Radioactive Contamination by the Accident of the Fukushima Daiichi Nuclear Power Plant, and the Transition of the Radioactive Concentration—Measurement of the Tea Leaf etc. of Bunkyo-ku Hongo and Tokorozawa—

Abstract

In the case of the metropolitan area, radioactive substances came flying from March 15 to 16 and from March 20 to 23. We measured the radioactive substance contained in leaves using a HPGermanium semiconductor detector.
As a result of the measurement, we confirmed the following. (a)The main radioactive substance are ¹³²Te, ¹³¹I, ¹³⁴Cs, and ¹³⁷Cs. (b)The ¹³⁴Cs and the ¹³⁷Cs were almost same quantity. (c)Radioactive concentration such as tea leaf etc. has decreased by the physical half life and the weather condition etc.