29 March 2011

Blunder and Confusion at Fukushima Reactor On Sunday

The utility at Fukushima (TEPCO) announced that radioactive water was found to be 10 million times normal levels at Unit 2, prompting evacuation of that site and world wide anguish and worry. This was a major story. Then, a few hours later, the utility made a rare apology and retracted that statement, stating that the water was only 100,000 times normal. What happened? How could the utility make such a blunder? 
Only now is it possible to piece together the events that led to this unusual apology. First, workers at Unit 2 were astonished to find that radiation levels in the water were extremely high. This prompted them to evacuate the site immediately. Second, they rushed out so fast that they did not do a second measurement of the water. Third, the first readings were slightly incorrect. The workers got iodine-134 (with a half-life of 53 minutes) confused with iodine-131 (with a half-life of 8 days). Also, cesium-137 was also found in the water (with a half - life of about 30 years). Fourth, by confusing the two, they also got the wrong level of radioactivity. They found more iodine-134 that was actually present in the water. The shorter the half-life, the more radioactive an isotope is - the longer the half-life, the less the radioactivity. So their calibration of iodine-134 was incorrect, yielding the false number of 10 million. Fifth, the utility did not send in another crew to check the measurements, so they got their calibration wrong, but they went public with this incorrect number. 
The main point, however, from the workers perspective, is that radiation levels are 1,000 milliseverts/hour. That does not change at all with this new calibration. This means that workers will come down with radiation sickness withonly 15 min. of exposure. Some workers will die after 6 hours of exposure. 
The meaning of all this is: if radiation levels continue to rise, and one day all workers are forced to evacuate, it means that the accident will be in free fall. If the workers abandon ship, and the cores will all be uncovered, then that is the point of no return; 3 nuclear power may inevitably have meltdowns making a tragedy worse than Chernobyl. Time is not on their side. Already, a new 6.5 earthquake has hit Japan, creating a small tsunami. Earthquakes, pipe breaks, cracks, etc. might cause radiation levels to increase until evacuation is unavoidable, then all hell might break out.

1 comment:

Andrew Spagnoli said...

That is the problem in a nutshell, Dr. Kaku... and the fact that most workers have not had their own radiation exposure monitors this whole time and your Homer Simpson comment the other day seems even more on target. Apparently the managers just look at the rad-detectors that some of them have and put down roughly the same number for the other workers when they fill the log of exposures out. Or maybe they just have been making the exposures numbers up completely... your guess is as good as mine.