2. 4. Results & Areas for Improvement 5. KHNP‘s Implementation Plan 3. Safety Review Overview1. Nuclear Power in Korea2. Outline of Fukushima Accident

3. Nuclear Power in Korea

4. 1970s1980s1990s2000s OPR1000 : Optimized Power Reactor 1000 APR1400 : Advanced Power Reactor 1400 2010s The first NPP Turn-key Localization Non-turn-key Technical Independence OPR1000 Construction APR1400 Construction APR+ Development Kori 1 Wolsong 1 Kori 2 Kori 3,4 Ulchin 1,2 Yonggwang 1,2 Yonggwang 3,4 Wolsong 2,3,4 Ulchin 3,4,5,6 Yonggwang 5,6 Shin-Kori 1 Shin-Kori 2(Constr.) Shin-Wolsong 1,2(Constr.) 1895 X-ray 1896 Rad. in Uranium 1942 First reactor, CP-1 Fission chain reaction success 1956 Calder Hall commenced operation 1995 HANARO Completion by Korean technology 1910 Einstein Published E=mc 2 1932 Discovered neutron 1938 Development of nuclear fission 1945 Hiroshima (death toll : 200,000) 1957 Shippingport commenced operation 1959 KAERI opened 1962 TRIGA MARK II Commenced operation 1978 Kori 1 Commenced operation Shin-Kori 3,4(Constr.) [First APR1400] Shin-Ulchin 1,2(Constr.) Localization of Core Technologies (Nu-tech 2012 Completion)

5. (31.8%) (9.8%) (25.5%) (9.6%) (23.3%) 17,716MW (40.8%) (5.3%) (20.3%) (2.2%) (31.3%) 148,596GWh Coal Gas Oil Others Coal Gas Oil Others Others : Hydroelectric, Renewal, etc. Source : KEPCO in Brief (2010 ) * Installed Capacity of Nuclear as of Feb. 2011 : 18.716 MW(23.9%) * Electricity generation considering the start-up of Shin-Kori # 1

6. Operation Construction Planning 21 Units 7 Units 6 Units 18,716MW 8,600MW 8,400MW Operation : 6 units Operation : 6 units Construction : 2 units Planning : 2 units Operation : 4 units Construction : 2 units Operation : 5 units Construction : 3 units Planning : 4 units Seoul Yonggwang NPP Kori NPP Wolsong NPP Ulchin NPP

7. ’93’94’95’96’97’98’9900’03’04’05’06’07’08’09’10’01’02 1.0 0.5 KoreaJapanFranceRussiaUSA World Avg. : 79.0% Source : Nucleonics Week (2011.6)(Year 2010. %) Stable Supply Chain through repeated construction Premier NPP Reliability proven by the world best operation performance Shortened construction duration via design standardization and the latest construction technology Economic advantage due to low construction cost “Korean NPPs have shown World-class safety and operational performance” CEO of ENEC Mohamed Al Hammadi Unplanned Shutdowns 0.1/unit_year

8. ※ Source : WNA(2011.1) (Unit : %) 100 89 79 70 68 57 60 65 63 61 58 55 53 52 (Unit : month) AP1000 (Sanmen 1,2) China (Lingao 2) Japan (Tomari 3) YG 3,4 UC 3,4 YG 5,6 UC 5,6 SK 1,2 SW 1,2 YG 3,4 UC 3,4 YG 5,6 UC 5,6 SK 1,2 F/C: First Concrete COD: Commercial Operation Date Based on construction cost of Yonggwang 3,4

9. Outline of Fukushima Accident

10. Unit123456 Capacity (MWe) 460784 1100 Commercial’71.3’74.7’76.3’78.10’78.4‘79.10 after Eq.Automatically trippedOutage in progress Unit1234 Capacity (MWe) 1,100 Commercial’82.4’83.2’85.6’87.8 after Eq.Automatically tripped √ distance from epicenter / resistance to earthquake(g) : 150km / 0.37g Fukushima I Fukushima II √ distance from epicenter / resistance to earthquake(g) : 160km / 0.37g 11 of 54 units around the epicenter automatically shut down Onagawa #1~3 units and Tokai #2 unit were automatically shut down

