Sunday, October 30, 2011

Tales from Japan: Decontamination and Local Radiation Monitoring

Workers use high-pressure water cleaners to decontaminate a roof in the city of Fukushima. Some say the method is insufficient. (Mainichi)
Workers use high-pressure water cleaners to decontaminate a roof in the city of Fukushima. Some say the method is insufficient. (Mainichi)



As the months go by and people begin to forget that there are dangerous amounts of radiation hidden in the ecosystem, many people have taken up Geiger counters in the quest to prove there is indeed something to be concerned about.  The vast majority of people are concerned about the potential problem of radiation but are ignorant to where it could be, how bad it could be for them, and ultimately how to decontaminate it or lower it in most cases.

The big news in Chiba last month was the discovery of a radiation hot spot in Funabashi. Yes just a few kilometers away!

Andersen Park Funabashi, Chiba Radiation Hot Spot- Japanese

The group of private citizens measured an area 1cm above the ground at HC Andersen Park and discovered that there was a external dose rate of 5.82 micro/sv per hour which is high even by Fukushima standards. Unfortunately many news outlets reported the story along with another radiation hot spot claim from Setagaya, in Tokyo that turned out to be unrelated to Fukushima. The obvious tactic of mainstream media to give a mixed report most likely caused the audience to doubt the authenticity of the Funabashi Chiba radiation claim as well, even though it was confirmed as a hotspot by officials afterward.

The claim in Funabashi, however, for many was very concerning, as city officials were quickly dispatched and measured a little less than 2microSv per hour. This does not mean that the private measurement was inaccurate or incorrect since radiation levels can change only with a mere 10cm in distance.  Since the initial measurement was done earlier, then the city measurement would not have been in the exact location but rather around the general area instead of the first measurement. But differences aside, the level of radiation before the meltdown of Fukushima was several hundred times lower.  The severe rise in radiation level prompted immediate removal of soil from the surrounding area, and further inspection and decontamination of the entire park.

So the positive outcome of this news story even though it was slightly botched, was that it brought attention to and immediate shutdown and eventual decontamination of the park. Good job Geiger Club!

The next big step for Japan is to get over the denial of the problem and begin hardcore decontamination before it is too late...

The three main methods of decontamination being undertaken in Fukushima and other hotspots are the removal of top soil, even up to 4 or 5 feet deep, the removal of mud accumaltion in gutters and other places where rain water collects, and finally high pressure water cleaning of concrete and ceramic surfaces. The first two are the most effective because soil and water usually absorb and transport radiation the most.  The third method has only proven to be a vain attempt to lower radiation levels where radioactive materials have embedded or bonded with solid materials, often rooftops or areas where rain water gathers.

Read more at...
Mainichi News: Contamination of radiation in Japan

I came across an interesting story of private school in Fukushima using a polymer as a cleaning agent to decontaminate its school from radiation. DeCon gel is being used by the school and is considered a safe, water-soluble, peelable hydrogel, with unique capacity to bind, encapsulate, and remove surface radioactive and chemical contaminants. The US company sees this as a great opportunity to show the power and potential of its product and most of all help those in Japan reduce the risk of exposure to harmful radiation.

Little Lamb Private School Decontamination Method

Japan is now forced to develop new and more effective methods of decontamination that do not just displace the radiation but can safely and properly remove it from the ecosystem and keep it away from its people, especially children. No doubt many companies are hurrying to develop new devices and products to measure and remove the danger of local radiation.
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