Case 481 Case 7
NSE 481
Fall 2017
Homework: #1 Date Due: October 5, 2017
1) Summary
The study by Yajima et al. (2015) details estimations of individual doses for returnees who were previously evacuated from the Fukushima Nuclear Disaster. Individual estimates were made for different categories of evacuees who were meant to return to three designated Iitate Village, Kawauchi Village, and Tamura City in Fukushima. The data required for the estimates was obtained from measurements of individual doses and ambient external dose rates in occupational and residential settings. The ratio of both sets of measurements was 0.7 while the uncertainty was 10%.
The effective dose per person in the area of study was calculated by incorporating 0.7 as a multiplying factor …show more content…
If so, possible limit and Why?
I would authorize the re-entry of evacuees in these town. The estimates provided by Yajima et al. (2015) show that internal exposure to the residents was significant because all foodstuffs in the market and quantitatively monitored for radiation contamination. The external doses for the outdoor critical groups in the present study exceeded that of the indoor participants. The highest estimate was reported in Iitate, as 17 mSvy-1. This value lies within the acceptable limit of 1 mSvy-1 – 20 mSvy-1 as recommended by the International Commission on Radiological Protection (ICRP 2007).
Still, the safety of these estimates can be compared with actual field measurements upon the return of the evacuees. However, the high degree of compliance with the stipulated limit in all the towns suggest that additional protection measures would be unnecessary, especially for the indoor residents. Overall, the relationship between the external ambient and individual doses was critical to predicting the annual doses per evacuee upon returning home to either of the areas under investigation. Generally, the doses for external exposure were much higher than those for internal exposure. Perhaps, the time of exposure in outdoor settings might have provided more realistic predictions of individual dose
Fall 2017
Homework: #1 Date Due: October 5, 2017
1) Summary
The study by Yajima et al. (2015) details estimations of individual doses for returnees who were previously evacuated from the Fukushima Nuclear Disaster. Individual estimates were made for different categories of evacuees who were meant to return to three designated Iitate Village, Kawauchi Village, and Tamura City in Fukushima. The data required for the estimates was obtained from measurements of individual doses and ambient external dose rates in occupational and residential settings. The ratio of both sets of measurements was 0.7 while the uncertainty was 10%.
The effective dose per person in the area of study was calculated by incorporating 0.7 as a multiplying factor …show more content…
If so, possible limit and Why?
I would authorize the re-entry of evacuees in these town. The estimates provided by Yajima et al. (2015) show that internal exposure to the residents was significant because all foodstuffs in the market and quantitatively monitored for radiation contamination. The external doses for the outdoor critical groups in the present study exceeded that of the indoor participants. The highest estimate was reported in Iitate, as 17 mSvy-1. This value lies within the acceptable limit of 1 mSvy-1 – 20 mSvy-1 as recommended by the International Commission on Radiological Protection (ICRP 2007).
Still, the safety of these estimates can be compared with actual field measurements upon the return of the evacuees. However, the high degree of compliance with the stipulated limit in all the towns suggest that additional protection measures would be unnecessary, especially for the indoor residents. Overall, the relationship between the external ambient and individual doses was critical to predicting the annual doses per evacuee upon returning home to either of the areas under investigation. Generally, the doses for external exposure were much higher than those for internal exposure. Perhaps, the time of exposure in outdoor settings might have provided more realistic predictions of individual dose