Nuclear Technology / Volume 156 / Number 2 / November 2006 / Pages 180-190
Technical Paper / Fuel Cycle and Management
In this paper, an efficient genetic algorithm has placed burnable poisons (BPs) into all of the fresh fuel positions in the core employing the optimized BP configurations and techniques developed in two previous papers. Of importance was the previous development of a Kinf filter, which greatly reduced the computational time. The Kinf filter eliminated many of the invalid genotypes/phenotypes before making a precise core depletion analysis. An extensive BP library was generated by the CASMO-4/TABLES-3 codes. The process was automated with a user-friendly program developed for this purpose. The BPs were vendor UO2/Gd2O3 fuel assembly designs used in a reference Three Mile Island Unit 1 core. The optimized UO2/Gd2O3 fuel pin configurations have small residual binding at end of cycle (EOC), and BP loading optimization results with 97.2 ppm soluble boron at EOC while it was 94.4 ppm with the available vendor designs. The result was that optimized UO2/Gd2O3 fuel pin configurations were developed with unique self-shielding properties and residual binding that also provided a 6.89% reduction in the total required Gd amount, providing extra savings in fuel cost.