Critical experiments with uranyl nitrate solutions with gadolinium additions

Results of 35 critical experiments are presented. The experiments were performed with solution of uranyl nitrate and gadolinium nitrate. Uranium enrichment was about 90 %. Uranium concentration in solutions varied from 70 g/l to 450 g/l, gadolinium concentration - from zero to 1.2 u/l. In all experiments the core had cylindrical form. The diameters of the cores were 25 cm and 40 cm. All cores had water reflectors at the bottom. A number of cores were surrounded by water reflector on the side. Calculational estimate of experimental results were performed. All presented experiments are considered to acceptable for use as benchmark experiments. 5 figs., 15 tabs