Distribution map of natural gamma-ray dose rates for studies of the additional exposure dose after the Fukushima Dai-ichi Nuclear Power Station accident

• Published in: Journal of environmental radioactivity Vol. 223-224; p. 106397
• Main Authors: Sanada, Yukihisa, Yoshimura, Kazuya, Urabe, Yoshimi, Iwai, Takeyuki, Katengeza, Estiner W.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-11-2020
• Subjects: Absorbed dose rate; Airborne radiation monitoring; Background; Fukushima dai-ichinuclear power station; Natural radionuclide; Natural radionuclide; Absorbed dose rate; Fukushima dai-ichinuclear power station; Airborne radiation monitoring; Background
• ISSN: 0265-931X; 1879-1700
• DOI: 10.1016/j.jenvrad.2020.106397

The information on the absorbed dose rate which is derived from natural radionuclides is needed to evaluate additional exposure dose. However, there is inadequate positional resolution and precision for such data around Fukushima Dai-ichi Nuclear Power Station (FDNPS). In this study, we created a map of the absorbed dose rate that is derived from natural radionuclides based on several airborne radiation monitoring data. The reliability and accuracy of the created map was verified by comparison with the many in-situ measurements on the ground. To evaluate the effectiveness of this study, the effective half-lives of the ambient dose rate at residential areas of Fukushima Prefecture were assessed by discriminating these absorbed dose rate of the natural background from the results of a periodic dose rate survey by local government. The results of the distribution of natural background absorbed dose rates are expected to contribute to the evaluation of the additional exposure dose after the FDNPS accident.
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•The absorbed dose rate around FDNPS was made.•To combine some airborne radiation monitoring data raises its reliability.•The reliability of the map was ensured by comparison with the ground-based measurement.•These data was helpful for evaluation of low-dose radiation exposure.