Abstract
During power ascension in boiling water reactor, both economic benefits and operation safety must be considered. For economic consideration, it should bring up the power to the full power level as soon as possible. As for the operation safety, it should ensure the fuel rod integrity under any operation condition and thus have to satisfy all the operation safety limits, including minimum critical power ratio, maximum linear heat generation rate, maximum average planar linear heat generation rate, fuel envelope, power oscillation, and so forth. For the time being, this task is designed by nuclear engineers who use POWERPLEX-III to figure out control rod withdrawal, xenon waiting, and watching the margin of the operation safety limits during the power ascension, which must be finished before start up operation. The goal of this research is to use ant colony optimization algorithm to search the power ascension path, in which using power search mode of SIMULATE-3 to calculate core status. In the algorithm, solution component set contains all the possible action, i.e., control rod withdrawal and core flow rate increment. To consider the thermal limits, power oscillation, maximum control rod line, envelope and so forth during the path search, those terms were formulated as the penalty terms of the quality function. The heuristic information was used to eliminate the unreasonable action when constructing solution. Using SIMULATE-3 to calculate the core status along the power ascension path, and then the quality function was calculated. The pheromone concentration was updated according to the quality function value, until the program converge to a best solution. The developed program was demonstrated by two cycle and the results show that the goal was achieved.