Influence of different thermodynamic parameters on variation across the aerosol size spectrum

Abstract

During a severe accident in a nuclear power plant, fission products can be released into the containment in the form of radioactive aerosols. The behavior of these aerosols is influenced by various thermodynamic parameters, including temperature, pressure, and relative humidity. Changes in these parameters can impact the aerosol size spectrum, leading to variation in aerosol transport and deposition. Having a comprehensive grasp of how thermodynamic parameters impact change in the aerosol size spectrum is crucial for managing and mitigating the consequences of a severe accident, as it allows for better prediction of aerosol behavior and appropriate interventions. A series of experimental works on in-/soluble aerosols and their mixtures has been carried out using the IN–EX facility located at the Forschungszentrum Juelich the Germany. The changes in the aerosol size spectrum of SnO2 , CsI and two different mass composition mixtures (SnO2 : CsI = 7:3 or 4:6) under various thermodynamic conditions are discussed and analyzed. The results show that increasing the temperature leads to a broader aerosol spectrum for SnO2 , but not for CsI aerosols. With the increasing pressure, the aerosol size spectrum shifts towards smaller particles for CsI, but not for SnO2 . Furthermore, increasing the relative humidity causes the aerosol size spectrum of both SnO2 and CsI particles to shift towards larger particles, whereas CsI particles are more pronounced. The behavior of such mixtures relies on the composition of the primary substance within it. These findings provide robust information for improving the strategies of severe accident management.