Spent fuel rods add to Japan's nuclear woes
As Japan's post-quake nuclear crisis deepens, concerns have been raised about the dangers of spent fuel rods.
The Unit 4 reactor at the Fukushima Dai-ichi power plant caught fire earlier Tuesday. Japanese officials told the International Atomic Energy Agency that the reactor fire was in a storage pond and that "radioactivity is being released directly into the atmosphere." Long after the fire was extinguished, a Japanese official said the pool, where used nuclear fuel is kept cool, might be boiling.
Hidehiko Nishiyama told reporters that "we cannot deny the possibility of water boiling" in the spent fuel storage pool at the facility.
If the water boils, it could evaporate, exposing the rods. The fuel rods are encased in safety containers meant to prevent them from resuming nuclear reactions, nuclear officials said, downplaying the risk of that happening.
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But if they did catch fire, they would pose a dangerous threat since the pools they occupy sit at the top of the reactor facility and could be more easily spread into the atmosphere.
"It's worse than a meltdown," David A. Lochbaum, a nuclear engineer at the Union of Concerned Scientists, told the New York Times. "The reactor is inside thick walls, and the spent fuel of Reactors 1 and 3 is out in the open."
Nishiyama, an official in the Economy Ministry, which oversees nuclear safety, avoided commenting on the potential risks from rising temperatures caused by a failure in the systems that keep the spent fuel rods cool. He said the plant's operator is considering what to do about the problem.
Unit 4 was not operating at the time of the tsunami, but its backup power systems failed afterward, preventing cooling systems from working properly. Three reactors already have been wrecked by explosions and nuclear officials confirmed that temperatures in two other reactors that had been shut down for inspections were also rising.
"The last 24 hours have been particularly bad time for even this dreadful crisis. We'd seen two explosions already in Units 1 and 3, but this third explosion, unlike the other two, was actually inside the containment building that surrounds the reactor and that's significant because that will make it harder to prevent the release of radioactivity," James Acton, from the nuclear policy program at the Carnegie Endowment for International Peace, told CBS' "The Early Show" Tuesday. "And the spent fuel ... the fact that it has caught fire is also serious because it now means there's another pathway [for radiation] to reach the environment."
The temperature of the water in the spent fuel storage pool for Unit 4 was 183 degrees Fahrenheit on Monday, when it was last measured. No measurements have been available since then, Nishiyama said.
"We have no information about whether the spent fuel rods are exposed," he said.
But officials acknowledged that there could have been damage to the containers. They also confirmed that the walls of the storage pool building were damaged.
Though Prime Minister Naoto Kan and other officials urged calm, Tuesday's developments fueled a growing panic in Japan and around the world amid widespread uncertainty over what would happen next. In the worst case scenario, one or more of the reactor cores would completely melt down, a disaster that could spew large amounts of radioactivity into the atmosphere.
Dangerous levels of radiation leaking from the plant forced Japan to order 140,000 people to seal themselves indoors. The crisis comes after the region was shattered by Friday's 9.0-magnitude earthquake and the ensuing tsunami that is believed to have killed more than 10,000 people, plunged millions into misery and pummeled the world's third-largest economy.
