Abstract Soluble boron-free reactors inherently have larger reactivity feedback than conventional pressurized water reactors during power transients. The purpose of this study is to verify the capability of the long-term load follow operation with only control rods for the soluble boron-free small modular reactors. The effects of the long-term load follow operation on burnup distribution, power distribution, reactivity balance and spatial xenon stability are investigated throughout the whole cycle. The reactivity balance results show that the control rod design of the soluble boron-free SMR successfully manages the reactivity changes introduced by power and xenon changes during the daily load follow operation. The spatial xenon stability analysis demonstrates that the SMR model has enough capability to suppress the axial and quadrant xenon oscillation without a second peak during the load follow operation. The load follow simulation results showed that safety parameters including peaking factor, axial offset and shutdown margin satisfy design limits.

中文翻译：

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可溶性无硼SMR长期日负荷跟踪运行能力研究

摘要 可溶性无硼反应堆在功率瞬变期间固有地具有比传统压水反应堆更大的反应性反馈。本研究的目的是验证可溶性无硼小型模块化反应堆仅使用控制棒的长期负载跟踪操作的能力。在整个循环中研究了长期负载跟踪操作对燃耗分布、功率分布、反应平衡和空间氙稳定性的影响。反应性平衡结果表明，可溶性无硼 SMR 的控制棒设计成功地管理了日常负载跟踪操作期间由功率和氙气变化引入的反应性变化。空间氙稳定性分析表明，SMR 模型具有足够的能力来抑制轴向和象限氙气振荡，而不会在负载跟随操作期间出现第二个峰值。负载跟随仿真结果表明，包括峰值系数、轴向偏移和停机裕度在内的安全参数满足设计限制。