Determining radiation dose to residents of radiation-contaminated buildings

There are more than one thousand residents who lived in about 140 radiation -contaminated buildings and received the assessed radiation dose equivalent over 5 mSv/year. In this paper, a systematic approach to dose reconstructi on is proposed for evaluating radiation dose equivalent to the residents. T he approach includes area survey and exposure measurement, source identific ation and energy spectrum analysis, special designed TLD-embedded badges fo r residents to wear and organ dose estimation with Rando phantom simulation . From the study, it is concluded that the ionization chamber should still be considered as the primary modality for external dose measurement. Howeve r, lacking of accurate daily activity patterns of the residents, the dose e quivalent estimation with the chamber measurements would be somehow overest imated. The encountered limitation could be compensated with the use of the TLD badges and Rando phantom simulation that could also provide more infor mation for internal organ dose equivalent estimations. As the radiation pat terns in the buildings are highly anisotropic, which strongly depends on th e differences of structural and indoor layouts, it demands a mathematical m odel dealing with the above concerns. Also, further collaborations with stu dies on biological markers of the residents would make the entire dose equi valent estimation more helpful and reliable.