【摘要】 传统预估-校正方法(Predictor-Corrector Method,PC方法)在采用较大步长进行含钆燃料燃耗计算时会出现显著的误差。为此,日本学者提出了微观反应率线性外推方法(Projected Predictor-Corrector Method,PPC方法),获得明显的改进效果。本文从钆的微观反应率随核子密度变化关系出发,进一步在PPC方法的基础上,针对155Gd和157Gd这两种核素,采用了反应率对数线性外推的方法。针对含钆压水堆组件的比较结果表明,当采用的燃耗步长大于25 d时,本文方法优于PPC方法。更多还原

【Abstract】 The accuracy of the conventional predictor-corrector(PC) fuel depletion method breaks down for the Gd-bearing fuel when coarse timestep is adopted.To resolve this issue,the projected predictor-corrector(PPC) method which assumes the reaction rates are linear functions of the nuclide’s atom density,was proposed by Yamamoto and significant accuracy gain was achieved for Gd-bearing fuel depletion calculation.This paper proposes an improved PPC method,which assumes a linear relation between the microscopic reaction rate and the natural logarithm of the nuclide’s atom density for nuclides 155Gd and 157Gd.Verification calculations are performed against a 17×17 PWR Gd-bearing fuel assembly test problem,numerical results demonstrate that once the timestep is coarser than 25 days the new PPC method is better than the original PPC method.更多还原