Primary functions of the first Japanese large-scale facility for exposing small animals to radon

Ishimori, Yuu  ; Mitsunobu, Fumihiro*; Yamaoka, Kiyonori*; Tanaka, Hiroshi ; Kataoka, Takahiro*; Sakoda, Akihiro*   

Japan Atomic Energy Agency (JAEA) and Okayama University have carried out the experimental animal study and its related studies since 2007 in order to examine the physical effect of radon in detail. Thus, a radon test facility for small animals was developed in order to increase the statistical certainty of our animal tests. This paper illustrates the performance of the facility, the first large-scale facility in Japan. The facility has a potential of about 150 mouse-scale test at the same time. Different concentration at each animal chamber group is available. Controlling radon and avoiding thoron were theoretically and experimentally shown as the fundamental performance of the facility. The relative standard deviation of the radon concentration at the highest concentration group was about 5%, although the lower concentration groups seemed to be affected by variation of background.