11. Earthquake Occurred Reactors Scrammed Emergency D/G Started up Station Black Out Due to Tsunami strike Fuels were superheated Due to Loss of Core Cooling Hydrogen Explosion Occurred All Motor Operated Pumps became inoperable due to Tsunami

12. Reactor, Spent Fuel Pool : Circulation Cooling in progress UnitCore Fuel Primary Containment Vessel Spent Fuel Temperature at Reactor vessel bottom FUKUSHIMA1FUKUSHIMA1 Unit 1 Core Melt 0.012MPag (400) Damage & Leakage suspected 23.0 ℃ (292) 76.5 ℃ [water injection : 3.6 ㎥ /hr] Unit 2 Core Melt 0.006MPag (548) Damage & Leakage suspected 25.0 ℃ (587) 91.8 ℃ [water injection : 10.8 ㎥ /hr] Unit 3 Core Melt -0.176MPag (548) Damage & Leakage suspected 23.5 ℃ (514) 76.1 ℃ [water injection : 10.2 ㎥ /hr] Unit 4 No fuels loadedNo damage 33.0 ℃ (1331) - Unit 5 23.8 ℃ 0.007MPag (548) No damage 26.9 ℃ (946) Heat removal of reactor is functioning Unit 6 22.6 ℃ 0.025MPag (764) No damage 27.0 ℃ (876) Heat removal of reactor is functioning ※ October 6, 2011 ※ RPV Bottom Temperature keeps decreasing below 100 ℃ since Sep 28

13. Unit 1(Installation of R/B Cover) Unit 2(No R/B damage) Unit 3(Removal of debris on top of R/B) Unit 4(Removal of debris)

14. Decommissioning of Reactor Remove Fuel From Reactor Remove Fuel From SFP Stable Cold Shutdown (below 100 ℃ ) Accident Mar 11, 2011 Jan, 2012 2014 2021 Decades later ※ Preventing release of radioactive materials ※ Transfer to a common storage place ※ Reactor Fuels were removed 6 years later in the TMI case ※ Require the development of Decommission Technology ※ Announced by TEPCO on July 10, 2011

15. Korean Nuclear Power Plant (PWR, Pressurized Water Reactor) Fukushima Nuclear Power Plant (BWR, Boiling Water Reactor) Steam is generated from SG Closed circuit primary system Low possibility of release of radioactive material to the atmoshere Steam is generated from RV RV and TBN are not separated High possibility of release of radioactive material to the atmosphere Turbine Containment Building CV Turbine Feed water Pump RCP Reactor Fuel Reactor Feed water Pump Steam Generator CV Containment Building

16. Safety Review Overview

17. KHNP Self Assessment : 21 nuclear units in operation : 2011.3.16 ～ 3.18 : Internal and external experts (44 inspectors from KHNP, KEPCO-ENC and KNFC) Inspection Overview Inspection Areas - Application - Duration - Inspection Team - On-off site power Integrity - Core cooling Integrity - Containment Integrity - Spent fuel pool Integrity

18. Special Safety Review by MEST* : 21 nuclear units in operation : 2011.3.28 ～ 4.13 : 73 External experts and KINS inspectors Safety review of domestic nuclear power facilities Safety review Areas - Application - Duration - Review Team - Safety of 6 areas and 27 provisions Close safety review for Kori #1 - Re-review of the evaluated safety areas for the approval of continued operation *MEST : Ministry of Education, Science and Technology

19. Safety of 6 areas considering the worst case scenario [Earthquake ⇒ Tsunami ⇒ SBO ⇒ Large Nuclear Accident] (1) Safety of structures and equipment against earthquake and tsunami (1) Safety of structures and equipment against earthquake and tsunami (2) Safety of electrical power and cooling system (2) Safety of electrical power and cooling system (3) Severe accidents (3) Severe accidents (4) Emergency response systems (4) Emergency response systems (5) Long-term operating NPPs and advanced NPPs (5) Long-term operating NPPs and advanced NPPs (6) Research reactor, nuclear fuel cycle facilities, and (6) Research reactor, nuclear fuel cycle facilities, and nuclear emergency medical center nuclear emergency medical center (6) Research reactor, nuclear fuel cycle facilities, and (6) Research reactor, nuclear fuel cycle facilities, and nuclear emergency medical center nuclear emergency medical center

