SURFACE TREATMENT METHOD AND SURFACE TREATMENT SYSTEM OF HEAT TRANSFER PIPE OF STEAM GENERATOR

• Main Authors: KUBO TATSUYA, SAYANO AKIO, ABE YUMIKO
• Format: Patent
• Language: English; Japanese
• Published: 18.06.2015
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; NUCLEAR ENGINEERING; NUCLEAR PHYSICS; NUCLEAR POWER PLANT; PHYSICS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

PROBLEM TO BE SOLVED: To provide a method and a system capable of suppressing Ni elution from inside a heat transfer pipe during PWR operation, and suppressing decline of AOA potential or rise of exposure dosage.SOLUTION: A surface treatment method of a heat transfer pipe of a steam generator comprising a Ni-based alloy includes steps for: conducting treatment liquid into the heat transfer pipe; adjusting pH of the treatment liquid to be 5.5 or higher and 6.5 or lower; and adjusting a surface potential of the heat transfer pipe to be 0 V.vs.SHE or higher. In the surface treatment method, a surface film comprising an oxide of Fe and/or a complex oxide of Cr and Fe is formed on the surface of the heat transfer pipe. 【課題】ＰＷＲ運転中の伝熱管内からのＮｉ溶出を抑制し、ＡＯＡポテンシャルの低下や被ばく線量の上昇を抑制する方法及びシステムを提供する。【解決手段】Ｎｉ基合金からなる蒸気発生器の伝熱管の表面処理方法であって、前記伝熱管内に処理液を通流する工程と、前記処理液のｐＨを５．５以上６．５以下に調整する工程と、前記伝熱管の表面電位を０Ｖ．ｖｓ．ＳＨＥ以上に調整する工程とを備え、前記伝熱管の表面にＦｅの酸化物及び／又はＣｒとＦｅの複合酸化物からなる表面皮膜を形成する表面処理方法。【選択図】図１