Improved Approach to Multiregion Supercritical Transient Analysis Based on the Integral Kinetic Model and Monte Carlo Method
Improved Approach to Multiregion Supercritical Transient Analysis Based on the Integral Kinetic Model and Monte Carlo Method
复制标题
基于积分动力学模型和蒙特卡罗方法的多区域超临界瞬态分析改进方法
DOI：
10.1080/00295639.2017.1337383
复制
发表时间：
2017
影响因子：
1.2
通讯作者：
T. Obara
中科院分区：
文献类型：
--
作者：
D. Tuya;H. Takezawa;T. Obara
摘要 进一步发展了基于积分动力学模型（IKM）和蒙特卡罗方法的多区域超临界瞬态分析方法，并具有新的特点。 IKM 使用二次裂变概率密度函数描述任意几何系统中瞬态期间的区域相关裂变速率，该函数考虑了跨区域连续裂变之间的显式中子传输时间。改进方法的新特点包括使用预先获得的动力学函数（即二次概率密度函数）之间的重复多维线性插值来处理多区域瞬态，使用连续能量蒙特卡罗代码MVP2.0计算动力学函数的新方法，以及直接在IKM中利用动力学函数而无需引入拟合误差的拟合函数。通过将改进的方法应用于无反馈的不同区域组合的简单Godiva系统中的超临界瞬态，验证了改进的方法。此外，我们尝试通过将改进的方法应用于具有热膨胀反馈的简化 Godiva 系统中的超临界瞬态来验证改进的方法，并将获得的结果与实验结果进行比较。验证结果表明，改进的方法适用于不同的区域组合，同时验证结果与实验结果显示出良好的一致性。这项研究是正在进行的研究活动的一部分，该研究活动旨在开发用于一般空间和时间依赖性动力学分析的多区域积分动力学 (MIK) 代码。
Abstract An approach to multiregion supercritical transient analysis based on the integral kinetic model (IKM) and Monte Carlo method is further developed with new features. The IKM describes the region-dependent fission rate during the transient in a system of arbitrary geometry using a secondary fission probability density function, which takes the explicit neutron transport time between successive fissions across the regions into account. The new features of the improved approach include treatment of the multiregion transient using repeated multidimensional linear interpolation between pre-obtained kinetic functions (i.e., secondary probability density function), a new method for calculating the kinetic functions using the continuous-energy Monte Carlo code MVP2.0, and utilization of kinetic functions directly in the IKM without the fitting function that introduces a fitting error. The improved approach is verified by applying it to the supercritical transient in simple Godiva systems of different region combinations without feedback. In addition, we attempt to validate the improved approach by applying it to the supercritical transient in a simplified Godiva system with thermal expansion feedback and compare the obtained and experimental results. The verification results indicate the improved approach works well with different combinations of regions while the validation results show promising agreement with the experimental results. This study is part of an ongoing research activity on the development of Multi-region Integral Kinetic (MIK) code for general space- and time-dependent kinetic analyses.