Radioactive dust from Fukushima plant hit N. America soon after meltdown: researchers
Radioactive materials spewed out from the crippled Fukushima No. 1 Nuclear Power Plant reached North America soon after the meltdown and were carried all the way to Europe, according to a simulation by university researchers.
The computer simulation by researchers at Kyushu University and the University of Tokyo, among other institutions, calculated dispersal of radioactive dust from the Fukushima plant beginning at 9 p.m. on March 14, when radiation levels around the plant spiked.
The team found that radioactive dust was likely caught by the jet stream and carried across the Pacific Ocean, its concentration dropping as it spread. According to the computer model, radioactive materials at a concentration just one-one hundred millionth of that found around the Fukushima plant hit the west coast of North America three days later, and reached the skies over much of Europe about a week later.
According to the research team, updrafts in a low-pressure system passing over the disaster-stricken Tohoku region on March 14-15 carried some of the radioactive dust that had collected about 1.5 kilometers above the plant to an altitude of about 5 kilometers. The jet stream then caught the dust and diffused it over the Pacific Ocean and beyond...
http://mdn.mainichi.jp/mdnnews/news/20110623p2a00m0na006000c.htmlWater treatment system not working as expected
TOKYO (Kyodo) -- Tokyo Electric Power Co. said Wednesday that part of a newly installed radioactive water treatment system at its crippled Fukushima Daiichi nuclear power plant is operating only at 10 percent of its expected decontamination capacity.
The utility said that although the system as a whole is performing above the minimum targeted decontamination level, it is investigating the cause of the insufficiency of a cesium-absorbing device developed by Kurion Inc. of the United States.
During recent trial operations, the installation of the device reduced the level of cesium-134 and cesium-137 in toxic water to one hundredth, although a reduction to one thousandth of the level had been anticipated...
...The 6.1 meter-deep water in the basement may be contaminated due to the effects of damage to the reactor as radiation doses of 430 millisieverts per hour have been found in the stairs of the building, a TEPCO official said.
(Mainichi Japan) June 23, 2011
http://mdn.mainichi.jp/mdnnews/news/20110623p2g00m0dm015000c.htmlValve likely set incorrectly from the beginning
The operator of the crippled Fukushima nuclear plant says it was unaware of an incorrectly opened valve that caused another disruption in its ongoing test run to filter radioactive water.
Tokyo Electric Power Company found on Wednesday that a US-made device attached to the water treatment system had lowered concentration of radioactive cesium by just 10 percent the planned amount...
...The amount of contaminated water on site is growing by about 400 tons a day, as fresh water is injected into reactors to cool them. The rainy season threatens to raise the water levels further.
The test-run was interrupted on Tuesday after a pump to send water into French-made decontamination equipment stopped, also due to the wrong setting of a valve.
Thursday, June 23, 2011 19:40 +0900 (JST)
http://www3.nhk.or.jp/daily/english/23_34.htmlWater filters at Fukushima still not working
The operator of the Fukushima Daiichi nuclear power plant is still struggling with a malfunctioning water-decontaminator---the key to dealing with highly-radioactive water accumulating at the site. The new water decontaminating system was shut down only 5 hours after it went into operation on Friday.
Tokyo Electric Power Company says an irregular flow of the water in the system could have hampered the system from working properly, causing it to malfunction.
The utility says it discovered on Wednesday that a US-made device in the system only succeeded in lowering the concentration of radioactive cesium in the water to one percent of the previous amount, instead of 0.1 percent as initially expected.
The device has 6 absorbent chambers lined up in a row. The utility says radioactive readings in the lower chambers surged to 15 millisieverts per hour on Wednesday from 3 millisieverts per hour on Tuesday...
Thursday, June 23, 2011 06:11 +0900 (JST)
http://www3.nhk.or.jp/daily/english/23_04.htmlCare to debunk any of these stories?