1.5MeV电子辐照平台屏蔽改造

针对一台功率为15kW的1.5 MeV电子辐照平台,进行了屏蔽计算分析与改造设计工作。根据辐照平台厂房布局建立三维模型,使用蒙特卡罗方法进行了相应屏蔽计算。通过对辐照平台主屏蔽体外光子剂量率的计算,对已有建筑物墙体的屏蔽效果进行评估。评估结果表明,建筑物四周墙体厚度满足设计要求。对辐照室和门洞等局部位置进行了屏蔽计算设计,通过对不同屏蔽厚度的计算结果进行比较,给出了满足设计要求的合理可行的设计方案。为验证屏蔽计算结果,在工程验收阶段,对周围人员活动区域进行了现场测量。测量结果表明,辐照平台原有主体屏蔽及新增局部屏蔽可使光子剂量率低于设计目标值,满足防护要求。

Shielding Structure Modification of 1.5 MeV Electron Irradiation Platform

The shielding calculation and design modification work were performed for a 1.5 MeV electron irradiation platform of 15 kW. Based on the structure of irradiation platform, a three-dimensional model was constructed for shielding calculation using Monte Carlo code. The shielding ability of the walls was evaluated through calculation, and it is found that the design meets requirements. The shielding structure of the irradiation chamber and the door was determined based on the comparison of different shielding calculation results. Measurements were carried out to verify the calculation results at the end of project phase. The measured results show that the wall and new shielding structure provide proper shielding, which reduces the photon dose rate below the design goal.