5th update on the crisis in Tokyo, focusing on radiation and business impact
Fukushima nuclear accident impact on Tokyo, 12 April 2011
This is our 5th update on the crisis in Tokyo, focusing mainly on the radiation and impact on business in Japan.
The continuing quakes (as shown below) do present risk. To my knowledge, earth quakes are “chaotic” (mathematically speaking), and there is considerable scientific argument that earth quakes cannot be reliably predicted. More in a future newsletter.
The Japanese Government has classified the Fukushima Dai-Ichi accident as a level 7 accident in the INES Scale. The official Japanese Government documents announcing this INES Scale classification can be found here in Japanese and here in English. Note however, that we are dealing here with nature, and human reactions. Nature does not care how we classify such accidents.
Damaged Fukushima reactors are “static” but not yet stable
Gregory Jaczko, Chairman of the US Nuclear Regulatory Commission on April 11, 2011 reported to the US Senate, that the condition of the damaged reactors is ” ‘static’, but with improvised cooling efforts, they are not ‘stable’ “.
Rebuilding is progressing at amazing speed. The Tohoku Shinkansen high-speed train was re-opened Tokyo-Fukushima yesterday, with relay train connections on regular track to Sendai. The full Tokyo-Shin-Aomori line is scheduled to open beginning of May. ANA has started to fly to the repaired Sendai airport.
Radiation measurement results for Tokyo are shown below. Measured radiation levels in Tokyo are now comparable to Austria, and there are many places on earth which have far higher levels than are reported for Tokyo now.
Quakes and after-quakes
The figures show that more than 300 earthquakes of magnitude 5 or larger occurred since the major quake on March 11, 2011 at 14:46. The epicenters of quakes lie mostly where the Pacific Plate moves under the North American Plate on which Tohoku lies.
According to our knowledge earth quakes are mathematically speaking a “chaotic” phenomenon, and scientific arguments are, that it is difficult if not impossible to predict earth quakes with precision. (Figure: Wolfram Alpha LLC)
Analyzing radiation levels in Tokyo/Shinjuku
Radiation levels in Tokyo (Shinjuku and Shibuya) and Tsukuba:
The blue curve above shows the radiation levels in Tokyo/Shinjuku as measured and published by the Tokyo Metropolitan Institute for Public Health here:
- each hour for the last 24 hours
- daily starting March 1
The red curves show maximum and minimum data as measured by TEPCO in Tokyo-Shibuya, and published here: TEPCO radiation data
The green curves show radiation data measured by Japan’s highly respected AIST Laboratory in Tsukuba (Ibaraki-ken, about 60 km north of Tokyo in direction of Fukushima) and published here: AIST radiation data.
Radiation levels in Tsukuba
The green curves show radiation data measured by AIST Laboratory in Tsukuba (Ibaraki-ken, about 60 km north of Tokyo in direction of Fukushima) and published here: AIST radiation data.
The radiation measurement results in Tsukuba are considerably higher than found in Tokyo, but have in the last few days decreased close to the top levels found naturally in Austria and in many other countries.
The differences in the data between Tokyo and Tsukuba could be because Tsukuba is 60km closer to Fukushima, could be cause by weather conditions, but they could also be caused by differences in the measurement equipment or a combination of these factors.
Drinking water (tap water) in Tokyo:
Analysis of tap water in Tokyo can be found here for each day starting with March 18. This analysis shows that Tokyo tap water currently contains some radioactive Iodine (I-131), and some Cesium (CS-134 and Cs-137) radioactive isotopes.
Interesting in this context is that according to a WHO report on Japan of March 22 (pdf-file), Japanese health limits for radioactive Iodine are about 10 times lower than global standards, ie if Japanese health limits are exceeded, the levels are still at 10% of global limits (we don’t intend to underestimate this problem however).
We conclude that currently radioactive Iodine (I-131) concentrations are about 0.2% of Japan’s limits set by Japan’s Nuclear Safety Commission, and about 0.02% of international health limits, and are currently on a downward trend.
Radioactive contamination of drinking water (Cesium)
Cesium contamination with radioactive Cs-134 (1/2-life = 2.1 years) and Cs-137 (1/2-life = 30 years) isotopes is currently on the order of 0.1% of the limits set by Japan’s Nuclear Safety Commission and are on a downward trend.
The relatively long 1/2-life of Cesium-134 and Cesium-137 means that these radioactive isotopes will stay with us for many years. To understand this situation it is necessary to compare these levels with natural levels, and with other sources of radioactivity, and how Cesium interacts with our bodies.
Where to find radiation measurement results (updated March 28, 2011):
Japan’s Government AIST laboratory:
Japan’s Science and Education Ministry MEXT publishes regional radiation data:
These data are graphically shown here:
Drinking water: http://atmc.jp/water/
Rain water: http://atmc.jp/ame/
Radiation data for Tokyo/Shinjuku are published here:
each hour for the last 24 hours
for each day starting March 1
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