核电厂设计基准源项计算可为核电厂安全评审提供依据,同时也是辐射屏蔽计算的基础。基于压水堆堆芯、一回路和气载源项的研究基础,类比衰变常数引入了迁移常数和核反应常数的概念,进而总结了一体化计算上述源项中裂变产物源项的源项方程。针对源项方程变系数、大型、稀疏和刚性的特点,在时间离散近似的基础上,基于线性子链算法编写程序求解了上述方程。通过与典型压水堆工程文件对比,证明了程序的正确性和必要性。

The design basis source terms provide a basis for safety analysis of nuclear power plant and the foundation of the radiation shielding calculation. In this paper, based on the research of reactor core, primary loop, secondary loop and airborne radioactive source term of pressurized water reactor, migration constants and nuclear reaction constants are introduced by analogy to decay constants, then an integrated calculation method is proposed for calculating the above source terms. The aforesaid equations are solved by program based on the TTA algorithm where the discrete time approximations are applied to, taking account of the source equation characteristics of variable, coefficient, large, sparse and stiff. The results comparing with the typical pressurized water reactor engineering documents are also given in this paper, which verify the correctness and necessity of the program.