Abstract The Molten Salt Reactor (MSR), one of the six advanced reactor types of the 4th generation nuclear energy systems, has many impressive features including economic advantages, inherent safety and nuclear non-proliferation. This paper introduces a system analysis code named TREND, which is developed and used for the steady and transient simulation of MSRs. The TREND code calculates the distributions of pressure, velocity and temperature of single-phase flows by solving the conservation equations of mass, momentum and energy, along with a fluid state equation. Heat structures coupled with the fluid dynamics model is sufficient to meet the demands of modeling MSR system-level thermal-hydraulics. The core power is based on the point reactor neutron kinetics model calculated by the typical Runge-Kutta method. An incremental PID controller is inserted to adjust the operation behaviors. The verification and validation of the TREND code have been carried out in two aspects: detailed code-to-code comparison with established thermal-hydraulic system codes such as RELAP5, and validation with the experimental data from MSRE and the CIET facility (the University of California, Berkeley’s Compact Integral Effects Test facility).The results indicate that TREND can be used in analyzing the transient behaviors of MSRs and will be improved by validating with more experimental results with the support of SINAP.

中文翻译：

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熔盐反应堆TREND动力学程序开发

摘要 熔盐反应堆（MSR）是第四代核能系统的六种先进反应堆类型之一，具有许多令人印象深刻的特点，包括经济优势、固有安全性和核不扩散。本文介绍了一种名为 TREND 的系统分析代码，该代码是为 MSR 的稳态和瞬态仿真而开发和使用的。TREND 代码通过求解质量、动量和能量守恒方程以及流体状态方程来计算单相流的压力、速度和温度分布。与流体动力学模型相结合的热结构足以满足 MSR 系统级热工水力建模的需求。堆芯功率基于通过典型的 Runge-Kutta 方法计算的点反应堆中子动力学模型。插入增量 PID 控制器以调整操作行为。TREND 代码的验证和验证已在两个方面进行：与已建立的热工液压系统代码（如 RELAP5）进行详细的代码到代码比较，以及与来自 MSRE 和 CIET 设施（大学）的实验数据的验证。加州，伯克利的紧凑积分效应测试设施。结果表明 TREND 可用于分析 MSR 的瞬态行为，并将通过在 SINAP 的支持下通过更多实验结果进行验证而得到改进。