1. CCTV System for Radiation Work Management Yonggwang NPP Unit 5 & 6

2. Contents Ⅰ. YGN Unit 5 & 6 Ⅱ. Brief Overview of Radiation Protection Ⅲ. Description of CCTV system Ⅳ. Cases for use of CCTV system Ⅴ. Effects Ⅵ. IAEA OSART Good Practice Ⅶ. Conclusion

3.  Type : PWR  Power Level : 1,050MWe  2 Loops, 2 S/Gs, 4 RCPs  177 Fuel Assy’s, 16 × 16 tubes  S/G : Vertical U-tube with Economizer  Condensor Heat Sink : Sea water □ Key Features Ⅰ. YGN Unit 5 & 6

4. Ⅱ. Brief Overview of Radiation protection □ Statutory Exposure Dose limit CategoryWorkersFrequent Visitors General Public Effective Dose Limit100mSv per 5 years12mSv per year1mSv per year □ Site Exposure Dose limit CategoryWorkersFrequent VisitorsGeneral Public Effective Dose Limit 16 mSv per year 10 mSv per year 1 mSv per year

5. Ⅱ. Brief Overview of Radiation protection [cont’d] □ Radiation Work Control Anticipated Exposure (man-mSv)Counter plan < 10 Review and check work order 10 ~ 70 Work Order Approval 70 ~ 200 ALARA Acting Level Committee Review > 200 ALARA Committee review

6. □ Collective Radiation Exposure Ⅱ. Brief Overview of Radiation protection [cont’d ] Year

7. Ⅲ. Description of CCTV system □ Purpose  Radiation Exposure Reduction  Efficient Radiation Safety Control in RCA  Continuous Check-up for important works and facilities integrity □ Characteristics  Real-time information by LAN  Movable Cameras can support important or high radiation work anywhere

8. Ⅲ. Description of CCTV system [cont’d] □ Composition Item# 5# 6RWB Monitoring System1 Set - Announcement System1 Set - Camera Fixed7 Sets 4 Sets Movable2 Sets - Data Cable3.3 Km 1.1 Km

9. Movable or Fixed Office Lobby Monitor HP Room Console lack LAN Ⅲ. Description of CCTV system [cont’d] □ Network

10. BuildingElevationLocation Details Main Function ACB100Locker Room AreaPrevention of robbery 100Entrance to RCACheck-up personnel coming in and out SAB100General Access Area “ 77General Access Area″ FHB100Truck Bay AreaCheck up entry and exit of equipment and person 142Storage Area″ PAB144Personal Airlock AreaControlling entry and exit in high radiation area RWB100Hot Machine ShopCheck-up personnel coming in and out 100Entrance of RCAControlling entry and exit in high radiation area 100Truck Bay AreaCheck-up entry and exit of equipment and person 70Access AreaCheck-up personnel coming in and out Ⅲ. Description of CCTV system [cont’d] □ Location (Fixed Camera)

11. Buildingelevation Number of jacks Main Function RCB 1002 Installation and removal of SG Nozzle dam Installation and removal of SG man-way ECT (Eddy current test) 1252 Maintenance of RCP and related works Lancing and FOSAR in secondary side of SG 1422 Reactor Maintenance fuel loading and withdrawal Check-up entry and exit of equipment and person Ⅲ. Description of CCTV system [cont’d] □ Location (Movable Camera)  Movable Cameras are communicated with main control center by using connecting jack

12. Ⅲ. Description of CCTV system [cont’d] □ View of Fixed Camera

13. Ⅲ. Description of CCTV system [cont’d] □ View of Movable Camera

14. Ⅲ. Description of CCTV system [cont’d] □ CCTV system Diagram PAB 144’ HP ROOM ACB 100’ LOCKER AREA ROOM ACB 100’ Entrance of RCA SAB 100’ GEN ACCESS AREA SAB 77’ GEN ACCESS AREA FHB 100’ TRUCK BAY AREA FHB 142’ STORAGE AREA PAB 144’ PERSONAL AIRLOCK AREA LINK FACILITY MATRIX SWITCHER MONITORING SERVER(DVR) KEYBOARD MONITOR to RWB 4SET 11SET LINK FACILITY

15. Ⅲ. Description of CCTV system [cont’d] □ HP Room Console Rack (Main control center)  Real time Monitoring all places where cameras are located.  Recording important works  Announcing  Auto Recording when any movement is detected.

