基于SuperMC的ITER下窗口生物屏蔽插件屏蔽分析

在国际热核聚变实验堆(ITER)中,窗口生物屏蔽插件需为电子设备和工作人员提供必要的辐射屏蔽防护。基于中子学分析的生物屏蔽插件设计是ITER设计的重要内容。本文基于超级蒙卡核模拟软件SuperMC,在ITER大厅三维中子学模型中整合了ITER设计整合部门(DIN)最新设计的下窗口生物屏蔽插件模型,对四种下窗口生物屏蔽插件进行了屏蔽分析。分析结果显示,低温恒温器低温泵生物屏蔽插件中子屏蔽性能最好,室内监视系统生物屏蔽插件屏蔽性能最差;室内检视系统生物屏蔽插件停堆剂量率最小,环形低温泵生物屏蔽插件停堆剂量率最大。在SA2辐照方案下,停堆12天后,环形低温泵生物屏蔽插件处停堆剂量率超过规定限值20倍。分析结果表明,ITER下窗口生物屏蔽插件设计有待优化。

Analysis for the Shielding of Bio-shield Plugs in Lower Ports of ITER Based on SuperMC

The bio-shield plugs could provide significant shielding and protection for electronic devices and staff workers in ITER. The design and neutronic analysis of bio-shield plugs is a big concern in ITER. The Design Integration Section (DIN) of ITER has designed a new model of bio-shield plugs in lower ports. In this study, based on SuperMC, a three-dimensional neutronic model of ITER building is created, and shielding analysis is conducted to evaluate the current design. The results indicate that Cryostat Cryopump plug provides the strongest shielding while IVVS plug provides the weakest one. IVVS plug has the least dose rate and Torus Cryopump plug has the utmost one. Under the radiation scenario of SA2, the dose rate in Torus Cryopump bio-shield plug exceeds the limit value. The current design is insufficient and needed to be improved.