Measurement of effective thermal conductivity of lithium oxide and beryllium sphere packed bed

Effective thermal conductivity of Li/sub 2/O and Be sphere packed bed was measured for the design of pebble layered type breeding blanket of ITER (CDA). Measurement runs were performed with 1 mm/spl phi/ Be sphere in the temperature range of 150 C to 650 C for Li/sub 2/O and 130 C to 320 C for Be. As the result, the effective thermal conductivity of 1 mm/spl phi/ Li/sub 2/O was influenced by contact area between spheres and packing fraction due to its reactivity. The measured value was about 0.9 W/mK with the packing fraction of 48%. Effective thermal conductivity of 1,2 and 3 mm/spl phi/ Be sphere packed beds were observed as k=1.56+3.25/spl times/10/sup -2/ T, k=2.43+2.15/spl times/10/sup -3/ T, k=2.51+1.45/spl times/10/sup -3/ T, respectively, where k is effective thermal conductivity [W/mK] and T is temperature [C]. Measured packing fraction was 56, 61 and 64% for 1, 2 and 3 mm/spl phi/ Be.