A new safety analysis code for pressurized water reactors, ARSAC (Advanced Reactor System Analysis Code), is developed to satisfy the new demand for nuclear industry development in China. The code utilizes a hierarchical reactor system model to build the reactor model more conveniently, applies the general non-equilibrium non-homogeneous Euler-Euler six equation two-fluid models, and adopts a high-efficiency system solving algorithm. A semi-implicit scheme is applied to the conservation equation and a NRLU algorithm is implemented. The code structure of the ARSAC is highly modular with C++ for further improvement. The preliminary code assessment on conceptual, separate effect, and integral effect experiments showed that the prediction is reasonable. The ARSAC code will be used for safety analysis of operating PWRs and the design of innovative reactors including small modular reactors.

为满足我国核工业发展的新需求，开发了一种新的压水堆安全分析规范ARSAC（Advanced Reactor System Analysis Code）。代码利用层次反应器系统模型，更方便地建立反应器模型，应用通用的非平衡非齐次欧拉-欧拉六方程二流体模型，采用高效的系统求解算法。对守恒方程应用了半隐式方案，并实现了 NRLU 算法。ARSAC 的代码结构采用 C++ 高度模块化，可进一步改进。对概念、分离效应和整体效应实验的初步代码评估表明预测是合理的。