i tried for 3 hours straight but the control rods are difficult little things i even tried the signal for the control rods didn´t work almost melted down again couse of 6 fuel rods having been inserted whith 1 uranium fuel each the design goes as 4 control rods around a central fuel rod and then fuel rods in the corners and next to the control rods the reactor houses 8 moderators all around fuel rods and there is like 13-ish fuel rods in the reactor in total