  The main aim of research is to investigate the physical features of spatial
distribution of the adsorbed radioactive chemical elements and their isotopes
in the granular filtering medium in the iodine air filters of the type of
AU1500 in the forced exhaust ventilation systems at the nuclear power plant.
The gamma activation analysis method is applied to accurately characterize the
distribution of the adsorbed radioactive chemical elements and their isotopes
in the granular filtering medium in the AU1500 iodine air filter after its long
term operation at the nuclear power plant. The typical spectrum of the detected
chemical elements and their isotopes in the AU1500 iodine air filter, which was
exposed to the bremsstrahlung gamma quantum irradiation, produced by the
accelerating electrons in the tantalum target, are obtained. The spatial
distributions of the detected chemical element 127I and some other chemical
elements and their isotopes in the layer of absorber, which was made of the
cylindrical coal granules of the type of SKT3, in the AU1500 iodine air filter
are also researched. The possible influences by the standing acoustic wave of
air pressure in the iodine air filter on the spatial distribution of the
chemical elements and their isotopes in the iodine air filter are discussed.
The comprehensive analysis of obtained research results on the distribution of
the adsorbed chemical elements and their isotopes in the absorber of iodine air
filter is performed.
