Research Activities on HLM Thermal-Hydraulics and Its Application to ADS Design
X. Cheng, R. Stieglitz and J.U. Knebel
Forschungszentrum Karlsruhe, Postfach 3640, 76021 Karlsruhe, Germany
Phone: +49-7247-824897, email:
Abstract
The Forschungszentrum Karlsruhe has intensively been working on the thermal-hydraulics of HLM-cooled systems, e.g. accelerator driven sub-critical systems (ADS). The main objectives of these activities are to establish basic HLM-technologies, to support the design of HLM cooled components and to develop comprehensive tools for assessing ADS systems. To achieve these goals, both experimental and numerical studies are carried out. The main thermal-hydraulic activities cover the following topics:
Basic technology of HLM and experimental thermal-hydraulics
Experiences and technologies are very limited in utilization of HLM in nuclear systems. The KArlsruhe Lead LAboratory (KALLA) represents a strategic key position in the field of HLM technologies in Germany and is becoming an international open user laboratory for experiments which are relevant for ADS applications. Two test loops of different capacities can be utilized for thermal-hydraulic studies with the following tasks envisaged:
-Measurement techniques for mean and local quantities, such as temperature, flow rate, pressure and velocity;
-Thermal-hydraulic performance of various spallation targets;
-Fuel element development;
-Thermal-hydraulic data base for physical model development and code validation.
Basic physical models and design tools
Establishing well validated numerical tools for ADS design is one of the key tasks running at the Forschungszentrum Karlsruhe. Different classes of computer codes are selected, which cover a wide range of applications, i.e. from integral system design to detailed 3-dimensional analysis. Although these tools were applied to ADS assessment in the past, reliable and well validated physical models, especially models for turbulent heat transfer and inter-channel exchange, are still missing for HLM flows. Therefore, large efforts are being made to develop new physical models and to improve the applicability of numerical tools to ADS design.
Support to ADS Design
The Forschungszentrum Karlsruhe is being strongly engaged in the thermal-hydraulic design of ADS components and sub-systems. Up to now efforts are mainly concentrated on spallation targets. Both numerical analysis and experimental investigations have been carried out to support the design of target cooling systems and to optimize their active parts. In the frame of this activity, both experimental techniques and numerical programs of specific purposes have been developed and adopted for future ADS applications.
In the present paper, an overview is given about the research activities at the Forschungszentrum Karlsruhe on HLM thermal-hydraulics and its application to ADS design. Examples are given of the R&D results recently achieved in the above mentioned topics.
Abstract to be submitted to the IEMPT-8, November 9-11, 2004, Las Vegas, USA