Regulation of the radionuclide content in commodities produced in areas affected by the Chornobyl accident. / Reguljuvannja vmistu radionuklidiv u tovarah, vyroblenyh na terytorijah, shho postrazhdaly vnaslidok avarii' na ChAES.

This paper discusses the approaches to regulation of the content of radionuclides in commodities and compares the international and Ukrainian standards, which establish permissible levels of the content of radionuclides in food-stuffs produced in the Chornobyl-affected areas. The paper gives the actual monitoring data and discusses the main causes of differences between Ukrainian, European and international standards. The need for improvement of current approaches to the regulation of the content of radionuclides in commodities is highlighted.

Analysis of aerosol distribution inside the object "shelter" at the Chernobyl nuclear reactor site.

Results of the aerosol sampling inside the Object Shelter at the Chornobyl nuclear reactor site are considered in the work. The results show a consistent and significant contribution of submicron fraction to the total aerosol activity. Different methods of interpretation of impactor data series are compared in order to indicate and detect in the most effective way the submicron fraction as a separate component of the distribution. The methods used are as follows-method of probabilistic-logarithmic scale, method of likelihood function, non-linear approximation by sum of several log-normal distributions, and restoration of the initial distribution using passage functions of impactor cascades. Practically all the collected data on aerosol distribution inside the Shelter show a distinct submicron component. The contribution of the submicron component into the total aerosol activity is about 35%. Influence of the actual aerosol distribution on the dose coefficients is analyzed.