in general, design and operational performance of pu-bearing recycle fuel are quite similar to those of uranium fuel. up to nov. 1976 153 pu-bearing fuel assemblies with altogether 8000 fuel rods, fabricated by alkem, have been or are in operation in german power reactors their performance is very satisfactory. in the obrigheim and in the gundremmingen plant up to 20 of the core are made up of pu-fuel. in either case all-pu fuel assemblies are used, graded in their pu-content for compatibility with the surrounding u-fuel. the physics calculations are accomplished with basically the same methods as applied for u-fuel. theoretical investigations and physics measurements have shown that differences in reactivity balance can be minimized by proper loading patterns. in additional experiments at elevated temperature (kritz) the neutron physics methods were verified in greater detail. the main feature of fabrication of mixed oxide pellets is mechanical blending of natural uo sub 2 - and puo sub 2 -powder before pressing green pellets, and a rather high degree of mechanisation in all fabrication steps including sintering, wet grinding, and rod filling operations. the zircaloy cladding know-how, welding techniques, final surface treatment etc. were all taken from the large experience of kwu in the lwr fuel area. several fuel assemblies have been examined in the spent fuel pools and in hot cell laboratories after a maximum burn-up of 30 gwd/t. the examinations revealed no significant differences compared to u-fuel. fission gas release is somewhat higher, attributed to the inhomogene