Decontamination efficiency and waste generation for the decontamination of radioactively contaminated urban and rural environments

A radioactive fallout following a nuclear accident can result in contamination of large areas of land. In order to protect human health against ionizing radiation, large-scale decontamination that includes multiple sets of clean-up measures may be necessary. Sweden lacks national experience of this type of large-scale decontamination. There are thus great uncertainties in the effect of such a decontamination which is dependent on the efficiency and waste generation of the individual remediation measures. In this report, the results from a literature review of the Japanese experience of decontamination after the nuclear accident in Fukushima-Daiichi, 2011, are highlighted. We show that the Japanese decontamination efficiency was on average about 12 percentage points lower than the decontamination efficiencies listed in reference literature on radioactive material decontamination. Removed contaminated soil is by far the largest contribution to radioactive waste production during decontamination. There is a positive correlation between reduced radiation dose rate and amount of soil removed during decontamination. Over time, however, ecological processes contribute by far the most to reduced radiation dose rates. The results can be an important contribution to current decontamination strategies and valuable for responsible agencies and authorities in the case of nuclear fallout incident