轻水堆燃料组件计算程序包TPFAP

TPFAP是一个同时适用于PWR和BWR的穿透几率法燃料组件燃耗计算程序包。它首先利用碰撞几率方法在库能群结构下完成三区或四区圆环几何的栅元输运计算。载钆燃料棒或硼棒可燃毒物栅元的有效吸收截面由微燃耗程序CMB产生,两维穿透几率法组件计算是在(x,y)几何下进行。基模计算用来考虑中子泄漏修正。根据反应率等效,计算组件等效扩散参数。在每一燃料棒和可燃毒物棒进行燃耗计算,TPFAP给出每一燃耗步的组件和栅元少群截面、功率分布,提供核设计和安全分析所需参数。

On the Second Harmonic Generation through Bell-Plesset Effects in Cylindrical Geometry

Generation of the second harmonic initiated by Bell-Plesset effects in a cylindrical geometry is studied analytically. For an initial single-mode velocity perturSation, the second-order mode-coupling formula is obtained by expanding the perturbation displacement and velocity potential up to the second-order accuracy. It is found that the initially symmetric interface evolves into a significant bubble-spike asymmetric pattern. The second-order solutions clearly show that the amplitude of the spike grows faster than that of the buSble. The temporal evolutions of the amplitudes of the 5ubSie and spike are dependent on the interface velocity Vo. The larger interface velocity leads to the smaller amplitude of the perturbation at an arbitrary interface position in a cylindrically convergent geometry.

三维圆柱几何格林函数节块法

为快速准确地求解三维圆柱几何中子扩散方程 ,研制了第二类边界条件 3- D圆柱几何格林函数节块法。首先通过横向积分将 3- D中子扩散方程化为 3个互相耦合的一维偏通量方程。在 R向 ,其相应的格林函数方程的解由 Bessel函数表示。在 θ向 ,经过近似可将偏通量方程化为平板几何的形式。 3个方向的方程按照平面几何格林函数节块法的思路进行求解。对高温堆模型进行的基准校算表明 :该方法计算本征值和堆芯内通量均具有较高的精度 ,其计算速度也与一般粗网格方法相当 ,因此可成为三维圆柱几何堆芯物理计算的有效方法。