ITER屏蔽包层活化分析

作为国际热核聚变实验堆(ITER)的重要部件之一,屏蔽包层承受高强度聚变中子辐照,需要定期更换和维修。当活化的屏蔽包层从ITER托卡马克装置移到热室时,可能会给工作人员造成严重的辐射照射,是ITER大厅和热室屏蔽设计的重要辐射源。文中基于ITER最新中子学分析基准模型和"二步法"停堆剂量计算方法,使用超级蒙特卡罗核计算仿真软件系统SuperMC针对15号屏蔽包层建立精细的中子学模型,并计算分析包层的活化情况及最严重情况下的周围辐射剂量率,并初步应用于ITER赤道窗口室的屏蔽分析。计算结果显示,单个包层周围最大剂量率为350 Sv/hr,当传送小车停留在赤道窗口室内时,窗口室屏蔽门外剂量率高于10 mSv/hr,不足以满足设计要求。

Activation analysis for ITER shielding blanket

As one of the key components of the International thermonuclear experiment reactor (ITER),blankets will sustain radiation from fusion neutrons with high intensity and may need to be replaced and maintained regularly. During the maintenance,the cask with activated blankets will be transferred to hot cell from Tokamak,which will cause high level of radiation in the building and radiation exposure for workers. Employing the Super Monte Carlo Simulation Program for Nuclear and Radiation Process (SuperMC),the activation of No.1 5 shielding blanket and the shutdown dose around was analyzed based on the latest ITER neutronics model named Blite-3. The results were applied in the shielding analysis for ITER equatorial port cell. From the results,the dose rate around one activated blanket should be as high as 350 Sv/hr. When the cask carrying four activated first walls was transferred to the equatorial port cell,the dose rate in the gallery outside the port cell could be more than 10 mSv/hr,not meeting with the design criteria.