[en] The requirements were for enriched uranium dicarbide particles coated with pyrolytic carbon and consolidated into fuel cartridges of total length 36 in. The required fuel loading was 28.7 g of U-235 uniformly distributed throughout 18 fuel cartridges, each of nominal length 2 in and nominal diameter 1.75 in. Fig. 1 shows the design of the fuel cartridge adopted for this irradiation. The six longitudinal channels at the outer circumference carry the fission product purge flow between the cartridge and the inner surface of the fuel tube. The chamfer at one end obviates the need to align the grooves during assembly, while the central 4 in diameter hole facilitates uniform deposition of carbon during the gas cracking operation. In addition to the fuel cartridges, 8 ''satellite'' fuel compact were supplied for burn-up determinations. Each satellite fuel compact of diameter 0.3% in and length 0.2 in contained 0.0046 g of U-235; this represented a similar fuel density to that of the fuel cartridges.