Experience on measurement methods for sodium fire aerosols

In sodium cooled fast breeder reactors sodium fires may occur accidentally by leaking pipes. One of the most important effects of sodium fires is the release of large amounts of aerosols. The knowledge of the physical and chemical properties of these aerosols is of great importance for the lay-out of filter systems, reactor components and for estimating the environmental impact of reactor accidents. During sodium fire tests in the FAUNA containment different devices for measuring the aerosol mass concentration and size distribution were used. A new developed automatically and continuously working sodium aerosol mass concentration analyzer is explained and its output data compared with data from the other methods. The analyzer was found to be the most reliable and sensitive instrument. During and after sodium fire the particle diameter was measured by an Andersen impactor, an aerosol centrifuge, a light scattering instrument, and by analysis of electron microscope photographs. The experience with these instruments is discussed. The measured data are compared and the errors in the measurements of aerosol size distribution derived. The influence of inaccuracies in mass concentration and particle size measurements on code validation is discussed