Review of DEMONA results

The purpose of the DEMONA experiments is to demonstrate the aerosol decay and retention in the containment of a KWU-design 1300 MWe PWR. The DEMONA test matrix is set up to investigate aerosol behavior under various stationary and transient thermodynamic conditions typical of core-melt scenarios and to demonstrate the proper interfacing between the containment thermodynamic and aerosol physics codes. Furthermore, experiments are planned upon which a comparison of single compartment and multicompartment calculations of aerosol decay will be made. Preliminary tests were carried out to demonstrate sufficient leak tightness of the Battelle-Frankfurt containment for pressures of up to 3 bar. Aerosol generation will be achieved by vaporization of metal powders in a plasma torch and subsequent oxidation. Extensive development work was necessary to optimize oxidation chamber geometry and cooling in order to assure reliable and efficient aerosol generation. A large scale dry test, which will demonstrate the capability of generating aerosols of the desired initial density of approximately 10 g/m3 in a dry containment atmosphere is underway. Full aerosol instrumentation is available for this test to measure both spacial and temporal distribution of total aerosol density as well as size distribution. Following the dry test, the first full-scale aerosol test in a wet atmosphere will be performed