2011 年 29 巻 3 号 p. 104s-108s
The cooling channels have to be installed in the first and side walls in current design of Japanese test blanket module for the international thermonuclear experimental reactor (ITER) and these walls are planned to be joined by electron beam (EB). Since the EB weld joint is intended near the cooling channels in the first wall, thermal elastic-plastic finite element analyses were conducted to examine the influence of cooling channels on the welding residual stress. From these results, it was found that there would be a risk of stress corrosion cracking (SCC) on the surface of cooling channels due to large tensile residual stress. As a result of serial numerical studies by using simplified model for examining the position of weld joint, it was revealed that the residual stress on the surface of channels would decrease by changing the distance between weld line and cooling channels from 10 to 16 mm. Also, the movement of weld line would make the plastic strain distribution on the surface of channels uniform and let the distribution to weld line symmetric. Then, it can be concluded that the uniformity and symmetrical distribution might make a selection of appropriate condition for post weld heat treatment simpler.
