Development of the uranium-enrichment screening method for particles by chemical etching of fission track detector, 2

Lee, C. G.; Iguchi, Kazunari; Suzuki, Daisuke   ; Inagawa, Jun; Esaka, Fumitaka  ; Magara, Masaaki  ; Sakurai, Satoshi ; Shinohara, Nobuo ; Usuda, Shigekazu

Safeguards environmental sample analysis has implications on the examination of the existence of uranium particles with a higher 235U enrichment in swipe samples. If such uranium particles can be preferentially detected in a sample, this will be significant in simplifying the particle analysis in the safeguards. In this study, a screening method for uranium particles according to their enrichment has been developed by using the characteristics of fission tracks, which depend on the enrichment of the uranium particles. A two-step filtration system that can collect particles with desired diameters was used for the collection of uranium particles from a swipe sample in order to avoid the influence of the differences in the diameter on the etching behavior of fission tracks. It was shown that the enrichment-based screening of the uranium particles is possible by controlling the etching time to detect fission tracks and by comparing fission track morphologies and particle diameters.