Evaluation of JNES Equipment 

Fragility Tests for Use in Seismic 

Probabilistic Risk Assessments 

for U.S. Nuclear Power Plants 

Office of Nuclear Regulatory Research 

NUREG/CR-7040

BNL-NUREG-94629-2011
Evaluation of JNES Equipment 

Fragility Tests for Use in Seismic 

Probabilistic Risk Assessments 

for U.S. Nuclear Power Plants 

Manuscript Completed: January 2011 

Date Published: April 2011 

Prepared by

R. Kennedy1

J. Nie and C. Hofmayer2 

1RPK Structural Mechanics Consulting

28625 Mountain Meadow Road

Escondido, CA 92026

2 Brookhaven National Laboratory

P.O. Box 5000

Upton, NY 11973-5000

S. Ali, NRC Project Manager 

NRC Job Codes N6076 and N6998

Office of Nuclear Regulatory Research

NUREG/CR-7040

BNL-NUREG-94629-2011

iii 

ABSTRACT 

The Japan Nuclear Energy Safety Organization (JNES) is conducting a multi-year equipment 

fragility test program to obtain realistic equipment fragility capacities for use in the seismic 

probabilistic risk assessments (SPRAs) of nuclear power plants (NPPs) in Japan. This test 

program started in 2002 and is planned to continue until 2012. The purpose of this test program 

is to improve the quality of the seismic fragility capacity database by determining realistic 

equipment fragility capacities from full-scale shaking table tests, and consequently to allow more 

accurate SPRAs to be performed to quantify the risk of NPPs during beyond-design-basis 

earthquakes. This test program reflects a philosophical shift from the design-proving test in the 

past that was intended to demonstrate the success of equipment under design basis or slightly 

larger earthquakes, to the current fragility test that determines the (ultimate) seismic capacity 

under beyond-design-basis earthquakes. This program consists of the test of a series of safety 

significant equipment, which are scheduled in two phases. Phase I includes large horizontal shaft 

pumps, large vertical shaft pumps, electrical panels, and control rod insertion capability and 

Phase II includes fans, valves, tanks, support structures, and overhead cranes. 

As part of collaborative efforts between the United States and Japan on seismic issues, the U.S. 

Nuclear Regulatory Commission (NRC) and Brookhaven National Laboratory (BNL) participated 

in this program by evaluating the results of the JNES equipment fragility tests. The goal of this 

research effort was to compare the JNES fragility results with the fragility data typically used in 

current U.S. SPRAs and assess the impact that the new test results may have on current SPRAs 

and how this data can be utilized for future SPRAs. The JNES fragility results are also useful for 

seismic margin analyses (SMAs), which are important in design certification (DC) or combined 

license (COL) applications because of the lack of full SPRAs at the DC or COL stage. This 

report summarizes the BNL evaluation of the JNES equipment fragility test data and provides 

insights on the applicability and application of this data in U.S. SPRA practices. 

v 

TABLE OF CONTENTS 

ABSTRACT ................................................................................................................................... iii

LIST OF FIGURES ...................................................................................................................... viii

LIST OF TABLES ........................................................................................................................ xii

EXECUTIVE SUMMARY .......................................................................................................... xiii

ACKNOWLEDGEMENTS ........................................................................................................ xvii

1 INTRODUCTION .................................................................................................................... 1

2 COMMON U.S. PRACTICE FOR ESTIMATING SEISMIC FRAGILITIES OF 

EQUIPMENT QUALIFIED BY TEST .................................................................................... 3

2.1 Introduction ........................................................................................................................ 3

2.2 Equipment Fragilities Based on Generic Data ................................................................... 4

2.3 Equipment Fragilities Based on HCLPF Screening Levels................................................ 5

2.4 Advanced Light Water Reactor “Achievable” Fragilities .................................................. 7

2.5 Comparison of Generic Fragility Estimates ....................................................................... 7

3 JNES EQUIPMENT FRAGILITY TESTS............................................................................. 11

3.1 Overview of the JNES Equipment Fragility Test Program .............................................. 11

3.2 Horizontal Shaft Pumps .................................................................................................... 13

3.2.1 Summary of Horizontal Shaft Pump Tests ............................................................ 13

3.2.1.1 Full Scale Test ................................................................................................... 13

3.2.1.2 Element Tests .................................................................................................... 14

3.2.2 Fragility Evaluation and Fragility Data ................................................................. 15

3.2.2.1 Fragility Evaluation for Active Function ........................................................... 15

3.2.2.2 Fragility Evaluation for Structural Strength ...................................................... 15

3.2.2.3 Summary of Fragility Data ................................................................................ 16

3.3 Electrical Panels ............................................................................................................... 16

3.3.1 Summary of Electrical Panel Tests ........................................................................ 16

3.3.1.1 Full Scale Tests.................................................................................................. 16

3.3.1.2 Element (Device) Tests ..................................................................................... 18

3.3.2 Fragility Evaluation and Fragility Data ................................................................. 18

3.4 Control Rod Insertion Capability ..................................................................................... 20

3.4.1 PWR Control Rod Insertion Capability ................................................................. 20

3.4.1.1 Full Scale Test ................................................................................................... 20

3.4.1.2 Fragility Evaluation and Fragility data .............................................................. 21

3.4.2 BWR Control Road Insertion Capability ............................................................... 21

3.4.2.1 Full Scale Test ................................................................................................... 21

3.4.2.2 Fragility Evaluation and Fragility Data ............................................................. 22

3.5 Large Size Vertical Shaft Pumps ...................................................................................... 23

3.5.1 Summary of Large Size Vertical Shaft Pump Test ................................................ 23

3.5.1.1 Full Scale Test ................................................................................................... 23

3.5.1.2 Element Tests .................................................................................................... 24

3.5.2 Fragility Evaluation and Fragility Data ................................................................. 25

3.5.2.1 Fragility Evaluation for Structural Strength ...................................................... 26
vi 

3.5.2.2 Fragility Evaluation for Rotation Function ....................................................... 27

3.5.2.3 Summary of Fragility Data ................................................................................ 27

4 EVALUATION OF JNES EQUIPMENT FRAGILITY TEST DATA .................................. 75

4.1 Introduction ...................................................................................................................... 75

4.2 Electrical Component Fragilities ...................................................................................... 77

4.3 Large Horizontal Shaft Pumps ......................................................................................... 79

4.4 Large Vertical Shaft Pump ............................................................................................... 81

4.5 Control Rod Insertion Capability ..................................................................................... 83

4.5.1 PWR Plants ............................................................................................................ 83

4.5.2 BWR Plants ........................................................................................................... 84

4.5.3 Applicability of Results for U.S. Fragility Assessments ....................................... 84

5 CONCLUSIONS .................................................................................................................... 87

5.1 Horizontal Shaft Pumps .................................................................................................... 87

5.2 Electrical Panels ............................................................................................................... 88

5.3 Control Rod Insertion Capability ..................................................................................... 89

5.4 Large Size Vertical Shaft Pumps ...................................................................................... 90

5.5 Summary .......................................................................................................................... 90

6 REFERENCES ....................................................................................................................... 93

Appendix A JNES FRAGILITY DATA OF EQUIPMENT FOR NUCLEAR 

FACILITIES BY SHAKING TESTS .................................................................................... A-I

Part-I Introduction ................................................................................................................. A-1 

1. Background of Study ............................................................................................... A-3 

1.1 Necessity of Fragility Data of Equipment ......................................................... A-3 

1.2 Fragility Capacity Evaluation Test of Equipment and Its Progress, and 

Positioning of the Report ................................................................................... A-3 

2. Evaluation Process for Fragility Capacity of Equipment ......................................... A-5 

Part-II Development of Fragility Data .................................................................................... A-7 

1. Outline ..................................................................................................................... A-9 

1.1 Outcome of Fragility Capacity Tests for Equipment ...................................... A-10 

1.1.1 Horizontal Shaft Pump .......................................................................... A-10 

1.1.2 Electrical Equipment ............................................................................. A-11 

1.1.3 Control Rod Inserting Capability .......................................................... A-12 

1.1.4 Large Size Vertical Shaft Pump ............................................................ A-14 

2. Evaluation Method of Fragility Capacity .............................................................. A-17 

2.1 Horizontal Shaft Pump .................................................................................... A-17 

2.2 Electrical Equipment ....................................................................................... A-25 

2.3 Control Rod Inserting Capability .................................................................... A-28 

2.4 Large Size Vertical Shaft Pump ...................................................................... A-33 

3. Fragility Data ......................................................................................................... A-47 

3.1 Horizontal Shaft Pump .................................................................................... A-48 

3.2 Electrical Equipment ....................................................................................... A-55 

3.3 Control Rod Inserting Capability .................................................................... A-79 

3.4 Large Size Vertical Shaft Pump ...................................................................... A-83 
vii 

4. Summary ................................................................................................................ A-93 

References .............................................................................................................................. A-95 

Appendix B ELECTRICAL PANEL TEST RESPONSE SPECTRA ..................................... B-1

B.1 Response Spectra Reported in September 2003 ............................................................. B-2

B.1.1 Reactor Control Center ........................................................................................ B-3

B.1.2 Power Center ....................................................................................................... B-6

B.1.3 Device Tests ........................................................................................................ B-9

B.2 Response Spectra Reported in July 2004 ......................................................................B-21

B.2.1 Main Control Board ............................................................................................B-22

B.2.2 Logic Control Panel ............................................................................................B-26

B.2.3 Protection Instrument Rack ................................................................................B-28

B.2.4 Instrument Rack ..................................................................................................B-31

B.2.5 Reactor Control Center .......................................................................................B-32

B.2.6 Power Center ......................................................................................................B-34

B.2.7 Metalclad Switchgear .........................................................................................B-37

B.2.8 Device Tests .......................................................................................................B-39

 
viii 

LIST OF FIGURES 

Figure 3-1 JNES Equipment Fragility Test Schedule ................................................................... 41

Figure 3-2 TADOTSU Shaking Table and the Amplification Device Table ................................ 41

Figure 3-3 RCW Pump Test Layout .............................................................................................. 42

Figure 3-4 Development of Envelop Floor Response Spectrum ................................................... 43

Figure 3-5 Basis Input Acceleration Time History Generated From Envelop FRS for 

Horizontal Shaft Pump Test ............................................................................................. 43

Figure 3-6 Response Spectra at the Top of the Amplification Table for Excitation Levels of 

2 g, 4g, and 6g in the Full Scale Horizontal Shaft Pump Test.......................................... 44

Figure 3-7 Change of Acceleration at Bearing Case With Respect to Input Acceleration ............ 45

Figure 3-8 Test Setup for Radial Ball Bearings ............................................................................ 45

Figure 3-9 Test Setup for Thrust Ball Bearings ............................................................................ 46

Figure 3-10 Surface Degradation of Bearings During Element Tests ........................................... 46

Figure 3-11 Analytical Models for Single Stage Horizontal Shaft Pump ..................................... 47

Figure 3-12 Analytical Models for Multi-stage Horizontal Shaft Pump ....................................... 48

Figure 3-13 Basis Input Acceleration Time History for Electrical Panel Tests ............................ 49

Figure 3-14 Illustration of Electrical Panels .................................................................................. 50

Figure 3-15 Test Setting for Electrical Panels ............................................................................... 51

Figure 3-16 Comparison of Front-Back 6 g Level Response Spectra for Reactor Control 

Center Test ....................................................................................................................... 52

Figure 3-17 Gas Circuit Breaker Installed on a Support Frame in Element Test .......................... 52

Figure 3-18 JNES Target Range of the Fragility Tests ................................................................. 53

Figure 3-19 Test Setup for PWR Control Rod Insertion System .................................................. 53

Figure 3-20 Mockup of A PWR Fuel Assembly ........................................................................... 54

Figure 3-21 Section View of the Test Setup for PWR Control Rod Insertion System .................. 55

Figure 3-22 Layout of 3 PWR Fuel Assemblies............................................................................ 55

Figure 3-23 Synthesized Wave for Full-Scale Test of PWR CRDM ............................................ 56

Figure 3-24 Filtered Wave for Fuel Excitation ............................................................................. 56

Figure 3-25 Comparison of PWR CRDM Target Input and Shaking Table Response (Still 

Water) ............................................................................................................................... 57

Figure 3-26 Comparison of PWR CRDM Target Input and Shaking Table Response (With 

Core Flow) ........................................................................................................................ 57

Figure 3-27 Comparison of PWR CRDM Target Input and Upper Core Plate Response (Still 

Water) ............................................................................................................................... 58

Figure 3-28 Comparison of PWR CRDM Target Input and Lower Core Plate Response (Still 

Water) ............................................................................................................................... 58

Figure 3-29 Comparison of PWR CRDM Target Input and CRDM Base Response (Still 

Water) ............................................................................................................................... 59

Figure 3-30 Comparison of PWR CRDM Target Input and Upper Core Support Plate 

Response (Still Water) ...................................................................................................... 59

Figure 3-31 Delay Ratio of PWR Control Rod Insertion .............................................................. 60

Figure 3-32 Test Setup for BWR Control Rod Insertion System .................................................. 60
ix 

Figure 3-33 Mockup of A BWR Fuel Assembly ........................................................................... 61

Figure 3-34 Section View of the Test Setup for BWR Control Rod Insertion System ................. 62

Figure 3-35 Layout of a BWR Fuel Assembly .............................................................................. 62

Figure 3-36 BWR CRDM Basis Input Wave C with Center Frequency 4.8 Hz ........................... 63

Figure 3-37 BWR CRDM Basis Input Wave C with Center Frequency 5.8 Hz and 10% 

broadening ........................................................................................................................ 63

Figure 3-38 Comparison of BWR Target Input and Shaking Table Response ............................. 64

Figure 3-39 Delay Ratio of BWR Control Rod Insertion .............................................................. 64

Figure 3-40 Test Setup for Vertical Shaft Pump ........................................................................... 65

Figure 3-41 Section View of the Test Setup for Vertical Shaft Pump .......................................... 66

Figure 3-42 Response Spectrum for A-Wave................................................................................ 67

Figure 3-43 Response Spectra for D-Wave (Horizontal) .............................................................. 67

Figure 3-44 Response Spectra for D’-Wave (Horizontal) ............................................................. 68

Figure 3-45 Comparison of A, D, and D’ Waves .......................................................................... 68

Figure 3-46 Response Spectra for Vertical Wave ......................................................................... 69

Figure 3-47 Liner Ring and Shaft Bearing .................................................................................... 69

Figure 3-48 Illustration of Shaft Bearing and the Nonlinear Load-Displacement Behavior ......... 70

Figure 3-49 Structural Types of Large Size Vertical Shaft Pumps ............................................... 70

Figure 3-50 Similar Structural Features of Vertical Mixed Flow Pump and Pit Barrel Type 

Pump ................................................................................................................................. 71

Figure 3-51 Equivalent Linear Stiffness of Barrel Support .......................................................... 71

Figure 3-52 Calculation of Impulsive Force.................................................................................. 72

Figure 3-53 Stick Model for the Pit Barrel Type Pump ................................................................ 73

Figure 3-54 Two Mass Model for the Vertical Response Analysis for the Vertical Shaft 

Pumps ............................................................................................................................... 74

Figure B-1 Reactor Control Center Test – Child Table RS – 5 g (Side to Side) ......................... B-3

Figure B-2 Reactor Control Center Test – Base Plate RS – 5 g (Side to Side) ........................... B-3

Figure B-3 Reactor Control Center Test – Panel RS at the Installation Point of Magnetic 

Contactor – 5 g (Side to Side) ........................................................................................ B-4

Figure B-4 Reactor Control Center Test – Child Table RS – 5 g (Back to Forth) ...................... B-4

Figure B-5 Reactor Control Center Test – Base Plate RS – 5 g (Back to Forth) ........................ B-5

Figure B-6 Reactor Control Center Test – Panel RS at the Installation Point of Magnetic 

Contactor – 5 g (Back and Forth) ................................................................................... B-5

Figure B-7 Power Center Test – Child Table RS – 4 g (Side to Side) ........................................ B-6

Figure B-8 Power Center Test – Base Plate RS – 4 g (Side to Side) .......................................... B-6

Figure B-9 Power Center Test – Panel RS at the Installation Point of the Ratio Differential 

Relay – 4 g (Side to Side) ............................................................................................... B-7

Figure B-10 Power Center Test – Child Table RS – 3 g (Back and Forth) ................................. B-7

Figure B-11 Power Center Test – Base Plate RS – 3 g (Back and Forth) ................................... B-8

Figure B-12 Power Center Test – Panel RS at the Installation Point of the Ratio Differential 

Relay – 3 g (Back and Forth) ......................................................................................... B-8

Figure B-13 Ratio Differential Relay (MELCO TUB-2-D) ........................................................ B-9
x 

Figure B-14 Over Current Relay (MELCO CO-18-D) ............................................................... B-9

Figure B-15 Auxiliary Relay (MELCO NRD-81) ......................................................................B-10

Figure B-16 Comparator Card (MELCO HALN) ......................................................................B-10

Figure B-17 AC Controller Card (MELCO HASN) ..................................................................B-11

Figure B-18 Power Supply Equipment (MELCO -) ...................................................................B-11

Figure B-19 Magnetic Contactor (MELCO MSO-A80) ............................................................B-12

Figure B-20 Breaker for Wiring (MELCO NF-100-SH) ............................................................B-12

Figure B-21 Module Switch (MELCO SSA-SD3-53) ...............................................................B-13

Figure B-22 Over Current Relay (Toshiba VCR520) and Auxiliary Relay (Toshiba UP3A) ....B-13

Figure B-23 Controller (Toshiba TOSMAP) .............................................................................B-14

Figure B-24 I/O Unit (Toshiba TOSMAP).................................................................................B-14

Figure B-25 Power Supply Equipment (Toshiba TFV) ..............................................................B-15

Figure B-26 Differential Pressure Transmitter (Toshiba AP3107) ............................................B-15

Figure B-27 Magnetic Contactor (Toshiba C-20J, T-20J) and Breaker for Wiring (Toshiba 

SH100) ..........................................................................................................................B-16

Figure B-28 Auxiliary Relay (HITACHI MY4Z), Timer (HITACHI H3M), and Breaker for 

Wiring (HITACHI F type) ............................................................................................B-16

Figure B-29 Flat Display (HITACHI 18” type) .........................................................................B-17

Figure B-30 Controller Display (HITACHI 18” type) ...............................................................B-17

Figure B-31 Differential Pressure Transmitter (HITACHI EDR-N6) ........................................B-18

Figure B-32 Pressure Transmitter (HITACHI EPR-N6) ............................................................B-18

Figure B-33 Cam Type Switch (HITACHI MS type) and Key Switch (HITACHI ACSNK 

type) ...............................................................................................................................B-19

Figure B-34 Test Module (S9186AW), Power Supply Module (S9016AW), and Monitor 

Module (S9146AW), All Produced by Yokogawa Electric Co. ....................................B-19

Figure B-35 Power Supply Module (S9980UD), Produced by Yokogawa Electric Co. ............B-20

Figure B-36 Differential Pressure Transmitter (UNE13), Produced by Yokogawa Electric Co.

