1. Introduction of the Decontamination Method Which Uses Blasting ISOE/ATC 2006/10/12 ALARA SYMPOSIUM Oct./12/2006 IN YUZAWA JAPAN

2. Contents 1. Outline 1. Outline Decontamination 2. History of Mitsubishi decontamination technologies 3. Decontamination using blasting 4. Cavitations jet (CJ) decontamination 5. CJ + blast decontamination 6. Revolving flow polishing method 7. Summary

3. 1. Outline 1. Outline Decontamination The purpose of decontamination Exposed reduction of a worker Loss in quantity of radioactive waste DF Configuration of an object （ structure, physical amount ） Schedule （ Time required ） The amount of secondary wastes Cost function of subject Area space Determination of the decontaminating method 1

4. 2. History of Mitsubishi decontamination technologies 2

5. 3. Decontamination using blasting ﾌﾞﾗｽﾄ材収ﾌﾞﾗｽﾄ材収 2 次ｻｲｸﾛﾝｾﾊﾟﾚｰﾀ Blaster （ Blast circulation system ） Vacume blast gun Blast tank (Vacuumed pressure) Recovery blower Blast equipment (primary cyclones separator ) Supply of air Bag filter dust sampler 3 facility which lifts Air pressure power control panel The control panel of a whole system Blaster Compressor Accumulator Drier Cooler Drier Filter Drum Drum with radiation shield Outdoors Blower Hose balancer R/V Hose balancer platform for shields Decontamination equipment R/V outlet shield plug R/V outlet nozzle neck

6. Nozzle （ Vacuumed blast gun ） Pipe （ nozzle neck mockup ） AIR Cylinder for forcing nozzle Guide roller 研削した跡 Functional examination situation 3. Decontamination using blasting 4

7. １． Decontamination equipment （１） Decontamination system ： Dryness type vacuumed blast （３） Guide system ： Trapezoid screw sending type nozzle rotation （４） Weight ： About ６００ kgf ／ set 2 ． Utilities （１） Used power supply ：ＡＣ２００Ｖ （２） Used air supply ： Station service air ０. ６ MPa 3. Decontamination using blasting main specifications 5

8. 3. Decontamination using blasting 6 alumina A ℓ 2 O 3 Glass SO 2 Boric IronSUS ParticleCut WireParticleCut Wire DFlargesmall middlelarge Remaining effects largemiddlesmalllargesmall Costlargesmall Damagelargesmall middlelarge Features of various blasting materials

9. Particle diameter of the blast materials ： Usual φ0.1 ～ 2mm Usual φ0.1 ～ 2mm ： Usua ｌ l5 ～ 6kg/cm 2 Blast pressure ： Usua ｌ l5 ～ 6kg/cm 2 ： Usual 45° ≦ Blast Angle ： Usual 45° ≦ 3. Decontamination using blasting Before （ × ２００） After 1-time use （ × ２００） The configuration before and after activity of blast material (stainless steel grid) Case of projection factory test to steel materials 7

10. When the amount of grinding is large When the amount of grinding is large ⇒ Reduction in thickness ⇒ Reduction in thickness Loss of a resisting pressure function Loss of a resisting pressure function 8.1 ～ 8.7μm/2times ， 13.3 ～ 15.1μm/3 times 8.1 ～ 8.7μm/2times ， 13.3 ～ 15.1μm/3 times When the amount of grinding is locally large When the amount of grinding is locally large ⇒ SCC ， Fatigue occurs ⇒ SCC ， Fatigue occurs Influence on the plant by remaining Influence on the plant by remaining （ Remainder of recovery ， Remainder of Pierced ） （ Remainder of recovery ， Remainder of Pierced ） They are 10cc remains at the blast of about 300ℓ They are 10cc remains at the blast of about 300ℓ 3. Decontamination using blasting The check of the soundness of target material 8

11. 4. Cavitations jet (CJ) decontamination  It compares with high-pressure water washing in mind, and is a high physical impulsive force efficiently ⇒ Compact equipment  With no pollution expansion of dust generating etc. into air because of underwater washing  With no influence which it has on lining in washing time of a decontamination level  Fundamentally, with no secondary waste by decontamination 9 bubbles Liquid Contraction avita Cavitation

12. Object PurposeBefore After DF Note Pit surface Pollution removal 22000 cpm 700 ～ 1200 cpm 18 ～ 30 ＣＪ＋ washing fuel rack cell inside Dose rate reduction 5.9 mSv/h0.9 mSv/h6.6 Underwater Measureme -nt data Track record ① Track record ② The part which has clad adhesion by contact to the fuel for a fuel extraction facility ＤＦ ２．１～１３．５（総平均８．８） Spent fuel pit surface of wall and fuel rack cell inside 4. Cavitations jet (CJ) decontamination 10

13. Before (Those with blackish brown clad) After (With no adhesion remains of clad) The application example to fuel extraction equipment 4. Cavitations jet (CJ) decontamination 11

