Niigataken Chuetsu-oki Earthquake and its Influences on the Kashiwazaki-Kariwa NPP

Summary of the Earthquake and Situation of the Kashiwazaki-Kariwa NPP 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

Rx. Coolant Temp. Rx. Water Level Unit 2 under Stat up 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 RPV Inspection Schedule August September October November December Phase 1 Phase 2 Phase 3 8/21 8/23 Visual inspection using under water TV camera

Unit 1 : Phase 1 Inspection Flange Upper Grid Guide Rod Feed Water Sparger Core Shroud 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.

Unit 1 : Flange Guide Rod Flange

Unit 1 :Guide Rod Guide Rod FW Sparger Core Spray Pipe

Unit 1 :Feed Water Sparger

Unit 1 :Core Spray Pipe

Unit 1 :Core Spray Sparger Core Shroud(upper ring) Core Spray Sparger

Unit 1 :Upper Grid LPRM

Unit 1 : RPV base bolts(A,As)

Unit 1 : Leakage of water into B5 floor 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 Leakage of water into B5 floor of the reactor combination building (Unit 1)

Unit 1 : Oil Tank (B,C) Land Subsidence

Unit 3 :Fire of House Transformer(1/3) (B,C) As for the duct, 16 - 18cm dropped

Unit 3 :Fire of House Transformer(2/3) Bedrock House Transformer Bus Duct 1 – 3 cm dropped 20 – 25 cm dropped

Unit 3 :Fire of House Transformer(3/3) 2 1 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

Unit 3 : DG(A,As) Upside Downside

Unit 3 : HCU (A,As)( Hydraulic Control System (CRD))

Unit 3 : MSIV (A,As)

Unit 3 : PLR Pump (A,As)

Unit 3 : RHR Pump (A,As)

Unit 3 : Blow-out Panel came off (B,C)

Unit 3 : Displacement of the main exhaust duct (B,C)

Unit 6 : Leakage of water including radioactive materials (B,C) Leakage of water including radioactive materials into non-controlled area in the reactor building

Unit 6 : Leakage of water including radioactive materials Leakage of water including radioactive materials into non-controlled area in the reactor building

Unit 6 : Damage of the reactor building overhead crane Motor Damaged Damage found on the coupling of the drive axis of the reactor building overhead crane

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

Other (B,C)

Solid waste storage warehouse