BETA experiments on melt-concrete interaction: the role of zirconium and the potential sump water contact during core melt-down accidents

• Published in: Nuclear engineering and design Vol. 154; no. 1; pp. 61 - 68
• Main Authors: Alsmeyer, H., Adelhelm, C., Dillmann, H.-G., Foit, J.J., Heinle, M., Ratajczak, W., Schneider, H., Schumacher, G., Skokan, A., Stiefel, S., Tromm, W.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.02.1995; Elsevier
• Subjects: Applied sciences; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; Installations for energy generation and conversion: thermal and electrical energy; Water; Zirconium; Melting; Simulation; Gas release; Concrete; Oxidation; Experimental study; Computer aided design; Reactor core; Erosion; Nuclear reactor
• ISSN: 0029-5493; 1872-759X
• DOI: 10.1016/0029-5493(94)00898-9

In the BETA test facility of Kernforschungszentrum Karlsruhe, prototypical core melts can be simulated in concrete structures sufficient in size to allow a computer-code-assisted extrapolation to be made to the reactor geometry. Three experiments have been carried out to investigate special aspects of molten corium interacting with concrete. The investigations and measurements show the dominance of Zr oxidation during concrete attack by the chemical reduction of SiO 2 to elemental Si and the subsequent Si oxidation by the gases from the concrete. Additionally, the failure of a cylindrical concrete wall was studied, which is eroded on the inner side by a heated melt while being cooled outside by stagnant water. In the experiment wall failure occurs and the melt relocates into the water annulus. Application of the experimental results to light-water reactor severe accidents is discussed.