Research of the depletion calculation method based on the core nuclear design software package TORCH

In the two-step method of reactor physics design calculation, depletion calculation is one of the most important modules for accuracy and efficiency. The depletion method has been researched in two aspects, including the micro-depletion and the macro-depletion. These researches were implemented in the TORCH software package and validated with actual measured data from Qinshan, Daya bay and Fuqing nuclear power plants. Numerical results of critical boron concentration and power peaking factor show that the calculation accuracy of predictor-corrector method, improved predictor-corrector method and logarithmic linear interpolation method is gradually improved in micro-depletion method and the critical boron concentration is underestimated by 20 ppm in macro-depletion method. All results show reasonable deviations and new options for the depletion calculation can be provided in these methods.