2022/09/14
私(M2 加子)の許に待ち望んだ知らせが参りました。
昨年開催されたITC30での発表内容をまとめ、Plasma and Fusion Research誌に投稿した論文が受理されました。
本論文のタイトルは「Probe design for the eddy current inspection of cooling tubes in the blanket of a fusion DEMO reactor」です。日本で建設予定の核融合DEMO炉冷却管の割れに対する検査手法として渦電流探傷法の適用性を調べるという内容となっています。冷却管の内径が小さいことから、単純形状のボビンプローブを設計し、適用性を評価しました。ボビンプローブであっても冷却管材料が強磁性体のF82H鋼であることから、割れの方向によらず検査が可能であることを確かめられました。
論文としてこれまでの成果を残すことが出来て嬉しく思います。ご尽力いただいた方々には感謝の気持ちでいっぱいです。
以下が概要です。
Title: Probe design for the eddy current inspection of cooling tubes
in the blanket of a fusion DEMO reactor
Abstract: This study investigated the applicability of eddy current testing (ECT) 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 and 11 mm, respectively, were prepared, and slits imitating cracks were fabricated on the pipe surfaces. ECT was performed using a differential type bobbin probe having one exciting and two detecting coils designed in this study. The results of the inspections and subsequent three-dimensional finite element simulations revealed that a bobbin probe is effective in detecting cracks appearing on the inner surface of a pipe. Moreover, the detectability does not deteriorate significantly when cracks oriented in the circumferential directions are targeted, unlike in the case of ECT of the heat exchanger tubes of the steam generators of the pressurized water reactors. This indicates that a probe with a more complicated structure, such as a plus-point probe, would be unnecessary to detect flaws on the inner surface of a pipe. In contrast, the ECT signals from a non-penetrating slit on the outer surface were buried in noise even though the slit was as deep as 0.9 mm.