Four atomic reactors in Fukushima, Japan, seem to be in partial meltdown. One of them, reactor No. 2, seems to have ruptured. The situation is spinning out of control as radiation levels spike. The US Navy has pulled back its aircraft carrier, the USS Ronald Reagan, after seventeen of its crew were exposed to radiation while flying sixty miles off the Japanese coast.
But despite three major explosions—at reactor No. 1, then No. 3, then No. 2—the Fukushima containment vessels seem to be holding. (Chernobyl lacked that precaution, having only a flimsy cement containment shell that collapsed, allowing the massive release of radioactive material.)
But there is another, potentially far more dangerous problem: the spent fuel rod pools that sit right next door to the reactors. The storage pools are packed with radioactive uranium, rise several stories above ground and are always close to the reactor, thus facilitating easy transfer of the fuel rods. Their name—especially “spent” and “pool”—conveys calm dissipation. But spent fuel rod pools are actually highly radioactive, very unstable, extremely dangerous and, compared with reactors, not well supported, contained or looked over.
The spent rods give off considerable amounts of “decay heat” and thus must be submerged in constantly circulating water. Expose them to air for a day or two, and they begin to combust, giving off large amounts of radioactive cesium-137, a very toxic, long-lasting, aggressively penetrating radioactive element with a half-life of thirty years. When cesium-137 it enters the environment, it essentially acts like potassium and is taken up by plants and animals that use potassium. (For the record, that includes you.)
The explosions at reactors No. 1 and No. 3 blew apart the respective containment buildings but left the vessels intact. Or so we think. But what did the blasts do to the nearby spent fuel rod pools? On Monday night the news in Japan confirmed that the pool next to reactor No. 3 lost its roof.
“I’ve been studying overhead photographs of Fukushima. It is very disturbing,” said Robert Alvarez, formerly a senior policy adviser at the Energy Department under Clinton and now a senior scholar at the Institute for Policy Studies.
“The steel wall of the pool seems to show damage. All the surrounding equipment, including the two cranes, has been destroyed. There is smoke coming from reactor No. 3, and steam coming from the spent fuel pool next to it. That indicates that the water in the pool is boiling. And that means the spent fuel rods are getting hot and could start burning.”
If the spent rods start to burn, huge amounts of radioactive material would be released into the atmosphere and would disperse across the Northern Hemisphere.
Unlike the reactors, spent fuel pools are not—repeat not—housed in any sort of hardened or sealed containment structures. Rather, the fuel rods are packed tightly together in pools of water that are often several stories above ground.