Testing CR-39 for surface alpha contamination monitoring

Alpha-track detectors made of CR-39 plastic were successfully tested in monitoring surface alpha contamination in decontamination and decommissioning. The alpha registration efficiency was about 70%. At 3.7 Bq cm-2 a 10:1 signal-to-noise response was obtained after a 100-min exposure. The alpha-track detector maps small-scale spacial variability of alpha contamination that conventional survey meters cannot. The detector recognizes hot particles. Small-sized detectors are deployable in difficult-to-access locations such as cracks or under tightly fitting equipment where dirt resists easy removal.