Civil Engineering Reference
In-Depth Information
Fig. 22.1
Contamination of cesium 137 in Bq/m
2
(JRodos screen shot), realistic estimate
encompassing 4 days of release beginning on March 12, 2011, 15:00 UTC (radii of circles:
20 km, 30 km, 60 km)
The maximum estimated soil contamination by cesium 137 was reflected rela-
tively well in the prognostic calculations with JRodos. It also became obvious that
the soil contamination by cesium amounts to some million Becquerel per m
2
,an
order of magnitude that is also measured in the highly contaminated areas of Russia,
Belorussia and Ukraine after the Chernobyl accident. The model calculations
overestimated the extension of the contaminated area in the northwesterly direction.
This is due to the impossibility to determine precisely the release times and release
quantities, but also to the meteorological data that were used.
Finally, estimates were made of the contamination of food, in particular of leafy
vegetables (in Japan, spinach) and milk. Especially for a region northwest of the
Fukushima-Daiichi nuclear power plant, levels clearly above Japanese and also
European limits were calculated. It should be noted that milk is likely to be
contaminated over a long period of time, as evident from Fig.
22.3
. In particular
with the Japanese limits for Cs-137 of 50 Bq/l in milk and baby food, the milk can
hardly marketed in the highly contaminated areas for decades.
