Base Information Q&A SiteJAEA

Radioactivity and Air Dose Rate

(2015)

How were the reliabilities of the environmental measurements verified?

We 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.

Calibration system with a standard radiation source

Fig.1 Calibration system with a standard radiation source

  • Fluctuations of measured values by direction of incidence

    Fig.2 Fluctuations of measured values by direction of incidence

  • Fluctuations of measured values by energy

    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

  • Scene showing comparison of results

    Fig.4 Scene showing comparison of results

  • Results of comparison

    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

  • Scene showing sample comparison

    Fig.6 Scene showing sample comparison

  • Results of comparison

    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))