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 are made. Preliminary tests were carried out to demonstrate sufficient leak tightness of the Battelle-Frankfurt containment for pressures of up to 3 bar (a leak rate of up to about 150 vol.% per day is considered tolerable from the aerosol physics point of view). Aerosol generation is 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 demonstrates the capability of generating aerosols of the desired initial density of approximately 10 g/m/sup 3/ in a dry containment atmosphere is also underway