Fuel Channel Thermal-Chemical Experiment CS28-3

Abstract

Three 28-element out-of-pile fuel-channel experiments have been performed to provide validation and assessment data for various high-temperatures fuel-channel codes and to further the understanding of CANDU fuel channel behaviour under severe accident conditions. The test section in these experiments consisted of a 28-element bundle of fuel-element-simulators surrounded by a reactor grade pressure tube mounted inside a Zr-2 calandria tube. During the experiment, high-temperature steam was heated by the electrically heated fuel element simulators until the steam and zirconium surfaces in the test section were at sufficient temperatures to initiate the exothermic zirconium-steam reaction. The fuel element simulators were powered until simulator temperatures reached 1700 degrees C then power was turned to zero. Analysis of experimental results indicated the exothermic zirconium-steam reaction within the channel was locally self-sustaining as fuel element simulator temperatures increased to values as high as 1950 degrees C and up to 57 moles of hydrogen were produced in the test section prior to shutting down the experiment.