Search - Number 1 - DESCRIPTION OF AEROSOL OF UNORGANIZED RELEASES FROM UKRYTTYA OBJECT

DESCRIPTION OF AEROSOL OF UNORGANIZED RELEASES FROM UKRYTTYA OBJECT
Cover not present DESCRIPTION OF AEROSOL OF UNORGANIZED RELEASES FROM UKRYTTYA OBJECT
Category: Number 1
Publication: 1
Summary

Radioactive aerosol is one of the main factors of radioactive influence onto the personnel working on the industrial site and the local zone of the Ukryttya object. Selection of air was conducted by different samplers and impactors begining with 1996 till 2003. Measurements of the radioactive particles release from the unorganized largest apertures with the total area 200 m2 were carried out in 1996 - 2000. Estimations of the mean contribution of 137Cs, 90Sr and 239+240Pu in the release was made up 78,80, 21,16 and 0,4% accordingly. The total flow rate of these nuclides was equal 274,1 Bq s-1 or 8,64 109 Bq y-1 (0,234 Ci y-1) from unorganized observed apertures. The estimation of the changeableness of the volume activity released from apertures was shown that the amplitude of the variations of concentrations 137Cs and 241Аm is reached two order of magnitude, for 90Sr 25 times, and for 239+240Pu 15 times. The mean median diameters of all released data (1996 - 2002) weighed by number measurements are equal: for 137Cs - 2,6 m, for 90Sr - 2,8 m, for 239+240Pu - 4,4 m, for 241Am - 2,0 m. At the territory around Shelter mean volume activities of 137Cs may reach 10 - 100 mBq m-3 and more at the removal of order 40 m from Shelter. At the building site (250 m from Ukryttya object ) volume activities of 137Cs were reached of 3 - 10 mBq m-3 for usual the meterology conditions and without the technogenic activities. At the industrial site of Ukryttya object the 137Cs activity distribution of size particles is differed from the activity distribution in releases at the expense of increasing micrometer and submicrometer aerodynamic aerosol.

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