Radioactivity and Air Dose Rate
(2015)
QHow were the reliabilities of the environmental measurements verified?
AWe verified the reliabilities of the measurements in three ways:
(1) calibrating the measurement instruments using a standard radiation source with a known accurate intensity
(2) obtaining comparative measurements using multiple measurement instruments
(3) having external experts check the obtained results.
◆ Performance verification of KURAMA-Ⅱsystem
The capability of obtaining measurements at the precision specified by the criteria in the JIS standard was verified using a standard radiation source.
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Fig.2 Fluctuations of measured values by direction of incidence
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Fig.3 Fluctuations of measured values by energy
(Tsuda et al, 139: 260-265 (2015))
In addition to checking the measurement systems and methods by calibrating and comparing the measurement instruments, the validity of the measurement results was verified by a committee of external experts.
◆ Comparison of in situ measurements using a portable Ge semiconductor detector
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Fig.4 Scene showing comparison of results
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Fig.5 Results of comparison
Similar inventory values were checked to ensure that they had been measured at the same position.
(Mikami et al., Jpn J Health Phys, 50: 182-188 (2015))
◆ Comparison of soil sample measurements using a stationary Ge semiconductor detector
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Fig.6 Scene showing sample comparison
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Fig.7 Results of comparison
Similar nuclide concentration values were checked to ensure that they had been measured on a common sample.
(Report on Preparation of Distribution Map of Radiation Doses, etc. (Part 1))
Related articles
Reference
- Tsuda, S. et al, Characteristics and verification of a car-borne system for dose rate in air: KURAMA-II, Journal of Environmental Radioactivity, vol.139, 2015, p.260-265.
- Mikami, S. et al, In situ gamma spectrometry intercomparison in Fukushima, Japan, Japanese Journal of Health Physics, vol.50, no.3, 2015, p.182-188.
- 原子力規制委員会, “放射線量等分布マップの作成等に関する報告書(第1編)”.