 .......................................................................................................................................B-20

Figure B-37 Main Control Board Test – Base Plate RS – 6 g ....................................................B-22

Figure B-38 Reactor Auxiliary Panel – Base Plate RS – 6g ......................................................B-23

Figure B-39 Reactor Auxiliary Panel Sensor Location ..............................................................B-24

Figure B-40 Reactor Auxiliary Panel – Panel RS – 6 g (Side to Side) ......................................B-24

Figure B-41 Reactor Auxiliary Panel – Panel RS – 6 g (Back and Forth) .................................B-25

Figure B-42 Logic Control Panel – Base Plate RS – 6 g ............................................................B-26

Figure B-43 Logic Control Panel – Panel RS – 6 g (Side to Side) .............................................B-27

Figure B-44 Logic Control Panel – Panel RS – 6 g (Back and Forth) .......................................B-27

Figure B-45 Protection Instrument Rack – Base Plate RS – 6 g ................................................B-28

Figure B-46 Protection Instrument Rack – Rack RS – 4 g (Side to Side) ..................................B-29

Figure B-47 Protection Instrument Rack – Rack RS – 4 g (Back and Forth) ............................B-29

Figure B-48 AC Controller Card – 7 g Excitation (Non-malfunction) ......................................B-30

Figure B-49 AC Controller Card – 7.1 g Excitation (Malfunction) ...........................................B-30

Figure B-50 Instrument Rack – Base Plate RS – 6 g ..................................................................B-31
xi 

Figure B-51 Reactor Control Center – Base Plate RS – 6 g .......................................................B-32

Figure B-52 Reactor Control Center – Panel RS – 6 g (Side to Side) ........................................B-33

Figure B-53 Reactor Control Center – Panel RS – 6 g (Back and Forth) ..................................B-33

Figure B-54 Power Center – Base Plate RS – 6 g ......................................................................B-34

Figure B-55 Power Center – Panel RS – 6 g (Side to Side) .......................................................B-35

Figure B-56 Power Center – Panel RS – 6 g (Back and Forth) ..................................................B-35

Figure B-57 RS of Ratio Differential Relay (TUB-2-D), Malfunctioned in 6 g Full Scale 

Power Center Test (Back and Forth, 10.9 g) .................................................................B-36

Figure B-58 Metalclad Switchgear – Base Plate RS – 6 g .........................................................B-37

Figure B-59 Metalclad Switchgear – Panel RS – 3 g (Side to Side) ..........................................B-38

Figure B-60 Metalclad Switchgear – Panel RS – 3 g (Back and Forth) .....................................B-38

Figure B-61 RS at Installation Points for Test Module (MHI S9166AW), Power Supply 

Module (MHI S9016AW), and Monitor Module (MHI S9146AW) .............................B-39

Figure B-62 RS at Installation Points for Power Supply Equipment (MHI S9980UD) and 

Diode Unit (S9154UT) ..................................................................................................B-40

Figure B-63 RS for Differential Pressure Transmitter (MHI UNE13) .......................................B-41

Figure B-64 RS of Recorded Time History for Feed Breaker (DS-416) in Power Center – 5 g B-42

Figure B-65 RS of Recorded Time History for Feed Breaker (DS-416) in Power Center – 6 

g .....................................................................................................................................B-42

Figure B-66 RS for Feed Breaker (DS-416) in Power Center – Malfunction ............................B-43

Figure B-67 RS for Feed Breaker (DS-416) in Power Center – Normal Function ....................B-43

Figure B-68 RS for Feed Breaker (DS-416) in Power Center ....................................................B-44

Figure B-69 RS for Feed Breaker (DS-416) in Power Center ....................................................B-44

Figure B-70 Test Module (MHI S9166AW), Power Supply Module (MHI S9016AW), and 

Monitor Module (MHI S9146AW) – Recorded Wave 10 g (Side to Side) ...................B-45

Figure B-71 Test Module (MHI S9166AW), Power Supply Module (MHI S9016AW), and 

Monitor Module (MHI S9146AW) – Recorded Wave 10 g (Back and Forth) .............B-45

Figure B-72 Test Module (MHI S9166AW), Power Supply Module (MHI S9016AW), and 

Monitor Module (MHI S9146AW) – Predicted Wave 10 g (Side to Side) ...................B-46

Figure B-73 Power Supply Equipment (MHI S9980UD) and Diode Unit (MHI S9154UT) – 

Recorded Wave 10 g (Side to Side) ..............................................................................B-46

Figure B-74 Power Supply Equipment (MHI S9980UD) and Diode Unit (MHI S9154UT) – 

Recorded Wave 10 g (Back and Forth) .........................................................................B-47

Figure B-75 Power Supply Equipment (MHI S9980UD) and Diode Unit (MHI S9154UT) – 

Predicted Wave 10 g (Side to Side) ...............................................................................B-47

Figure B-76 Power Supply Equipment (MHI S9980UD) and Diode Unit (MHI S9154UT) – 

Predicted Wave 10 g (Back and Forth) .........................................................................B-48

Figure B-77 Differential Pressure Transmitter (MHI UNE13) – Recorded Wave 10 g (Side 

to Side) ..........................................................................................................................B-48

Figure B-78 Differential Pressure Transmitter (MHI UNE13) – Recorded Wave 10 g (Back 

and Forth) ......................................................................................................................B-49
xii 

LIST OF TABLES 

Table 2-1 Device Capacity Factors ................................................................................................. 8

Table 2-2 Estimated Generic Fragilities for Electrical Equipment ................................................. 8

Table 2-3 Cabinet Amplification Factors ........................................................................................ 9

Table 2-4 “Function During” Spectral Acceleration SA Fragility for Pneumatic Timing Type 

Auxiliary Relay Panel Mounted in 15 Hz Control Cabinet ................................................ 9

Table 2-5 Generic “Function After” Spectral Acceleration SA Fragility Levels in Terms of 

Component Input Motion Based on Screening Levels ....................................................... 9

Table 2-6 “Function During Achievable” Spectral Acceleration .................................................. 10

Table 2-7 Comparison of Generic Fragilities for Typical Electrical Cabinets .............................. 10

Table 3-1 Types of Horizontal Shaft Pumps in Japan NPPs ......................................................... 29

Table 3-2 Element Types for Horizontal Shaft Pumps .................................................................. 29

Table 3-3 Summary of Selected Critical Values for the Fragility Evaluation ............................... 30

Table 3-4 Summary of Fragility Data for Horizontal Shaft Pumps ............................................... 31

Table 3-5 Summary of Fragility Data for Ball Bearings used in Horizontal Shaft Pumps ........... 31

Table 3-6 Summary of Fragility Data for Slide Bearings used in Horizontal Shaft Pumps .......... 32

Table 3-7 Summary of Fragility Data for Liner Rings used in Horizontal Shaft Pumps .............. 32

Table 3-8 Properties of the Tested Electrical Panels ..................................................................... 33

Table 3-9 Electrical Parts in JNES Element Tests and Fragility Data .......................................... 34

Table 3-10 Summary of Fragility Data for Electrical Panels ........................................................ 36

Table 3-11 Selected Results for the Full-scale Vertical Shaft Pump Test ..................................... 37

Table 3-12 Element Types for Large Size Vertical Shaft Pumps .................................................. 38

Table 3-13 Summary of Fragility Data for Large Size Vertical Shaft Pumps (Horizontal 

Vibration) ......................................................................................................................... 39

Table 3-14 Summary of Fragility Data for Large Size Vertical Shaft Pumps (Vertical 

Vibration) ......................................................................................................................... 39

Table 3-15 Summary of Fragility Data for Bearings and Liner Rings used in Large Size 

Vertical Shaft Pumps ........................................................................................................ 40

Table 4-1 JNES Fragilities for Electrical Components ................................................................. 86
xiii 

EXECUTIVE SUMMARY 

This report presents an assessment of the equipment fragility test program performed by the Japan 

Nuclear Energy Safety Organization (JNES). JNES is carrying out a multi-year equipment 

fragility test program to obtain realistic equipment fragility capacities for use in the seismic 

probabilistic risk assessments (SPRAs) of nuclear power plants (NPPs) in Japan. The JNES 

equipment fragility test program started in 2002 and is planned to continue until 2012. The 

purpose of the JNES equipment fragility test program is to improve the quality of the seismic 

fragility capacity database by determining realistic equipment fragility capacities from full-scale 

shaking table tests, and consequently to allow more accurate SPRAs to be performed to quantify 

the risk of NPPs during beyond-design-basis earthquakes. 

As part of collaborative efforts between the United States and Japan on seismic issues, the U.S. 

Nuclear Regulatory Commission (NRC) and Brookhaven National Laboratory (BNL) participated 

in the JNES program by evaluating the results of the JNES equipment fragility tests. The goal of 

this research effort was to compare the JNES fragility results with the fragility data typically used 

in current U.S. SPRAs and to assess the impact that the new test results may have on current 

SPRAs and how this data can be utilized for future SPRAs. The JNES fragility results are also 

useful for seismic margin analyses (SMAs), which are important in design certification (DC) or 

combined license (COL) applications because of the lack of full SPRAs at the DC or COL stage. 

All of the test results and information about the test equipment included in this report were 

provided by JNES to NRC/BNL. The unique advantage of this particular collaborative effort is 

obvious because of the rareness of full-scale high-level seismic equipment fragility data. 

Seismic equipment fragilities, representing the seismic capacities of the equipment and the 

associated uncertainties, are the fundamental ingredient in SPRAs. The quality of seismic 

fragility capacity directly affects the quality of SPRAs in quantifying the risk of NPPs during 

beyond-design-basis earthquakes. The need for high quality seismic equipment fragility data led 

to many industry and U.S. NRC sponsored research programs, the results of which are still being 

applied in current SPRAs. Fragility capacities and the associated uncertainties of the most critical 

equipment items have historically been derived from qualification test data from equipment 

vendors. However, in situations when specific qualification data may not be readily available, 

generic component capacity data are commonly used. For various electrical components and 

relays, the Generic-Equipment-Ruggedness-Spectra (GERS) and the high confidence low 

probability of failure (HCLPF) capacities can be found in various industry and NRC publications. 

For many Central and Eastern U.S. (CEUS) SPRAs, the seismic fragilities of less critical 

components have been based on the HCLPF screening levels. These U.S. fragility data are all 

based on pre-1990 vintage components. The applicability of this data for modern components 

will depend upon the amount of changes that have occurred for any particular component class 

since 1990. More recently, EPRI TR-016780 [1999] presents “achievable” fragilities proposed to 

be used for preliminary analyses for modern advanced light water reactor (ALWR) seismic 

evaluations. However, they need to be verified by qualification tests before being used for any 

SPRA preceding fuel load. 

Albeit the amount of the generic fragility data is large, it has been extremely rare, except perhaps 

in the case of relays, that fragility data is directly obtained from full-scale tests of equipment 

under seismic excitations that greatly exceed the design basis earthquake. In the equipment 

qualification tests, from which some high quality equipment fragilities have been derived, the 

input seismic waves are only at or slightly higher than the design basis earthquake. The 

prohibitive cost associated with full-scale seismic fragility tests is the major reason for the 
xiv 

unavailability of high excitation level test-based fragility data. The JNES equipment fragility test 

program is a very comprehensive and conscientious effort to determine realistic seismic 

equipment fragility capacities based on full-scale high-level shaking table tests. 

The JNES equipment fragility test program consists of tests of a series of important equipment 

that were determined in an SPRA to be safety significant according to their effect on core damage 

frequency. The selected test equipment were typical for boiling water reactor (BWR) and 

pressurized water reactor (PWR) plants in Japan. The test program for the selected equipment 

was scheduled in two phases. The phase I test program includes large horizontal shaft pumps, 

large size vertical shaft pumps, electrical panels, and control rod insertion capability. The phase 

II test program includes fans, valves, tanks, support structures, and overhead cranes. This report 

documents the evaluation of the fragility data for the JNES phase I equipment. As additional 

information is made available by JNES for the phase II equipment, a supplement to this report 

will be prepared to document the corresponding evaluation results. 

The fragility capacities of the tested equipment were developed based on the full-scale test results, 

element tests, and analyses. The JNES fragility evaluation considered both structural and 

functional limit states. In the full-scale tests, actual equipment as used in typical BWR and PWR 

nuclear power plants in Japan were shaken under excitations much larger than the design basis 

earthquakes which have been used in previous equipment qualification tests and design proving 

tests. The purpose of the full-scale tests was to identify critical acceleration levels and failure 

modes of the equipment. The element tests were conducted with multiple samples for each 

element type, and therefore their median capacity and the associated variation were able to be 

determined statistically. The purpose of the element tests was to evaluate threshold acceleration 

levels of parts and to assess median capacities and the associated uncertainties. The purpose of 

the various analyses was to estimate the seismic fragility capacities of the equipment based on the 

element fragility data and numerical models representing the appropriate failure modes as 

determined from the full-scale tests. 

The horizontal shaft pump in the full-scale test was a reactor building closed cooling water (RCW) 

pump used in Japan BWR plants, which appears to be very similar to RCW pumps in U.S. 

nuclear plants. Therefore, it is judged that this test result could be used to estimate the median 

fragility of RCW pumps in U.S. plants. The function of the RCW pump was confirmed at a zero 

period acceleration (ZPA) of 6.0 g in the full-scale test. The median functional fragilities of the 

tested RCW pump, a larger RCW pump, and a charging injection pump were estimated to be 8.4 

g, 8.6 g, and 17.3 g, respectively. The potentially controlling fragility appears to be slip of the 

motor on the pump frame. As large uncertainties exist for the slip phenomenon, calculated 

fragilities were designated as reference fragilities. The reference fragilities for the tested RCW 

pump, the larger RCW pump, and the charging injection pump were reported to be 6.1 g, 5.3 g, 

and 2.6 g. 

For large and critical horizontal pumps such as RCW pumps and Charging High Pressure 

Injection pumps, it has been common U.S. fragility practice to base their fragility estimate on a 

review and scaling of the qualification stress report for the specific pump involved. For lower 

Central and Eastern U.S. (CEUS) seismic regions, and for less critical horizontal pumps, based on 

a screening level spectral acceleration of 1.2 g, the median ZPA capacity of horizontal pumps can 

be estimated to be about 2.0 g, which is much less than the function confirmed ZPA = 6.0 g 

obtained in the JNES RCW pump full-scale test. The JNES tests demonstrate that these screening 

level based fragility estimates are exceedingly conservative for horizontal pumps, and thus 

confirm the judgment that the screening level approach should not be used for risk important 

horizontal pumps. 
xv 

Eight electrical panels were selected for the JNES full-scale tests, including a main control board, 

a reactor auxiliary control board, a logic circuit control panel, an instrumentation rack, a reactor 

protection rack, a reactor control center, a power center, and a 6.9 kV metal-clad switchgear. The 

median spectral fragilities for these panels, converted from the JNES test data, range between 5.5 

g and 14.2 g; while the generic median fragilities in the U.S. SPRA practice range between 2.2 g 

and 5.1 g. This comparison indicates that generic fragilities commonly used in U.S. SPRAs for 

existing CEUS plants might be conservatively biased by more than a factor of two. The JNES 

test data median fragility levels for electrical components are comparable to the ALWR 

“achievable” fragilities, which are in the range of 8.3 g to 9.8 g. 

However, the natural frequencies for all eight tested electrical components ranged between 21 Hz 

and 44 Hz. It is not clear whether these reported frequencies include local panel modes of 

vibration. Most of these electrical components in U.S. plants exhibit local panel mode 

frequencies in the 4 Hz to 15 Hz range when tested at higher shaking levels. Cabinet response 

amplification factors AFC were reported for representative device mounting locations in the JNES 

tested components to be 1.0 to 2.5; while the recommended median AFC values at the worst 

location for the existing U.S. cabinets range between 2.8 to 4.4. Based both on the natural 

frequency comparisons and the response amplification comparisons, it appears that the JNES 

tested electrical components are much stiffer than most electrical components in existing U.S. 

plants. The JNES reported median fragilities should not be used for U.S. electrical components 

unless it can be shown that the component has stiffnesses similar to those tested by JNES. 

However, they might be representative of electrical components to be used in new U.S. standard 

plants not yet built. 

Electrical element tests included 37 types of devices. Seismic time history tests were conducted 

up to a ZPA=10g level or slightly higher. All but eight of these 37 types of devices had function 

confirmed at ZPA levels of about 10g or slightly higher. The smallest ZPA at which loss of 

function occurred for eight types of devices was 2.5 g. Additional seismic reinforcement to some 

of the devices increased the fragility level. With the exception of the air and gas circuit breakers, 

and the grounded potential transformer, all of these device fragilities exceed the median fragility 

level used for similar devices in existing U.S. SPRAs. The circuit breaker and transformer 

capacities are consistent with those used in existing U.S. SPRAs. Because the tested devices are 

identified by manufacturer and model number, the JNES electrical equipment device fragility 

data is a highly valuable resource for future SPRAs. 

JNES performed a full-scale test on a control rod drive mechanism, control rod, and fuel bundle 

assembly representative of 3 and 4 loop PWR plants. The fuel assembly was the 17x17 type. 

The input motion and resulting maximum fuel assembly displacement were 3.2 g (ZPA) and 48 

mm, respectively. The reported computed median fragility for fuel assembly displacement is 77 

mm. The median ZPA fragility for 3 and 4 loop PWR plants is estimated as 3.9 g in this report. 

For 2 loop PWR plants with 14x14 type fuel assembly, a median functional limit displacement of 

66 mm and the median ZPA and displacement fragilities are estimated in this report as 3.7 g and 

69 mm, respectively. 

JNES also conducted a full-scale test on a control rod drive mechanism, control rod, and fuel 

bundle assembly representative of a BWR5 plant with a high speed scram type control rod drive 

mechanism. JNES estimated that the same fragility estimates were applicable for 80 mil and 120 

mil channel boxes. The input motion and resulting maximum fuel bundle assembly displacement 

were 3.0 g (ZPA) and 83 mm, respectively. JNES estimated the median fragility for the fuel 
xvi 

bundle displacement was 91 mm. The corresponding median ZPA fragility is estimated as 3.1 g 

to 3.3 g. 

The JNES fragility results are applicable for failure modes associated with fuel assembly 

displacements. Within the U.S., control rod insertion fragilities are generally derived based on a 

detailed review and scaling of NSSS vendor submitted qualification reported results. For PWR 

plants, the derived fragilities are generally controlled by the supports of the control rod drive 

mechanism. The failure modes that have typically been considered to be controlling in U.S. 

fragility assessments for control rod insertion could not have occurred during these tests because 

the entire fuel assembly was supported by very stiff frames in the JNES tests. 

The large size vertical shaft pump in the full-scale test was a pit barrel type pump in the reactor 

residual heat removal system (RHR). Function was confirmed at an input ZPA of 1.6 g and a 

corresponding response ZPA of 14.0 g at the top of motor, and separately at an input ZPA of 2.8 

g and a corresponding response ZPA of 31 g at the bottom of barrel. Based on the test results of 

the submerged bearings, the functional fragilities in terms of the bottom of barrel were estimated 

to be 37.1 g for the tested RHR pump. This computed submerged bearing functional limit was 20% 

higher than the highest test level. The functional failure of submerged bearings has not been 

considered in U.S. fragility analyses of vertical pumps. The JNES data on bearings should be 

considered in future U.S. practice; however, the submerged bearing functional limit data did not 

seem to control the pump fragilities. 

Similarly as for the large horizontal pumps, the lowest reported fragility is a motor slip reference 

fragility reported in terms of the top of the motor ZPA response. The slip reference fragility for 

the tested RHR pump, a high pressure core injection system pump, a component cooling seawater 

pump (PWR), and a component cooling seawater pump (BWR) was 3.6 g, 3.5 g, 6.2 g, and 2.8 g, 

respectively. However, a fragility capacity of 14 g at the top of motor was achieved in the fullscale test after tightening the anchor bolts, confirming that large uncertainties exist for the slip 

reference fragility. 

In summary, the JNES tests make a valuable contribution to the overall state of knowledge of 

equipment fragility levels for use in SPRAs. The JNES fragility capacities were determined 

based on full-scale component tests and element tests under simulated seismic excitations that 

were much larger than the design basis earthquakes commonly used in previous qualification tests 

or design proving tests. The fragility levels found in the JNES tests are in general much higher 

than those used in current U.S. SPRAs. Additional failure modes, such as relative motor slip on 

pump frame and functional failure of submerged bearings, have been identified for consideration 

by fragility analysts. These test results should be considered by fragility analysts in performing 

future SPRAs. However, caution must be applied to assess the applicability of the results to the 

specific equipment being considered. In particular, an analysis of the component anchorage and 

support fragility needs to be performed as a necessary supplement to the equipment fragility data 

for a proper application. 
xvii 

ACKNOWLEDGEMENTS 

The research program described in this report was sponsored by the Office of Nuclear Regulatory 

Research of the U.S. Nuclear Regulatory Commission. The authors would like to express their 

gratitude to Dr. Syed Ali, NRC Project Manager, for the technical and administrative support he 

provided in performing this study. 

This research program was performed as part of the Implementing Agreement between the U.S. 

Nuclear Regulatory Commission and the Japan Nuclear Energy Safety Organization (JNES) in 

the area of seismic engineering research. This agreement is an item of the Implementing 

Arrangement between the United States Nuclear Regulatory Commission and the Nuclear and 

Industrial Safety Agency (NISA) of Japan for Cooperation in the Field of Nuclear Regulatory 

Matters and Nuclear Safety Research and Development. 

All of the test results and information about the test equipment included in this report were 

provided by JNES and are greatly appreciated. The authors especially thank Dr. Katsumi 

Ebisawa, Mr. Yuichi Uchiyama, Mr. Hiroshi Abe, and Dr. Kenichi Suzuki of JNES for their 

support and technical guidance throughout this collaborative study. 

The authors also wish to express special thanks to Mrs. Lynda Fitz for her administrative support 

in the preparation of this report and throughout the duration of this project. 

1 

1 INTRODUCTION 

Seismic equipment fragilities, representing the seismic capacities of the equipment and the 

associated uncertainties, are the fundamental ingredient in seismic probabilistic risk assessments 

(SPRAs) of nuclear power plants (NPPs). The quality of seismic fragility capacity directly 

affects the quality of SPRAs in quantifying the risk of NPPs during beyond-design-basis 

earthquakes. The need for high quality seismic equipment fragility data led to many industry and 

U.S. Nuclear Regulatory Commission (NRC) sponsored research programs, the results of which 

are still being applied in current SPRAs. Fragility capacities and the associated uncertainties of 

the most critical equipment items have historically been derived from qualification test data from 

equipment vendors. However, in situations when specific qualification data may not be readily 

available, generic component capacity data are commonly used. Generic-EquipmentRuggedness-Spectra (GERS) are available for various electrical components and relays in EPRI 

NP-5223 and EPRI NP-7147 [Merz, 1991a, b]. In addition, HCLPF capacity data for various 

electrical components and relays is presented in NUREG/CR-4659 Vols. 1-4 [Bandyopadhyay 

and Hofmayer, 1986, Bandyopadhyay, et. al. 1987, 1990, 1991], NUREG/CR-4900 [Holman, et. 

al. 1987], and NUREG/CR-5470 [Tsai, et. al. [1989]. For many Central and Eastern U.S. (CEUS) 

SPRAs, the seismic fragilities of less critical components have been based on the HCLPF 

screening levels described in EPRI NP-6041-SL [1991]. 

The GERS, HCLPF, and HCLPF screening level data presented in the above references is all 

based on pre-1990 vintage components. The applicability of this data for modern components 

will depend upon the amount of changes that have occurred for any particular component class 

since 1990. More recently, EPRI TR-016780 [1999] presents “achievable” fragilities proposed to 

be used for preliminary analyses for modern advanced light water reactor (ALWR) seismic 

evaluations. However, they need to be verified by qualification tests before being used for any 

SPRA preceding fuel load. 

