AN EXPERIMENTAL AND THEORETICAL THERMAL-ANALYSIS OF A SIMULATED CANDU37-ELEMENT SPENT FUEL BUNDLE WITH AIR BACKFILL

Using a thermal mock-up of a simulated CANDU 37-element spent fuel bun dle within a fuel basket, a series of experiments was performed to obt ain the maximum fuel rod temperature along with the radial and axial t emperature distributions within the fuel bundle. The main purpose of t hese 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 rang ing from 5 to 40 W while using 6 different band heaters power from 0 t o 250 W (to maintain the basket wall at a desired boundary condition t emperature) at the steady state. Comparisons between the measured and predicted maximum fuel rod temperatures of the simulated CANDU 37-elem ent spent fuel bundle for all 48 tests show that the MAXROT code sligh tly over-predicts and the agreement is within 2.8% and mean deviation is 3.2 degrees C. From this result, it is concluded that the MAXROT co de can be used in the second step of the two-step thermal analysis met hod proposed earlier to obtain the maximum fuel rod temperature of the CANDU 37-element spent fuel bundle within a fuel basket in a given sp ent fuel dry storage canister with an uncertainty of about 2.8%. (C) 1 998 Elsevier Science Ltd. All rights reserved.