Development of dust monitor for rapid detection of plutonium with background compensation system

Sanada, Yukihisa   ; Kobayashi, Hirohide ; Hashimoto, Tetsuo*

The dust monitor for rapid detection of artificial nuclides such as Plutonium with Rn-progeny background compensation system was developed to apply a time interval analysis (TIA). The TIA method was applied to beta and decay events with microsecond scale (half-life of Po: 164 microsecond). In actual experiments, dust sample on the filter (HE-40T pore size: 8micrometer) was collected in a workspace at the JAEA reprocessing facility to compensate Bi-Po correlated events. As a result, total alpha-ray counting rate except for Po was 0 0.05 cps. The small Am source with dust sampling was measured for simulation of unexpected additional -ray emitted radionuclides. The increment for -ray counting rate due to the Am source could be clearly detected. The present method will apply for on-line monitoring of -ray measurement, because the method is able to detect artificial nuclides by compensating any changes of background due to Rn-progeny.