Establishment of a clean laboratory for ultra trace analysis of nuclear materials in safeguards environmental samples

Hanzawa, Yukiko  ; Magara, Masaaki  ; Watanabe, Kazuo; Esaka, Fumitaka  ; Miyamoto, Yutaka   ; Yasuda, Kenichiro   ; Gunji, Katsubumi*; Sakurai, Satoshi ; Takano, Seinojo*; Usuda, Shigekazu; Adachi, Takeo

The JAERI has established a cleanroom facility with cleanliness of ISO Class 5: the Clean Laboratory for Environmental Analysis and Research (CLEAR). It was designed to be used for the analysis of nuclear materials in environmental samples for the safeguards, the Comprehensive Nuclear-Test-Ban Treaty verification and research on environmental sciences. The CLEAR facility was designed to meet double conflicting requirements of a cleanroom and for handling of nuclear materials according to Japanese regulations, i.e., to avoid contamination from outside and to contain nuclear materials inside the facility. This facility has been intended to be used for wet chemical treatment, instrumental analysis and particle handling. A fume-hood to provide a clean work surface for handling of nuclear materials was specially designed. The performance of the cleanroom and analytical background in the laboratory are discussed. It can be concluded that the CLEAR facility enables analysis of ultra trace amounts of nuclear materials at the sub-picogram level in environmental samples.