HTTR水素製造システム実規模単一反応管試験装置触媒粉塵用フィルタノズル部損傷の原因調査と再発防止対策に関する報告(受託研究)

Cause investigation and repair of breakage of catalyst dust filter on mock-up model test facility with a full-scale reaction tube for HTTR hydrogen production system (Contract research)

森崎 徳浩; 林 光二; 稲垣 嘉之; 加藤 道雄; 藤崎 勝夫*; 前田 幸政; 水野 貞男*

Morisaki, Norihiro; Hayashi, Koji; Inagaki, Yoshiyuki; Kato, Michio; Fujisaki, Katsuo*; Maeda, Yukimasa; Mizuno, Sadao*

実規模単一反応管試験装置の触媒粉塵用フィルタのノズルフランジと鏡の溶接部近傍の損傷(き裂)に関し、損傷の原因調査及び再発防止対策等について審議検討を行った。損傷の原因は、内面側から発生した応力腐食割れ(SCC)によるものと推定された。このため、触媒粉塵用フィルタ内の凝縮水発生防止,溶接残留応力低減,溶接鋭敏化低減を行うためのフィルタの改修を行った。また、試験装置の類似継ぎ手構造部の健全性確認を実施した結果、いずれの箇所にも欠陥は検出されず、健全性が確保されていることを確認した。

The breakage of the catalyst dust filter was found at the nozzle flange, which was welded onto the end plate of the filter, by the bubbling test using nitrogen gas of the mock-up model test facility. We investigated the cause of breakage and devised a repairing method. The cause of the breakage was the stress corrosion cracking (SCC) generated from the inside of the filter. The filter was repaired based on the following countermeasures such as reduction of condensed water in the filter, tensile stress and sensitization at welding joints. Furthermore, the inspection was carried out to investigate the structural integrity of the welding joints in the test facility of which structure, material and operating condition were similar to the filter. As the results, it was confirmed that the structural integrity was maintained.