No abstract

The thermal conductivity of MOX fuel co~taining FP precipitates such as oxide and metallic inclusions was evaluated by using a finite element method. (UO.8PUo.z)Oz and (Mo.94Ndo.06)OZ (M: UO.8PUo.z) were employed as the fuel matrix, and BaU0 3 and Mo-Ru-Rh-Pd alloy as the inclusions. The dispersed phase size and concentration were determined from post irradi~tion examination results of about 10 at. % burnup MOX fuel. 2.5 vol. % of the spherical inclusions with the diameter of 25~m were disperse.d in the fuel matrix cube with a size of 400x400x400~m. The effect of the inclu~ions on the thermal conductivity of the fuel pellet was calculated to be. at most several percents, which is about one order lower than that of the dissolved FPs.

Thermal properties D 3000Thermal and Mechanical Properties of AgPb 9 (VO 4 ) 6 I and AgBa 9 (VO 4 ) 6 I. -The title compounds are synthesized as a potential waste form to immobilize radioactive iodine from stoichiometric amounts of M3(VO4)2 (M: Ba, Pb) and AgI (973 K, 5 h). The samples are characterized by XRD, EDX, TG-DTA, and thermal and mechanical measurements. The crystal systems of the Ba and Pb containing compounds are rhombohedral and monoclinic, respectively. Both compounds are stable up to 950 K under Ar. The thermal conductivity of the samples is lower than that of borosilicate glasses used for high-level nuclear waste forms. -(UNO*, M.; KOSUGA, A.; MASUO, S.; IMAMURA, M.; YAMANAKA, S.; J. Alloys Compd. 384 (2004) 1-2, 300-302; Dep. Nucl. Eng., Fac. Eng.,