"Japan’s nuclear crisis verged toward catastrophe on Tuesday after an explosion damaged the vessel containing the nuclear core at one reactor and a fire at another spewed large amounts of radioactive material into the air, according to the statements of Japanese government and industry officials," reports The New York Times.
According to the article, "The two critical questions over the next day or so are how much radioactive material is spewed into the atmosphere, and where the winds carry it. Readings reported on Tuesday showed a spike of radioactivity around the plant that made the leakage categorically worse than in had been, with radiation levels measured at one point as high as 400 millisieverts an hour. Even 7 minutes of exposure at that level will reach the maximum annual dose that a worker at an American nuclear plant is allowed. And exposure for 75 minutes would likely lead to acute radiation sickness."
The story adds, " ‘We are on the brink. We are now facing the worst-case scenario,’ said Hiroaki Koide, a senior reactor engineering specialist at the Research Reactor Institute of Kyoto University. ‘We can assume that the containment vessel at Reactor No. 2 is already breached. If there is heavy melting inside the reactor, large amounts of radiation will most definitely be released.’ "
The article explains, "If all workers do in fact leave the plant, the nuclear fuel in all three reactors is likely to melt down, which would lead to wholesale releases of radioactive material — by far the largest accident of its kind since the Chernobyl.
"Even if a full meltdown is averted, Japanese officials have been facing unpalatable options. One was to continue flooding the reactors and venting the resulting steam, while hoping that the prevailing winds did not turn south toward Tokyo or west, across northern Japan to the Korean Peninsula. The other was to hope that the worst of the overheating was over, and that with the passage of a few more days the nuclear cores would cool enough to essentially entomb the radioactivity inside the plants, which clearly will never be used again. Both approaches carried huge risks."
Another question is how much of a risk, if any, is the West Coast of the U.S. to radiation from the damaged nuclear plants in Japan.
Speaking on Fox News, "Nuclear expert Joe Cirincione warns that radiation from Japan’s multiple potential nuclear meltdowns could spread to the US west coast and that the threat represents an “unprecedented crisis,” as another explosion rocked the Fukushima complex and officials admitted that nuclear fuel rods at reactor number two have been fully exposed," according to an article found at Current TV.
Cirincione also told Fox News, the story says, "Some of the radioactivity could carry in the atmosphere to the West Coast of the United States.”…"When host Chris Wallace questioned whether radioactivity could travel thousands of miles across the Pacific, Cirincione responded, ‘Oh, absolutely. Chernobyl, which happened about 25 years ago, the radioactivity spread around the entire northern hemisphere. It depends how many of these cores melt down and how successful they are on containing it once this disaster happens.’ "