A Facility for Determining the Heat Transfer Characteristics at Present and Novel CANDU Fuels

Abstract

There is a large economic incentive to improve the thermalhydraulic characteristics of nuclear fuel. An increase in critical power of only a few percent will result in a considerable reduction in energy costs. Several bundle design changes (different number of fuel elements. end cap modifications, graded elements, etc.) have been proposed which look very promising. A test facility, the Fuel Heat Transfer Assessment Rig, has been constructed to provide a tool for evaluating the proposed improvements, and preliminary tests have been carried out with a 37 element simulated fuel string to establish reference values of pressure drop and maximum heat rejection rates for various flows, subcooling and bundle junction alignments. This paper describes the test facility, instrumentation and test procedures.