Production of reference sources of radioactive aerosols in filters for proficiency testing.

In the framework of the organization of proficiency testing, filters with deposits of Cs and Sr+Y radioactive aerosols have been submitted to laboratories for radionuclide measurement. Procedures for the special preparation and characterization of filters have been developed. The different steps of filter preparation, determination of the deposited radionuclide activity and characterization of the homogeneity of these deposits are presented.