© Hitachi-GE Nuclear Energy, Ltd All rights reserved. コピーライトの表示については、作成元で責任を持って適宜変更してください。 ⇒ 2010 ISOE Asia ALARA Symposium Hitachi- ＧＥ Nuclear Energy, Ltd. Development of Hi-F Coat for Carbon Steel Piping H. Matsubara, N. Usui, M. Nagase Energy & Environmental Research Laboratory, Hitachi, Ltd. T. Ito, H. Hosokawa

© Hitachi-GE Nuclear Energy, Ltd All rights reserved. 1 M. Nagase, et al.,2009 ISOE Asian ALARA Symposium Low recontamination by Hi-F Coat was confirmed for Stainless Steel. １． Application result of Hi-F Coat for SS Hi-F Coat ; Hitachi Ferrite Coating NWC ; Normal water chemistry HWC ; Hydrogen water chemistry

© Hitachi-GE Nuclear Energy, Ltd All rights reserved. 2 CUW piping is one of the biggest sources of radiation exposure. 2 ． Enlargement of Hi-F Coat application area SystemMaterialProblemCountermeasure RRS ※ 1 SS ※ 3 ・ RI deposition Ｈｉ - Ｆ RWCU ※ 2 SS CS ※ 4 ・ RI deposition ・ Corrosion No method after chemical decon. 【 System and its countermeasure 】 60 Co in oxide film No treatment Hi-F Coat Decon. Recontaminatio n Operation Reduction Principal: Reduction of 60 Co deposition by reducing base metal corrosion 【 Countermeasure to reduce recontamination 】 ※ 1 ; Reactor recirculation system ※ 2 ; Reactor water clean up ※ 3 ; Stainless steel ※ 4 ; Carbon steel

© Hitachi-GE Nuclear Energy, Ltd All rights reserved. 3 Hi-F Coat procedure for SS is not applicable for CS. 3 ． Problem of Hi-F Coat for CS Oxidation Decomposition, clean-up KMnO 4 Repeat C2H2O4N2H4C2H2O4N2H4 Heat-up Reduction, clean-up Final clean-up Hi-F Coat treatment Decomposition Fe （ HCOO ） 2 H 2 O 2 N 2 H 4 【 Problem of film formation 】 SUS CS Base metal corrosion SUSCS Film amount （ μ ｇ /cm 2 ） ＨＯＰ method Hi-F Coat method 【 Procedure of Hi-F Coat 】

© Hitachi-GE Nuclear Energy, Ltd All rights reserved. 4 Higher pH is a key parameter to reduce CS corrosion. 4 ． Idea for Hi-F Coat procedure for CS Solution pH (-) Solution pH (-) Fe(HCOO) 2 H 2 O 2 & N 2 H 4 Film formatio n 【 Procedure of film formation for SS 】 CS corrosion rate （ g/m 2 /h ） Time Apply to CS ・ Surface corrosion ・ No film Countermeasure ・ Low corrosion at higher pH 【 Idea for film formation 】 Pure water BM BM ; Base Metal

© Hitachi-GE Nuclear Energy, Ltd All rights reserved. 5 5 ． Conditions of film formation Pure water １ ℓ N 2 bubblin g Heat up （ 90 ℃） Reaction Start Film formation 3 hours Test piece Chemical s Chemical conc. (ppm) 123 Former Ｆｅ (HCOO) 2 (300) H 2 O 2 (15) N 2 H 4 (600) New method Mixing all chemicals in advance Analysis Analysis method ・ Crystal structure ・・・・ X ray deflection ・ Binding status ・・・・ XPS ・ Film structure ・・・・ SEM ・ Film composition ・・・・ Raman spectrum ・・・・ Auger spectrum 【 Experimental apparatus 】 Ni 金属皮膜形成 【 Injection order and pH 】 7 4 Mixed chemicals F ｅ (HCOO) Former New method pH （ - ） N 2 gas pH TP 90 ℃ N 2 H 4, H 2 O 2

© Hitachi-GE Nuclear Energy, Ltd All rights reserved. 6 The new method enables to make a enough film amount on CS. 6 ． Film amount Former New method 2μm CS Ｈｉ - Ｆ Coat film Weight change （ μ ｇ /cm 2 ） Target film amount (90μg/cm 2 )

© Hitachi-GE Nuclear Energy, Ltd All rights reserved. 7 Fine mono layer of polycrystalline Fe 3 O 4 was identified. 7 ． Detail analysis of formed film 2μm CS Formed film Protect film for work Fe 3 O 4 BM Polycrystalline Fe 3 O 4 Raman shift (cm -1 ) Formed film Fe(OH) 3 Fe 2 O 3 Fe 3 O 4 Identified as Fe 3 O Fe 2+ Fe 3+ Existing ratio agrees with Fe 3 O 4 【 Cross section 】 【 Crystal structure 】 【 Film composition 】 【 Binding status 】 Relative strength

© Hitachi-GE Nuclear Energy, Ltd All rights reserved. 8 Test was performed under simulated NWC conditions. 8 ． Co deposition test conditions DO Demi. Cooler E. C. Hx. Pressure Control Valve Test section Temperature 280 ℃ Time500 h Pressure7.8 MPa Concentration (ppb) DO100 DH10 H2O2H2O2 200 Cr5 Co-6030 Test conditions （ NWC ） P P

© Hitachi-GE Nuclear Energy, Ltd All rights reserved Weight change Weight gain of CS was reduced to about 1/4 under simulated NWC.

© Hitachi-GE Nuclear Energy, Ltd All rights reserved Co-60 deposition Co-60 deposition on CS was reduced to about 40% under simulated NWC.

© Hitachi-GE Nuclear Energy, Ltd All rights reserved Summary Film formation method on CS was studied in order to reduce corrosion and Co-60 deposition and its effect was confirmed. 【 Results 】 ・ Film formation was realized by reducing CS corrosion. ・ Target film amount of 90 μg/cm 2 was realized. ・ Weight gain was reduced to about 1/4 by Hi-F coat film under simulated NWC. ・ Deposition amount of Co-60 was reduced to about 40% by Hi-F coat film under simulated NWC.

© Hitachi-GE Nuclear Energy, Ltd All rights reserved. 12