Thursday, August 11, 2011

Japan withheld nuclear radiation data, leaving evacuees in peril

The New York Times (August 9, 2011, pg. A8) has provided a second radiometric sketch of Fukushima Daiichi-derived fallout. The source of this map, which uses the standard reporting unit for ground contamination of Bq/square meter, is cited as the Nuclear Emergency Response Headquarters Office of Japan. The Times map caption notes “A Japanese computerized early warning system started to generate maps projecting the trajectory of radiation plumes from the Fukushima Daiichi plant within hours of the accident on March 11, but none of the maps were made available to the public until nearly two weeks later. The map below shows information made available to the prime minister’s office on March 16.” This clearly indicated Japan’s capacity to accurately monitor ground contamination on an hourly basis. The plume direction on March 16th matches the direction of maximum contamination noted in the Times on August 2nd, but contamination levels are significantly less at this early stage of the accident.

One of many flies in the ointment is the IRSN (France) sketch illustrating accident-derived air contamination dispersion on March 19th, reprinted on page 33 of the Davistown Museum’s Nuclear Information Handbook. The prevailing wind on this date resulted in significant but as yet undocumented ground contamination to narrow but extensive shoreline regions ~300 kilometers north of the accident site. This additional region of contamination highlights the need for public disclosure of a systematic survey of ground contamination throughout Japan – data the Japanese government is obviously still withholding.

All Japanese and concerned world citizens should also be reminded the cumulative ground deposition of Cs-137 from weapons testing-derived fallout is significantly less than 5,000 Bq/square meter in most nations. Given the map legend of soil contamination reprinted in the Aug. 2nd New York Times, which illustrates Fukushima Daiichi-derived fallout levels below 28,000 Bq/ square foot (300,000 Bq/square meter) in white without further analysis, Japan’s Nuclear Energy Response Headquarters has a moral as well as practical obligation to provide accident fallout-derived concentrations of radiocesium in a radiometric survey range of 300,000 Bq/square meter down to at least 5,000 Bq/square meter, the upper range of cumulative weapons testing fallout. This survey must be accompanied by full disclosure of the seven multiple interlocking meltdown event (MIME) hourly emissions since the accident began. A survey of washout pathway emissions, including gallons in/gallons out, gallons in storage, filtered gallons, curies recovered, and estimated releases of the Fukushima Daiichi accident is another component that needs further documentation.

On another related topic, Alex Roslin has written an informative review of radiation levels in Canada, as tabulated in March and April by Health Canada, which “detected massive amounts of radioactive material from Fukushima in Canadian air in March and April at monitoring stations across the country. The level of radioactive iodine spiked above the federal maximum allowed limit in the air at four of the five sites where Health Canada monitors levels of specific radioisotopes… The iodine-131 level in the air in Sidney peaked at 3.6 millibecquerels per cubic metre on March 20. That’s more than 300 times higher than the background level, which is 0.01 or fewer millibecquerels per cubic metre… One of the highest post-Fukushima radiation readings in North America came on March 27 in rainwater in Boise, Idaho. It contained 14.4 becquerels of iodine-131 per litre – 130 times the U. S. Environmental Protection Agency’s maximum level of 0.11 millibecquerels per litre… But nobody seemed to investigate how long the rainwater in Boise remained radioactive. Inexplicably, the EPA stopped monitoring Boise’s rainwater after the extremely high reading on March 27. The agency’s only other reading for the city was on March 22.”

Many thanks to Ken Belson, Norimitsu Onishi, and Martin Mackler of The New York Times and Alex Roslin of for providing updates on the accident emissions from Fukushima Daiichi.

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