1. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 1 Equipment Fragility Tests by JNES 11 March 2009 Incorporated Administrative Agency Japan Nuclear Energy Safety Organization ( JNES ) Seismic Safety Division Hiroshi ABE USNRC’s 21st Annual Regulatory Information Conference (RIC) Technical Session : “New Developments in Seismic Hazard Assessment”

2. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 2 Contents Ⅰ. Nuclear Safety Regulation in Japan Ⅱ. Major Subjects and typical items of JNES Seismic Safety Research Ⅲ. Fragility test for Assessment of Seismic Margin and Seismic PSA 1 Background 2 Test example 1st term : Electric panel 2nd term: Overhead crane Ⅳ. Summary

3. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 3 Ⅰ． Nuclear Safety Regulation in Japan METI, NISA Nuclear and Industrial Safety Agency Established in 2003, Staff: ～ 350 ・ Safety review ・ Licensing, etc. METI, NISA Nuclear and Industrial Safety Agency Established in 2003, Staff: ～ 350 ・ Safety review ・ Licensing, etc. NSCJ Nuclear Safety Commission of Japan Established in 1988, Staff: ～ 100 ・ Safety review ・ Regulatory guides NSCJ Nuclear Safety Commission of Japan Established in 1988, Staff: ～ 100 ・ Safety review ・ Regulatory guides JNES Japan Nuclear Energy safety Organization Established in 2006 Staff: ～ 460 ・ Support of review, inspection ・ R & D, etc. JNES Japan Nuclear Energy safety Organization Established in 2006 Staff: ～ 460 ・ Support of review, inspection ・ R & D, etc. Utilities Apply for permit Report Over- sight Report of cross check analysis Instruction of review Safety review Do Cross check analysis: Review the utility report technically as TSO of NISA Establish Seismic Safety Division in Oct.2007, after Niigataken Chuetsu-oki EQ Do Cross check analysis: Review the utility report technically as TSO of NISA Establish Seismic Safety Division in Oct.2007, after Niigataken Chuetsu-oki EQ 1

4. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 4 Ⅱ. Major Subjects and typical items of JNES Seismic Safety Research 1.Basic Ground Motion Ss, Deterministic Assessment for Structure Integrity Deterministic Assessment for Structure Integrity 1-1 Earthquake and Seismic Ground Motions 1-1 Earthquake and Seismic Ground Motions ◆ Observation of seismic motion in deep ground structure 1-2 Issue Accompanying Earthquakes 1-2 Issue Accompanying Earthquakes ◆ Slope/foundation soil-stability ◆ Tsunami-analysis including the sediment movement 1-3 Structure Integrity 1-3 Structure Integrity ◆ 3-D response assessment considering the flexibility of the building floor Integrity assessment considering aging 1-4 Integrity assessment considering aging

5. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 5 2. Residual Risk* Assessment （ External Events PSA ） * plant risk due to beyond design earthquake * plant risk due to beyond design earthquake 2-1 Seismic PSA 2-1 Seismic PSA ◆ ◆ Fragility test ◆ ◆ Risk assessment improvement in the multi-unit site ◆ ◆ Improvement of the measures for earthquake risk mitigation 2-2 Tsunami, Fire, and Flooding PSAs 2-2 Tsunami, Fire, and Flooding PSAs 3. Assessment for the Seismic Margin ◆ Quantitative assessment of the seismic margin ◆ Improvement of the loss-of-function assessment of the structure and equipment 4.Plant Integrity Assessment after Large Earthquake, ◆ Communication ◆ Communication establishment and plant restart procedures

6. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 6 6 198 5 199 0 199 5 200 0 2003/ 10 Phase Ⅰ（ Verification of Heavier Equipment ） Reactor containment, Pressure vessel, Core internals, etc. Phase Ⅱ（ Verification of Systems ） Emergency diesel generator system, Computer system, etc. Steam generator supported by vibration suppression supports, Ultimate strength of the piping system, etc. 198 0 2005/ 3 （４） Tank, Valve （５） Crane, Anchoring （６） Fan （７） Damping Test, etc. 2007 2008 1st term 200 2 2nd term 2012 Function Limit Test (Fragility Test) Ⅲ. Fragility test for Assessment of Seismic Margin and Seismic PSA （１） Horizontal Pump(RCW), Vertical Pump （ RHR ） （２） Control Rod Insertability (BWR,PWR ） （３） Electrical Panel Nuclear Power Engineering Corporation JNES 1st term JNES 2nd term Closure of the Tadotsu Shaking Table Amplifier of the Shaking Table (Horizontal, ３ g ⇒ ６ g ） Horizontal Pump Phase Ⅲ（ Verification of New Technologies and Functions Limit ）

7. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 7 1.Background of the tests Old Seismic Guide:1987 Revised Seismic Guide:2006 Prevent to become inducible factors of big accidents against all earthquakes to be assumed Cannot deny the possibility of occurrence of the earthquake which exceed assumed ones. “Residual risk” should be considered. Revision of Seismic Design Guide Investigation of Fragility Design Proving Shift of Objective of Tests

8. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 8 Background : Margin 中央値 Response Value to Chuetsu-oki EQ by Design Base Analysis Design Allowable Limit （ III AS : Elastic Limit) Allowance at Design Allowance at Chuetsu-oki Margin at Chuetsu-oki Allowable Design Limit （ IV AS : Functional Limit) 中央値 Margin at Design Functional Limit Median Actual Response at Design Design Response Median Actual Response to Chuetsu-oki EQ of SSCs Seismic Safety is Secured by the Design which has Certain Margin （「 Seismic Margin 」＝「 Functional Limit 」／「 Actual Response 」） （ Large ）

9. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 9 (1)Current Fragility Data Currently UsedIssue Estimation from Domestic Previous Research Thought to be smaller than the actual value, and may overestimate core damage frequency Partial Diversion of the U.S. Data Grasp Realistic Fragility Data for Accurate Seismic Margin Evaluation and Seismic PSA (2)Objective of Tests Current Fragility Values Large Fragility Value=Small Core Damage Freq. Small Large Small Image of Core Damage Frequency Evaluation Fragility Value Damage Probability Core Damage Freq. Background : Necessity of Fragility Test 0 0.2 0.4 0.6 0.8 1 012345 Functional Limit of Horizontal Shaft Pump(x9.8m/s 2 ) Core Damage Freq. （ Relative ）

10. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 10 Background : History of Test Method Investigation of Fragility and Functional Limit Proving of Seismic Design Test Objective ○Proving Test ： Shaking Test based on Design Response Spectra up to a Little Larger Level than Design Base ○Fragility Test Beyond Design Test to Acquire Fragility Data, using Sub- Table to Amplify Acceleration on Main Table. Up to 6G ○Functional Limit Test Shaking Test to Acquire Functional Limit or Fragility Curve Combining Partial Tests Test Method

11. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 11 Panel (partial model of real size) Mass (t) Main Control Board1.0 Reactor Auxiliary Board2.5 Logic Circuit Panel1.0 Reactor Protection Rack2.2 Instrumentation Rack0.7 Reactor Control Center0.6 Power Center4.0 6.9kV Metal-Clad Switch Gear 5.6 (1) Specimens (2) Input Motion and Test Condition ItemCondition Basic Excitation Motion Synthetic Motion Enveloped Actual Design Spectra (Max:1.2x9.8m/s 2 ) Excitation Level Basic to 6x9.8m/s 2 Electrical Condition Active Simulating Real Operating Condition Excitation Direction Front to Back and Side to Side 2 Test Example 1st term: Electric Panel

12. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 12 Actuator Amplification Table Spec. Max. Acce.6×9.8m/s2 Max. Pay-Load10ton -2.0 0.0 1.0 2.0 0.05.010.015.020.025.030.035.0 Time (sec) Acceleration (x9.8m/s 2 ) Panel Test: Power center and Control center Main Shaking Table Amplification Table

13. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 13 Element test for electric panel ItemCondition Basic Input MotionT.H. from Response Analysis of Panels Input LevelDesign Value to 10 x 9.8m/s 2 Electrical ConditionSame as Operation Condition Excitation DirectionFront to Bach and Side to Side Test Condition Differential Relay Modified Fuse Holder After Modification of Fuse Holder : Function Maintained up to 6x9.8m/s2 (Element Test) Drop off of Fuse at 2.5x9.8m/s 2 in Metal-Clad S.G. Test 2.3 Electric Panel Test Additional Element Test (Fuse of Metal-Clad Switch Gear)

14. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 14 Summary of 1st term SpecimenSummary of Test Concrete Containment- Boundary Integrity is Secured until Destruction of Concrete - Margin against S 2 : 6 Times for PCCV, 7 Times for RCCV Piping8.5 Times of Design Allowable (Pipe Break Occurred at Fifth Excitation of 8.5 S2 Test ) Electric Panels-No Abnormality in 6G Excitation for Main Control Board etc. -Malfunction Occurred in Some Panels around 2.5G Excitation, but Robustness can be Increased around 4G by Relatively Small Modification for Heavy Moving Parts or Fuse Holder Vertical Shaft PumpFunctional Integrity was Confirmed up to 12G at the Top of Motor Control Rod Insertion PWR ： Insertion Integrity was Confirmed up to 45mm Fuel Bundle Displacement BWR ： Insertion Integrity was Confirmed up to 80mm Fuel Bundle Displacement Horizontal Shaft PumpFunctional Integrity was Confirmed up to 8.4G Excitation

15. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 15 ■ Test Object ・ Overhead crane with garters, a trolley, a hanging load, lugs, etc. ■ Contents of the Test ● Component Tests （ in FY 2007 ） (1)Factor analyses of the functional limit (2)The mutual uplift and the collision assessment of garter/trolley/hanging load (3) The assessment of the restitution coefficient of wheels ● Reduced Scale Model Test ( in Oct. 2008) (1) Additional investigation point from NCE ⇒ Effect confirmation of the fall-prevention work （ lug ）, etc. (2) Analysis is ongoing. ・ Effectiveness of lugs was confirmed. ・ The uplift behavior was understood. ⇒ The nonlinear analysis of uplift mechanism for the vertical motions will be improved. The results will be applied to the integrity criteria in the seismic re- evaluation. Revised Seismic Design Review Guide requires assessment of dynamic vertical response. At the Chuetsu-oki Earthquake a overhead crane in the Kashiwazaki-Kariwa NPP was damaged. Fall-prevention Work （ Lug ） Garter Trolley Lug Rail Video of Whole View Video of Whole View Video of Wheel Part Video of Wheel Part 2nd term: Overhead Crane

16. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 16 Is Designed Function Maintained? How SSCs Response to Earthquake? How far can Design Endure? Where is Functional and Structural Limit? Evaluation of Residual Risk* * Risk due to beyond design earthquake Application of Fragility Test is; Ⅳ. Summary

17. Incorporated Administrative Agency Japan Nuclear Energy Safety Organization 17 Thank you for your attention After Niigataken Chuetsu-oki earthquake, JNES refined the road map of seismic safety research for; １． Earthquake ground motion evaluation 2. Residual risk assessment 3. Seismic margin assessment 4. After earthquake action Today I present outline of fragility test for item 2 and3. If we have next opportunity, we hope to report the updated status of these researches. We continue, through collaboration with NRC or the chance like RIC or contribution to IAEA seismic safety program, to inform and to share our data and knowledge to worldwide nuclear community.