去射线效应堆外探测器响应函数计算研究

Research on Calculation of Ex-core Detector Response Function with Ray Effect Elimination

堆外探测器响应函数表征了堆芯活性区各位置处的裂变中子对堆外探测器响应的贡献,通过共轭SN输运计算可快速得到堆外探测器的响应函数。然而,堆外探测器远离堆芯且相对于堆芯体积很小,SN方法的计算结果会受到射线效应的影响。为解决堆外探测器响应函数计算中的射线效应问题,研究了共轭首次碰撞源射线效应消除方法。此外,为克服共轭首次碰撞源方法在三维堆芯计算中面临的计算量大、内存需求高等问题,研究了共轭首次碰撞源的并行化计算方法和动态内存管理方法。基于韩国Kori-1压水堆的计算结果表明:共轭首次碰撞源SN方法和多群蒙特卡罗方法具有相当的计算精度,但计算效率高1个量级。

The response functions of the ex-core detector represent the contribution of fission neutron in the core to the response of the detector.The response function can be calculated efficiently by the adjoint SN transport calculation.However,the result of the SN method is distorted by the ray effect because the ex-core detector is far away from the core and is very small in size relative to the core.In order to overcome this problem,the adjoint first-collision source method was studied.Moreover,the parallel calculation method and dynamic memory management method were also implemented to ensure the massive adjoint first-collision source calculation efficiency.Calculations based on the Korean Kori-1 reactor indicate that the SN method with adjoint first-collision source ray effect elimination technique has the comparable accuracy with multi-group Monte-Carlo method,and can achieve much higher efficiency.