, Japan's biggest power company, has suffered numerous scandals over its role in the nuclear industry. In 2002, the company's president and four of his top executives were forced to resign on suspicion of falsifying nuclear plant safety records.
Japan Faces Potential Nuclear Disaster as Radiation Levels Rise [NYT]
Radiation levels rise in Japan following third blast [BBC]
In Fuel-Cooling Pools, a Danger for the Longer Term [NYT]
Japan’s nuclear crisis leads to dangerous spike in radiation levels [WP]
Japan PM to nuclear power firm: "What the hell's going on?" [Reuters]