Title: The applicability of remote field eddy current testing to outer flaws
on cooling tubes in the blanket of a fusion DEMO reactor (核融合DEMO炉ブランケットの冷却管外面きず検査に対するリモートフィールド渦電流探傷法の適用性評価)
Abstract: This study investigated the applicability of remote field eddy current testing (RFECT) to the non-destructive inspection of cooling tubes in the blanket of a fusion DEMO reactor. Pipes made of F82H steel with inner and outer diameters of 9.0 and 11.0 mm, respectively, were prepared, and artificial grooves were machined on the outer surface of the pipes. The pipes were inspected using an RFECT probe consisting of one exciter and one detector. The results confirmed that RFECT was capable of etecting a groove with a depth of 0.5 mm if the axial length of the groove was 5 mm or more. Subsequently, stress analysis was performed using the three-dimensional finite element method to evaluate the stress caused by the presence of a groove. The calculated stress was compared with the strength of the F82H steel. The stress caused by undetectable flaws was smaller than the strength.