Albeit the amount of the generic fragility data is large, it has been extremely rare, except perhaps 

in the case of relays, that fragility data is directly obtained from full-scale tests of equipment 

under seismic excitations that greatly exceed the design basis earthquake. In the equipment 

qualification tests, from which some high quality equipment fragilities have been derived, the 

input seismic waves are only at or slightly higher than the design basis earthquake. The 

prohibitive cost associated with full-scale seismic fragility tests is the major reason for the 

unavailability of high excitation level test-based fragility data. Nevertheless, the need to obtain 

the realistic (true) seismic equipment fragility capacities remains obvious so as to achieve higher 

quality SPRAs and consequently better risk management in NPPs in the U.S. and other countries. 

 

As a very comprehensive and conscientious effort to fulfill such a need, a multi-year seismic 

equipment fragility test program is currently being carried out by the Japan Nuclear Energy 

Safety Organization (JNES) to obtain realistic equipment fragility capacities for use in SPRAs of 

nuclear power plants (NPPs) in Japan. The JNES equipment fragility test program started in 2002 

and is planned to continue until 2012. The purpose of this test program is to improve the quality 

of the seismic fragility capacity database by determining realistic equipment fragility capacities 

from full-scale shaking table tests, and consequently to allow more accurate SPRAs to be 

performed to quantify the risk of NPPs during beyond-design-basis earthquakes. In contrast to 

the equipment qualification tests by vendors and some earlier design-proving tests performed by 

the Nuclear Power Engineering Corporation (NUPEC, Japan), in which the intent was to 

demonstrate the success of equipment under design basis or slightly larger earthquakes, the 

equipment fragility tests performed by JNES are aimed at determining the (ultimate) seismic 

capacity under beyond-design-basis earthquakes. 
2 

The JNES equipment fragility test program consists of tests of a series of important equipment 

that were determined in an SPRA to be safety significant according to their effect on core damage 

frequency. The selected test equipment were typical for boiling water reactor (BWR) and 

pressurized water reactor (PWR) plants in Japan. The test program for the selected equipment 

was scheduled in two phases. The phase I test program includes large horizontal shaft pumps, 

large size vertical shaft pumps, electrical panels, and control rod insertion capability. The phase 

II test program includes fans, valves, tanks, support structures, and overhead cranes. The fragility 

capacities of the tested equipment were developed based on the full-scale test results, element 

tests, and analyses. The JNES fragility evaluation considered both structural and functional limit 

states. 

As part of collaborative efforts between the United States and Japan on seismic issues, the U.S. 

Nuclear Regulatory Commission (NRC) and Brookhaven National Laboratory (BNL) participated 

in this program by evaluating the results of the JNES equipment fragility test. The goal of this 

research effort was to compare the JNES fragility results with the fragility data typically used in 

current U.S. SPRAs and to assess the impact that the new test results may have on current SPRAs 

and how this data can be utilized for future SPRAs. The JNES fragility results are also useful for 

seismic margin analyses (SMAs), which are important in design certification (DC) or combined 

license (COL) applications because of the lack of full SPRAs at the DC or COL stage. All of the 

test results and information about the test equipment included in this report were provided by 

JNES to NRC/BNL. The unique advantage of this particular collaborative effort is obvious 

because of the rareness of full-scale, high-level seismic equipment fragility data. 

This report summarizes the BNL evaluation of the JNES Phase I equipment fragility test data and 

provides the insights on the applicability and application of this data in the U.S. SPRA practices. 

Following this introduction, Section 2 presents a brief discussion of the current U.S. SPRA 

practices and in particular, the generic fragility data and screening levels as described in the 

references introduced in this section. Section 3 summarizes the JNES equipment fragility test 

program, fragility evaluation procedures, full-scale and element tests, and equipment fragility 

data, based on the JNES equipment fragility report 08TAIHATV-0027 [JNES, 2009] and other 

references provided by JNES. The JNES equipment fragility report 08TAIHATV-0027 is 

reproduced as Appendix A to this report for completeness of the fragility data presentation in this 

report. Appendix B describes the test response spectra for the electrical panel fragility tests. 

Section 4 describes a detailed evaluation of the JNES equipment fragility data and whether and 

how this data can be applied to the U.S. SPRA practices. The major insights obtained from this 

evaluation are summarized in Section 5. 

It should be emphasized that the fragility data from the JNES equipment fragility tests, as well as 

from the equipment qualification tests, generic data, or screening levels, must be supplemented 

with an analysis of the component anchorage and support fragility. About half the time the 

overall component fragility is governed by anchorage or support capacity. 

The details of the results of the JNES phase II tests are still being provided to NRC/BNL. When 

this transfer of information is complete, a supplement to this report will be prepared to address 

additional classes of equipment. 
3 

2 COMMON U.S. PRACTICE FOR ESTIMATING SEISMIC FRAGILITIES OF 

EQUIPMENT QUALIFIED BY TEST 

2.1 Introduction 

Within the U.S. practice for components qualified by test, component seismic fragilities are 

generally defined in terms of a 5% damped spectral acceleration SA for a broad frequency Test 

Response Spectrum (TRS). In a fragility analysis, this component fragility is defined in terms of 

a median SA50% and randomness βr

 and uncertainty βu natural logarithm standard deviations 

(approximate coefficient of variations). In a seismic margin analysis, the component fragility is 

defined in terms of a conservatively biased High-Confidence-Low-Probability-of-Failure 

Capacity (HCLPF) SAHCLPF equivalent to about a 1% non-exceedance probability capacity SA1%. 

Guidance on estimating SA50%, βr, and βu are given on Pages 3-57 through 3-70 of EPRI TR103959 [Reed and Kennedy 1994], whereas guidance on estimating SAHCLPF are given in 

Appendix Q of EPRI NP-6041-SL [1991] for various types of available test data. This guidance 

will be briefly summarized in Section 2.2. 

To define the fragility of the most critical equipment items qualified by test, it is preferable to 

start from the highest component specific qualification test data available for the specific 

equipment item. However, this information may not be readily available. In that situation, 

generic component capacity data is commonly used. Generic-Equipment-Ruggedness-Spectra 

(GERS) are available for various electrical components and relays in EPRI NP-5223 and EPRI 

NP-7147 [Merz, 1991a, b]. In addition, HCLPF capacity data for various electrical components 

and relays is presented in NUREG/CR-4659 Vols. 1-4 by Bandyopadhyay and Hofmayer [1986] 

and Bandyopadhyay, et. al. [1987, 1990, 1991], NUREG/CR-4900 by Holman, et. al. [1987], and 

NUREG/CR-5470 by Tsai, et. al. [1989]. These EPRI reports and NUREG/CR reports represent 

the generally available U.S. data base for generic fragilities. 

For many Central and Eastern U.S. (CEUS) seismic probabilistic risk assessments (SPRAs), the 

seismic fragilities of less critical components have been based on the HCLPF screening levels 

SASL presented in Table 2-4 of EPRI NP-6041-SL [1991]. The use of these screening levels will 

be discussed in Section 2.3. 

The GERS, HCLPF, and screening level data presented in the above references is all based on 

pre-1990 vintage components. The applicability of this data for modern components will depend 

upon the amount of changes that have occurred for any particular component class since 1990. 

Electrical component fragilities based on these references will be presented in the next two 

sections. 

EPRI TR-016780 [1999] presents “achievable” fragilities proposed to be used for preliminary 

analyses for modern advanced light water reactor (ALWR) seismic evaluations. The basis for 

these fragility values could not be located during the course of this study. In any regard, they 

need to be verified by qualification tests before being used for any SPRA preceding fuel load. 

Electrical component fragilities based on EPRI TR-016780 will be presented in Section 2.4, and 

will be compared with fragilities based on GERs, HCLPF, and screening levels data as previously 

described. 

Lastly, for equipment qualified by test, the fragility obtained from qualification test, generic data, 

or screening levels must be supplemented with an analysis of the component anchorage and 
4 

support fragility. About half the time the overall component fragility is governed by anchorage or 

support capacity. 

2.2 Equipment Fragilities Based on Generic Data 

EPRI TR-103959 [1994] recommends median factor FD, 50% and variabilities βr

 and βu to be used 

to convert qualification test, GERS, and HCLPF capacities into fragility estimates for a 

component, as shown in Table 2-1. The factors given in Table 2-1 depend on the operational 

requirements (i.e., “function during” or “function after”) and the physical results of the test (i.e., 

anomalies or no anomalies). If structural anomalies such as weld cracking, sheet metal tearing, 

screw pull out, local cabinet distortion, etc. are found, then the fragility analyst will have to use 

judgment to estimate how much higher the motion could be raised above the test level before 

damage is severe enough to cause the cabinet function to fail. 

“Function during” fragilities are fragilities associated with a device within the equipment being 

able to appropriately change state during seismic shaking and are commonly associated with relay 

chatter or breaker trip during seismic shaking. “Function after” fragilities are fragilities 

associated with devices being capable of functioning properly after the strong shaking has ended. 

These “function after” fragilities are based on an unacceptable level of structural damage 

occurring to the device or cabinet. Their usage in an SPRA is conditioned on assuming that an 

operator can recover from an inappropriate change of state during seismic shaking. 

Example electrical equipment fragilities based on GERS capacities [Merz, 1991a] are shown in 

Table 2-2 based on the FD,50%, βr

, and βu values shown in Table 2-1. Specific caveats and 

checklist issues are listed in EPRI NP-5223 [Merz, 1991a] for use of these GERS capacities. 

Confirmation of compliance with these caveats and checklist issues need to be confirmed before 

using the generic fragilities. Two GERS capacities are reported for both low voltage and metal 

clad switchgear depending upon the degree of restraint provided for the breakers within the 

switchgear. The GERS based fragilities in Table 2-2 are shown for the purpose of comparison 

against fragilities reported by JNES for electrical equipment based on high amplitude shake table 

testing of Japanese equipment. This comparison will be made in Section 4.2 of this report. 

Except as specifically noted in EPRI NP-5223 caveats, the GERS based fragilities are “function 

during” fragilities that include consideration of functionality of typical components within the 

relevant equipment classifications. However, to use these GERS based fragilities as “function 

during” fragilities, the analyst must confirm the lack of weak elements with the component. 

The GERS based fragilities tend to be applicable only for the weakest tested equipment in the 

generic equipment class. Therefore, they are likely to be very conservatively biased for the 

majority of equipment in the generic equipment class. Typically, higher fragility estimates can be 

obtained using component specific test data. 

“Function during” fragilities of electrical components are generally confirmed based upon 

element testing of the individual devices such as relays mounted within the electrical component. 

Relay specific test data can be obtained from testing conducted in accordance with IEEE C37.98 

[1984]. For many relays, data is available in EPRI NP-7147 and NUREG/CR-4659. Table 2-1 

provides recommended FD,50%, βr

, and βu values to be applied to capacity data from these sources. 

The resulting device median fragility SAD,50% is applicable for broad frequency input motion at 

the device. To obtain SA50% at the base of cabinet, the device fragility must be divided by an 

appropriate cabinet amplification factor AFC, i.e.: 
5 

% =

	,%


,%

 (2-1) 

where AFC,50% is the median value of AFC. 

The overall random variability βr

 and βu for this device fragility at the base of the cabinet are 

given by: 

 = ,

 + ,
 (2-2) 

 = ,

 + ,
 (2-3) 

where βr,D and βu,D are device capacity variabilities from Table 2-1, and βr,AF and βu,AF are cabinet 

amplification factor variabilities. The resulting composite variability βc is given by: 

 = 

 +  (2-4) 

Cabinet amplification factor median, variability, and uncertainty values are recommended in 

EPRI TR-103959 [1994], as shown in Table 2-3. These recommended amplification factors were 

determined at the worst location using 5%-damped response spectra. As an example, Table 2-4 

reports the estimated “function during” fragility for a pneumatic timing type auxiliary relay 

mounted on a panel in a 15 Hz control cabinet based on the relay GERS value from Page B-9 of 

EPRI NP-7147 [Merz, 1991b] and Table 2-1 and Table 2-3. 

2.3 Equipment Fragilities Based on HCLPF Screening Levels 

As previously noted, many CEUS SPRAs have used generic fragilities for less critical 

components based on HCLPF screening levels from EPRI NP-6041-SL [1991] in lieu of 

obtaining the highest available component specific qualification test data. This approach should 

not be used for higher seismic sites, or for components whose fragility significantly influences the 

reported seismic risk. However, currently, this seems to be a common practice. It should be 

noted that these HCLPF screening level based fragilities are only appropriate for “function after” 

fragilities since they don’t consider the ability of elements to properly function during strong 

shaking. Lastly, separate fragilities must also be computed for anchorage and component 

supports. Often these anchorage and support fragilities govern. 

The screening level HCLPF capacities shown in Table 2-4 of EPRI NP-6041-SL [1991] are 

defined in terms of a broad frequency 5% damped spectral acceleration SA, and the following two 

screening levels are defined in that table: 

SASL = 0.8g 

SASL = 1.2g 

Most components satisfy the conditions for the use of the SASL=1.2g screening level. 
6 

Practice has varied concerning the development of fragility median values and composite βc

estimates based on these SASL screening levels. The following approach is recommended by the 

authors. 

The component screening levels presented in Table 2-4 of EPRI NP-6041-SL were primarily 

developed by Campbell, Reed, and Kennedy based on the consideration of a diverse body of 

information summarized in Appendix A of EPRI NP-6041-SL. These component screening 

levels were defined in terms of the peak 5% damped spectral acceleration at the ground (SAG) 

instead of the peak 5% damped spectral acceleration (SA) at the base of the component. Most of 

the data base summarized in Appendix A of EPRI NP-6041-SL was reported in terms of ground 

motion instead of in-structure response spectra (ISRS). Furthermore, it was judged that realistic 

median ISRS might not exist in many cases where these component screening levels might be 

used. However, footnote (y) in Table 2-4 of EPRI NP-6041-SL cautions against the use of the 

SAG screening level for situations where the SA level from realistic ISRS exceeds 1.67⋅SAG (i.e. 

SA exceeds 2.0g for SAG of 1.2g) 

Furthermore, each component category in Table 2-4 of EPRI NP-6041-SL represents a broad 

diverse group of components from multiple manufacturers. For each diverse group, no “function 

after” failures have been observed below the screening level SASL and numerous successes have 

been observed for ground motions significantly exceeding SASL. Thus, for individual components 

within these broad diverse component class, it is recommended to use a composite variability βc

in the range of 0.4 to 0.5. Using a generic estimate for βc of 0.45 for individual components: 

Median/HCLPF = exp[2.326(0.45)] = 2.85 

Thus, for individual components: 

% = 2.85 

 =  = 0.45

!"#
 = 

(2-5) 

is appropriate. 

The screening tables are in terms of ground motion SAG. Both the earthquake experience data 

and the past SPRA fragility data used to develop these screening tables are in terms of ground 

motion. The amplification factor AF and its variability βAF are automatically embedded in these 

HCLPF screening levels and the overall βSAG estimate. It is necessary to remove these 

amplification factor effects from the screening table data so as to have generic fragilities defined 

at the base of the component instead of at the ground. EPRI 1019200 [2009] Appendix B 

recommends an approach for estimating HCLPF and generic fragility levels for individual 

components in terms of SA at the base of the component from the screening level SASL given in 

Table 2-4 of EPRI NP-6041-SL. This approach is based on the following estimates of the median 

amplification factor AF50% and its logarithmic standard deviation βAF for the experience data: 

AF50% = 1.4 (2-6) 

βAF = 0.17 (2-7) 

The median SA50%, variability βSA, and SAHCLPF in terms of the ISRS SA for an individual 

component can then be estimated by: 
7 

SA50% = AF50% ⋅ SAG50% = 4.0 SASL (2-8) 

 = 

 − 
 = 0.42 (2-9) 

SAHCLPF = SA50% ⋅ exp(-2.326βSA) = 1.5 SASL (2-10) 

since βAF is included as part of the βSAG estimate. Thus, for SASL=1.2g, the corresponding SAHCLPF

is reasonably estimated to be 1.8g. Table 2-5 shows the resulting recommended “function after” 

spectral acceleration SA fragilities in terms of motion at the component base. These screening 

level based generic fragilities shown in Table 2-5 will be compared with the JNES results in 

Section 4 of this report. 

2.4 Advanced Light Water Reactor “Achievable” Fragilities 

EPRI TR-016780 [1999] provides median “achievable” fragilities in terms of a broad frequency 5% 

damped spectral acceleration at the ground, SAG50% and a corresponding composite βSAG. In order 

to estimate fragility levels for individual components in terms of SA at the base of the component, 

the AF50% and βAF corrections shown in Equations 2-6 through 2-10 need to be applied. Table 2-6 

shows representative natural frequencies and “achievable” fragilities for electrical components 

based on EPRI TR-016780. 

2.5 Comparison of Generic Fragility Estimates 

Table 2-7 compares generic fragilities for electrical components based on several data sources. 

Electrical component fragilities based on GERS [Merz, 1991a] and on screening levels [EPRI 

NP-6041-SL, 1991] are reasonably consistent with each other. However, these fragilities are 

based on data for pre-1990 vintage components. The ALWR “achievable” fragilities from EPRI 

TR-016780 are intended for preliminary evaluations for modern components. These fragility 

levels are about twice the GERS and screening level based fragilities. The basis for this increase 

could not be located during this study. As shown in Section 4, the JNES test data median fragility 

levels for electrical components are comparable to the ALWR “achievable” fragilities. However, 

all of the electrical components tested by JNES were very stiff and not representative of most 

similar existing electrical components in U.S. plants. Therefore, the use of the ALWR 

“achievable” fragilities requires verification by means of qualification tests. 
8 

Table 2-1 Device Capacity Factors 

Data Source FD,50% βr βu FD,HCLPF

HCLPF Capacities 

 (NUREG/CR-4659 and NUREG/CR-4900) 

GERS – Non relay 

(EPRI NP-5223) 

GERS – Relay 

(EPRI NP-7147) 

IEEE C37.98 – Relay Fragility 

Qualification Test 

 Function During 

 Function After 

 (no anomalies) 

 Function After 

 (anomalies) 

1.75 

1.45 

1.07 

1.5 

1.4 

1.95 

1.1 – 1.65

0.11 

0.11 

0.09 

0.09 

0.09 

0.09

0.09

0.23 

0.23 

0.18 

0.18 

0.22 

0.28

0.28 

1.0 

0.83 

0.69 

0.96 

0.84 

1.06 

0.6 – 0.9

Table 2-2 Estimated Generic Fragilities for Electrical Equipment 

Component 

5% Damped Spectral Acceleration Capacity SA (g) 

GERS SA50% βr βu βc SAHCLPF

Distribution Panels 

 Floor Mounted 

 Wall Mounted 

3.5 

2.5 

5.1 

3.6 

0.11 

0.11

0.23 

0.23

0.25

0.25

2.9 

2.1 

Motor Control Centers 

 “Function After” 

 “Function During”

2.5 

1.5 

3.6 

2.2 

0.11 

0.11

0.23 

0.23

0.25

0.25

2.1 

1.25 

Switchgear 

 Low Voltage 

 Metal Clad 

1.8 – 2.5

1.8 – 2.5

2.6 – 3.6

2.6 – 3.6

0.11 

0.11

0.23 

0.23

0.25

0.25

1.5 – 2.1 

1.5 – 2.1 
9 

Table 2-3 Cabinet Amplification Factors 

Cabinet Types 

AFC

Median βr βu

Motor Control Center 

Switchgear (flexible panels) 

Control Room Electrical 

Benchboards and Panels 

(with frequency ≥ 13 Hz) 

2.8 

4.4 

3.3 

0.10 

0.13 

0.11

0.23 

0.37 

0.27

Table 2-4 “Function During” Spectral Acceleration SA Fragility for Pneumatic Timing Type 

Auxiliary Relay Panel Mounted in 15 Hz Control Cabinet 

(Median AFC = 3.3, βr,AF = 0.11, βu,AF = 0.27) 

GERS

SAGERS (g)

Device Location Cabinet Base 

SAD,50% (g) βr,D βu,D SA50% (g) βr βu βc SAHCLPF (g)

10.0 10.7 0.09 0.18 3.2 0.14 0.32 0.35 1.5 

Table 2-5 Generic “Function After” Spectral Acceleration SA Fragility Levels in Terms of 

Component Input Motion Based on Screening Levels 

Screening Level 

SASL (g) 

Component Fragility Cabinet Base 

Median SA50% (g) Composite Variability βc SAHCLPF (g) 

0.8 

1.2 

3.2 

4.8 

0.42 

0.42 

1.2 

1.8 

 
10 

Table 2-6 “Function During Achievable” Spectral Acceleration 

Component 

Natural 

Frequency 

(Hz) 

Ground Motion Cabinet Base 

SAG50% (g) βSAG SA50% (g) βSA SAHCLPF (g) 

Panel boards and 

Instrumentation Panels 5-10 7.0 0.46 9.8 0.43 3.6 

Switchgear and 

Motor Control Centers 4-12 5.9 0.46 8.3 0.43 3.1 

Table 2-7 Comparison of Generic Fragilities for Typical Electrical Cabinets 

GERS 

(Function During)

Screening Levels 

(Function After) 

ALWR Achievable 

(Function During) 

SA50% (g) 2.2-5.1 3.2-4.8 8.3-9.8 

βSA 0.25 0.42 0.43 

SAHCLPF (g) 1.25-2.9 1.2-1.8 3.1-3.6 
11 

3 JNES EQUIPMENT FRAGILITY TESTS 

3.1 Overview of the JNES Equipment Fragility Test Program 

Japan Nuclear Energy Safety Organization (JNES) is carrying out a multi-year equipment 

fragility test program to obtain realistic equipment fragility capacities for use in the seismic 

probabilistic risk assessments (SPRAs) of nuclear power plants (NPPs) in Japan. As shown in 

Figure 3-1, the JNES equipment fragility test program started in 2002 and continued through 

2009. Additional tests are planned during the period of 2009 to 2012. The purpose of this test 

program is to improve the quality of seismic fragility capacity database by determining realistic 

equipment fragility capacities from full-scale shaking table tests, and consequently to allow more 

accurate SPRAs to be performed to quantify the risk of NPPs during beyond-design-basis 

earthquakes. 

