控制棒位置及局部温度扰动对熔盐堆有效倍增因数影响的研究

熔盐堆是第四代反应堆中唯一一种以液体为燃料的反应堆,因此对于熔盐堆反应性的研究不同于其他反应堆。基于蒙特卡洛方法,利用 Monte Carlo N-Particle(MCNP)软件模拟控制棒在堆芯径向不同位置及轴向不同插入深度对熔盐堆堆芯有效倍增因数的影响。随后将熔盐堆堆芯由上到下划分成八个区域,分别计算熔盐与石墨在八个不同区域发生多普勒效应以及发生膨胀效应对整个堆芯的有效倍增因数的影响。结果表明控制棒位于熔盐堆不同位置对反应堆有效倍增因数影响不同,沿径向21.21 cm处插入深度80 cm时控制棒有效利用价值最高。熔盐在不同区域发生多普勒效应时,顶部和底部对反应堆有效倍增因数影响相对较大。不同区域熔盐发生膨胀效应时,轴向中心处对有效倍增因数的影响相对较大。石墨发生局部温度扰动对有效倍增因数的影响较小。

Study the Effect of Control Rods Position and Local Temperature Disturbance on the Effective Multiplication Factor of Molten Salt Reactor

Molten salt reactor was the only one of the fourth generation of reactors with liquid fuel, so the study of the reaction of molten salt reactor was different from other reactors. It took different reaction of molten salt reactor when control rod distributed at different region. The region of the reactor occurred temperature disturbance would influence the effective multiplication factor of the molten salt reactor. Studying the influence was important when different region occurred temperature disturbance. Based on Monte Carlo method, the effect of the control rods at different radial positions and different axial depths on effective multiplication factor of the molten salt reactor was simulated by Monte Carlo N-Particle (MCNP) software. Then the molten salt reactor was divided into eight zones from top to bottom. The effective multiplication factor of the whole reactor was calculated by MCNP when the Doppler effect and the expansion effect of the molten salt and graphite occurred at different zones. The results showed that the effective multiplication factor of the molten salt reactor changed with the different radial positions and insertion depths of control rods. The effect of the Doppler effect which occurred at different regions on the effective multiplication factor of the reactor was obtained. When the control rods were inserted half depth and distanced axis 21.21cm it produced the highest value. The effect of the Doppler effect which occurred at different regions on the effective multiplication factor of the reactor was obtained which showed that it was most strongly influenced by the top and bottom regions of the reactor and least affected by the region of the axial center. However, it was just the opposite to the above result when the molten salt expanded.