压力容器快中子注量有效降低的堆内屏蔽策略研究

Study on the In-reactor Shielding Strategies for Effectively Reducing Neutron Fast Fluence in the Reactor Pressure Vessel

压力容器是反应堆不可更换部件,有效降低压力容器所受快中子注量、降低压力容器材料辐照损伤,对确保压力容器全寿期的完整性具有重要意义。为此,本文通过构建典型的压水堆简化模型,采用基于遗传算法的屏蔽优化方法,对反应堆堆内设置不锈钢反射层、设置不锈钢热屏,以及二者的结合等三种堆内屏蔽策略的有效性进行了研究,并形成了相应的结论。最后,将研究的堆内屏蔽策略应用于“华龙一号”反应堆,通过高精度的蒙特卡罗方法分析表明压力容器快中子注量获得了显著的降低,验证了本文提出的堆内屏蔽策略对降低压力容器快中子注量的有效性。

As the non-replaceable components of the nuclear reactor,the effective reduction of the neutron fast flux and related material irradiation damage of the reactor pressure vessel is of great significance to ensure the integrity of the pressure vessel throughout its life.For this reason,this paper carried out the study for three kinds of in-reactor shielding strategies including setting stainless steel reflector,setting stainless steel neutron shielding in the down comer water,and the combination of the previous strategies,through construction of a simplified model of the typical pressurized water reactor,and adoption of the shielding optimization method based on the genetic algorithm,.Corresponding conclusions have been formed.Finally,the in-reactor shielding strategies have been applied to HPR1000,shielding calculations have been carried out using high precision Monte Carlo method,and the neutron fast fluence of the pressure vessel has been significantly reduced,which verified the effectiveness of the in-reactor shielding strategies proposed in this paper.