Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1738891 | Journal of Environmental Radioactivity | 2009 | 6 Pages |
Abstract
In case of an accidental release of radioactive substances into the environment, it is important to quickly and reliably estimate the radiation dose received by people in the affected area, and to determine the extent of the contamination. Measurements of the extent of the release and the subsequent contamination can be facilitated if there are predetermined reference sampling sites with known background radiation and inventory of radionuclides. Since 1996, 34 reference sites for soil sampling, field gamma, and intensimeter measurements have been established in western Sweden. Time series data for dose rates and radioisotope inventory have been collected at these sites, allowing for the investigation of changes in these parameters over time. The mass activity densities for the uranium and thorium series elements varied approximately between 10 and 50Â Bq/kg and between 10 and 40Â Bq/kg, respectively. The mass activity density of 40K was approximately in the range 300-800Â Bq/kg. The radiation exposure due to 137Cs was rather small in this area. The dose rates calculated from in situ measurement data showed that the contribution to the total dose rate was almost entirely due to naturally occurring radionuclides. The measured dose rate was about twice as high as the calculated rate, even after subtracting the contribution from cosmic radiation. This may be explained by the fact that intensimeters generally are calibrated to measure the quantity ambient dose equivalent, which should not underestimate the effective dose.
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Physical Sciences and Engineering
Energy
Nuclear Energy and Engineering
Authors
Sara Almgren, Mats Isaksson,