The Experience of the 7th Collaborative Materials Exercise of the Nuclear Forensics (CMX-7) and future tasks

Matsui, Yoshiki; Kimura, Yoshiki  ; Umino, Yuji*; Hosoi, Masaharu*; Matsumoto, Tetsuya*; Shinohara, Nobuo ; Yamazaki, Hitoshi; Yamaguchi, Tomoki 

The Integrated Support Center for Nuclear Nonproliferation and Nuclear Security (ISCN) of the JAEA is developing technologies for nuclear forensics to identify the origin and intended use of nuclear and radioactive materials. The Nuclear Forensics International Technical Working Group (ITWG) regularly holds the Collaborative Materials Exercise (CMX) to share the experience on nuclear forensics analysis and to improve analytical methods in the international community. The ISCN participated in the 7th exercise (CMX-7) this time. This paper discusses the experience of the ISCN during the CMX-7 including the results of laboratory analysis and nuclear forensics interpretation, as well as future challenges for laboratory capability at the ISCN. In the CMX-7, under the hypothetical case scenario (illegal transferring of nuclear materials), uranium samples and other conventional forensics evidence were provided for the exercise. During the exercise, participants reported the analytical results according to the timeframes recommended by the Nuclear Forensics Guidelines of the IAEA (24 hours, 1 week, and 2 months from sample receipt). The ISCN reported the physical characteristics and the results NDA analysis on the uranium samples at the first two timeframes, and the results of mass spectrometry with the data interpretation as the 2 months report. The results of uranium isotope ratio and trace elements measurements were exceedingly good, but the results of age dating were significantly deviate from the overall average. Reducing the time for destructive analysis that allows timely provisions of the results, as well as the improvement of the confidence in age dating are future tasks for the nuclear forensics analysis of the ISCN laboratory.