Sunday, March 13, 2011

The Situation Remains Dire In Japan As Rescue and Relief Efforts Continue

Japan faces a three-pronged disaster, with recovery and relief efforts focusing on searching for survivors and victims from the massive 9.0 earthquake (revised upwards from 8.9 by Japanese scientists) and ensuing tsunami, and warily eying the dire situation at several nuclear reactors in the hard stricken area.

Reports are indicating that perhaps 10,000 or more were killed in Miyagi prefecture alone, and that's on top of the 1,000 that are officially listed as killed from the tsunami and quake.

Video from Chiba, where the tsunami came roaring through:

Meanwhile, while much of the world has seen the flooding at Sendai's airport, video has emerged showing the tsunami striking from within one of the terminal buildings and the onlookers at first staring in wonderment and then quickly moving away from the windows and walls as the wall of water approaches:

At the same time, there continues to be mixed reports about the seriousness of the situation at several nuclear reactors. Some headlines are indicating that meltdowns are in progress, while others are noting that there hasn't been any breach of the reactor containment vessels nor a release of massive amounts of radiation. The explosion witnessed yesterday was the result of hydrogen gas exploding during the release of gas to bring down the pressure within the reactor. Japanese scientists are bringing down the temperature at the reactors in the Fukushima complex with sea water and boric acid, which tamps down the nuclear chain reactions.

MSNBC - headlines the term meltdown, but dig a little deeper, and the term isn't clearly defined.
A "meltdown" is not a technical term. Rather, it is an informal way of referring to a very serious collapse of a power plant's systems and its ability to manage temperatures. Yaroslov Shtrombakh, a Russian nuclear expert, said a Chernobyl-style meltdown was unlikely.

"It's not a fast reaction like at Chernobyl," he said. "I think that everything will be contained within the grounds, and there will be no big catastrophe."
In 1986, the Chernobyl nuclear reactor exploded and caught fire, sending a cloud of radiation over much of Europe. That reactor — unlike the Fukushima one — was not housed in a sealed container, so there was no way to contain the radiation once the reactor exploded.

Edwin Lyman, a senior scientist with the Union of Concerned Scientists, which opposes nuclear energy, told Friday that TEPCO was facing a potential catastrophe.

"What's critical is, are they able to restore cooling and prevent fuel damage? If the fuel starts to get damaged, eventually it will melt through the reactor vessel and drop to the floor of the containment building," raising the odds that highly radioactive materials could be released into the environment, he said.

But Steve Kerekes, spokesman for the U.S.-based Nuclear Energy Institute, said that while the situation was serious, a meltdown remains unlikely and, even if it occurred would not necessarily pose a threat to public health and safety.
Scientists are trying to get a handle on the nuclear chain reactions to keep the pressure within the reactor from getting to supercritical levels causing an explosion and breach of the containment vessel in which the uranium cores sit. Moderator rods are present to soak up the energy but even a reactor that is shut down is still releasing tremendous amounts of energy - and requires coolant systems. It is those systems that failed, particularly the backup systems that should have kicked in when the quake struck.

Here are before/after images of many of the areas hardest hit by the tsunami. Of particular note is one of the Fukushima nuclear power plant, which shows many of the secondary buildings wiped away by the tsunami. That could explain why the coolant systems failed.

Rethinking sea walls against tsunami is already underway - but it will take some time before the full effect of whether they saved lives in some areas and provided a false sense of security in others - particularly around the Fukushima reactor complex.

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