Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 1 Niigataken Chuetsu-oki Earthquake and its Influences on the Kashiwazaki-Kariwa NPP

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 2 Summary of the Earthquake and Situation of the Kashiwazaki-Kariwa NPP Summary of the Earthquake –Occurrence: July 16, 2007 at 10:13 am JST –Earthquake Source: 17km below the seabed off Jo-chuetsu area in Niigata prefecture (37°33.4′North 、 138°36.5′East ） Epicenter Distance: 16km from the NPP –Magnitude: 6.8 Situation of the NPP –When the earthquake occurred: Unit 2 was in start-up Unit 3, 4 and 7 were in normal operation Unit 1, 5 and 6 were out of operation for the periodic inspections –Units 2, 3, 4 and 7 were automatically shut down following the high seismic acceleration trip signals Kashiwazaki-Kariwa NPP Niigata city Epicenter

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 3 Maximum Acceleration measured at Kashiwazaki-Kariwa NPP Maximum Acceleration at the Lowest Floor in the Reactor Building （ Unit: GAL ） Measured （ Designed ） Direction Unit 1Unit 2Unit 3Unit 4Unit 7Unit 6Unit 5 Direction S-N 311 (274) 304 (167) 308 (192) 310 (193) 267 (263) 271 (263) 277 (249) S-N E-W 680 (273) 606 (167) 384 (193) 492 (194) 356 (263) 322 (263) 442 (254) E-W Vertical 408 (235) 282 (235) 311 (235) 337 (235) 355 (235) 488 (235) 205 (235) Vertical

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 4 Rx. Coolant Temp. Unit 2 under Stat up Rx. Water Level 19:40 <100 ℃ Unit 3 100% Power 23:07 <100 ℃ Unit 4 100% Power 7/17 6:54 <100 ℃ Unit 7 100% Power 7/17 1:15 <100 ℃ Unit 1 Unit 5 Unit 6 Unit 2 Unit 3 Unit 4 Unit 7

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 5 Unit 1 RPV Inspection Schedule AugustSeptemberOctoberNovemberDecember Phase 1 Phase 2Phase 3 Visual inspection using under water TV camera 8/218/23

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 6 Unit 1 : Phase 1 Inspection Flange Guide Rod Feed Water Sparger Core Shroud Upper Grid Core Spray Pipe Core Spray Sparger As a result of phase 1 inspection, the abnormality such as the damage / transformation / the falling off was not confirmed.

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 7 Unit 1 : Flange Guide Rod Flange

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 8 Unit 1 :Guide Rod FW Sparger Guide Rod Core Spray Pipe

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 9 Unit 1 :Feed Water Sparger

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 10 Unit 1 :Core Spray Pipe

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 11 Unit 1 :Core Spray Sparger Core Spray Sparger Core Shroud(upper ring)

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 12 Unit 1 :Upper Grid LPRM

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 13 Unit 1 : RPV base bolts(A,As)

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 14 Unit 1 : Leakage of water into B5 floor Leakage of water into B5 floor of the reactor combination building (Unit 1) Leakage of water into B5 floor of the reactor combination building (Unit 1) Break of Fire Extinguishing Pipe (B,C) B1 Floor B2 Floor B3 Floor B4 Floor B5 Floor Sump Duct Reactor Combination Building Pene Water Flow-in

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 15 Unit 1 : Oil Tank (B,C) Land Subsidence

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 16 Unit 3 :Fire of House Transformer(1/3) As for the duct, cm dropped (B,C)

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 17 Unit 3 :Fire of House Transformer(2/3) Bedrock House Transformer Bus Duct 1 – 3 cm dropped 20 – 25 cm dropped

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 18 Unit 3 :Fire of House Transformer(3/3) Unit Unit 3 Main Transformer Unit 3 Main Generator House Transformer Start-up Transformer Emergency Bus Normal Bus Fire of House Trans. was not safety related problem

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 19 Unit 3 : DG(A,As) Upside Downside

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 20 Unit 3 : HCU (A,As) ( Hydraulic Control System (CRD))

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 21 Unit 3 : MSIV (A,As)

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 22 Unit 3 : PLR Pump (A,As)

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 23 Unit 3 : RHR Pump (A,As)

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 24 Unit 3 : Blow-out Panel came off (B,C)

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 25 Unit 3 : Displacement of the main exhaust duct (B,C)

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 26 Unit 6 : Leakage of water including radioactive materials Leakage of water including radioactive materials into non-controlled area in the reactor building (B,C)

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 27 Unit 6 : Leakage of water including radioactive materials Leakage of water including radioactive materials into non-controlled area in the reactor building

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 28 Motor Damaged Unit 6 : Damage of the reactor building overhead crane Damage found on the coupling of the drive axis of the reactor building overhead crane Damage found on the coupling of the drive axis of the reactor building overhead crane

