CHARACTERIZATION OF MIXED OXIDE FUEL PELLETS WITH RESPECT TO THEIR THERMAL CONDUCTIVITY
The characterization of (U,Pu)O-2-x mixed oxide fuel pellets with respect to their heat conductivity includes, besides the determination of the heat conductivity itself, the determination of the O/M ratio and the respective closed and open porosity. (Open pores - microcracks diminish heat conductivity significantly.) The analysis of the open porosity as function of pore dimensions covers the range of mesopores where the microcracks appear. This characterization is extended using models which describe the correlation between porosity and heat conductivity under a special assumption on the shape of the pores. It is assumed that the pores can be approximated by ellipsoids. On this basis, effective pore shape factors have been deduced which are characteristic for mixed oxide fuel pellets being in certain temporary states defined by their actual O/M ratio and pore structure. The use of effective pore shape factors improves the analysis of the thermal behaviour of mixed oxide fuel pellets under operation conditions.
Bibliographic Reference: CONFERENCE ON NUCLEAR FUEL PERFORMANCE, STRATFORD- UPON-AVON (UK), MARCH 25-29, 1985 WRITE TO CEC LUXEMBOURG, DG XIII/A2, POB 1907 MENTIONING PAPER E 31589 ORA
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Record Number: 1989124009300 / Last updated on: 1987-01-01
Available languages: en