An assessment of the doses received by members of the public in Japan following the nuclear accident at Fukushima Daiichi nuclear power plant

Abstract

The earthquake and tsunami on 11 March 2011, centred off the east coast of Japan, caused considerable destruction and substantial loss of life along large swathes of the Japanese coastline. The tsunami damaged the Fukushima Daiichi nuclear power plant (NPP), resulting in prolonged releases of radioactive material into the environment. This paper assesses the doses received by members of the public in Japan. The assessment is based on an estimated source term and atmospheric dispersion modelling rather than monitoring data. It is evident from this assessment that across the majority of Japan the estimates of dose are very low, for example they are estimated to be less than the annual average dose from natural background radiation in Japan. Even in the regions local to Fukushima Daiichi NPP (and not affected by any form of evacuation) the maximum lifetime effective dose is estimated to be well below the cumulative natural background dose over the same period. The impact of the urgent countermeasures on the estimates of dose was considered. And the relative contribution to dose from the range of exposure pathways and radionuclides were evaluated. Analysis of estimated doses focused on the geographic irregularity and the impact of the meteorological conditions. For example the dose to an infant's thyroid received over the first year was estimated to be greater in Hirono than in the non-evacuated region of Naraha, despite Hirono being further from the release location. A number of factors were identified and thought to contribute towards this outcome, including the local wind pattern which resulted in the recirculation of part of the release. The non-uniform nature of dose estimates strengthens the case for evaluations based on dispersion modelling.

Cryptorchidism after the Fukushima Daiichi Nuclear Power Plant accident:causation or coincidence?

“…Fujimura et al also reported that children between the ages of 0 and 15 years (n = 4,571) had a mean radiation dose of 1.5 mSv/year 6 months after the disaster, 1.5 mSv/year in 2012, 1.0 mSv/year in 2013, and 0.65 mSv/year in 2014, in Nihonmatsu City in Fukushima Prefecture 71) . Bedwell et al assessed the doses received by members of the public in Japan following the nuclear accident at the Fukushima Daiichi Nuclear Power Plant and demonstrated that across most of Japan the estimates of the dose were very low, and were estimated to be less than the annual average dose from natural background radiation in Japan 72) . Even in regions closest to the Fukushima Daiichi Nuclear Power Plant, the maximum lifetime effective dose is estimated to be well below the cumulative natural background dose over the same period 72) .…”

“…Bedwell et al assessed the doses received by members of the public in Japan following the nuclear accident at the Fukushima Daiichi Nuclear Power Plant and demonstrated that across most of Japan the estimates of the dose were very low, and were estimated to be less than the annual average dose from natural background radiation in Japan 72) . Even in regions closest to the Fukushima Daiichi Nuclear Power Plant, the maximum lifetime effective dose is estimated to be well below the cumulative natural background dose over the same period 72) .…”

“…Thus, the majority of people in Japan and Fukushima Prefecture were not significantly affected by accidentrelated radiation 89) . Bedwell et al reported that in the north, south, and west of Japan, all estimates of the lifetime effective dose received by members of the public following the accident are very low, and in all cases are less than 1 mSv 72) . Furthermore, the estimated dose received in these regions is less than the typical Japanese and worldwide average annual doses from natural background of 2.1 mSv 90) and 2.4 mSv 91) , respectively.…”

Dose assessment following an overexposure of a worker at a Swiss nuclear power plant

“…While a lot work is published on the exposure of personnel working at nuclear power plants and the public around the facility, and the impact on the environment, in the event of a radiation accident [1][2][3], there is little published on acute radiation overexposure of the operators. Coeytaux et al compiled the reported radiation overexposure accidents worldwide in the period 1980-2013, from various sources in various fields including the nuclear industry [4].…”