束流瞬变下CiADS次临界反应堆燃料包壳响应特性研究

通过修改系统分析程序RELAP5 MOD4.0的点堆动力学模型与流动传热模型，使其具备了模拟液态铅铋冷却次临界反应堆动力学特性的能力；利用改进的程序模拟了加速器驱动嬗变研究装置（CiADS）的次临界反应堆燃料包壳在发生束流瞬变时的响应特性；利用ANSYS17.0程序分析了CiADS次临界反应堆燃料包壳束流瞬变下的应力变化。研究表明：失束时间越短，燃料包壳的温度回升越慢；燃料包壳不会因可能发生的束流超功率事件而发生熔毁；燃料包壳内外壁面的温差变化是影响应力变化的主要因素；CiADS次临界反应堆的燃料包壳不会因束流瞬变而发生应力破坏。

Study on Response Characteristic of CiADS Sub critical Reactor Fuel Cladding under Beam Transient

The point kinetic model and the heat transfer model of the reactor system analysis code RELAP5 MOD4.0 were modified, which provided the capacity to simulate the dynamic characteristics of the liquid lead-bismuth cooled sub-critical reactor. The response characteristics of the fuel rods in the sub-critical reactor of China Initiative Accelerator Driven System (CiADS) under beam transient were simulated by the improved code RELAP5 MOD4.0. The variation of stress of the fuel cladding in CiADS under beam transient was analyzed by ANSYS17.0 code. The results show that the shorter the time of beam trip the slower the temperature of the fuel rod recovery. The fuel cladding will not melt in the possible overpower event of the beam. The change of temperature difference between inner wall and outer wall of fuel cladding is the main factor of stress variation. The beam transient will not cause stress damage to the fuel cladding in CiADS sub-critical reactor.