This test program reflects a philosophical shift from the design-proving test in the past that was 

intended to demonstrate the success of equipment under design basis or slightly larger 

earthquakes, to the current fragility test that determines the (ultimate) seismic capacity under 

beyond-design-basis earthquakes. In the past, equipment fragility data were mostly not obtained 

from full-scale high level shaking tests, but, for example, by scaling equipment qualification test 

data or by converting from screening levels as described in Section 2. The true (realistic) 

equipment seismic fragility capacities have not been widely available because it is prohibitively 

costly to determine such capacities using high level shaking tests of full-scale equipment. Prior to 

the establishment of JNES, Nuclear Power Engineering Corporation (NUPEC, Japan) conducted 

multi-phase/multi-year proving tests of large structures, systems, and components (SSCs), but the 

shaking levels were not as great as the current JNES fragility tests (see Figure 3-1). The current 

fragility data used in the Japan SPRAs are either from Japanese lower level tests such as NUPEC 

tests or from the U.S. fragility databases. These fragility capacities are believed to be smaller 

than the actual values and accordingly the core damage frequency (CDF) may have been 

overestimated. The JNES equipment fragility tests were planned to identify the realistic seismic 

fragilities of important NPP equipment using high level shaking tests. 

As stated above, a direct determination of median fragility capacity and the associated variation 

from full-scale tests is prohibitive. Therefore, in order for JNES to make the equipment fragility 

tests more achievable, element (device) tests, analyses, and use of some existing data are required 

along with the full-scale tests to establish the final fragility values. For each selected equipment 

category, only one or two representative full-scale equipment specimens were tested. The main 

purpose of the full-scale tests was to identify critical accelerations and failure modes of the 

equipment. The purpose of the element tests was to evaluate threshold acceleration of parts and 

median and deviation. The element tests were conducted with many samples, and therefore their 

median capacity and the associated variation were able to be determined statistically. For some 

cases, the variability was specified as those reported in the industry codes and standards. Based 

on the full-scale test results, analyses combined with element tests were performed to calculate 

the fragility capacities. 

Some of the JNES equipment fragility tests were conducted at the TADOTSU shaking table of 

NUPEC. The TADOTSU shaking table has a plan dimension of 15 m × 15 m. Some of the test 

results were limited to the table capacity and therefore only function confirmed (FC) capacities 

were achieved. For some of the full-scale equipment tests and the element tests, higher 

acceleration input was required to identify their seismic fragility capacity. To this end, a 

vibration amplifying system was installed on top of the TADOTSU shaking table. Figure 3-2 

illustrates how the amplification table was installed on top of the TADOTSU shaking table, also 
12 

showing an electrical panel sitting on top of the amplification table. The amplification table has a 

plan of 5 m × 5 m. The combined input acceleration capacity of the TADOTSU shaking table 

and the amplification table can reach about 6g around 10 Hz [Iijima, et al, 2004]. 

The input acceleration level was determined from JNES’s sensitivity analysis of CDF. For 

example, it was shown in a preliminary SPRA that if the critical acceleration of a large horizontal 

shaft pump is higher than 4g or 5g, CDF was decreased by half. This finding was used to 

determine how much the capacity of the TADOTSU shaking table should be increased by an 

amplification table [Iijima, et al, 2004]. 

The JNES equipment fragility test program consists of a series of important equipment that were 

determined in a seismic probabilistic safety analysis (PSA) to be safety significant according to 

their effect on core damage frequency. More specifically, the F-V (Fussell-Vesely) importance 

measure was obtained in a preliminary seismic PSA performed by JNES and was used to select 

the safety significant equipment. The FV importance of a component is defined as the fraction 

that the baseline CDF would be reduced if the subject component was always available (with 

infinite high seismic fragility). Another criterion used for the equipment selection is that the 

equipment must be an active component, because the fragility of such active equipment is 

difficult to be estimated by analysis [Iijima, et al, 2004]. The test program for the selected 

equipment was scheduled in two phases, as shown in Figure 3-1. The phase I test program 

includes large horizontal shaft pumps, large vertical shaft pumps, electrical panels, and control 

rod insertion capability. The fragility data of the JNES phase I tests are documented in the JNES 

report 08TAIHATV-0027 [JNES, 2009], which is reproduced as Appendix A to this report for 

reference. 

The JNES phase II test program includes fans, valves, tanks, support structures, and overhead 

cranes. The results of the JNES phase II tests were not yet available and will be evaluated and 

documented in the future once available. 

The Phase I program was conducted from FY 2002 to 2005 (Japan). The fragility test equipment 

were typical for boiling water reactor (BWR) and pressure water reactor (PWR) plants in Japan. 

The phase I fragility test was conducted in three parts: Part 1 included the horizontal shaft pumps 

and electrical components, Part 2 included BWR and PWR equipment related to control rod 

inserting capacity, and Part 3 included large size vertical shaft pumps. Following these tests, a 

comprehensive evaluation was performed to produce the fragility data. During this 

comprehensive evaluation process, for electrical devices (elements) where an abnormality 

occurred at relatively low acceleration, some additional tests were performed after improvement 

was implemented to the devices. Fragility data were also developed using the test results of the 

improved devices. It should be pointed out that Appendix A of this report was prepared by JNES 

and is an English translation of the Chapter IV, “Development of Fragility Data,” of the JNES 

comprehensive evaluation report. 

Two limit states were considered for the fragility analysis for the Phase I equipment: (1) 

structural damage should not occur; (2) loss of active function should not occur during earthquake. 

Examples of active function include rotation for horizontal and vertical pumps, electrical state 

change for electrical components, and control rod insertion. 

The JNES fragility report 08TAIHATV-0027 [JNES, 2009] presents the fragility capacities in 

terms of the maximum input acceleration (zero period acceleration, or ZPA), response 

accelerations or displacements, or a set of response multiplying factors with respect to input 

motion. As noted in the same report, response of equipment depends on the dynamic 
13 

characteristics of the equipment and the supporting structure as well as the earthquake condition 

at any particular site. More rigorous fragility capacity can be determined by using site-specific 

earthquake conditions. 

The JNES fragility report 08TAIHATV-0027 [JNES, 2009] does not include test response spectra 

(TRS) associated with the ZPA fragilities. TRS for some tests were later provided by JNES 

separately using several JNES fragility reports in Japanese with English annotations. In general, 

these TRS are fairly narrow banded spectra developed for 1%, 4%, or 5% damping ratios, in 

contrast to the broad-frequency 5% damping response spectra typically used in U.S. qualification 

tests. The JNES TRS are representative of in-structure response spectra in Japanese NPPs, with 

many of the input spectra peaking in a frequency range of 7-10 Hz and containing little frequency 

content above about 12 Hz. 

The 1% or 4% damping TRS may be converted to 5% damping TRS using appropriate methods, 

e.g., the random vibration methods or the empirical methods provided in NUREG/CR-6728 

[McGuire, et al, 2001], if a direct assessment is needed for the applicability of these TRS in U.S. 

SPRAs. However, the accuracy of these methods must be evaluated and any potential bias 

induced by using these methods must be considered in the TRS-based fragility comparison. 

The response spectra shown later in this section and in Appendix B were extracted from the 

annotated JNES fragility reports. The relevant legend and labels are created based on the 

annotations. The unit for the spectral acceleration may be in g, gal (cm/s2), or m/s2, following the 

same convention as in the JNES fragility reports. Similarly, the horizontal axis can be in period 

(s) or in frequency (Hz). 

This section provides a summary of the JNES phase I test program, based on various JNES 

presentations [e.g., Uchiyama, 2008a, b], the JNES equipment fragility report 08TAIHATV-0027 

[JNES, 2009], and the annotated JNES fragility reports in Japanese. The fragility capacities are 

mostly described in this section in terms of input ZPA and peak response acceleration and/or 

displacement at critical locations, following the convention in the JNES report 08TAIHATV0027. Whenever available and appropriate, the TRS associated with these fragility capacities are 

also documented in this section. Some more detailed TRS are documented in Appendix B 

particularly for electrical panels and devices, as more TRS data are available for these tests. 

An evaluation of the JNES equipment fragility data and assessment of the impact of these data on 

the U.S. SPRA practices is provided in Section 4. 

3.2 Horizontal Shaft Pumps 

3.2.1 Summary of Horizontal Shaft Pump Tests 

3.2.1.1 Full Scale Test 

Table 3-1 shows a list of common horizontal shaft pumps in Japan BWR and PWR NPPs. JNES 

preliminary PSA analysis showed that single stage pumps have high F-V importance values. A 

reactor building closed cooling water (RCW) pump used in Japan BWR plants was selected as a 

representative single stage horizontal shaft pump for full-scale test. This pump has a flow rate of 

1250 m3/h, a length of 2.8 m, and a height of 1.5 m; and weighs 5.7×103 kg. Figure 3-3 shows 

the layout of the full-scale RCW pump test system, which included the RCW pump, an electric 

motor, piping, valves, a tank, and power cabinets. It should be noted that the RCW pump and the 

motor were installed on top of the amplification table while other test elements were sitting on top 

of the main shaking table. 
14 

A basis input acceleration time history was generated from an envelope floor response spectrum 

(FRS) that covers FRSs at floors where major horizontal shaft pumps were located in Japan BWR 

and PWR plants, as shown in Figure 3-4 and Figure 3-5. The duration of the input waves were 

about 36 seconds. The basis input motion was scaled to a peak acceleration of 1g. The damping 

ratio was chosen as 1% for FRS. This basis input acceleration time history was gradually scaled 

from 2g to 6g in the test. The pump was tested in axial and transverse directions for both 

operating and standby conditions. 

No damage was found up to the maximum input acceleration level of 6g, and no obvious decrease 

of performance was observed as well in terms of flow rate and head [Iijima, et al, 2005]. The 

TRS at the top of the amplification table for the 2 g, 4 g, and 6 g excitation levels are shown in 

Figure 3-6. These TRS are for the axial direction; however, they are reported to be fundamentally 

the same in the radial direction. The damping ratio for these spectra is 1%. As shown in Figure 

3-7, acceleration measured at the bearing case showed only a slight increase as the input 

acceleration increased, from a base-line rattling acceleration about 10 m/s2 to 18 m/s2 before 

application of the simulated seismic motion. Significant damage to surface roughness of the 

bearing was not found during the post-test check. 

3.2.1.2 Element Tests 

Bearings and liner rings from both single stage and multi-stage horizontal shaft pumps were 

selected for the element tests. Liner rings were reported to have lower seismic margin than other 

parts and can be damaged due to impact between liner rings and the impeller during transverse 

vibration. Although bearings generally have high seismic margin, they are selected because they 

are the very fundamental parts for the pump’s rotational function. Tested bearings included radial 

and thrust bearings of ball and slide types. Figure 3-8 and Figure 3-9 show the test setups for 

radial ball bearings and thrust ball bearings, respectively. Table 3-2 shows the types of element 

in the tests and their size and the number of specimens. As indicated in the note to Table 3-2, a 

ball bearing type 6316 and 270 mm liner ring were used for the RCW pump. 

Two types excitations were used in the test: sinusoidal excitation and simulated seismic wave 

excitation. The sinusoidal excitation test was for investigation of the dynamic properties of the 

parts under large input excitation, which were then used in dynamic analysis. The seismic wave 

excitation test was for determination of fragility capacity and failure mode. For the seismic 

motion test, the basis input acceleration time history for the element tests was the same as the one 

for the full-scale test. For the type 6310 thrust ball bearing, the maximum input load for the 

sinusoidal test was about 10 kN, which in the test was equivalent to an acceleration of 12g; and 

the maximum input load for the seismic wave excitation test was about 33 kN, which in the test 

was equivalent to an acceleration of 39g. Input loads for other types of pump parts can be found 

in Appendix A. 

Rattling acceleration at the bearing significantly increased after a threshold input load, which was 

about 20 kN (equivalent to 20g) for bearing 6310. The surface roughness of balls and the internal 

surface ball/slide bearing were degraded after the test, as shown Figure 3-10. However, this 

damage was found not to be significant enough to present an immediate stop of the pump, but the 

damage could cause a reduction of pump life. No significant damage was found for the tested 

liner rings. It is important to note that the input loads were very large (exceeding 10g equivalent 

force) when the minor damage occurred. 
15 

3.2.2 Fragility Evaluation and Fragility Data 

3.2.2.1 Fragility Evaluation for Active Function 

Safety related pumps in NPPs are required to operate continuously for a certain period of time 

after an earthquake. Although the full-scale test of the RCW pump showed no abnormality of the 

pump function up to an input acceleration of 6g, the element tests did show that at very large 

input load some degradation of the parts could lead to reduction of pump bearing life. Therefore, 

the load that could cause the bearing life reduction was conservatively specified as the critical 

load of the bearing. For cases where no abnormality occurred in the element tests, the maximum 

input load in the element test was specified as the critical load. The critical loads of the bearing 

were used in nonlinear time history analysis of pump models to determine the fragility capacities. 

Figure 3-11 and Figure 3-12 show the axial and lateral analytical models for a single stage 

horizontal shaft pump and for a multi-stage horizontal shaft pump, respectively. The axial 

models were single mass models, with the nonlinear spring constant and the damping factor 

obtained from the element sinusoidal tests. The lateral models were multi-mass systems, with the 

nonlinear spring constants for the bearings and liner rings determined from the element tests. The 

pump casing was assumed rigid in the analysis. For the parts other than the bearings and liner 

rings, the damping ratio was specified as 1% in the seismic response analyses, in line with the 

damping factor recommendation by JEAG 4601, “Technical Guidelines for Seismic Design of 

Nuclear Power Plants.” 

Table 3-3 summarizes selected critical values of the JNES fragility evaluation of the horizontal 

shaft pumps. It should be noted that for slide bearing, the surface pressure-velocity (PV) critical 

values were used as indicators of the contact pressure limit of the slide bearing in the fragility 

evaluation. 

The median fragility value for active function was specified as the critical acceleration calculated 

based on the above procedure. Based on the element tests, maximum logarithmic standard 

deviations of 0.21 for the deep groove ball bearing and 0.12 for the slide (radial) bearing were 

used to represent the uncertainties in the fragility values. 

3.2.2.2 Fragility Evaluation for Structural Strength 

A simple static analysis method was used for the limit state of structural strength. The seismic 

acceleration used in the static analysis was specified as 1.2 times the floor response acceleration. 

Foundation bolts and mounting bolts between the pump/motor and pump frame were reported to 

have the lowest seismic margins among structural members, and therefore were evaluated for 

fragility capacity based on the static analysis procedure in JEAG 4601-1991. 

Pump/motor relative slip motion on the pump frame can cause abnormality in the pump rotational 

function. As it was difficult to perform a detailed analysis of this slip phenomenon, a simplified 

static analysis using frictional force was used to estimate the acceleration that caused the relative 

slip. As noted in Appendix A, because many uncertainties exist for the slip phenomenon, the 

acceleration so determined by JNES was termed “reference fragility.” Slip was not reported in 

the full-scale test of the RCW pump, which was tested to accelerations slightly less than the 

“reference fragility.” 

In the fragility evaluation, as shown in Table 3-3, the critical tensile stress was set to 0.75Su/η, 

where Su is the design tensile stress as specified in the Japan Society of Mechanical Engineers 

(JSME), “Standards for Nuclear Power Generation Equipment: Design and Construction 

Standards.” The median capacity was obtained by considering a 0.75 factor for thread portion 
16 

and a confidence coefficient η. The critical shear stress was specified as Su/√3. For evaluation 

of relative slip of motor and pump on the pump frame, tightening force and pump/motor weight 

were considered for the frictional capacity. The fragility was calculated by comparing the 

seismic load in the horizontal direction to the frictional capacity. 

The calculated bolt strength and critical slip acceleration were specified as median fragility 

capacities. The logarithmic standard deviation β in bolt strength was calculated to be 0.07 by 

assuming 0.75Su as 1% and 0.75Su/0.856 as the median (η = 0.856 for general steel materials). 

3.2.2.3 Summary of Fragility Data 

Before the JNES horizontal shaft pump test, the seismic fragility capacity of horizontal shaft 

pumps in previous SPRAs was 1.6g, which was developed from previous vibration tests [Iijima, 

et al, 2005]. The function confirmed capacity of the RCW pump is 6g, about 4 times of the 

previously determined value. 

Table 3-4 shows a summary of fragility data for three horizontal shaft pumps. Besides the RCW 

pump in the full-scale test, a larger RCW pump and a charging/HP injection pump were studied. 

The larger RCW pump is about 3.72 m long and 1.59 m tall, and has a flow rate of 2050 m3/h. Its 

mass is about 8.2×103

 kg. The charging/HP injection pump was of a multi-stage centrifugal type, 

with a length of 2.6 m, a height of 1.5 m, a flow rate of 34.1 m3/h or 147 m3/h depending on pump 

head, and a mass of 6.05×103 kg. 

The minimum median fragility for the functional limit state is 8.4g, about more than 5 times of 

the previously used fragility value. The reference fragility for the motor slip is 2.6 g for the 

charging/HP injection pump, about half of the other two horizontal pumps. This reference 

fragility capacity appears to be controlling; however, as the level of uncertainty in this estimate is 

unknown, further investigation is required to justify its proper use. 

Table 3-5 through Table 3-7 summarizes the fragility data for tested ball bearings, slide bearings, 

and liner rings. For some, only function confirmed values are available. The tabulated values 

are indexed by their part id or diameters. 

3.3 Electrical Panels 

3.3.1 Summary of Electrical Panel Tests 

JNES performed tests on full-scale electrical panels that were of the same types as in Japan NPPs 

to investigate their critical acceleration and failure modes due to seismic accelerations. It also 

conducted tests on elements (devices) with multiple specimens to obtain the dispersion in 

addition to the threshold acceleration. The fragility data were developed using results of the fullscale tests, element tests, and analyses. 

3.3.1.1 Full Scale Tests 

Eight electrical panels were selected for the JNES full-scale tests: 

• Main control board (BWR) 

• Reactor auxiliary control board (PWR) 

• Logic circuit control panel (BWR) 

• Instrumentation rack (BWR) 

• Reactor protection rack (PWR) 
17 

• Reactor control center (PWR) 

• Power center (PWR) 

• 6.9 kV Metal-clad switchgear (BWR) 

Table 3-8 shows the properties of these eight electrical panels, including their dimensions, weight, 

and fundamental frequency. The frequency of these electrical panels was in a range of 21 Hz to 

44 Hz. The fundamental frequency of each panel was identified on a resonance curve that was 

generated in the low-level random wave excitation test before the fragility test. Figure 3-14 

shows the major features and dimensions of these electrical panels [Iijima, et al, 2007]. Figure 

3-15 shows the electrical panels sitting on the amplification table. 

Similar to the full-scale horizontal shaft pump test, a basis seismic input wave was generated for 

the full-scale electrical panel tests using an FRS that enveloped the design FRS of the main 

electrical panels. The duration of the input seismic waves were about 36 seconds, as shown in 

Figure 3-13. The JNES preliminary SPRA showed that a fragility capacity of 5g to 6g would 

decrease the CDF by half; therefore, the amplified TADOTSU shaking table with a total capacity 

of 6g was judged to be satisfactory. The electrical panels were shaken in both front-to-back and 

side-to-side directions. Each panel was tested in the simulated operating condition, with some 

being tested with smaller current for safety reasons. 

The main control board, the instrumentation rack, the reactor auxiliary control board, and the 

logic circuit control panel maintained their function up to a maximum input acceleration of 6g. 

The other four panels lost their functions during the test; the failure mode and the critical 

acceleration are summarized in the following: 

Reactor control center: at an input acceleration of 6.1g in the front-back direction, chatter of 

auxiliary relays caused an error in the magnetic contactor. Figure 3-16 shows a comparison of 

the target response spectra and the response at the base plate for a 6 g level front back excitation 

in the reactor control center test. A 4% damping ratio was used for these spectra and all other 

response spectra for the electrical panel and device tests. The various levels of excitations were 

achieved in the JNES equipment fragility tests by scaling basis input motions. Therefore, a 

particular response spectrum at the base plate shows the characteristics of the frequency contents 

of the input motion but may not directly relate to the critical failure acceleration. Appendix B 

provides all available response spectra for the electrical panel and device tests. 

Reactor protection rack: at an input acceleration of 4.3g in the side-side direction, chatter of 

miniature relays on the AC controller caused the malfunction of the panel. 

Power center: at an input acceleration of 3.7g in the front-back direction, unexpected vibration of 

a manual close button caused an air circuit breaker to abnormally close. At a higher acceleration 

of 5g in the front-back direction, structural damage of the air circuit breaker occurred. 

