Development of selective detection method of the particles containing highly enriched uranium in safeguards environmental samples

Lee, C. G.; Suzuki, Daisuke   ; Esaka, Fumitaka  ; Magara, Masaaki  ; Kimura, Takaumi ; Shinohara, Nobuo 

A method to selectively detect uranium particles with higher U enrichment has been developed; this method can contribute to improving particle analysis on nuclear safeguards environmental samples. The newly developed method involves three key components, (1) a two-step filtration system for particle recovery from swipe samples, (2) a system for controlling the etching time of fission track (FT) detector, (3) a system for comparing the FT morphologies and particle sizes. In order to verify the effectiveness of the screening method developed, a mixture sample containing uranium particles with natural composition and those with 10% enrichment is used. It was shown that enrichment-based screening of uranium particles is possible by comparing the FT morphologies and particle sizes, in addition to controlling the etching time. The method is expected to serve as an effective tool of the particle analysis on nuclear safeguards environmental samples.