ISOEATC 2006 ALARA Workshop Our decontamination technologies for

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ISOE/ATC 2006 ALARA Workshop Our decontamination technologies for NPSs Tadasu Yotsuyanagi Advanced Chemistry &

ISOE/ATC 2006 ALARA Workshop Our decontamination technologies for NPSs Tadasu Yotsuyanagi Advanced Chemistry & Decontamination System Group Chemical System Design & Engineering Dept. Toshiba Corporation October 12, 2006 Copyright © 2006 Toshiba Corporation. All rights reserved.

ISOE/ATC 2006 ALARA Workshop Contents l Radiation exposure in BWR plants l What is

ISOE/ATC 2006 ALARA Workshop Contents l Radiation exposure in BWR plants l What is decontamination ? l Chemical decontamination ü T-OZON l Mechanical decontamination ü Jet Cleaning ü Zirconia Blast l Summary October 12, 2006

ISOE/ATC 2006 ALARA Workshop Behavior of Radioactivity in Reactor Water Materials of the primary

ISOE/ATC 2006 ALARA Workshop Behavior of Radioactivity in Reactor Water Materials of the primary system Corrosion Product n Reactor internals Activation Fuel crud Insoluble activity Crud activity Source (CRD, LPRM etc. ) Reactor Water Soluble activity RWCU Ionic activity Source (PLR & RWCU Piping) Radiation Exposure October 12, 2006

ISOE/ATC 2006 ALARA Workshop Source of Radioactivity in Reactor Water Material Crud Reactor Water

ISOE/ATC 2006 ALARA Workshop Source of Radioactivity in Reactor Water Material Crud Reactor Water Crud 54 Mn Ion  60 Co  58 Co 60 Co Material Oxide Film Ionic Activity Source Crud Activity Source Activation Reaction of Major Corrosion Product 59 Co (n, γ) 60 Co 58 Ni (n, p) 58 Co 70. 9 d 54 Fe(n, p) 54 Mn 312. 2 d 58 Fe(n, γ) 59 Fe 50 Cr(n, γ)51 Cr Half Life 5. 3 y 45. 1 d 27. 7 d October 12, 2006

ISOE/ATC 2006 ALARA Workshop Measures for Reducing Radiation Dose Rate in BWRs ○:Design Base

ISOE/ATC 2006 ALARA Workshop Measures for Reducing Radiation Dose Rate in BWRs ○:Design Base △:Partial Application or Retrofit *:In Consideration -:No Application Crud Generation Reduction & removal Impurity removal Radiation Dose Rate Level Reduction ACP Reduction Low Cobalt Material Water Control Surface Treatment ACP Removal Optimal Shielding Improvement of components & Systems Mechanical Decon. Chemical Decon. Corrosion Resistant Material Oxygen Injection Shutdown Lay-up Dual Condensate polishing Sys. RWCU Capacity Optimization Feedwater Heaters Core materials Others/SS & Stellite Ni/Fe Control Zn Injection Ultra Low Fe Control Fuel Springs Recirculation Piping RWCU Piping Fuel Out of Core Components System Equipments Drywell Reactor Building RWCU Pump Early Plant Newly Plant ABWR △ △/○ △ △ △ -/△ △ △ - * * △ △ - △ △ △ △ - ○ ○ ○ ○ △/○/- * △ △/○ -/○ ○ ○ ○ ○ - - - ○ - ○ October 12, 2006

ISOE/ATC 2006 ALARA Workshop Occupational Radiation Exposure in Japanese Plants October 12, 2006

ISOE/ATC 2006 ALARA Workshop Occupational Radiation Exposure in Japanese Plants October 12, 2006

ISOE/ATC 2006 ALARA Workshop Occupational Radiation Exposure Trend of Japanese BWRs October 12, 2006

ISOE/ATC 2006 ALARA Workshop Occupational Radiation Exposure Trend of Japanese BWRs October 12, 2006

ISOE/ATC 2006 ALARA Workshop What is Decontamination ? l Maintenance of high dose rate

ISOE/ATC 2006 ALARA Workshop What is Decontamination ? l Maintenance of high dose rate piping & equipment 1. Distance 2. Shield 3. Time 4. Removal of Source Decontamination October 12, 2006

ISOE/ATC 2006 ALARA Workshop Categories of Decontamination Chemical Dissolution of Oxide Film T-OZON, CORD

ISOE/ATC 2006 ALARA Workshop Categories of Decontamination Chemical Dissolution of Oxide Film T-OZON, CORD Electrochemical Re-use Radiation Build-up Tight films Loose Deposits Material Electro-chemical Dissolution of material W/O Contact Mechanical Removal of Deposits Jet-Cleaning, Blast Strong Chemical Dissolution of material strongly For Disposal Formic Acid October 12, 2006

ISOE/ATC 2006 ALARA Workshop Principle of Chemical Decontamination High Decontamination Factor (DF) Minimize Secondary