6.9 kV Metal-Clad Switchgear: at an input acceleration of 2.5g in the front-back direction, 

malfunction of a grounded potential transformer (GPT) occurred when the fuses fell out. At a 

higher acceleration of 4.1g in the side-side direction, structural damage of a vacuum breaker 

occurred. 

For these loss-of-function cases, error or damage of electrical parts that caused the malfunction of 

the panels occurred before any damage to the panel structures. 
18 

3.3.1.2 Element (Device) Tests 

For element tests, JNES selected more than 30 different types of electrical parts (devices) from an 

initial list of about 300 devices, considering their potential weakness under seismic motion. 

Table 3-9 lists the different types of devices in the element test, including the number of 

specimens. This table also includes four types of additional element tests of grounded potential 

transformer and breakers, as they failed in the full-scale panel tests at relatively low level 

excitation. In the additional test, the fuse that fell out from the grounded potential transformer in 

the full-scale test was improved by installing a fuse slide stopper. As shown in Figure 3-17, the 

parts were installed on a support frame that was attached to the shaking table. The support frame 

was intended to simulate the electrical panels. The installation of the parts in the element test was 

the same as in the panels, for example, using the same number and size of bolts. 

Seismic waves for the element tests were generated from response analyses of the panels, in order 

to reflect the dynamic characteristics of the panels and the position of the devices in the panels. 

Therefore, the input waves for the element tests were different from each other. The devices were 

tested in both front-to-back and side-to-side directions, with the input maximum acceleration 

increased gradually from design level to about 10g. The TRS for the devices listed in Table 3-9 

are shown in Appendix B. 

Failure of a device during the shaking test occurred when the device could not maintain its 

normal function. For relays, their failure was defined as a chattering time longer than 2 ms 

according to the IEEE standard. 

The input acceleration to the parts was measured at the mounting position. Most of the tested 

devices performed normally up to the maximum input accelerations, which were mostly about 

10g, as shown in Table 3-9. Malfunction occurred for eight types of devices during the test, 

which include: 

• 1 protection relay 

• 1 auxiliary relay 

• 1 AC controller card 

• 2 air circuit breakers 

• 1 vacuum circuit breaker 

• 1 gas circuit breaker 

• 1 grounded potential transformer 

The critical acceleration for the devices that malfunctioned was as low as 2.5g. Some simple 

reinforcement to the devices that malfunctioned can greatly increase the seismic capacity as 

shown in Table 3-9. For example, the original GPT failed at an acceleration of 2.5g in the frontback direction, while the improved GPT reached an acceleration of 9.4g without evidence of 

malfunction. 

3.3.2 Fragility Evaluation and Fragility Data 

The fragility data of the 8 tested panels can be directly applied to those installed in current NPPs. 

However, as there are many more panels in NPPs that may not have similar configurations to 

those of the tested panels, JNES suggested an analytical method to compute the fragility of a 

panel based on the fragility data from the element tests. The full-scale panel tests showed that the 

malfunction of electrical parts, not the damage of the panel structure, caused the malfunction of 

the panels. The method includes four steps: (1) determine through analysis (e.g. finite element 

analysis) the amplification factor (AFi) of the panel at the location of a device i; (2) determine the 
19 

fragility capacity of the device fDi , from the JNES device fragility database or from test if not 

available in the database; (3) the corresponding panel fragility fPi for the subject device i can be 

determined as fPi = fDi/AFi; and (4) find the minimum of fPi among all major devices in the panel. 

Although structural strength is not controlling, the fragility capacity associated with the limit state 

of structural strength was also calculated using response spectrum analysis. The panel anchor 

bolts and housing structure were considered in the stress evaluation to determine the structural 

fragility capacity. The median tensile stress is defined as Su/η, where η = 0.856 for general steel 

and Su is the design tensile stress as specified in JSME “Standards for Nuclear Power Generation 

Equipment: Design and Construction Standards.” 

The dispersion of an electrical component was assumed to take the dispersion of either the critical 

acceleration of electrical parts or critical stress of structural members, depending on which 

dominates the fragility capacity of the panel. 

Table 3-9 also shows fragility data for those devices where malfunction occurred during the test, 

along with maximum input accelerations in the test for devices that did not lose their function. 

Appendix A provides fragility data for all devices. For cases where loss of function occurred, the 

fragility level was the average of the input acceleration at which loss-of-function occurred and the 

highest input acceleration when the function was maintained. For cases where no loss of function 

occurred, the fragility level was the average of the maximum input acceleration in the test and the 

assumed next step input acceleration at which loss-of-function was assumed. 

Table 3-10 shows the seismic capacity determined from the full sale test for the electrical panels, 

as either function confirmed if no abnormality occurred or the critical acceleration at which 

abnormality occurred. Table 3-10 also presents the fragility data from analysis for functional and 

structural limit states. It can be seen that structural fragility capacities are generally much greater 

than the functional fragility capacities. For panels that did not fail in the full-scale test, the 

tabulated fragility from analysis is conservative, because the fragilities of the electrical parts were 

assumed to be the maximum input acceleration in the element test. For the power center and the 

6.9 kV metal-clad switchgear, the fragilities (4.4g and 4.2 g, respectively) were estimated using 

the improved air circuit breaker and the improved GPT, respectively; therefore, the fragility 

capacities are higher than the loss of function accelerations (3.72 g and 2.52 g) in the full-scale 

test. For the reactor protection rack, the estimated fragility capacity (4.4 g) is very close to the 

loss of function acceleration (4.3 g) determined in the full-scale test. For the reactor control 

center, the fragility capacity was calculated to be 4.5 g based on the function critical acceleration 

of an auxiliary relay and the actual amplification factor at the mounting position of this auxiliary 

relay. It should be noted that the full-scale fragility test of this reactor control center reached an 

input acceleration of 6.12 g to generate abnormality. The reported smaller fragility capacity of 

this reactor control center was conservative. This difference may also be used to assess the level 

of uncertainty associated with the reported fragility capacity and in general with the hybrid 

experimental/analytical approach to derive the fragility capacities, although the reported 

uncertainties are generally very small in the JNES fragility report. 

From earlier NUPEC vibration tests, JNES estimated the previous seismic fragility to be 3.6g, 

which had been applied uniformly to all electrical panels in Japan NPPs [Iijima, et al, 2007, Fujita, 

et al, 1997]. All estimated fragility capacities, using improved parts in two cases, are greater than 

3.6 g. However, it should be noted that without improvement to the GPT, the 6.9 kV metal-clad 

switchgear had a loss of function acceleration of 2.52 g in the full-scale test, which is smaller than 

the estimated fragility (3.6g) based on the earlier NUPEC tests. 
20 

3.4 Control Rod Insertion Capability 

The JNES control rod insertion capability tests included full size mockup specimens for PWR and 

BWR systems. The purpose of the tests was to examine the functional fragility of PWR and 

BWR control rod insertion systems during strong seismic motions that exceed the design level, to 

develop fragility evaluation methodology, and to establish a fragility database for PWR and BWR 

control rod insertion systems [Inagki, et al, 2006]. Figure 3-18 shows the target range of the 

fragility tests in terms of the insertion period versus the displacement response of the fuel 

assembly, showing a significant increase of displacement response compared to previous NUPEC 

tests. 

A summary of the JNES tests will be presented separately for the PWR and BWR control rod 

insertion systems in the following subsections. 

3.4.1 PWR Control Rod Insertion Capability 

3.4.1.1 Full Scale Test 

Figure 3-19 through Figure 3-22 show the test setup for the PWR control rod insertion capacity 

test, the mockup of a PWR fuel assembly, a section view of the test setup, and a plan view of the 

three fuel assemblies including the control rod, respectively. The main test components such as 

the fuel assemblies, control rod, and control rod drive mechanism (CRDM) were all 

manufactured with the same specification as in representative 3/4 loop PWR plants except for the 

material of the fuel pellets. The fuel assembly is 17 × 17 type. As shown in Figure 3-21, the test 

specimen stands above the top of the shaking table for 10 m (mainly the CRDM) and below the 

table for 6.3 m (mainly the fuel assemblies and control rod). The fuel assemblies and the control 

rod were enclosed in a cylindrical vessel, which was supported by tie rods connecting to a very 

sturdy frame above the shaking table and to the shaking table under the table. A pump flow loop 

was installed for the investigation of the effect of core flow on the control rod insertion. 

Seismic input motion was generated based on a survey of Japanese PWR plant design conditions 

and a preliminary seismic analysis of the main test components. Input motion was controlled at 

the top of the shaking table. The magnitude of the input seismic motion was up to 3.3×S2, which 

is the extreme design earthquake ground motion in Japan. The maximum input acceleration in 

the JNES test was about 3.2 g, while it was 1.1 g in a similar earlier NUPEC test. 

Figure 3-23 shows the response spectrum of the synthesized S2 level input motion for the PWR 

CDRM tests, featuring two peaks of about the same magnitude. These two peaks correspond to 

the fundamental modes of the control rod cluster and the fuel bundle, respectively. Figure 3-24 

shows a filtered version of the same spectrum that contains only the peak corresponding to the 

fuel bundles. The filtered input motion was used in the tests in order to achieve larger fuel 

response than using the unfiltered motion. These input motions were scaled to various levels to 

determine the fragility capacities. The scale factor for the unfiltered input motion was in the 

range of 0.25 to 3.3. Figure 3-25 through Figure 3-30 show comparison of the target input 

motion at 3.3×S2 level to responses at various locations (the top of the shaking table, upper core 

plate, lower core plate, CRDM base, and upper core support plate). Still water and core flow 

conditions were considered in the tests. The filtered input motion was scaled up to 3.6×S2 level. 

The damping ratio for these spectra is 5%. 

Unlike the fragility tests for horizontal shaft pumps and electrical panels, element tests for the 

PWR control rod insertion capability was not intended to develop element fragility data but to 

identify the dynamic characteristic of the fuel assembly in water under large vibration. The 

maximum fuel response in water reached about 80 mm in the test. The results of this element test 
21 

were used to develop a stick model for the fuel assembly, which can reproduce the natural 

frequency and the response dependent damping. 

Under an input seismic motion up to 3.3×S2, the maximum displacement of the fuel assemblies 

was about 48 mm (corresponding to a fuel response displacement of 45 mm), and no abnormality 

was found in the test. The maximum fuel displacement was more than twice the past test data 

(about 22 mm). The maximum displacement of the CRDM was about 17.2 mm, compared to 3.3 

mm in the earlier NUPEC test. Figure 3-31 shows the test data for delay ratio of the PWR control 

rod insertion. The test results of PWR control rod insertion capability were in excellent 

agreement with the existing NUPEC test results for low range displacement response of the fuel 

assembly (proving test range). It should be emphasized that the JNES fragility test and the 

NUPEC proving test were performed using different test facilities and different input motions. 

The JNES fragility test also showed that the functional capacity of the control rod insertion 

system was at least twice of that proved in the previous NUPEC test [Inagaki, et al, 2006]. 

3.4.1.2 Fragility Evaluation and Fragility data 

Based on results of the NUPEC seismic verification test of PWR core internals, displacement 

response of the fuel assembly was used by JNES as the control variable (performance indicator) 

in the fragility analysis. Excessive displacement of the fuel assemblies can cause damage to the 

guide thimble, which was considered as the critical event for the PWR control rod insertion 

system. Fragility data was developed based on an analytical method which was validated against 

the test results for the PWR control rod insertion capability. 

Based on analysis considering the actual plant situation, such as operating temperature and flow 

rate, the median displacement of a fuel assembly was specified as 77 mm for 3/4 loop 

representative PWR plants, which corresponds to a seismic load of 4×S2. The logarithmic 

standard deviation was specified as 0.19, considering the dispersions of tensile strength and the 

dimensional tolerance of guide thimbles. This response dispersion was confirmed in the fullscale test. 

For a 2 loop PWR plant with fuel assemblies of a 14 × 14 type, the median displacement of a fuel 

assembly was specified as 69 mm. The logarithmic standard deviation was specified as 0.19, the 

same as for 3/4 loop PWR plant. 

In the past Japanese fragility evaluation, a scram time of 2.2 seconds was prescribed as the target 

of the control rod insertion time. However, an insertion time exceeding this scram time limit does 

not directly result in a problem. In NUPEC report INS/M03-05, “FY 2003, Report on 

Development of Probabilistic Safety Evaluation Method for Earthquake, Part III, Sophistication 

of Evaluation Method (In-core Thermal Hydraulic Analysis for Time Delay of Control Rod 

Insertion in PWR),” it was determined that core damage would not occur if the control rod can be 

inserted by the time when the pressurizer safety valve is initially actuated (about 8 seconds). 

This time limit was specified as the new target of the control rod insertion time used in the 

fragility capacity evaluation. 

3.4.2 BWR Control Road Insertion Capability 

3.4.2.1 Full Scale Test 

Figure 3-32 through Figure 3-35 show the test setup for the BWR control rod insertion capacity 

test, the mockup of a BWR fuel assembly, a section view of the test setup, and a plan view of the 

fuel assemblies and the control rod, respectively. The main test components, such as the fuel 

assemblies, control rod, and CRDM, were manufactured with the same specification as in 
22 

representative BWR plants (BWR5) with 100 mil channel boxes, except for the material of the 

fuel pellets. The BWR5 plant features a high speed scram type CRDM. As shown in Figure 3-34, 

the test specimen stands above the top of the shaking table for 9.3 m (mainly the fuel assemblies 

and control rod) and below the table for 3.8 m (mainly the CRDM). The four fuel assemblies and 

the control rod were enclosed in a cylindrical vessel, which was supported by tie rods connecting 

to a very sturdy frame above the shaking table and to the shaking table under the table. 

Seismic input motion was generated based on a survey of Japanese BWR plant design conditions 

and a preliminary seismic analysis of the main test components. Input motion was controlled at 

the top of the shaking table. The magnitude of the input seismic motion was up to 4×S2. The 

maximum input acceleration was about 3g, while it was 1.5g in the past NUPEC test. 

Synthesized input motion (designated as Input Wave A) developed based on the envelop of the 

design spectra of Japanese BWR plants was found in the test not to be able to achieve adequate 

excitation, neither did a filtered version (designated as Input Wave B) that contains mainly the 

frequency contents for the fuel assembly. Therefore, the Input Wave C was developed by 

superposing sinusoidal wave components with dominant frequency range around 4.8 Hz, which is 

the fundamental frequency of the fuel assembly. The Input Wave C at S2 level is shown in 

Figure 3-36. The Input Wave C was further adjusted for use in the full scale test by shifting the 

center frequency to 5.8 Hz (measured frequency) and broadening the target spectrum by 10%, to 

consider the plastic behavior of the fuel assembly under large excitation. Figure 3-37 shows the 

adjusted Input Wave C. These motions were used in the test with various scale factors. Figure 

3-38 shows a comparison of the target spectrum and the response at the top of the shaking table 

for a scale factor of 4.4. The damping ratio for these spectra is 5%. 

The element test for BWR control rod insertion capability included a material test, buckling test, 

load-displacement history test, and repeated loading test of a channel box, which is the main 

structural member of a fuel assembly. The test confirmed that the plastic deformation at 

operating temperature was larger than at room temperature. The maximum fuel displacement was 

about 100 mm in the element test. The test results were also used to develop an analytical model. 

Under an input seismic motion up to 4×S2, the maximum displacement of the fuel assemblies 

was about 83 mm and no abnormality was found in the test. The maximum fuel displacement 

was significantly larger than in the past test (about 34 mm). Figure 3-39 shows the test data for 

delay ratio of the BWR control rod insertion. The test results of BWR control rod insertion 

capability showed excellent agreement with the existing NUPEC test results for low range 

displacement response of the fuel assembly (proving test range). It should be emphasized that the 

JNES fragility test and the NUPEC proving test were performed using different test facilities and 

different input motions. The JNES fragility test also showed that the functional capacity of the 

control rod insertion system was at least twice of that proved in the previous NUPEC test [Inagaki, 

et al, 2006]. 

3.4.2.2 Fragility Evaluation and Fragility Data 

Based on results of the NUPEC seismic verification test of a BWR in-core structure, 

displacement response of the fuel assembly was used by JNES as the control variable 

(performance indicator) in the fragility analysis. Excessive displacement of the fuel assemblies 

can cause collision of the fuel bundle and shroud, which was considered as the critical event for 

the BWR control rod insertion system and was defined as the fragility capacity limit. Fragility 

data was developed based on an analytical method which was validated against the test results for 

the PWR control rod insertion capability. 
23 

Based on analysis considering the actual plant situation such as temperature, the median 

displacement of a fuel assembly was calculated as 91mm for BWR plants with 100 mil channel 

boxes. This calculation assumed that the fuel displacement had a log-normal distribution, with 83 

mm as the 5% percentile and 100 mm as the 95% percentile. The logarithmic standard deviation 

was specified as 0.10 (it appears that the calculated value should be 0.06 based on the above 

assumption). 

For representative BWR plants with 80 mil or 120 mil channel boxes, the median fragility was 

specified as 91 mm, the same as for BWR plants with 100 mil channel boxes, while the 

logarithmic standard deviation was 0.1 for BWR plants with 80 mil channel boxes and 0.09 for 

BWR plants with 120 mil channel boxes. 

In the past Japanese fragility evaluation, a scram time of 1.62 seconds was prescribed as the target 

of the control rod insertion time. However, an insertion time exceeding this scram time limit does 

not directly result in a problem. This prescribed scram time was also used in the fragility 

evaluation, because it was confirmed by analysis that the delay of the control rod insertion was 

still below the prescribed scram time even when the fuel assembly response reaches 100 mm, at 

which fuel-shroud collision would initiate (see Figure 3-39). 

3.5 Large Size Vertical Shaft Pumps 

3.5.1 Summary of Large Size Vertical Shaft Pump Test 

The JNES test program for large size vertical shaft pumps included a full-scale equipment test for 

a pit barrel type pump of the reactor residual heat removal system (RHR) and element tests of 

submerged bearings, liner rings, and thrust bearings. 

 

3.5.1.1 Full Scale Test 

Figure 3-40 and Figure 3-41 show the test setup for the RHR pit barrel pump and a section view 

of the RHR pump installed on the TADOTSU shaking table. As shown in Figure 3-41, the RHR 

pump stands above the top of the shaking table for 7 m (mainly motor and motor stand) and 

below the table for 8 m (mainly the pump and pump barrel). The RHR pump has a flow rate of 

1691 m3/h, a head of 92 m, and a mass of 61×103 kg (about 49×103 kg for pump and 13×103 kg 

for motor). The test specimen also included piping and other components in order to simulate the 

operating condition. The diameter of the barrel support, as indicated in Figure 3-41, varied in the 

test such that the diametric clearance had a value of 1 mm, 2 mm, or 4 mm, depending on the test 

purposes. 

Both horizontal and vertical excitations, while applied separately, were considered for normal 

operating conditions and shutdown conditions. The input seismic waves were generated using a 

response spectrum that envelops the design floor response spectra for large size vertical shaft 

pumps in Japanese BWR and PWR NPPs. Multiple simulated seismic waves utilized in the test 

had different frequency characteristics to investigate different parts of the pump system, e.g., the 

horizontal A wave for barrel without gap (16.1 Hz) and the horizontal D wave for barrel body 

(6.4 Hz). 

Figure 3-42 through Figure 3-44 shows the response spectra for the A wave, D wave, and D’ 

wave, respectively. Figure 3-45 shows a comparison of these three waves. The maximum 

acceleration is 1.24 g and the damping ratio for these horizontal spectra is 1%. Figure 3-46 

shows a comparison of the response spectra for the target and the vertical wave. Quite differently 
24 

from the horizontal direction, the damping ratio for the vertical wave was 5%. The maximum 

acceleration for the vertical wave is 0.22 g. As indicated by Figure 3-45, the A wave was 

developed by filtering the D wave with a high pass filter with a corner frequency of 11.1 Hz, and 

the D’ wave was developed by reducing by half the D wave response spectrum in the frequency 

vicinity around fundamental modes of the motor portion and the barrel portion with no gap. Both 

the A wave and the D wave are adequate if the gap at the barrel support is negligible, although the 

D wave produces smaller shaking table acceleration. For cases where the gap at the barrel 

support is not negligible, regardless of whether barrel collision would occur, the D wave is 

adequate but not the A wave. The test was performed in the following steps: 

Step 1: Using A wave with 4 mm gap (design gap) for function limit test assuming 

gap effect at barrel support is negligible. 

Step 2a: Using D (or D’) wave with 4 mm gap to investigate the gap effect. 

Step 2b: Using D (or D’) wave with narrower gap (2 mm) to investigate the effect of 

gap width. 

Step 2c: Using D (or D’) wave with no gap (0 mm) to investigate the effect of gap 

width. 

Step 3: Using vertical wave with 0 mm gap for function limit test. 

Step 4: D (or D’) wave (horizontal) and the vertical wave with 0 mm gap to compare 

responses obtained from one directional loading. 

The horizontal test showed that although the motor mounting bolt yielded at a response 

acceleration of 12 g at the top of the motor (12 g-TOM, for short), motor function was maintained 

even at 14 g-TOM. The barrel yielded at a response acceleration of 31 g at the bottom of the 

barrel (31 g-BOB, for short). Nonlinear response behavior as a function of the diameter clearance 

at the barrel support was identified in the horizontal test. These horizontal confirmed response 

capacities greatly exceeded the existing function-confirmed response accelerations 10 g-BOB and 

2.5 g-TOM as reported in JEAG4601. The vertical test showed that the function of the pump was 

maintained at 31 g-BOB and 12 g-TOM. No abnormality was found during the test and in the 

after-test disassembling inspection. Table 3-11 shows selected test results for the large size 

vertical shaft pump test. 