14. High-pressure pump 長靴 Nozzle 2m About 6m Ｃ／Ｖ Ａ／Ｂ Pure water for work Lifting frame Track frame Transfer pipe Drain part washing Nearly drain Floor surface washing Operation floor Cavity Enforcement example ： Fuel transfer pit Outline specification  High-pressure pump ： 16MPa － 18L/min (Hand-pushed conveyance type)  Nozzle ： 10MPa － 4.4 L/min  Required utility ： The power supply for pumps 220V － 23A ， Water for washing about 4 ｍ 3 4. Cavitations jet (CJ) decontamination 12

15. The polish grain mixed in the cj grinding-removes adhered clad The decontamination effect higher than what added the decontamination effect of CJ and a blast simply 5. CJ + blast decontamination ［ Finishing patent application ］ ◎ Influence examination to in service equipment and apparatus ◎ Influence examination to in service equipment and apparatus ・ In a system application test, it affection-evaluates with a mock-up The faculty of a facility is not affected even if it executes for 30 The faculty of a facility is not affected even if it executes for 30 minutes minutes ◎ The faculty of a facility is not affected even if it executes 13

16. 5. CJ + blast decontamination crane control panel Blast grain suction nozzle Turn table Frame ＣＪ + stream Blast grain SGinsert plate When collecting Blast grains return line strainer Circulation pump ( Mono flex pump ) Surplus water return line Water recovery line Manometer Filter housing To air filter Air purge line フィルター Water drain line To floor drain High-pressure pump 22MPa,15 ℓ /min High-pressure pump feed line Nozzle feed device Container 14

17. 5. CJ + blast decontamination Before After 15 Applicability test with actual machine Object ： SG insert plate

18. 5. CJ + blast decontamination  The decontamination result in a system application test application test Notes : ( ) inside value is the dose rate to extracted Object BeforeAfter Decontami nation time D.F. Ｂ - ＳＧ ＨＯＴ40mSv/h(14.97mSv/h)0.7mSv/h(0.09mSv/h) 60 min. 166 Ｄ - ＳＧ ＣＯＬＤ25mSv/h(9.96mSv/h)0.63mSv/h(0.09mSv/h) 90 min. 111 16

19. 6. Revolving flow polishing method ［ Finishing patent application ］ 〈 Aim 〉 Inside contamination of long piping which has a crookedness part is decontaminated A revolution style is given to a flow Blast grain Blast grain In the conventional blasting, it checks that the piping crookedness part round which an Blast grain does not spread can also be decontaminated efficiently. 17

20. 6. Revolving flow polishing method The outline of the gas revolution flow grinding method 18 Principle of generating revolving flow Q1: Air to be used for revolving flow Q2: Air to be used for suppressing revolving flow Q3: Air to be used with abrasive Fluidics Abrasive Insertion typeRevolving flow type Tube to be decontaminationed Insert the sliding nozzle from tube end and make it move. Range of decontamination is small Sliding nozzle Tube to be decontaminationed Range of decontamination is small Butt tube ends Fixed nozzle Distances the revolving flow can reach Distance from nozzle outlet L (m) Characteristic between speed of abrasion and distance (Long tube) δ μ

21. 6. Revolving flow polishing method Since the flux which induces revolution speed is Q1, if a flux ratio becomes large, degree centrifugal force will become weaker and grinding speed will become small. Element examination 19 Average speed in piping Relation between grinding speed and the average flow velocity in piping Flux ratio Relation between grinding speed and a flux ratio If the average speed in piping is made quick, grinding speed will increase

22. 6. Revolving flow polishing method Separator Vacuum cleaner Fluidics ＊A＊A Oil pressure pump ＊ B ＊ C ＊F＊F ＊G＊G Discharge side （ Hot side ） Inhalation side （ Cold side ） Suction plug Seal plug Hopper 管 板 Preliminary recovery line Supply line Recovery line ＊D＊D Steam generator heat-exchangers tube inside decontamination equipment System composition figure ＊ A ： For blast material supply ＊ B ： For revolution style generating ＊ C ： For revolution style control ＊ D ： For hopper pressurization ＊ E ： For vibration ＊ F ： For discharge part seals ＊ G ： For inhalation part seals ＊E＊E Steam generator Channel head SG Heart exchanger tube ① Supply air former Pressure ： 0.5MPa ② amount of grinding airstreams ａ． For revolution style generating （ Q1 ）： 1200NL/min ｂ． For revolution style control （ Q2 ）： 400 NL/min ｃ． For grinding material supply （ Q3 ）： 180NL/min ③ Blast material ： 200μm Alumina grain ④ Decontamination time ： 40 分 System application examination 20 Seal plug Oil pressure pump

23.  Reduction of the amount of secondary generation wastes  Improvement in the speed of decontamination speed  Cost reduction  Radiation exposure reduction 7. Summary The needs for decontamination 【 Former is also from now on 】 21 The spirit of ALARA has been, and will be respected in our efforts forever.