Thermalhydraulic and material specific investigations into the realization of an accelerator driven system (ADS) to transmute minor actinides. 1999 status report

At Forschungszentrum Karlsruhe an HGF Strategy Fund Project entitled "Thermalhydraulic and Material Specific Investigations into the Realization of an Accelerator-Driven System (ADS) to Transmute Minor Actinides" is performed which is funded by the Hermann von Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF) in the section "Energy Research and Energy Technology" over a time period from 07/1999 to 06/2002 (Forderkennzeichen 01SF9926/3). The objective of this HGF Strategy Fund Project is the development of new methods and technologies to design and manufacture thin-walled and thermally highly-loaded surfaces which are cooled by a corrosive heavy liquid metal (lead-bismuth eutectic). The beam window is a vital component of an ADS spallation target. The results of this project will provide the scientific-technical basis which allows the conception and the design of an ADS spallation target and later on a European Demonstrator of an ADS system. The work performed at Forschungszentrum Karlsruhe is embedded in a broad European research and development programme on ADS systems. The project is divided in three sub-projects: Sub-Project SP1: Thermalhydraulic Investigations In the field of experimental thermalhydraulics physical models are developped for conductive and convective heat transfer along thin-walled and thermally highly-loaded surfaces (e.g. beam window) in turbulent lead-bismuth flow. In parallel, a thermalhydraulic computer programme is validated for the low Prandtl number fluid lead-bismuth. Finally, a complete spallation target is numerically designed. Sub-Project SP2: Material Specific Investigations In the field of material science physical methods are developped to describe corrosion mechanisms and to solve the corrosion challenge for potential structure and window materials with and without surface treatment for flowing lead-bismuth. Sub-Project SP3: Oxygen Control System In the field of reaction kinetics a physical / chemical method is developped to measure and control the oxygen potential in a lead-bismuth loop in order to prevent the corrosion of the materials used. The experimental investigations are performed in the KArlsruhe Lead LAboratory KALLA. The investigation of the complex system ,,heat transfer along thermally highly-loaded surfaces that are in contact with liquid corrosive lead-bismuth under well-defined chemical and material specific boundary conditions" has not been performed up to now. It will be done within this project and directly applied to the design of a spallation target, one key component of an ADS. This report gives the results achieved during the year 2000.