ISOE/ATC 2006 ALARA Workshop Principle of Chemical Decontamination High Decontamination Factor (DF) Minimize Secondary Waste Optimum Temp. , LV and Reagents Conc. Oxi. Cr Fe Red. Resins Oxidizing Reagents Ferrites Chromites Material Integrity of material Reducing Reagents To be Decomposed Cr. O 42 Fe 2+ Ion exchanger To RW system October 12, 2006

ISOE/ATC 2006 ALARA Workshop History of Chemical Decontamination in TOSHIBA 2001 First T-OZON for

ISOE/ATC 2006 ALARA Workshop History of Chemical Decontamination in TOSHIBA 2001 First T-OZON for re-use 2000 1997 Optimum method for various needs First T-OZON for disposal T-OZON First Full System Decon. (FSD) For NPSs 1990 s CORDTM Minimize Waste 1980 s TED-40 High DF Reduce Waste October 12, 2006

ISOE/ATC 2006 ALARA Workshop Principle of T-OZON Ferrites Chromates Reducing reagents:oxalic acid (COOH)2  Fe

ISOE/ATC 2006 ALARA Workshop Principle of T-OZON Ferrites Chromates Reducing reagents:oxalic acid (COOH)2  Fe 2 O 3+(COOH)2+ 4 H+ → 2 Fe 2++3 H 2 O+2 CO 2 Oxidizing reagents:Ozone Cr 2 O 3+3 O 3+2 H 2 O→ 2 Cr. O 42 -+4 H++3 O 2 Reagents decomposed easily Material Example of decontamination conditions Reducing : 95 o. C, 2000 ppm oxalic acid Oxidizing : 80 o. C, a few ppm ozone October 12, 2006

ISOE/ATC 2006 ALARA Workshop Main Features of T-OZON l High DF l Minimum Secondary

ISOE/ATC 2006 ALARA Workshop Main Features of T-OZON l High DF l Minimum Secondary waste volume l No adverse impacts on material integrity Volume of Secondary Waste Results of Lab. Tests Reagents Before DF > 100 Arb. unit Ozone = 1 ppm Mn After Fe TED-40 Fe Fe CORD T-OZON October 12, 2006

ISOE/ATC 2006 ALARA Workshop Experiences of Chemical Decon. in NPSs Number of Chemical Decon.

ISOE/ATC 2006 ALARA Workshop Experiences of Chemical Decon. in NPSs Number of Chemical Decon. In 13 BWRs, T-OZON applied to system decon. T-OZON CORD TED-40 ’ 80~‘ 85 ’ 85~‘ 90 ’ 90~‘ 95 ’ 95~‘ 00 ’ 00~ 05  October 12, 2006

ISOE/ATC 2006 ALARA Workshop Application to System Decon. in BWR PLR piping Before After

ISOE/ATC 2006 ALARA Workshop Application to System Decon. in BWR PLR piping Before After DF = 10 - 20 October 12, 2006

ISOE/ATC 2006 ALARA Workshop Categories of Decontamination Chemical Dissolution of Oxide Film T-OZON, CORD

ISOE/ATC 2006 ALARA Workshop Categories of Decontamination Chemical Dissolution of Oxide Film T-OZON, CORD Electrochemical Re-use Radiation Build-up Tight films Loose Deposits Material Electro-chemical Dissolution of material W/O Contact Mechanical Removal of Deposits Jet-Cleaning, Zirconia Blast Strong Chemical Dissolution of material strongly For Disposal Formic Acid October 12, 2006

ISOE/ATC 2006 ALARA Workshop Water Jet Cleaning Spiral nozzle Guide Pump Hose reel Nozzle

ISOE/ATC 2006 ALARA Workshop Water Jet Cleaning Spiral nozzle Guide Pump Hose reel Nozzle Filter Short period to get reasonable DF October 12, 2006

ISOE/ATC 2006 ALARA Workshop Zirconia Blasting Chamber l Main Features Exhaust Dust Nozzle Feeder

ISOE/ATC 2006 ALARA Workshop Zirconia Blasting Chamber l Main Features Exhaust Dust Nozzle Feeder Object Compressor Abrasive Compressed air Fraction (%) ü High repetition ü Good Separation ü High DF Duster Cyclone separator Diameter (um) October 12, 2006

ISOE/ATC 2006 ALARA Workshop Summary l Line-up of decontamination technologies ü Chemical Decontamination Ø

ISOE/ATC 2006 ALARA Workshop Summary l Line-up of decontamination technologies ü Chemical Decontamination Ø We promote T-OZON application to NPPs ü Mechanical Decontamination Ø Zirconia blast has high performance for reducing wastes l Future scope Decon. Equipment Inlet ü T-OZON application to FSD ü Application to Back-End Facilities Ø Decommissioning Ø Recycle Facilities MCR Clearance Monitor Zirconia Blast October 12, 2006