核数据对HTR-10和HTR-PM堆芯k_(eff)不确定性贡献的差别与机理分析

Mechanism Analysis of Difference between the Contribution of Nuclear Data to k_(eff) Uncertainty in HTR-10 and HTR-PM

使用SCALE6.1程序中TSUNAMI-3D-K5模块,建立了10 MW球床高温气冷实验堆HTR-10和球床模块式高温气冷堆HTR-PM的完整三维堆芯模型,并采用其内置的44群协方差矩阵,分析了核数据不确定性对HTR-10及HTR-PM两种不同堆芯有效增值因子(keff)的影响。通过比较不同物质组成、不同堆芯状态下两种堆芯keff对不同核素、不同核反应的敏感性及不确定性,从机理上分析了核数据不确定性对HTR-10及HTR-PM两种不同堆芯keff不确定性贡献的差别。研究结果表明,堆芯尺寸不同导致中子泄漏不同、239Pu和235U物质比例不同及其平均裂变中子反应是造成两种堆芯keff不确定性差别的主要原因。

Based on the TSUNAMI-3D-K5 model of SCALE6.1 code, the complete 3d models of sphere bed high temperature gas cool experimental reactor HTR-10 and sphere bed model high temperature gas cool reactor HTR-PM core have been established to carry out the research of keffuncertainty by using the 44 groups covariance matrix of nuclear data built-in the SCALE6.1. Through the uncertainty and sensitivity analysis of different nuclear reactions in HTR-10 and HTR-PM, the mechanism of difference between the contributions of nuclear data to the keffuncertainty has been understood. The results show that the difference in neutron leakage due to the difference between the core sizes, the difference between material content of 239 Pu and 235 U and the average fission neutrons are the main reason for the difference between the contributions of nuclear data to the uncertainty of keff.