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 29 Unit 7 : Detection of radioactive materials in the main exhaust duct Detection of radioactive materials in the main exhaust duct resulting from loss of the steam seal inside the turbine Main Exhaust Duct Monitoring House Main Exhaust Duct Filter Reactor Building Turbine Building Reactor Turbine Conden- ser Rare Gas Hold -up Equipment Turbine Gland Steam Exhauster Building Ventilation Still Working after Plant Shutdown

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 30 Other (B,C)

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 31 Solid waste storage warehouse

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 32 Influences of the Earthquake on the NPP Inspections have been performed from just after the earthquake, and the followings are main incidents found up to August 30. –Incidents related to radioactive materials Leakage of water including radioactive materials into non-controlled area in the reactor building (Unit 6) Flooding on the operating floor in the reactor building (Unit 1 ～ 7) Leakage of water into B5 floor of the reactor combination building (Unit 1) Displacement of the main exhaust duct (Unit 1 ～ 5) Detection of radioactive materials in the main exhaust duct (Unit 7) etc –Incidents not related to radioactive materials Damage found on the coupling of the drive axis of the reactor building overhead crane (Unit 6) Fire on the house transformer B (Unit 3) Deviations from LCO (Unit 1 ～ 3) Fall of the service platform into the spent fuel pool (Unit 1, 4) Fall down of drums (Solid waste storage warehouse) etc

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 33 The IAEA Mission to the NPP The objectives were to conduct a fact finding mission in relation to the current conditions at the nuclear power plant and to identify the preliminary lessons learned from the event. –Mission Date: August 6 to 10, 2007 –Location: Kashiwazaki-Kariwa NPP and NISA Headquarter etc –IAEA Review Team: Team Leader (Mr. Philippe Jamet, Director of the Division of Nuclear Installation Safety) and 5 international experts

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 34 Outlines of the IAEA Mission Report Based on the report release dated August 17 on the IAEA HP, main findings and lessons learned are as follows: –Operating plants were automatically shutdown and all plants behaved in a safe manner, during and after the earthquake. The three fundamental safety functions of (a) reactivity control, (b) removal of heat from the core and (c) confinement of radioactive materials were ensured. –Very minor radioactive releases to the environment were estimated to result in an individual dose well below the authorized limits. –Safety related structures, systems and components seem to be in a general condition much better than expected for such a strong earthquake. This is probably due to the conservatisms introduced at different stages of the design process. –In accordance with the new seismic guidelines, a re-evaluation of the seismic safety needs to be done taking into account the effects of the Niigataken Chuetsu-oki earthquake and the potential existence of active faults underneath the site. –The possibility that a component remains functionally available under normal operating conditions but sustains hidden damage, should be considered.

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 35 Approach for Further Actions (1/2) "Subcommittee for Investigation and Response to the Nuclear Facilities affected by Chuetsu-oki earthquake" will be established to make fact-finding on the detailed impacts of the earthquake on the power plant and to identify the responses and issues to be addressed by the government and nuclear operators. The Subcommittee will discuss the following items : –Operator's self-defense fire-fighting system, information communication system and information service for local communities during/after the earthquake –Seismic safety evaluation with account taken of lessons learned from the 2007 Niigataken Chuetsu-Oki Earthquake –Plant operational management and facility integrity during/after the earthquake the 2007 Niigataken Chuetsu-Oki Earthquake, and future actions –Other necessary items The Subcommittee will have 3 meetings by the end of September and one meeting a month from October and on.

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 36 Approach for Further Actions (2/2) The Nuclear and Industrial Safety Subcommittee, Advisory Committee for Natural Resource and Energy The Seismic and Structural Design Subcommittee Nuclear Emergency Preparedness Subcommittee Subcommittee for Investigation and Response to the Nuclear Facilities affected by Chuetsu-oki Earthquake WG on Operational Management and Facility Integrity Evaluation ( Provisional ) WG for Self-Defense Fire Fighting and Information Communication ( Provisional ) (existing) reportingadvice reporting To discuss operator's self- defense fire-fighting system, information communication system and information service for local communities during/after the earthquake To examine plant operational management and facility integrity during/after the earthquake and to discuss future actions

Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 37 Maximum Acceleration at the Base-Point of Japanese NPPs Unit: GAL Tomari NPP: 370 Kashiwazaki-Kariwa NPP:450 Shika NPP: 490 Tsuruga NPP: 532 Mihama NPP: 405 Takahama NPP: 370 Higashi-Dori NPP: 375 Onagawa NPP: 375 Fukushima Daiichi NPP: 370 Fukushima Daini NPP: 380 Tokai Daini NPP: 380 Sendai NPP: 372 Ikata NPP: 473 Hamaoka NPP: 600 Genkai NPP: 370 Ohi NPP: 405 Shimane NPP: 398