20. Safety was verified for expected maximum earthquake and Safety was verified for expected maximum earthquake and tsunami based on up to date investigation and research tsunami based on up to date investigation and research The continued operation of Kori #1 was re-verified The continued operation of Kori #1 was re-verified and no safety-related problems were found and no safety-related problems were found Identified 50 short to long term improvements to secure safety, even for worst case events such as the Fukushima accident in Japan. (KHNP : 46, Other Institutions : 4) Identified 50 short to long term improvements to secure safety, even for worst case events such as the Fukushima accident in Japan. (KHNP : 46, Other Institutions : 4)

21. Results & Areas for Improvement

22. Results Improvements Improvements Improvement of reactor shutdown system in order for the reactor to automatically shutdown in case an earthquake whose magnitude is greater than 0.18g occurs. (for all units, 2013) Reevaluating seismic performance of safe shutdown systems such as shutdown cooling system, residual heat removal system, etc. and strengthening the system to a level of new reactor's design earthquake (0.3g). (for all units, 2014) ※ DBEs for OPR1000: 0.2g, for APR1400: 0.3g A comprehensive reassessment of maximum potential earthquake. (for all sites, 2013) Improvement of reactor shutdown system in order for the reactor to automatically shutdown in case an earthquake whose magnitude is greater than 0.18g occurs. (for all units, 2013) Reevaluating seismic performance of safe shutdown systems such as shutdown cooling system, residual heat removal system, etc. and strengthening the system to a level of new reactor's design earthquake (0.3g). (for all units, 2014) ※ DBEs for OPR1000: 0.2g, for APR1400: 0.3g A comprehensive reassessment of maximum potential earthquake. (for all sites, 2013) Sufficient safety margins exist for all units against maximum potential earthquake Goal : To secure safety against strong earthquake beyond design basis

23. Results Improvements Improvements To extend seawall of Kori site whose safety margin to tsunami is relatively low compared to the level of other sites (10 m). (for Kori site, 2012) To install water-proof doors and water-proof drain pump in relevant facilities to prevent flooding of emergency power systems and major safety systems. (for all units, 2014) A study and examination of maximum potential tsunami on the Korean peninsula. (for all sites, 2013) To extend seawall of Kori site whose safety margin to tsunami is relatively low compared to the level of other sites (10 m). (for Kori site, 2012) To install water-proof doors and water-proof drain pump in relevant facilities to prevent flooding of emergency power systems and major safety systems. (for all units, 2014) A study and examination of maximum potential tsunami on the Korean peninsula. (for all sites, 2013) Sufficient safety margins exist for all units against maximum potential sea levels (5.7 m~8.4 m) Units are located 10m above sea level for Yonggwang and Ulchin, 12m for Wolsong, 7.5m for Kori Units 1&2, and 9.5m for Kori Units 3&4 Goal : To secure safety against huge tsunami beyond design basis

24. Results Improvements Improvements To cope with flooding, a mobile car equipped with emergency generator and battery will be deployed in a safe place. (for each site, 2014) To cope with the loss of cooling for spent fuel pool, a countermeasure includes supplying makeup water using fire engines. (for all units, 2012) Improvement of design standard of AAC considering incidents in multiple reactors at the same site. (for all units, 2014) ※ e.g. - modification of capacity of alternative emergency diesel generator, diversification of cooling method (air & water cooling) for EDGs and AACs To cope with flooding, a mobile car equipped with emergency generator and battery will be deployed in a safe place. (for each site, 2014) To cope with the loss of cooling for spent fuel pool, a countermeasure includes supplying makeup water using fire engines. (for all units, 2012) Improvement of design standard of AAC considering incidents in multiple reactors at the same site. (for all units, 2014) ※ e.g. - modification of capacity of alternative emergency diesel generator, diversification of cooling method (air & water cooling) for EDGs and AACs Equipped with redundant power supply system To cope with loss of off-site power, 2 EDGs per unit + Alternative AC Multiple sources of water for emergency cooling of spent fuel pool Goal : To secure safety against site flooding and multi-unit power loss

