Thermal analysis mode of the CANDU fuel bundle in a dry storage canister

Abstract

The purpose of present experimental research work with the mock-up test is performed to verify and validate the MAXROT code which is a two-step thermal analysis method for Wolsong (CANDU) spent fuel dry storage canister developed by M.H. Chun and J.W. Park. The three(3) test cases are performed. In the first case, the apparatus was initially tested to ensure that the components and instrumentation to perform as designed prior to the final assembly setup of the experimental apparatus. The initial test results were examined to ensure that the apparatus provided the desired information. In the second case, after assembly of the heater rod bundle into the containment vessel, the experimental apparatus was operated for the heater rod bundle power of 5 watts, 7 watts, 10 watts, 15 watts, and 20 watts. Then, the temperatures of the heater rods in each row were measured and reduced at the saturated condition for each heater rod bundle power. In the third case, in order to make the same boundary condition as an interim dry storage condition at the nuclear power plant site, the band heaters on the outside surface of the containment vessel were operated and the power of the heater rod bundle were kept at a constant power of 6 watts. The average temperatures and the sample standard deviation of the meaured temperatures of the heater rod at each saturated condition were compared with the predicted data obtained by the MAXROT code. This experiment was conducted simulating the heat transfer characteristics of combinations of equilateral triangular and square pitch arrays of heater rod, similar to a CANDU spent fuel bundle, and by recording the temperatures of the heater rods at a various of power levels. The reduced data from this experiment has been utilized to verify a model developed to predict the maximum fuel rod surface temperature in a fuel bundle and further to characterize the relevant heat transfer mechanisms in a fuel bundle. For the step-2 analysis, the temp...