Civil Engineering Reference
In-Depth Information
Deposition of Cs-134/Cs-137
(kBq/m²)
6 000 to 30 000
3 000 to 6 000
1 000 to 3 000
600 to 1 000
300 to 600
Fig. 9.12
Areas of Cs-134 and Cs-137 deposits in kBq/m
2
as well as estimates for radiation
exposure of the Japanese public in certain locations during the first year after the Fukushima-
Daiichi accident [
18
,
21
]
9.3.4 Contamination by Cs-134 and Cs-137
While iodine-131, with a halflife of 8 days, had decayed within a month, deposi-
tions of Cs-134 stay on the ground for about 10 years, and depositions of Cs-137
remain for roughly 100 years. Japanese, French, and American measurements of
ground depositions of cesium are shown in Fig.
9.12
.