3.5.1.2 Element Tests 

Table 3-12 lists 9 parts that were included in JNES element tests for the large size vertical shaft 

pumps, including large and small size carbon bearings, solid lubricant distributed oilless bearings, 

resin bearings, rubber bearings, Kingsbury type thrust bearings, parallel plane type thrust bearings, 

and liner rings of two sizes. Three or four specimens were tested for each of the 9 parts. This 

table also presents the typical dimensions and materials of these parts. These parts were used in 

the selected large size vertical shaft pumps in the JNES equipment fragility evaluation. Figure 

3-47 shows a liner ring sample and a bearing sample. 

The selected elements (parts) were tested under simulated seismic excitations that were much 

larger than the excitations used for the full-scale test. The purpose of the element tests for the 

large size vertical shaft pumps was to confirm whether lose of function occurred for the parts 

subjected to very large seismic load and to obtain their dynamic characteristics (such as spring 
25 

constant, damping, and PV value (pressure-slide velocity)). Figure 3-48 shows the nonlinear 

load-displacement behavior of a shaft bearing under large excitation, in which the impulse shaped 

response was due to the diametric clearance. 

The element tests showed that the rotation function of submerged bearings was maintained up to 

a surface pressure that was 5 times the design allowable surface pressure. Excessive deformation 

occurred for rubber and resin bearings although their rotation function was maintained. The 

rotation function of the liner rings was maintained under the maximum vibrating load of about 

17.0 kN, which was equivalent to 3×S2 (S2 was the enveloping design floor response of 

BWR/PWR plants, with a ZPA of 1.24 g). Using the spring constant that was determined from 

the tests, an uplift analysis showed that under a vertical acceleration of 1.3 to 1.5 g, the bearing 

load of the slide type thrust bearings reached the maximum load (determined in the element test) 

or collision occurred between the liner ring and the pump impeller. The acceleration that caused 

liner ring-impeller collision was conservatively defined as the uplift limit of the vertical shaft 

pumps. This level of acceleration corresponds to 6×S2 (S2 was vertical ground motion with a 

ZPA of 0.22 g). 

3.5.2 Fragility Evaluation and Fragility Data 

According to their structural characteristics, large size vertical shaft pumps can be classified into 

three categories (as shown Figure 3-49): pit barrel type, vertical mixed flow type, and vertical 

single-stage floor type. Vertical single-stage floor type pumps are structurally very similar to the 

motor portion (above installation floor) of the other two types of vertical shaft pumps. It was 

further confirmed in the full-scale test that the response of the motor portion and that of the pump 

portion could be evaluated separately. Therefore, the vertical single-stage floor type pumps were 

not considered in the fragility analysis. 

The pit barrel type pumps and the vertical shaft mixed flow pumps share many structural features, 

as shown Figure 3-50. The barrel support in the pit barrel type pumps is similar to the 

intermediate support in vertical mixed flow pumps. Therefore, the same analytical procedure was 

used for both types of pumps to calculate the seismic capacity for fragility analysis. 

The full-scale test of the RHR pump showed that the response of the pump portion included both 

fundamental frequency response and high frequency response, the latter of which was due to the 

collision at the clearance of the barrel support. It was also confirmed that the response of the 

motor portion consisted of only fundamental frequency response. 

For cases where the diametric clearance existed at the barrel support of bit barrel type pumps or 

the intermediate support of mixed flow pumps, an equivalent linear analysis and an impulse 

response analysis were performed for the pump portion to calculate the fundamental frequency 

response and the high frequency response, respectively. The overall response was the algebraic 

summation of the fundamental frequency response and the impulsive response. Seismic load at 

the motor portion was calculated by linear analysis using a model identical to the equivalent 

linear analysis for the pump portion. Figure 3-51 illustrates how the equivalent linear stiffness of 

the barrel support was obtained from the nonlinear stiffness (similar to the nonlinear load 

displacement relationship obtained in the element test, see Figure 3-48) at the maximum 

displacement y. The mode shape vector was used to determine the maximum displacement at the 

bottom of the pump. 

In the impulsive analysis, the momentum change of the pump system in the collision of the barrel 

and barrel support was calculated, using equivalent lumped masses at the fundamental mode and 
26 

velocities at these masses, as shown in Figure 3-52. The impulsive force was then calculated 

assuming an impulsive duration ∆t = 1/600 seconds, which was judged sufficiently small 

compared to the high frequency response below 100 Hz. 

 

Figure 3-53 shows the one dimensional multi-mass model that JNES developed for the horizontal 

response analysis of the vertical shaft pumps. Both shear and flexible deformations were 

included in the beam model. Figure 3-54 shows the JNES two mass model for the vertical 

response analysis of the vertical shaft pumps. In the vertical response analysis, the uplift at the 

thrust bearing and the design clearance between the liner ring and impeller were considered as the 

criteria. 

The damping ratios for various parts were chosen to be in the range of 1% to 3%. 

Both rotating function and structural strength were considered in the fragility evaluation. For the 

rotating function limit state, the evaluation focused on the motor body, submerged bearing, and 

liner ring. For the structural strength limit state, the evaluation focused on the pump foundation 

bolt, mounting bolts (pump, motor, and motor stand), barrel, and column. 

 

3.5.2.1 Fragility Evaluation for Structural Strength 

Both earthquake load and the initial tightening force were considered in the evaluation of the 

tensile stress of bolts. The tensile stress was calculated using the overturning moment. The load 

factor for the bolts, which is the ratio of the portion of earthquake load taken by a bolt over the 

total earthquake load on the bolt connection, were conservatively assumed to be 0.5. The load 

factor for a bolt connection reflects the relative stiffness of the bolt versus the flange. The median 

value of the tensile stress of the bolt was specified Su/η, where η = 0.856 for general steel or 

0.885 for stainless steel (confidence coefficient) and Su is the design tensile strength described in 

JSME “Standards for Nuclear Power Generation Equipment: Design and Construction Standards.” 

A critical stress of 0.75Su/η was used in cases where nominal diameter of the bolt was used in the 

calculation. 

Slip at the mounting surfaces was not identified in the full-scale test; however, as the relative slip 

between the motor and the pump may critically affect the rotation function of the pump, potential 

slip was evaluated at the motor mounting surface and at the motor stand mounting surface. The 

shear force during earthquake was assumed to be shared by all bolts in the same shear plane. The 

uncertainty in the torque was specified as β = 0.25 according to Japanese Industrial Standard 

“Points of Screw Tightening Mechanism Design.” A friction coefficient of 0.3 was used in the 

evaluation, with a logarithmic standard deviation β = 0.123, based on “Guide for Design and 

Construction of Lightweight Steel Structure, and its Interpretation” (a Japan standard). JNES 

recognized that many uncertain factors existed for the slip phenomena, and the resultant fragility 

capacity was reported as reference values. Su/(√3η) was specified as the critical shear stress 

based on shear stress strain theory. 

For bolts that do not affect the rotation function of pumps, the dispersion of critical stresses was 

0.07 for general steel and 0.05 for stainless steel. For bolts that may affect the rotation function 

of pumps, the dispersion of critical stresses was 0.09 for general steel and 0.07 for stainless steel. 

For barrel and column, Su/η was specified as the median tensile strength. The corresponding 

dispersion was specified as 0.07 for general steel and 0.05 for stainless steel. The strength of 

barrel and column was evaluated using the greater of the axial stress and the hoop stress. The 
27 

axial stress was the sum of the stresses due to bending moment, internal pressure, self-weight, and 

water weight in the barrel. The hoop stress was due to internal pressure. 

3.5.2.2 Fragility Evaluation for Rotation Function 

Up to the maximum vibration capacity of the shaking table, loss of function did not occur in the 

element tests for the submerged bearings and liner rings. Therefore, the minimum function 

confirmed PV values were conservatively specified as the rotation function limit. The median 

capacity and the corresponding logarithmic standard deviation were not calculated for the carbon 

bearing, solid lubricant distributed non-lubricated bearing, and liner ring. However, for rubber 

bearing and resin bearing, even though no loss of function had occurred, since the end surface of 

the bearings were found to be deformed at the maximum vibration load, the PV values were 

considered as indicators of the limit of rotation function. Accordingly, the median capacity and 

the logarithmic standard deviation were calculated as reference values. In the calculation of PV 

values, the velocity during the rated operation state of the pumps was used. 

For the liner ring made of martensitic stainless steel, the PV values were specified based on the 

element test results in the horizontal shaft pump fragility test. 

The maximum response acceleration 14 g-TOM (at the top of the motor) obtained in the full-scale 

test was considered to be a function confirmed response acceleration. The maximum response 

acceleration at the top of the motor was treated as the index variable for the rotating function limit 

of the pump system. 

3.5.2.3 Summary of Fragility Data 

In addition to the pit barrel type RHR pump which was tested in full scale, the JNES fragility 

evaluation for large size vertical shaft pumps also included a high pressure core injection system 

pump, a component cooling seawater pump (PWR), and a component cooling seawater pump 

(BWR). 

The high pressure core injection system pump is a pit barrel type, with a flow rate of 727 m3/h, a 

total pump head of 190 m, and a mass of 62×103

 kg (about 52.5×103 kg for pump portion and 

8.5×10

3

 kg for motor portion). 

The component cooling seawater pump (PWR) is a vertical mixed flow pump, with a flow rate of 

5300 m3/h, a total pump head of 48 m, and a mass of 31×103 kg (about 17.8×103 kg for pump 

portion and 13×103

 kg for motor portion). 

The component cooling seawater pump (BWR) is a vertical mixed flow pump, with a flow rate of 

1080 m3/h, a total pump head of 40 m, and a mass of 15×103 kg (about 10×103 kg for pump 

portion and 5×103

 kg for motor portion). 

Table 3-13 and Table 3-14 summarize some selected fragility data for the large size vertical shaft 

pumps under horizontal and vertical excitations, respectively. It should be emphasized that all 

reported fragility data related to loss of function of bearings or liner rings should be interpreted as 

function confirmed capacities, because the element tests and full-scale test of the RHR pump did 

not show any damage that would hinder the rotation functions of the parts. For horizontal 

excitations, the fragility data were reported as response acceleration at the top of the motor or at 

the bottom of the barrel; the corresponding input acceleration at the top of the shaking table was 

not reported. Most of the fragility data were estimated by analysis using element test data as 

shown in Table 3-15. The relative slip at the motor mounting surface was controlling, with 
28 

fragility capacities between 2.8 to 6.2 g-TOM. Since the slip phenomena involves a large amount 

of uncertainty and the corresponding capacity could be increased simply by tightening the anchor 

bolts, the fragility data were designated as reference values. In fact, a horizontal fragility capacity 

of 14 g-TOM was achieved in the full-scale test of the pit barrel type RHR pump after tightening 

the anchor bolts, compared to 3.6 g-TOM as estimated in the analysis. 

Either no or a very small logarithmic standard deviation was reported for the large size vertical 

shaft pumps. A slightly larger logarithmic standard deviation β of 0.12 was calculated based on 

the distributions of friction factor of slip surface, torque constant of bolt, and tensile strength of 

material; while a smaller β of 0.09 was calculated based on distribution of tensile strength of 

material. 

Table 3-15 shows the median capacities for the resin bearings and rubber bearings, and the 

minimum confirmed capacities for other submerged bearings, liner rings, and thrust bearings, 

which were determined in the element tests for the large size vertical shaft pumps. It should be 

pointed out that the fragility data was reported in terms of PV value (MPa × m/s) and/or load (kN) 

in the JNES equipment fragility report, while only load capacities are summaries in Table 3-15. 

Most of the fragility capacities were function confirmed except for resin bearings and rubber 

bearings. In these cases excessive deformation occurred but rotational function was maintained 

in the test. The logarithmic standard deviation for the resin bearings and rubber bearings, 0.06 

and 0.03, respectively, were derived using three samples (the 4th sample had different test 

conditions and was not counted in the statistics); these values were reported as reference values. 
29 

Table 3-1 Types of Horizontal Shaft Pumps in Japan NPPs 

[from Iijima, et al, 2004] 

Pumps Reactor Single Stage Multi-stage

Reactor Building Closed Cooling Water Pump 

BWR 

× 

Residual Heat Removal Cooling Water Pump × 

Emergency Equipment Cooling Water Pump × 

High Pressure Core Spray Cooling Water Pump × 

Reactor Core Isolation Cooling Pump × 

High Pressure Core Injection Pump × 

Component Cooling Water Pump 

PWR 

× 

Residual Heat Removal Pump × 

C/V Spray Pump × 

Charging Pump × 

Safety Injection Pump × 

Table 3-2 Element Types for Horizontal Shaft Pumps 

[from Iijima, et al, 2005] 

Element (Device) Size (Type) Number of 

Specimens 

Radial Bearing 

Ball 110 mm O.D. (6310) 

170 mm O.D. (6316) 

3 

3 

Slide 60 mm I.D. 

80 mm I.D. 

3 

3 

Thrust Bearing 

Ball 

110 mm O.D. (6310) 

170 mm O.D. (6316) 

170 mm O.D. (7316B) 

3 

3 

3 

Slide 127 mm I.D. 3 

Liner Ring 

Flat 

270 mm I.D. 

267 mm I.D. 

195 mm I.D. 

175 mm I.D. 

88 mm I.D. 

3 

3 

3 

3 

3 

Groove 95.5 mm I.D. 3 

⋆ Ball bearing type 6316 and 270 mm liner ring were used in the RCW pump. 
30 

Table 3-3 Summary of Selected Critical Values for the Fragility Evaluation 

[from Appendix A, JNES, 2009 ] 

Function Direction Critical portion Fragility evaluation item Description Item Set value* 

Active function 

Axial 

Deep groove ball 

bearing 

Bearing load

Coa×1/3 

• Coa: Run-onto static rated load of bearing • To be set based on friction generation load 

decrease of operating life of bearing, using results 

Angular ball 

bearing Coa • To be more conservatively set than functio

the element test 

Slide bearing PV value 129MPa・m/s • Minimum value of function-confirmed loa

Lateral 

Deep groove ball 

bearing Bearing load Cor×1/1.5 • Cor: Basic static rated load of bearing • To be more conservatively set than functio

Angular ball the element test 

bearing 

Slide bearing PV value 121MPa・m/s 

• To be set based on the minimum value of lo

change, considering generation of plastic fcause decrease of operating life of bearing 

Structural strength Axial/ Lateral Foundation bolt Mounting bolt Tensile stress Shear stress 0.75Su/η (Su/√3)/η • Su: Design tensile stress η: Confidence coefficient (general steel pr

steel: 0.885) • Simplified evaluation for bolt strength Axial/ Lateral Mounting bolt Horizontal load μ・(F+W) (As reference value) • μ: Friction coefficient (0.3) F: Sum of bolt tightening forces W: Dead load of pump or motor 

• Simplified evaluation for slip of mounting 

* Set value: Reference value used for fragility evaluation 
31 

Table 3-4 Summary of Fragility Data for Horizontal Shaft Pumps 

Component Limit 

State 

Shaking 

Direction 

Median 

Fragility (g) 

Logarithmic 

Std (β) Failure Mode 

RCW Pump 

(full-scale test) 

Functional Axial 8.4 0.21 Wearing of ball bearing 

Structural 

Lateral 28.5 0.07 Damage of foundation 

bolt 

Axial/ 

Lateral 6.1* - Slip of motor 

RCW Pump 

2 

Functional Axial 8.6 - 

Structural 

Lateral 23.5 0.07 Damage of foundation 

bolt 

Axial/ 

Lateral 5.3* - Slip of motor 

Charging/HP 

Injection 

Pump 

Functional Axial 17.3 - 

Structural 

Laterial 11.0 0.07 Damage of foundation 

bolt 

Axial/ 

Lateral 2.6* - Slip of motor 

* Reference fragility 

Table 3-5 Summary of Fragility Data for Ball Bearings used in Horizontal Shaft Pumps 

Model Number /Load 

Case 

Median Fragility 

(kN) Logarithmic Std (β) 

6310 / Thrust 24.0 0.21 

6316 / Thrust 25.3 0.01 

7316B / Thrust > 59 FC 

6310 / Radial 26 FC 

6316 / Radial >31 FC 

FC: function confirmed, no fragility value was specified.
32 

Table 3-6 Summary of Fragility Data for Slide Bearings used in Horizontal Shaft Pumps 

Diameter (mm) 

/Load Case 

Median Fragility 

Logarithmic 

Function Critical Std (β) 

Load (kN) 

Maximum 

Surface Pressure 

(MPa) 

Function Critical 

PV Value 

(MPa*m/s) 

80 I.D. / Radial 42.9 8.9 134 0.03 

60 I.D. / Radial 21.2 8.0 121 0.12 

127 O.D. / Thrust 45 (FC) 5.24 129 FC 

 FC: function confirmed, no fragility value was specified. 

Table 3-7 Summary of Fragility Data for Liner Rings used in Horizontal Shaft Pumps 

Inner Diameter 

(mm) 

Function 

Confirmed Load 

(kN) 

Maximum 

Surface Pressure 

(MPa) 

Function 

Confirmed PV 

Value (MPa×m/s) 

270 20.9 1.9 47.9 

175 6.0 1.2 20.1 

267 20.9 2.0 49.0 

88 11.0 1.28 28.0 

195 7 1.89 58 

95.5 5 0.58 10 

Note: all values are the smallest function confirmed values among the specimens. 
33 

Table 3-8 Properties of the Tested Electrical Panels 

Panel Dimension (m) 

W × H × D 

Weight 

(kg) 

Frequency 

(Hz) 

Main Control Board 2.65 × 1.01 × 1.35 1010 44 

Reactor Auxiliary Control Board 2.1 × 2.3 × 2.6 2580 31 

Logic Circuit Control Panel 1.0 2.3 × 1.0 750 22 

Reactor Protection Rack 1.8 × 2.3 × 0.9 2160 29 

Instrumentation Rack 2.3 × 1.9 × 0.6 670 33 

Reactor Control Center 0.8 × 2.3 × 0.8 640 36* 

Power Center 1.8 × 2.3 × 2.0 4050 24 

6.9 kV Metal-Clad Switchgear 2.0 × 2.3 × 2.5 5600 21 

* Front-back direction, all other frequencies are for side-side direction.
34 

Table 3-9 Electrical Parts in JNES Element Tests and Fragility Data 

Part Category Part Type 

Number 

of 

Specimens

Front-Back Side-Side 

Failure 

Median Mode 

(g) β

Median 

(g) β

Protection relay 

TUB-2-D 3 9.5 0.13 10.0 chatter 

CO-18-D 9 10.6 10.0 

VCR62D 3 12.0 12.7 

Auxiliary relay 

NRD-81 9 5.9 0.0 10.6 Chatter 

UP3A 9 11.0 11.5 

MY4Z 9 10.1 10.0 

Timer H3M 9 10.1 10.0 

Comparator card HALN 3 9.9 9.5 

AC controller 

card HASN 3 9.9 8.3 0.17 Chatter of 

miniature relay 

Flat display 18 inch 3 10.2 9.5 

Controller 18 inch 3 10.4 10.4 

Controller 

(CPU) TOSMAP 3 10.8 10.9 

I/O Unit TOSMAP 3 10.6 10.6 

Test module S9166AW 3 10.5 10.1 

Power module S9016AW 3 10.5 10.1 

Monitor module S9146AW 3 10.5 10.1 

Power unit 

TFV 3 11.0 10.2 

S9980UD 1 10.5 10.1 

Differential 

pressure 

transmitter 

EDR-N6L 4 10.0 10.1 

AP3107 3 10.5 10.5 

UNE13 3 10.0 10.0 
35 

Part Category Part Type 

Number 

of 

Specimens

Front-Back Side-Side 

Failure 

Median Mode 

(g) β

Median 

(g) β

Pressure 

transmitter EPR-N6L 1 10.4 10.1 

Magnetic 

Contactor 

MSO-A80 9 9.7 10.1 

C-20J, T-20J 9 10.3 10.0 

Molded case 

circuit breaker 

NF100-SH 9 9.8 9.6 

SH100 9 10.4 10.1 

F type 9 10.1 10.0 

Module Switch SSA-SD3-53 9 10.3 9.9 

Cam-operated 

switch MS 9 10.1 10.0 

Key switch ACSNK 9 10.1 10.0 

GPT VTZ-E6EP 1* 2.5 --- 8.8 --- Fuses fell 

out 

VTZ-E6EP 

(improved) 1* 9.4 10.3 

Air circuit 

breaker 

B10-1 1* 9.1 10.1 

DS-416 1* 3.8 --- NA NA Error of 

closing 

DS-416 

(improved) 1* 7.9 NA NA 

DS-840 

(from panel test) 1 3.3 --- NA NA Error of 

closing 

Gas circuit 

breaker 6-SFG-40S 1* 3.5 --- 6.7 Structural damage 

Vacuum circuit 

breaker 

VF-6M63 

(from panel test) 1 4.4 --- 8.4 --- Structural 

damage 

Notes: (1) * Additional test of GPT and breakers, 

(2) A blank β means maximum tested acceleration at which no malfunction occurred for 

all specimens, 

(3) A β = --- means only one specimen tested, and β could not be evaluated, 

(4) NA means not tested for the subject case or data was not available. 
36 

Table 3-10 Summary of Fragility Data for Electrical Panels 

Panel Test 

(g) Abnormality 

Analytical Fragility Evaluation 

Limit State Median (g) β Failure Mode 

Main control 

board 

5.69 

(SS) No 

Functional 5.6 (SS) - Flat display 

Structural 42.2 (SS) 0.07 Foundation Bolt 

Reactor 

auxiliary panel 

5.90 

(BF) No 

Functional 9.8 (BF) 0.02 Module switch 

Structural 82.4 (SS) 0.07 Cabinet 

Logic circuit 

control panel 

5.88 

(BF) 

