An Experimental and Theoretical Thermal Analysis of a Simulated CANDU 37-Element Spent Fuel Bundle with Air Backfill

Using a therml mock-up of a simulated CANDU 37-element spent fuel bundle within a fuel basket, a series of experiments was performed to obtain the maximum fuel rod temperature along with the radial and axial temperature distributions within the fuel bundle. The main purpose of these experiments was to compare the data with the predictions made by the use of MAXROT code developed earlier. A total of 48 runs were made with 8 different power input to the 37-element heater rod bundle ranging from 5 to 40 W while using 6 different band heaters power from 0 to 250 W (to maintain the basket wall at a desired boundary condition temperature) at the steady state. Comparisons between the measured and predicted maximum fuel rod temperatures of the simulated CANDG 37-element spent fuel bundle for all 48 tests show that the MAX ROT code slightly over-predicts and the agreement is within 2.8% and mean deviation is 3.rc. From this result, it is concluded that the MAXROT code can be used in the second step of the two-step thermal analysis method proposed earlier to obtain the maximum fuel rod temperature of the CANDU 37-element spent fuel bundle within a fuel basket in a given spent fuel dry storage canister with an uncertainty of about 2.8%.