16. Ⅲ. Description of CCTV system [cont’d] □ Monitoring in HP Room Console Rack All locations under surveillanceThe main work place

17.  Comparison (use or not) Ⅲ. Description of CCTV system [cont’d] WorkYear Number of workers Working Time (man-hr) Exposure Dose (man-mSv) CCTV use or not SG Nozzle Dam 20036110111.02Not 200652626.30Use ECT 20034351,04438.3Not 200629069823.41Use SG Man-way 2003831566.23Not 2006811774.33Use

18. Ⅳ. Cases for use of CCTV system □ Removal of remaining Thermal Sleeve (T/S)  2005.05 Unit 5 third Planned Outage (37 days) Case 1 During the first outage of unit 5, a metal object was discovered in the Reactor Bottom Head. (conformed by Remote Video Inspection). As a result of the specific inspection, three metal objects were discovered. These objects have been identified as missing thermal sleeves from the Safety Injection Nozzle. A remaining T/S was planned to be removed during the third Outage

19. Ⅳ. Cases for use of CCTV system Material : Inconel 690 Size (mm) : 304(W)×554(H)×4.5(T) Weight (kg) : 20Kg Dose rate (removal): 6mSv/hr

20. Ⅳ. Cases for use of CCTV system [cont’d] □ Monitoring T/S Work through CCTV System

21. Ⅳ. Cases for use of CCTV system [cont’d] □ Result of ALARA Control Target (mSv)Result (mSv)% Dose16073.9153.8  Reason of exposure Reduction Content Reduction Rate(%) Work control (Lead shielding and vest)10 Reduction of the Number of person( Effect of CCTV)10 Optimization of Working time (Effect of CCTV)6 Cancellation of some work28.8 SUM53.8

22. Ⅳ. Cases for use of CCTV system [cont’d] □ Effect of using CCTV System  Reduction of Exposure : 16 man-mSv (10%)  About 15 persons supervised the work through CCTV during the working period (11days) = persons x staying time x Radiation level in the area  Optimization of Working Time : 9.6 man-mSv (6%)  Reduction of Radioactive Waste : 1 Drum  About 220 pairs of Rubber gloves / paper protection Clothes

23. Ⅳ. Cases for use of CCTV system [cont’d] □ Maintenance of leak Valve (SI-V522) in SI System  Date : ’07. 7.17(unit 6 fourth outage)  Work Description At the time of NOT/NOP, SI- check Valve 522 of High Presser Safety injection Header leaked Piping was isolated throughout Ice plugging and Valve was Maintained CCTV System was used to monitor the maintenance work and ALARA Control Case 2

24. Ⅳ. Cases for use of CCTV system [cont’d] □ Result of ALARA Control Target (mSv)Result (mSv)% Dose6.695.7514  Number of workers : 16  Total working time : 6 hrs

25. Ⅴ. Effects  R R R Reduction of the number of person coming in and out  R R R Reduction of exposure dosage  R R R Reduction of radioactive waste  S S S Savings in protection supplies  R R R Real-time checkup in the office  R R R Radiation safety control in high radiation areas

26. Ⅵ. OSART GOOD PRACTICE □ IAEA OSART Review  Duration : 2007. 4.16 ~ 5.3  Reviewed items - 7 items besides management, organization, & administration sections of YGN 5&6  Result of review in Radiation Protection Section - 2 good practices out of 10 good practices (No proposal for improvement) - CCTV System was evaluated as “ Good Practice”  the other is RIS (Radiation Information System)

27. Ⅵ. Conclusion  R R R Radiation safety control is requisites for lasting nuclear industry  O O O Our various efforts will help to improve radiation safety control whether it is large or not  A A A Actually, CCTV system is small effort but the such effort will makes a good fruit Our will and endeavor should be followed

29. Maintenance of Leak Valve (SI-V522)

30. Maintenance of leak Valve (SI-V522)