No 

(but door hinge 

was broken)

Functional 6.7 (SS) 0.027 Power supply 

unit 

Structural 15.3 (SS) 0.07 Anchor bolt 

Reactor 

protection rack 

4.3 

(SS) 

Malfunction of 

Miniature relay 

Functional 4.4 (SS) 0.166 AC controller card 

Structural 15.8 (SS) 0.07 Anchor bolt 

Instrumentation 

Rack 

5.69 

(SS) No 

Functional 4.2 (SS) - Differential pressure 

transmitter 

Structural 18.2 (BF) 0.07 Anchor bolt 

Reactor control 

center 

6.12 

(BF) 

Malfunction of 

auxiliary relay 

Functional 4.5 (BF) - Auxiliary relay 

Structural 22.6 (SS) 0.07 Foundation bolt 

Power center 3.72 

(BF) 

Air circuit 

breaker closed 

Functional 4.4 (BF) - Receiving circuit 

breaker 

Structural 8.1 (SS) 0.07 Housing 

6.9 kV Metalclad switchgear 2.52 

(BF) 

Fuse drop 

out 

Functional 4.2 (SS) - Circuit breaker 

Structural 8.6 (SS) 0.07 Foundation bolt 

Note: SS stands for the side to side direction; 

BF stands for back to forth direction 
37 

Table 3-11 Selected Results for the Full-scale Vertical Shaft Pump Test 

Test Condition Test Results 

Input Wave 

Diametric 

Clearance 

(mm) 

BOB 

Acceleration 

(g) 

TOM 

Acceleration 

(g) 

Input 

Acceleration 

(g) 

Loss of Function 

Horizontal D’ (1) 1.0 31 - 2.8 

No, but yield of 

barrel at barrel 

support 

Horizontal D’ (2) 1.0 35 - 2.8 No 

Vertical 1.0 2.2 - 1.9 No 

Horizontal A 4.0 - 14 1.6 No 

Vertical 1.0 - 2.3 1.9 No 

Horizontal D 1.0 - 12 1.5 

No, but yield of 

motor mounting 

bolts 

Notes: 

BOB: bottom of barrel 

TOM: top of motor 

A wave: input wave including frequency content at 16.1 Hz for barrel (assuming no 

diametric clearance at barrel support) 

D wave: input wave including frequency content at 6.4 Hz for barrel body (assuming 

diametric clearance is large enough to avoid collision) 

D’ wave: a modified D wave with the motor frequency content (at about 20 Hz) reduced by 

half, in order to suppress motor response but produce large barrel response 
38 

Table 3-12 Element Types for Large Size Vertical Shaft Pumps 

Element Type 

Inner 

Diameter 

(mm) 

Length / 

Height 

(mm) 

Diametric 

Clearance 

(mm) 

Number 

of 

Specimens

Remarks 

Carbon bearing (large) 100 115 0.41~0.48 3 Graphite 

Carbon bearing (small) 55 50 0.41~0.48 3 Graphite 

Solid lubricant distributed 

oilless bearing 100 80 0.39~0.58 4 

Sintered metal of 

lead bronze alloy 

and graphite 

Resin bearing 120 120 0.14~0.34 4 

High polymer of 

fluorine and 

carbon 

Rubber bearing 100 120 0.14~0.34 4 

Copolymer of 

butadiene and 

acrylonitrile 

Flat type liner ring 355 50 0.53 3 Austenitic 

stainless steel 

Flat type liner ring 550 45 1.17 3 Austenitic 

stainless steel 

Kingsbury type thrust 

bearing 

270 

(540 O.D.) 270 - 3 Slide bearing 

Parallel plane type thrust 

bearing 

250 

(470 O.D.) 184 - 3 Slide bearing 
39 

Table 3-13 Summary of Fragility Data for Large Size Vertical Shaft Pumps (Horizontal Vibration) 

Pump Median Value (g) β Damage Mode 

Pit barrel type RHR 

pump 

37.1 (BOB) - Loss of function of submerged 

bearing 

3.6 (TOM) 0.12 (Reference) Slip at motor mounting surface 

14.0 (TOM) - 

Achieved in the full-scale test 

after reinforcing mounting bolts 

High pressure core 

injection system 

pump 

17.7 (BOB) - Loss of function of submerged 

bearing 

3.5 (TOM) 0.12 (Reference) Slip at motor mounting surface 

14.0 (TOM) - 

Component cooling 

seawater pump 

(PWR) 

96.9 (BOB) - Loss of function of submerged 

bearing 

6.2 (TOM) 0.12 (Reference) Slip at motor mounting surface 

6.3 (TOM) 0.09 Yielding of motor stand 

mounting bolt 

Component cooling 

seawater pump 

(BWR) 

14.6 (BOB) - Loss of function of submerged 

bearing 

2.8 (TOM) 0.12 (Reference) Slip at motor mounting surface 

4.3 0.09 Yielding of motor stand 

mounting bolt 

Notes: 

BOB: bottom of barrel 

TOM: top of motor 

Table 3-14 Summary of Fragility Data for Large Size Vertical Shaft Pumps (Vertical Vibration) 

Pump Maximum Input 

Acceleration (g) Thrust Bearing Type 

Pit barrel type RHR pump 1.9 Ball bearing 

Component cooling seawater 

system pump (PWR) 1.5 (6.7S2) Kingsbury bearing 

High pressure core injection 

system pump 1.3 (5.7S2) Parallel plane bearing 
40 

Table 3-15 Summary of Fragility Data for Bearings and Liner Rings used in Large Size Vertical 

Shaft Pumps 

Element Type Median / 

Minimum FC Loads (kN) β 

Carbon bearing (large) 95.9 FC 

Carbon bearing (small) 51.9 FC 

Solid lubricant distributed 

oilless bearing 98.8 FC 

Resin bearing 61.1 0.06 (Reference) 

Rubber bearing 69.8 0.03 (Reference) 

Flat type liner ring 

(355 I.D.) 20.0 FC 

Flat type liner ring 

(550 I.D.) 17.5 FC 

Kingsbury type thrust 

bearing 1,500 FC 

Parallel plane type thrust 

bearing 1,500 FC 

Notes: 

 FC: function confirmed. 
41 

Figure 3-1 JNES Equipment Fragility Test Schedule 

Figure 3-2 TADOTSU Shaking Table and the Amplification Device Table 
42 

Figure 3-3 RCW Pump Test Layout 
43 

Figure 3-4 Development of Envelop Floor Response Spectrum 

Figure 3-5 Basis Input Acceleration Time History Generated From Envelop FRS for Horizontal 

Shaft Pump Test 
44 

Figure 3-6 Response Spectra at the Top of the Amplification Table for Excitation Levels of 2 g, 

4g, and 6g in the Full Scale Horizontal Shaft Pump Test 

Period (s) 

Period (s) 

Period (s) 

Target 

Recorded

Target 

Recorded

Target 

Recorded

Spectral Acceleration (g) Spectral Acceleration (g) Spectral Acceleration (g) 

2 g Excitation Level 

Damping: 1% 

4 g Excitation Level 

Damping: 1% 

6 g Excitation Level 

Damping: 1% 
45 

Figure 3-7 Change of Acceleration at Bearing Case With Respect to Input Acceleration 

Figure 3-8 Test Setup for Radial Ball Bearings 
46 

Figure 3-9 Test Setup for Thrust Ball Bearings 

(A) Ball Surface Roughness of Bearing 6310 

(B) Inner Surface Degradation of Slide Bearing (60 mm I.D.) 

Figure 3-10 Surface Degradation of Bearings During Element Tests 
47 

(A) Model for Axial Direction 

(B) Model for Lateral Direction 

Figure 3-11 Analytical Models for Single Stage Horizontal Shaft Pump 
48 

(A) Model for Axial Direction 

(B) Model for Lateral Direction 

Figure 3-12 Analytical Models for Multi-stage Horizontal Shaft Pump 
49 

Figure 3-13 Basis Input Acceleration Time History for Electrical Panel Tests 
50 

 (A) Main Control Board (B) Reactor Anxiliary Control Board 

 

 (C) Logic Circuit Control Panel (D) Reactor Protection Rack 

 

 (E) Instrumentation Rack (F) Reactor Control Center 

 

 (G) Power Center (H) 6.8 kV Metal-Clad Switchgear 

Figure 3-14 Illustration of Electrical Panels 
51 

Figure 3-15 Test Setting for Electrical Panels 
52 

Figure 3-16 Comparison of Front-Back 6 g Level Response Spectra for Reactor Control Center 

Test 

 

Figure 3-17 Gas Circuit Breaker Installed on a Support Frame in Element Test 

Period (s) 

Recorded at Base Plate 

Target 

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 
53 

Figure 3-18 JNES Target Range of the Fragility Tests 

Figure 3-19 Test Setup for PWR Control Rod Insertion System 
54 

Figure 3-20 Mockup of A PWR Fuel Assembly 
55 

Figure 3-21 Section View of the Test Setup for PWR Control Rod Insertion System 

Figure 3-22 Layout of 3 PWR Fuel Assemblies 
56 

Figure 3-23 Synthesized Wave for Full-Scale Test of PWR CRDM 

Figure 3-24 Filtered Wave for Fuel Excitation 

Period (s) 

Spectral Acceleration (cm/s

2) 

S2 Wave 

Damping: 5% 

Period (s) 

Spectral Acceleration (cm/s

2) 

S2 Wave 

Damping: 5% 
57 

Figure 3-25 Comparison of PWR CRDM Target Input and Shaking Table Response (Still Water) 

Figure 3-26 Comparison of PWR CRDM Target Input and Shaking Table Response (With Core 

Flow) 

Period (s) 

Spectral Acceleration (m/s

2) 

3.3 S2 Wave 

Damping: 5% 

Target 

Recorded 

Period (s) 

Spectral Acceleration (m/s

2) 

3.3 S2 Wave 

Damping: 5% 

Target 

Recorded 
58 

Figure 3-27 Comparison of PWR CRDM Target Input and Upper Core Plate Response (Still 

Water) 

Figure 3-28 Comparison of PWR CRDM Target Input and Lower Core Plate Response (Still 

Water) 

Period (s) 

Spectral Acceleration (m/s

2) 

3.3 S2 Wave 

Damping: 5% 

Target 

Recorded 

Period (s) 

Spectral Acceleration (m/s

2) 

3.3 S2 Wave 

Damping: 5% 

Target 

Recorded 
59 

Figure 3-29 Comparison of PWR CRDM Target Input and CRDM Base Response (Still Water) 

Figure 3-30 Comparison of PWR CRDM Target Input and Upper Core Support Plate Response 

(Still Water) 

Period (s) 

Spectral Acceleration (m/s

2) 

3.3 S2 Wave 

Damping: 5% 

Target 

Recorded 

Period (s) 

Spectral Acceleration (m/s

2) 

3.3 S2 Wave 

Damping: 5% 

Target 

Recorded 
60 

Figure 3-31 Delay Ratio of PWR Control Rod Insertion 

Figure 3-32 Test Setup for BWR Control Rod Insertion System 
61 

Figure 3-33 Mockup of A BWR Fuel Assembly 
62 

Figure 3-34 Section View of the Test Setup for BWR Control Rod Insertion System 

Figure 3-35 Layout of a BWR Fuel Assembly 
63 

Figure 3-36 BWR CRDM Basis Input Wave C with Center Frequency 4.8 Hz 

Figure 3-37 BWR CRDM Basis Input Wave C with Center Frequency 5.8 Hz and 10% 

broadening 

Period (s) 

Spectral Acceleration (g) 

S2 Wave 

Damping: 5% 

Period (s) 

Spectral Acceleration (g) 

S2 Wave 

Damping: 5% 
64 

Figure 3-38 Comparison of BWR Target Input and Shaking Table Response 

Figure 3-39 Delay Ratio of BWR Control Rod Insertion 

Frequency (Hz) 

Spectral Acceleration (m/s

2) 

4.4 S2 Wave 

Damping: 5% 

Target 

Recorded
65 

Figure 3-40 Test Setup for Vertical Shaft Pump 
66 

Figure 3-41 Section View of the Test Setup for Vertical Shaft Pump 

Motor

Motor Stand

Pump 

Barrel Support Barrel 

Shaking 

Table

7000 8000 

Water
67 

Figure 3-42 Response Spectrum for A-Wave 

Figure 3-43 Response Spectra for D-Wave (Horizontal) 

Period (s) 

Spectral Acceleration (g) 

Damping: 1% 

Envelope of Design Spectra 

Target Spectrum 

D Wave 

High Pass Filtered at 11.1 Hz 

Spectral Acceleration (cm/s

2) 

Period (s) 

Damping: 1% 
68 

Figure 3-44 Response Spectra for D’-Wave (Horizontal) 

Figure 3-45 Comparison of A, D, and D’ Waves 

Envelope of Design Spectra 

Target Spectrum 

D’ Wave 

Spectral Acceleration (cm/s

2) 

Period (s) 

Damping: 1% 

A Wave 

D Wave 

D’ Wave 

Spectral Acceleration (cm/s

2) 

Period (s) 

Damping: 1% 

Natural Period of Max. Acceleration 1.24 g 

Motor Portion 

0.049 s 

(20.5 Hz) 

Natural Period of Barrel 

Portion with No Gap 

0.062 s 

(16.1 Hz) 

Natural Period of Barrel 

Portion without Barrel 

Support 

0.156 s 

(6.4 Hz) 

A Wave, filtered 0.09 s 

above

D’ wave: Half in Resonance Region 
69 

Figure 3-46 Response Spectra for Vertical Wave 

Figure 3-47 Liner Ring and Shaft Bearing 

Spectral Acceleration (cm/s

2) 

Period (s) 

Damping: 5% 

Max. Acceleration 0.22 g 

Vertical 

Target 
70 

 

 

Figure 3-48 Illustration of Shaft Bearing and the Nonlinear Load-Displacement Behavior 

Figure 3-49 Structural Types of Large Size Vertical Shaft Pumps 
71 

Figure 3-50 Similar Structural Features of Vertical Mixed Flow Pump and Pit Barrel Type Pump 

 

(A) Load Displacement Relationship for Barrel Support (B) Barrel Mode Shape 

Note: Kb: barrel support stiffness 

 Kc: Linearized stiffness for the equivalent linear analysis 

 C: clearance of barrel support 

 X and Xc: mode vector 

Figure 3-51 Equivalent Linear Stiffness of Barrel Support 
72 

Figure 3-52 Calculation of Impulsive Force 
73 

Figure 3-53 Stick Model for the Pit Barrel Type Pump 
74 

Figure 3-54 Two Mass Model for the Vertical Response Analysis for the Vertical Shaft Pumps 
 75

4 EVALUATION OF JNES EQUIPMENT FRAGILITY TEST DATA 

4.1 Introduction 

Review and evaluation of the JNES equipment test results are based on the JNES equipment 

fragility test report [JNES, 2009], which is included in Appendix A of this report, and the JNES 

status presentations [Uchiyama, 2008a, b]. The purpose of this evaluation is to: 

• compare the JNES fragility results with the fragility data typically used in current 

U.S. seismic probabilistic risk assessments (SPRAs), 

• assess the impact that the new test results may have on current SPRAs and how 

this data can be utilized for future SPRAs. 

As described in the previous section, JNES has performed a series of high amplitude shake table 

tests on full-scale components supplemented by additional analyses. The purpose of these tests 

was to determine the functional seismic fragility levels during strong shaking (called herein 

“function during” fragility levels) for these components. These full-scale component tests were 

generally limited by the shake table capability to about 6.0g zero period acceleration (ZPA). If no 

functionality anomaly occurred prior to reaching the upper limit of the testing, a function 

confirmed (FC) capacity was reported. In this case, no fragility level was actually found, and the 

reported median fragility was set either at or only slightly above the FC capacity. For situations 

where a functional anomaly was observed, the reported median fragility was set midway between 

the highest ZPA level for which no functional anomaly occurred, and the ZPA level at which the 

anomaly occurred. 

One of the primary objectives of these JNES tests was to test full-scale components at shaking 

levels significantly higher than the function confirmed qualification tests to which they had 

previously been subjected. Therefore, these tests greatly improve the median fragility estimates 

for the specific components tested. In this regard, they provide a very valuable addition to the 

available fragility data base for U.S. NPPs. However, an open question exists as to how well this 

JNES fragility data can be extrapolated to similar components in U.S. NPPs. This section of the 

report will be devoted to address this issue. 

As discussed in Section 3, the JNES equipment fragility report presents detailed fragility 

information for the Phase I four classes of components: 

• Electrical components and devices mounted therein 

• Horizontal shaft pumps 

• Large vertical shaft pumps 

• Control rod insertion capability 

The review of the JNES equipment fragility tests focused on these Phase I four classes of 

components. As additional information is provided by JNES, a supplement to this report will be 

prepared to address additional classes of equipment. 

The bases presented in the JNES equipment fragility report were reviewed for the median 

fragilities reported therein for the specific components considered in the four classes. These 

reported fragilities are based on a combination of full-scale component shake table testing, device 

(element) shake table testing, and analyses. It can be stated categorically that a very 

comprehensive and conscientious effort appears to have been performed to develop realistic 
 76

median fragility estimates for the specific components being considered. Therefore, it can be 

concluded that the median fragilities reported in the JNES equipment fragility report [JNES, 2009] 

and summarized in this report are reasonable for the specific components considered in each of 

the four classes. 

Therefore, the next four subsections will concentrate on (1) comparing the JNES fragility results 

with the fragility data typically used in current U.S. SPRAs and (2) assessing the impact that the 

new test results may have on current U.S. SPRAs and how this data can be utilized for future 

SPRAs. The purpose of this assessment is to provide comparisons and assessments of the 

applicability of the JNES equipment fragility information for similar components in existing U.S. 

NPPs. 

For the purposes of making comparisons, Section 2 of this report presents a summary of common 

U.S. practice for estimating seismic fragilities for equipment that has been qualified by test. The 

emphasis of Section 2 is to present generic fragility estimates that are commonly used for Central 

and Eastern U.S. (CEUS) SPRAs. Examples of such fragility estimates are presented in Table 

2-2 through Table 2-6. Of course, higher fragility capacities can generally be justified for any 

specific component by a detailed review of the qualification test data and/or stress analyses 

performed on that specific component. However, for many components included in CEUS 

SPRAs, this additional effort is not performed. Instead, generic fragilities similar to those 

summarized in Section 2 are used. For higher seismic sites, these generic fragilities are generally 

not used. 

All of the generic fragilities summarized in Table 2-2 through Table 2-6 of Section 2 are defined 

in terms of a broad frequency 5% damped spectral acceleration SA at the base of the component. 

For these broad frequency generic fragilities summarized in Table 2-2 through Table 2-6 of 

Section 2, the relationship between the broad frequency 5% damped spectral acceleration SA and 

the zero period acceleration (ZPA) can be approximated by: 

SA ≈ 2.4 ∗ ZPA (4-1) 

The JNES fragilities reported in the JNES equipment fragility test report and summarized in 

Section 3 of this report are commonly defined in terms of ZPA. However, the response spectrum 

shape used in the JNES tests was very different from the broad frequency response spectrum 

shape used to define the Section 2 U.S. generic fragilities. As noted in Section 3, the JNES tests 

typically had more highly amplified and narrower frequency response spectrum shapes. In the 

JNES tests, the response spectra typically peaked in the 7 to 10 Hz frequency range. Over this 

narrower frequency range, the ratio of 4% damped spectral acceleration SA to ZPA was about 3.0. 

Therefore, between about 7 to 10 Hz, the ratio of SA/ZPA for the JNES tests was higher than the 

2.4 ratio defined by Eqn. (4-1) for the U.S. generic fragilities. However, below about 7 Hz and 

between about 10 to 20 Hz, the SA/ZPA for the JNES tests was lower than the SA/ZPA ratio 

appropriate for the U.S. generic fragilities summarized in Section 2. This difference in spectra 

shapes makes it more difficult to make an appropriate comparison between the JNES test results 

and the U.S. generic fragilities reported in Section 2. It was considered to be most appropriate, 

on average, to convert the JNES reported ZPA fragilities to equivalent broad frequency 5% 

damped SA fragilities by the use of Eqn. (4-1) for the purpose of these comparisons. 
 77

4.2 Electrical Component Fragilities 

For this section, the term “component” is used to define a complete piece of equipment such as a 

motor control center or control cabinet, and “device” to define an individual element such as a 

relay within a component. 

JNES fragility results are reported in Section 3 and the JNES equipment fragility test report 

[JNES, 2009] for eight different electrical components. These fragility results are summarized 

herein in Table 4-1. The reported ZPA capacities are directly from the JNES equipment fragility 

test report. The corresponding 5% damped spectral acceleration SA capacities in Table 4-1 have 

been estimated by Equation 4-1. Reported fragilities followed by (FC) indicate that no anomaly 

occurred at the highest test level. Therefore these reported values are actually function confirmed 

qualification values; the actual fragility level is higher than these FC levels. 

