米国EMLにおけるラドン共同比較実験

抄録

A past intercomparison on radon gas concentration measurements using radon integrating monitors revealed that a systematic difference (about 10 to 30%) existed between the estimated values of the National Institute of Radiological Sciences (NIRS) and those of the Environmental Measurements Laboratory (EML) of the USA and the Australia Radiation Laboratory (ARL). In order to find out the reasons, another intercomparison was conducted using an EML radon chamber in which both EML and representative Japanease research institutes participated. On this occasion, the main device were ionization chambers, the standard device in Japan. However, measurements of radon with radon gas integrating monitors and measurements of radon progeny were also taken simultaneously. Good agreement was obtained among estimated radon gas concentrations by the Japanese teams, though the values were lower than those of the EML by 5%. On the other hand, radon progeny concentrations were in agreement among all the participants within statistical uncertainty.