Effect of Radial Peaking Factor Limitation on Discharge Burnup

Abstract

Effect of the radial peaking factor limitation on the discharge burnup was examined. In general, lower limitation of the radial peaking factor places restrictions on feasible loading patterns and decreases core performance and economic efficiency. In this paper, relationship between limitation of the radial peaking factor and the discharge burnup was quantitatively investigated in 2-loop and 3-loop PWRs for several cycle lengths and fuel types. Equilibrium cores were generated assuming various radial peaking factor limitations and the change in discharge burnup, which can be considered an index of fuel cycle costs, was evaluated for each case. In order to make accurate comparisons, the generated equilibrium cores were optimized using the OPAL code by the simulated annealing method. From the calculation results, it was revealed that the limitation of the radial peaking factor has considerable impact on the discharge burnup. Relationship between the prediction accuracy of the radial peaking factor and the fuel cycle cost can be also quantitatively estimated from the above results. Therefore, the results can provide a strong motivation to improve in-core fuel management methods.