Development of method for detection of alpha contamination with using UV-camera “DayCor” by OFIL

Remote monitoring of alpha-ray contamination is very important problem for activities connected with decommission of installation of nuclear fuel processing. Large problem in this approach is solar (or other sources) UV background. New UV cameras are suitable for imaging of α-contamination by fluorescence of atmospheric air the as they are so called solar blind (SB)- they are sensitive to UV this wavelength less 290 nm only and are no sensitive to solar UV. At measurements with accumulation of a signal, for exposure of 600 sec it is possible to expect, that for a point source of alpha radiation (Ea = 5MeV) located on distance 3 m the activity, at which it can be found out, is equal 10⁴ Bq. Homogeneous superficial pollution, which can be revealed in this case makes 100 Bq/cm². We present results of practical application of DayCor SuperB camera for imaging of alpha sources. Our approach is based on processing of single images, processing of initial frames, summing of processed images and special filtration of final image. Instruments sensitivity for alpha contamination registration in terms of minimum measurable activities (MMA) have been estimated as, 40 - 100 Bq/cm² (measurement time is 3600 - 600 sec correspondently).