25. Results Improvements Improvements To install passive hydrogen removal equipment to prevent hydrogen explosion. (for all units, 2013) To equip venting/depressurization devices to cope with pressure buildup in containment during severe accident. (for all units, 2015) To install coolant injection lines from outside the primary and secondary system for emergency cooling. (for all units, 2015) To strengthen education and training to enhance operator’s ability in case of severe accidents. (8hrs/2years→10hrs/year, all units, 2011) To install passive hydrogen removal equipment to prevent hydrogen explosion. (for all units, 2013) To equip venting/depressurization devices to cope with pressure buildup in containment during severe accident. (for all units, 2015) To install coolant injection lines from outside the primary and secondary system for emergency cooling. (for all units, 2015) To strengthen education and training to enhance operator’s ability in case of severe accidents. (8hrs/2years→10hrs/year, all units, 2011) Severe accident management guidelines had been prepared for all units Appropriate education and training for severe accident Various types of igniters or recombiners for hydrogen control in containment Goal : To secure safety against core melting from loss of core cooling

26. Results Improvements Improvements To secure additional radiation protection medicine (potassium iodide) and gas masks for residents near sites. (2012) ※ Prepared for population within 10km radius→ within 16km radius To modify the 'radiological emergency plan' for an emergency response organization to be set up considering multiple emergencies, and to have declaration criteria considering tsunami magnitude. (2011) To double the protective clothing, gas mask filters and radiation detection equipment to cope with a longer-lasting emergency situation. (2012) To secure additional radiation protection medicine (potassium iodide) and gas masks for residents near sites. (2012) ※ Prepared for population within 10km radius→ within 16km radius To modify the 'radiological emergency plan' for an emergency response organization to be set up considering multiple emergencies, and to have declaration criteria considering tsunami magnitude. (2011) To double the protective clothing, gas mask filters and radiation detection equipment to cope with a longer-lasting emergency situation. (2012) Appropriate emergency measures, including organization, facilities, protective action guidelines Regular educations and drills Designated medical treatment centers for radiation emergency Goal : To effectively respond to a worst case multi-unit accident

27. Results Improvements Improvements To add the issues regarding continued operation (monitoring the lifetime of major equipment, etc.) into the scope of periodic inspections. (2012) To shorten the period of in-service inspection on reactor vessel welds (10 years → 5 years) and to expand the scope of in-service inspection on major safety related piping (25% → 50%). (2012) To add the issues regarding continued operation (monitoring the lifetime of major equipment, etc.) into the scope of periodic inspections. (2012) To shorten the period of in-service inspection on reactor vessel welds (10 years → 5 years) and to expand the scope of in-service inspection on major safety related piping (25% → 50%). (2012) Continued operation of Kori unit 1 was permitted in May 2007 ※ Appropriate implementation of aging management program is verified by periodic inspection (every 12 months) Major evaluation items of continued operation (lifetime of equipment, pipes and penetrations of containment vessel, and reliability of emergency diesel generator) are managed appropriately Goal : To enhance safety control of long term operating NPPs

28. KHNP’s Implementation Plan

29. Application MEST’s requirements KHNP’s additions : 21 nuclear units in operation : 5 nuclear units under construction Duration NPPs in operation and under construction : 2011. 5 ~ 2015.12 Implementation 21 nuclear units in operation 5 nuclear units under construction : 46 Action items : 33 Action items

30. Post-Fukushima Task Force Organization and Operation Established to implement and manage progress Post-Fukushima Team was established on May 31, 2011 Check and Report Progress status meetings are subject to be held monthly Report to MEST(every half-year) and MKE(monthly) Plan to continuously derive additional improvements Through the review of Recommendations and Action Items of International Organizations and Other Countries & Through Self-Analysis and Review

31. Coastal Barrier Portable EDG Battery Pump Making the coastal barrier higher at Kori site Preparing a vehicle with a portable EDG at each site Installing watertight doors at EDG Building Securing the safety of emergency battery power from flooding Installing passive H 2 removal systems which operate without electricity 1 2 3 4 5 6 Installing exhaust and decompression equipment 7 1 billion USD investment over 5 years Improvements against natural disasters Containment Pressurizer S/G Reactor Control Rod Water-proofing Sump pumps Sea 46 short and long term plans

32. Enhancing public involvement and communication Allowing NPP private environmental monitoring organizations to observe the periodic NPP’s inspection on their request Holding periodic meetings with the local public to hear their opinions Amending the information disclosure procedure in the event of a radiological emergency - real-time information disclosure lists, radiation contamination, guide to protecting residents and the period of information disclosure