AbstractPreliminary radiation protection design of Large Helical Device (LHD) was performed. At first, neutron source strength was estimated. Then, shield wall thickness was designed to match the dose limitation of non-controlled area. Shield door was checked from the simple slit streaming calculation. Duct streaming contributions are calculated to estimate the doses at the cellar and the adjacent room. Finally neutron and γ-ray skyshine was calculated. Air and water radioactivity were estimated to decide controlled area. Activation of the device was estimated for accessibility consideration after operation.
大型螺旋装置（LHD）的初步辐射防护设计已完成。首先估算了中子源强度。随后，根据非管理区域的剂量限值设计了屏蔽墙厚度。通过简单的缝隙流计算对屏蔽门进行了验证。计算了管道流贡献，以评估地下室及相邻房间的剂量。最后计算了中子和γ射线的天空照射。为确定管理区域，对空气和水的放射性进行了评估。同时，为考虑运行后的可达性，对装置的活化情况进行了估算。