High-efficiency dc electromagnetic pumps and flow couplers for LMFBRs. Final report

Abstract

The objective for the study reported here was to evaluate high efficiency direct current electromagnetic pump concepts for use in pool-type liquid metal cooled fast breeder reactors. It was concluded that the conventional direct current pump would not be practical for the high flow rates required, primarily because of the adverse high-current low-voltage supply requirements. However, a relatively new concept - the flow coupler - appears to be much more promising. In this concept, the primary and intermediate fluid flows are linked magnetically - with the intermediate fluid acting as a generator of the current that is used in a pump to drive the primary fluid. In this way the requirement for an external direct current supply and associated busbars is eliminated. Techniques to analyze such flow couplers have been developed and show that overall efficiencies in excess of 60% are attainable in relatively small volumes (3.5m in length, 2.5m in dia). This may permit a reduction in the size of the reactor vessel. Several flow coupler concepts are described which require further evaluation.