MC计算放射性废液铅屏蔽质量吸收系数

MC Calculation of Mass Absorption Coefficient of Lead Shield in Radioactive Waste Liquid

实验模型围绕放射性废液罐侧面、上下底面分别建立15层1 cm厚的铅,将源项数据转化为MC程序可读的注量能谱,分别计算出各铅层外表面半径、高度和角度方向的网格剂量率值.实验结果:MC计算拟合出铅在该源项下的质量吸收系数μ/ρ为0.07008 cm2/g;随着屏蔽厚度的增加,源项能谱中屏蔽材料弱吸收区光子占比减少,光电效应产生的特征X射线减少电子对效应增加,呈现出拟合μ/p计算出的厚度值与MC值先逐渐减少后略微负增加.该计算方法可为复杂源项的屏蔽设计优化提供参考.

For the complicated radioactive source,the thickness and weight of shielding material can be estimated by MC sim ulation,greatly reduce the cost and time of shielding design.The experimental model is to establish 15 times and 1cm thick lead around the bottom and bottom of the radioactive waste tan k,the source item data is converted into a MC readable volume spectrum,The grid dose rate values of the outer surface radius,direction,height direction and angle direction of the lead layer are calculated respectively.Experimental results shows th a t:the mass absorption coefficient of the lead shielding material calculated by MC is 0.07008cm2/g,With the increase of shielding thickness,the photon absorption ratio of the shielding material will decrease gradually in the source spectrum,The characteristic of photoelectric effect is that the X ray decrease and the electron pair,fitting the mass absorption coefficient,the calculated thickness values and MC effect increases firsthand then decrease slightly.The calculation method of this research has important guiding significant for shielding design optimization of complex source terms.