A knowledge-based expert system was developed for generating a pressurized water reactor fuel reload design. First, an initial loading pattern was generated according to the fuel assembly's infinite multiplication factor, by using heuristic rules. Then, the fuel assembly was swapped or rotated, using heuristic rules, to satisfy an assumed search target. The search target was the defined nuclear enthalpy rise hot-channel factor FH at each fuel assembly location. When FH's of a trial loading pattern satisfied the search target, the pattern met the design limit at each exposure checkpoint for all control rods out and D-bank control rods half-inserted conditions, which is the design requirement. The developed program successfully generated several reload cycles for the Maanshan nuclear power plant in Taiwan.