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

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

2. Kashiwazaki-Kariwa NPP Niigata city Epicenter Summary of the Earthquake andSituation 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

3. Rx. Water Level Rx. Coolant Temp. Unit 2under Stat up 19:40 <100℃ Unit 3100% Power 23:07 <100℃ Unit 4100% Power 7/17 6:54 <100℃ Unit 7100% Power 7/17 1:15 <100℃ Unit 5 Unit 3 Unit 4 Unit 7 Unit 6 Unit 2 Unit 1

4. 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

5. 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.

6. Guide Rod Flange Unit 1 : Flange

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

8. Unit 1 :Feed Water Sparger

9. Unit 1 :Core Spray Pipe

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

11. LPRM Unit 1 :Upper Grid

12. Unit 1 : RPV base bolts(A,As)

13. Reactor Combination Building Pene B1 Floor Duct Water Flow-in B2 Floor B3 Floor B4 Floor B5 Floor Sump Unit 1 : Leakage of water into B5 floor Break of Fire Extinguishing Pipe (B,C) Leakage of water into B5 floor of the reactor combination building (Unit 1)

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

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

16. House Transformer Bus Duct 1 – 3 cmdropped 20 – 25 cmdropped Bedrock Unit 3 :Fire of House Transformer(2/3)

17. Start-up Transformer Unit 7 6 5 4 2 1 Unit 3 Main Transformer House Transformer Unit 3Main Generator Normal Bus Emergency Bus Unit 3 :Fire of House Transformer(3/3) Fire of House Trans. was not safety related problem

18. Upside Downside Unit 3 : DG(A,As)

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

20. Unit 3 : MSIV (A,As)

21. Unit 3 : PLR Pump (A,As)

22. Unit 3 : RHR Pump (A,As)

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

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

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

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

27. Motor 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

28. Building Ventilation Reactor Building Still Working after Plant Shutdown Turbine Building Main Exhaust Duct Filter Main Exhaust Duct Monitoring House Reactor Turbine Gland Steam Exhauster Turbine Conden-ser Filter Rare Gas Hold -up Equipment 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

29. Other (B,C)

30. Solid waste storage warehouse