小波尺度函数展开共振自屏计算方法在有温度分布共振自屏计算问题中的应用研究

Study on Application of Resonance Self-Shielding Calculation Method Applying Wavelets Scaling Function Expansion in Resonance Self-Shielding Calculation Problem with Temperature Distribution

采用小波尺度函数展开方法来获得燃料栅元的径向功率分布,以及共振能区连续能量能谱在燃料栅元有径向温度分布情况下的径向变化。为了求解复杂几何多共振核素共振问题的,提出了小波尺度函数连续能量共振计算方法。通过与蒙特卡罗方法程序MCNP的计算结果进行比较,验证了方法的几何适应性和精度。该方法共振能区的连续能量核数据来自核数据处理程序NJOY,而非共振能区的多群核数据采用国际原子能机构发布的69群WIMSD4格式的数据库jeff31。由于多普勒温度效应,连续能量核数据随温度变化而不同,而数据库中不可能提供任意温度下的连续能量核截面。因此,本文采用插值方法来获得任意温度下的连续能量核截面,并验证了连续能量核截面温度插值对最终计算结果的影响。最终给出了存在径向温度分布的燃料栅元共振能区的连续能量能谱、反应率和无限增值系数,并与MCNP程序的结果比较。

The radial power distribution in the fuel cell and the continuous-energy spectrums in the fuel cell with a temperature distribution are obtained by the wavelets scaling function expansion method.Wave-lets scaling function expansion continuous-energy self-shielding method is developed,in order to solve the nuclide resonance problem with multiple resonances in complicate geometry.It has been validated and veri-fied by comparison to Monte Carlo calculations.In this method,the continuous-energy cross-sections are processed by NJOY,while the multi-group nuclear data library is jeff31 issued by IAEA.However,for dif-ferent temperature problems,because of Doppler effect,the continuous-energy data library is different,and should be updated by applying NJOY.The calculation efficiency is a problem needed to be improved.There-fore,in this paper,the interpolation is utilized to obtain the continuous-energy cross-sections for other tem-peratures between those given temperatures.Also the precision of the temperature interpolation is discussed.Finally,the differences of continuous-energy spectrums,reaction rates and kinf results are presented and compared with MCNP calculation.