10 Times Denser Than Chernobyl's Radiation
There is an alarming argument about the Fukushima Daiichi nuclear accidents.
The amount of radioactive material accidentally discharged from Fukushima Daiichi is one tenth of that having been discharged from the Chernobyl nuclear power plant. But, the area where the radioactive material has been littered and sprayed in the Fukushima case is 100 times smaller than that of the Chernobyl case. Accordingly, the density of radioactive material in the affected area for the Fukushima case is (1/10)/(1/100) = 10 times denser than that for the Chernobyl case.
The radioactively contaminated area around Fukushima Daiichi has 10 times stronger radiation density than that around the Chernobyl plant.
It is very shocking and alarming, since the Japanese Government has not announced this calculation result to give a warning to residents around Fukushima Daiichi, though those who have lived within 20 km of the Fukushima plant were already evacuated.
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Today I went out to inspect part of Fukushima Prefecture.
I took to a coastal line to get into a city of the prefecture 190 km north of Tokyo.
Farmers are introducing water to paddy fields for rice planting. Even I could see some cows grazing. Factories, such as Hitachi's, look normal. High school students are behaving as usual. Business is going on as usual on the streets of the city just 30 km south of Fukushima Daiichi.
However, one gram of uranium-235 has 2.56 x 10^21 atoms.
If these uranium atoms were discharged in the air and distributed in an area with the size of 1000 km x 1000 km, how many atoms will be in an area of 1 meter by 1 meter (3 feet by 3 feet)?
It is: 2.56 x 10 ^21 divided by (1000 x 10^3) x (1000 x 10^3)
= 2.56 x 10 ^21 divided by 10^12
= 2.56 x 10 ^9
= 2560000000
= 2.56 billion
All the atoms in one gram of uranium can be evenly distributed in an 1000 km x 1000 km area to have density of 2.56 billion uranium atoms in one square meter.
If all these atoms undergo radioactive decay once per second, it is measured as 2.56 billion becquerels.
However, the allowable dose limit of radioactive iodine for drinking water of 1 liter (kg) is 300 becquerels for grownups in Japan. And, all the drinking water in Japan is within this limit except the area close to Fukuhima Daiichi.
Usually in a nuclear reactor, 1 kilo-grams to 3 kg of uranium is consumed per day, being transformed to radioactive iodine and other types of radioactive atoms.
In this context, mankind can indeed produce electricity by burning uranium but has no technology to control such a large number of atoms which are so small to be 2.56 x 10^21 atoms for 1 gram of uranium.
It is truly sparkling in the world of atoms.
Each radioactive one might look really sparring with one another to fall into further decay.
(A thermal power plant in Ibaraki Prefecture between Fukushima and Chiba/Tokyo; Can be enlarged.)