MCADS程序的开发和ADS基准题计算

由于加速器驱动次临界堆存在外中子源,堆芯结构复杂,中子注量的各向异性严重,所以相关燃耗计算在次临界系统设计中起着重要作用。为实现次临界系统的燃耗计算,结合粒子输运程序MCNP处理复杂几何和燃耗程序LITAC处理核素全面的特点,开发了接口程序MCADS耦合MCNP和LITAC。然后选取IAEA-ADS基准题对耦合程序进行了验证计算。结果表明,燃耗、外源强度、空泡效应、初始功率分布等方面的计算结果和其他国家的计算结果相比有很好的一致性,证实了MCADS在次临界模式计算中的可靠性。     

应用蒙特卡罗方法对比研究ADS颗粒靶和块状靶（英文）

应用蒙特卡罗软件FLUKA对比研究了颗粒靶和块状实体靶在中子、质子泄露,中子、质子流强,能量沉积,残余核活度及Gamma射线剂量率的差异。最终结果显示在靶的轴对称方向,相较块状靶,颗粒靶中的中子流强和能量沉积更加均匀,且侧壁泄露中子更多而反冲中子较少。除此之外,在散裂产物放射性方面,尽管有部分核素两种靶具有相似的活度,但是颗粒靶总的放射性活度要比块状靶低。因此以上特性使得颗粒靶相较块状实体靶更适合用于ADS的靶。Using the Fluka Monte Carlo code,the comparison study between granular target and monolith target in neutron and proton leakages,neutron and proton fluxes,energy deposition density and residual radioactivity as well as gamma dose rates were presented.Results shows that the neutron flux and energy deposition in tungsten spheres target are more homogeneous along the axial direction than monolith target.What's more,the granular target has a more lateral neutron yield and a relatively small amount of neutrons in the backward direction.In addition,the total radioactivity is found to be comparatively lower in granular target,although for some nuclei,the value of their activities are similar for both targets.So the above features make the granular target more suitable as a ADS target.