The fragility levels reported in Table 4-1 for anomalies lie midway between the highest test level 

for which the function was confirmed and the test level at which the anomaly occurred, which is 

in accordance with the criteria specified in the JNES equipment fragility test report. 

The median SA50% fragility levels reported in Table 4-1 based on JNES test data for electrical 

components range between 5.5g and 14.2g. Generic median SA50% fragilities reported in Table 

2-2, Table 2-4, and Table 2-5 for similar electrical components range between 2.2g and 5.1g. 

This comparison indicates that generic fragilities commonly used in U.S. SPRAs for existing 

CEUS plants might be conservatively biased by more than a factor of two. The JNES test data 

median SA50% fragility levels for electrical components are comparable to the ALWR “achievable” 

fragilities from EPRI TR-016780 [1999] shown in Table 2-7. 

However, considerable caution must be exercised before extending the use of these JNES median 

fragilities for electrical components to existing electrical components in the U.S. plants. The 

natural frequencies reported in the JNES equipment fragility test report for all eight tested 

electrical components ranged between 20 Hz and greater than 50 Hz. All of these electrical 

components tested by JNES were very stiff and not representative of most similar existing 

electrical components in U.S. plants. Most of these electrical components in U.S. plants exhibit 

local panel mode frequencies in the 4 Hz to 15 Hz range when tested at higher shaking levels. 

Cabinet response amplification factors AFC (called k in the JNES equipment fragility test report 

[JNES, 2009]) were reported for representative device mounting locations in each of the eight 

electrical components considered. For the JNES tested components, these reported response 

amplification factors ranged between: 

 JNES Cabinets 

AFC = 1.0 to 2.5 (4-2) 

These very low cabinet response amplification factors AFC for the JNES tested components are 

not surprising considering that: 

(1) the JNES tested components had natural frequencies in excess of 20 HZ, and 

(2) the JNES test input had very little frequency content in excess of about 12 Hz. 
 78

For comparison, Table 2-3 reports generic median AFC values recommended for use in 

representative existing U.S. electrical components. These recommended median AFC values 

range between: 

 Existing U.S. Cabinets 

AFC = 2.8 to 4.4 (4-3) 

It should be noted that the values in Table 2-3 are median response amplification factors for the 

worst location in the cabinet whereas the JNES reported values are for representative mounting 

locations. Even so, the differences are substantial. 

Based both on the natural frequency comparisons, and the response amplification comparisons, it 

appears that the JNES tested electrical components are much stiffer than most electrical 

components in existing U.S. plants. However, they might be representative of electrical 

components to be used in new U.S. standard plants not yet built. 

Therefore, the JNES reported median fragilities shown herein in Table 4-1 should not be used for 

U.S. electrical components unless it can be shown that the component has stiffnesses similar to 

those tested by JNES. In particular, the minimum natural frequency at high shaking levels should 

be in excess of 20 Hz before using the median fragility levels shown in Table 4-1 for an electrical 

component. 

In addition to full-scale electrical component testing, the JNES equipment fragility test report also 

presents either function confirmed data or fragility data on 37 types of devices (elements) 

mounted within electrical components. Each type of device included a number of individual 

devices in the test. Seismic time history tests were conducted up to a ZPA=10g level or slightly 

higher. Therefore, this data provides very high amplitude fragility data for these 37 tested 

devices. This data is directly usable for future U.S. SPRAs because the tested devices are 

identified by manufacturer and model number (see Table 3-9 for a summary of the fragility data 

for electrical parts, and pages A-64 through A-78 of Appendix A for details). 

Fragility data is provided on: 

• 3 protective relays 

• 3 auxiliary relays 

• 1 timing device 

• 12 control equipment devices 

• 4 pressure transmitters 

• 2 magnetic contactors 

• 3 molded case circuit breakers 

• 3 switches 

• 3 air circuit breakers 

• 1 vacuum circuit breaker 

• 1 gas circuit breaker 

• 1 grounded potential transformer 
 79

All but 8 of these 37 types of devices had function confirmed (FC) at ZPA of about 10g or 

slightly higher. Thus, their device fragility level is even higher than ZPA of 10g for seismic input 

at the device mounting location. 

The eight types of devices for which loss of function occurred were: 

• 1 protective relay: ZPA ≈ 9.0g 

• 1 auxiliary relay: ZPA ≈ 5.9g 

• 1 AC controller card: ZPA ≈ 7.0g 

• 2 air circuit breakers: ZPA ≈ 3.5g* 

• 1 vacuum circuit breaker: ZPA ≈ 4.4g 

• 1 gas circuit breaker: ZPA ≈ 3.5g* 

• 1 grounded potential transformer: ZPA ≈ 2.5g* 

Subsequent to the initial test, additional seismic reinforcement was added to the devices identified 

above with an asterisk (*) and their capacities were increased. It should be noted that for these 

loss of function device types, the capacities listed above represent the smallest; the other 

specimens in the same device group exhibited higher capacities, for example, one protective relay 

succeeded at a ZPA of 10.9g in the test. 

With the exception of the air and gas circuit breakers, and the grounded potential transformer, all 

of these device fragilities exceed the median fragility level used for similar devices in existing 

U.S. SPRAs which have often been based on EPRI NP-7147 [Merz, 1991b]. The circuit breaker 

and transformer capacities are consistent with those used in existing U.S. SPRAs. 

The JNES electrical equipment device fragility data is a highly valuable resource for future 

SPRAs. 

4.3 Large Horizontal Shaft Pumps 

As described in Section 3, JNES performed a full-scale test on one reactor building closed 

cooling water (RCW) pump (single stage centrifugal type) that was 9-feet long by 4.4-feet high. 

This tested pump appears to be very similar to RCW pumps in U.S. nuclear plants. Therefore, it 

is judged that this test result could be used to estimate the median fragility of RCW pumps in U.S. 

plants. 

For the tested pump, function was confirmed at: 

 RCW Pump 

ZPA ≈ 6.0g (FC) (4-4) 

which indicates that the median fragility level should be set at a ZPA level somewhat higher than 

6.0g. 

JNES also performed fragility tests on two sizes of deep groove ball bearings and one type of 

angular ball bearing. The load to generate sufficient friction to result in a decrease of bearing 

operating life was confirmed to exceed 20 kN (4.4 kips) in the thrust direction and somewhat 

higher in the radial direction for deep groove ball bearings. The function confirmed load for the 

tested angular ball bearing was 60 kN (13.5 kips) in the thrust direction. 
 80

JNES performed analyses to compute the ZPA levels at which bearing wear would result in 

decreased operating life. These analyses were performed for two different size RCW pumps and 

one Charging High Pressure Injection pump (multi-stage centrifugal type). Based on these 

analyses, the following median bearing wear functionality limits were computed by JNES: 

 Bearing Wear Median Fragility 

 

 Tested RCW Pump: ZPA50% = 8.4g 

Larger RCW Pump: ZPA50% = 8.6g (4-5) 

Charging Injection Pump: ZPA50% = 17.3g 

JNES also calculated the median capacity of the pump frame anchorage to the foundation and the 

capacity at which the motor might slip on the pump frame potentially resulting in damage to the 

pump shaft and/or bearings. The pump frame to foundation anchorage median capacities reported 

in the JNES equipment fragility test report for the three evaluated pumps ranged between 

ZPA=11.0g to 28.5g and were not controlling. 

The potentially controlling fragility appears to be slip of the motor on the pump frame due to 

inadequate torqueing of the mounting bolts and oversize bolt holes. The JNES equipment 

fragility test report calls the computed fragility for this onset of motor slip failure mode a 

reference fragility. The reported computed values for this onset of motor slip reference fragility 

are: 

 Motor Slip Reference Fragility 

 Tested RCW Pump: ZPA = 6.1g 

 Larger RCW Pump: ZPA = 5.3g (4-6) 

 Charging Injection Pump: ZPA = 2.6g 

The onset of motor slip reference fragilities were based on a coefficient of friction of 0.3. It is not 

reported what bolt tightening force was assumed in these slip calculations. 

There is considerable uncertainty in the coefficient of friction that should be used in these slip 

calculations. For a specified minimum bolt torque applied to the mounting bolts, there is 

significant variability in the bolt tension preload. There are limits as to how far the motor might 

slip due to oversized or slotted bolt holes. It is also not known how much motor slip is likely to 

damage the pump shaft and/or bearings. It would be highly desirable to have additional testing 

performed to address the topic of horizontal pump functionality limits associated with motor slip 

on pump frames. This mode may be a controlling functionality failure mode for large horizontal 

pumps. 

For large and critical horizontal pumps such as RCW pumps and Charging High Pressure 

Injection pumps, it has been common U.S. fragility practice to base their fragility estimate on a 

review and scaling of the qualification stress report for the specific pump involved. In addition, 

the anchorage of the pump frame to the foundation and the capacity of the motor mounting to 

pump frame are evaluated. The degree of rigor with which motor slip has been assessed, and the 

parameters used in this assessment have likely varied among fragility analysts. 

For lower CEUS seismic regions, and for less critical horizontal pumps, horizontal pumps have 

often been assigned a ground motion screening level spectral acceleration of SASL = 1.2g based on 

EPRI NP-6041-SL [1991] screening tables as discussed in Section 2.3. Thus, from Table 2-5, the 
 81

median spectral acceleration capacity at the base of the pump frame would be about SA50% = 4.8g 

which, based on the approximation of Equation 4-1, would correspond to a median ZPA capacity 

of only about: 

ZPA50% ≈ 4.8g/2.4 = 2.0g (4-7) 

which is much less than the function confirmed ZPA = 6.0g obtained in the JNES RCW pump 

full-scale test. These screening level based fragility estimates are exceedingly conservative for 

horizontal pumps within our experience. This screening level approach should not be used for 

risk important horizontal pumps. 

4.4 Large Vertical Shaft Pump 

JNES performed a full-scale test on a large Residual Heat Removal System (RHR) pump of the 

pit barrel type. The barrel extended 32-ft below the top of the pump base but was intermediately 

supported at about mid-depth. The motor extended 17.3-ft above the top of the pump base. 

Function was confirmed separately for the Barrel/Column portion of the pump and for the Motor 

portion. Results are reported both in terms of the input ZPA and the response ZPA. 

No loss of function was confirmed at the following horizontal input and response ZPA levels: 

 Function Confirmed 

 Motor (4-8) 

 Input ZPA = 1.6g 

 Top of Motor ZPA = 14.0 g 

Barrel/Column (4-9) 

Input ZPA = 2.8g 

Bottom of Barrel ZPA = 31g 

Bottom of Column ZPA = 35 g 

The JNES equipment fragility test report indicates that yielding of the motor mounting bolts was 

confirmed at an input ZPA of 1.5g (top of motor ZPA of 12.0g) and that yielding of the barrel was 

confirmed at a bottom of barrel ZPA of 31.0. However, there was no loss of function. 

In higher quality fragility analyses, the median fragility of vertical pumps is typically determined 

by analysis in which median capacities are based on 90% of the fully plastic moment capacity for 

each of the following elements: 

• Motor mounting bolts 

• Lower motor stand 

• Pump barrel, casing, column, or shaft 

whichever controls when compared to the estimated moment demand. The JNES large vertical 

pump test results seem to confirm the reasonableness of this approach. 

For low seismic CEUS sites and for less critical vertical pumps, the screening levels reported in 

Table 2-4 of EPRI NP-6041-SL [1991] have often been used as discussed in Section 2.3. For 

vertical pumps with unsupported barrel or casing lengths less than 20-feet, as is the case for the 
 82

JNES tested pump, the spectral acceleration screening level is SASL = 1.2g. As shown in the last 

paragraph of Section 4.3, this screening level corresponds to a median ZPA capacity of about: 

ZPA50% ≈ 2.0g (4-10) 

This value should not be used for large critical vertical pumps. Instead, the fragility should be 

based on pump specific analysis. 

Median loss of function fragility evaluations are also reported in the JNES equipment fragility 

test report for four large vertical pumps including the full-scale tested pump discussed above. 

These fragility evaluations are based on analysis. Similarly as for the large horizontal pumps, the 

lowest reported fragility is a motor slip reference fragility reported in terms of top of motor ZPA

response (ZPATOM) 

For the four analyzed pumps: 

Motor Slip Reference Fragility (4-11) 

 Tested Pump: ZPATOM = 3.6g 

Other Three Pumps: ZPATOM =2.8g-6.2g 

The JNES equipment fragility test report states on Page A-41 that there was no slip during the 

full-scale test. However, a footnote on Page A-84 indicates that the motor mounting on the pump 

base was strengthened prior to the function confirmed test for which Equation 4-8 summarizes the 

results. 

The comments in Section 4.3 about motor slip for large horizontal pumps equally apply to large 

vertical pumps. This issue deserves further investigation, including testing. 

Element testing was performed on submerged bearings. Results are reported in Table 3.4-4 of the 

JNES equipment fragility test report. Capacities are reported in terms of bearing surface pressure 

times rotating velocity on the bearing, i.e., PV value. The median PV fragility levels reported for 

bulging and cracking of resin and rubber bearings are approximately 60 MPa⋅m/s and 70 MP⋅m/s, 

respectively. Function was confirmed at a PV level of at least 70 MPa⋅m/s for carbon bearings 

and solid lubricant distributed oil-less bearings. Based on these bearing capacities and seismic 

analyses of the pump shafts, the following median loss of submerged bearing function limits are 

reported in terms of the bottom of barrel (casing) acceleration ZPABOB: 

 Submerged Bearing Functional Limit 

Tested Pump: ZPABOB = 37.1g 

Other Three Pumps: ZPABOB = 14.6g-96.9g (4-12) 

For the tested pump, this computed submerged bearing functional limit was 20% higher than the 

highest test level. Therefore, this computed functional limit was not confirmed in the full-scale 

test. 

To the best knowledge of the authors, the functional failure of submerged bearings has not been 

considered in U.S. fragility analyses of vertical pumps. The JNES data on bearings should be 

considered in future U.S. practice. Clearly JNES is concerned about these potential failure modes. 

However, in the JNES data, the submerged bearing functional limit data does not seem to control 

the pump fragilities since these fragilities are controlled by other failure modes. 
 83

Lastly, JNES performed a vertical input seismic shaking on the RHR Pump. The concern is with 

vertical loads being imposed on the motor thrust bearing, and with lifting the shaft more than the 

clearance that exists between the impeller and the lower liner ring. For the tested pump, no loss 

of function was confirmed for a vertical ZPA level of 1.9g. 

To the best knowledge of the authors, this potential for failure to function of the motor thrust 

bearing or exceedance of vertical clearance due to vertical shaking has also not been considered 

in U.S. fragility analyses of vertical pumps. The reported thrust bearing capacity and vertical 

clearance capacity were Function Confirmed capacities since no loss of function occurred at a 

vertical ZPA of 1.9g. Therefore, the actual vertical ZPA fragility level is unknown. The 

importance of this JNES concern is unknown. No guidance can be given for future U.S. practice. 

4.5 Control Rod Insertion Capability 

4.5.1 PWR Plants 

JNES conducted a full-scale test on a control rod drive mechanism, control rod, and fuel bundle 

assembly representative of 3 and 4 loop PWR plants. The fuel assembly was the 17x17 type. 

The input motion and resulting maximum fuel assembly displacement were: 

ZPA = 3.2g 

 Displacement = 48mm (4-13) 

Control rod insertion simulation analyses were performed and JNES estimated the following 

median value and composite variability βC for functionality limit on control rod insertion: 

PWR (3 and 4 Loop) Functional Limit Fuel Assembly Displacement 

Median βC

77mm 0.19 (4-14)

No input motion level corresponding to the 77mm fuel assembly displacement was explicitly 

defined in the JNES equipment fragility test report. However, on Page A-28 of the JNES report it 

is stated that the full-scale test was conducted at 3.3 times the S2 input. Later on Page A-28, it is 

reported that the 77mm displacement corresponds to 4 times the S2 input. On this basis, the 

median ZPA fragility is estimated to be: 

 PWR (3 and 4 loop) 

ZPA50% ≈ (4.0/3.3) ∗ 3.2g = 3.9g (4-15) 

Based on simulation analysis, the JNES report also reports a median functional limit displacement 

δ50% of 66mm for PWR (2 loop) plants with 14x14 type fuel assembly. Based on scaling, the 

median fragilities for the 2 loop PWR plants can be estimated as: 

 PWR (2 loop) 

 

δ50% = 69m 

ZPA50% ≈ 3.7g (4-16) 
 84

4.5.2 BWR Plants 

JNES also conducted a full-scale test on a control rod drive mechanism, control rod, and fuel 

bundle assembly representative of a BWR5 plant with a high speed scram type control rod drive 

mechanism. The full-scale test had a 100 mil thick channel box. However, JNES has estimated 

that the same fragility estimates are applicable for 80 mil and 120 mil channel boxes. For the 

full-scale test the input motion and resulting fuel assembly displacement were: 

ZPA = 3.0g 

 Displacement = 83mm (4-17) 

JNES considered that the critical damage state was reached when the fuel bundle collided with 

the shroud. They estimated a 5% probability of damage at 83mm displacement, and 95% 

probability of damage at 100mm displacement. Based on these estimates, JNES reports the 

following fuel assembly displacement fragility: 

BWR5 Fuel Assembly Displacement Fragility 

Median βC 

91mm 0.10 (4-18)

The basis for βC is not clear. With 83mm displacement at the 5% probability level and 100mm 

displacement at the 95% probability level, a βC can be computed as: 

" =

ln[100/83]

2 ∗ 1.645 = 0.06 (4-19) 

However, a βC of 0.10 already seems to be very low for this complex of a phenomena, therefore it 

is not recommended that the JNES βC=0.10 be further reduced for U.S. NPP applications without 

further information. 

No median ZPA50% corresponding to a 91mm fuel assembly displacement is reported. However, 

since an 83mm displacement corresponds to a ZPA=3.0g, the median fragility is estimated as: 

BWR5 

 ZPA50% = 3.1g – 3.3g (4-20) 

4.5.3 Applicability of Results for U.S. Fragility Assessments 

The JNES fragility results are applicable for failure modes associated with fuel assembly 

displacements. However, these results do not address structural failure modes since the entire 

assembly was supported by very stiff frames in the test. 

 

Within the U.S., control rod insertion fragilities are generally derived based on a detailed review 

and scaling of Nuclear Steam Supply System (NSSS) vendor submitted qualification reported 

results. For PWR plants, the derived fragilities are generally controlled by the supports of the 

control rod drive mechanism. During the JNES test, the control rod drive mechanism was very 

substantially supported by a very rigid frame. The failure modes that have typically been 

considered to be controlling in U.S. fragility assessments for control rod insertion could not have 
 85

occurred during these tests. Fragilities for control rod insertion need to be primarily addressed by 

the NSSS vendors. 

 
 86

Table 4-1 JNES Fragilities for Electrical Components 

Component ZPA (g) SA (g)

BWR Main Control Board 5.7 13.7 (FC) 

PWR Reactor Auxiliary Board 5.9 14.2 (FC) 

BWR Logic Circuit Control Cabinet 5.9 14.2 (FC) 

PWR Reactor Protection Instrumentation Rack 

 (malfunction of a miniature relay in 

 AC controller card) 

3.7 8.9 

BWR Instrument Rack 5.7 13.7 (FC) 

PWR Reactor Control Center 

 (error of magnetic contactor caused by 

 auxiliary relay chatter) 5.5 13.2 

PWR Power Center 

 (receiving circuit breaker misclosed) 

 (air circuit breaker broke) 

3.3 

4.3 

7.9 

10.3 

69kV Metal Clad Switchgear 

 (fallout of fuses from GPT instrument transformer) 

 (damage to vacuum circuit breaker) 

2.3 

3.8 

5.5 

9.1 
 87

5 CONCLUSIONS 

This report presents an assessment of the equipment fragility test program performed by the Japan 

Nuclear Energy Safety Organization (JNES). The goal of this assessment was to compare the 

JNES fragility results with the fragility data typically used in current U.S. SPRAs and assess the 

impact that the new test results may have on current SPRAs and how this data can be utilized for 

future SPRAs. The JNES fragility results are also useful for seismic margin analyses (SMAs), 

which are important in design certification (DC) or combined license (COL) applications because 

of the lack of full SPRAs at the DC or COL stage. This report includes a brief overview of the 

current U.S. SPRA practices, a description of the JNES equipment fragility test program, and an 

evaluation of the JNES fragility data. This section presents the major findings and insights on 

whether and how the JNES fragility data can be applied to the U.S. SPRA practices. 

The JNES equipment fragility test program started in 2002 and is planned to continue until 2012. 

The tests of the safety significant active equipment in the JNES equipment fragility test program 

were scheduled into two phases. In the phase I program, the tested equipment included horizontal 

shaft pumps, electrical panels, control rod insertion capability, and large size vertical shaft pumps. 

The phase II program included fans, valves, tanks, support structures, and overhead cranes. This 

report documents the evaluation of the fragility data for the JNES phase I equipment. As 

additional information is made available by JNES for the phase II equipment, a supplement to this 

report will be prepared to document the corresponding evaluation results. 

The seismic fragility data described in the JNES equipment fragility test report 08TAIHATV0027, also reproduced as Appendix A to this report, was developed based on high level shaking 

table tests of full-scale equipment, element tests, and analyses. In the full-scale tests, actual 

equipment as used in typical BWR and PWR nuclear power plants in Japan were shaken under 

excitations much larger than the design basis earthquakes which have been used in previous 

equipment qualification tests and design proving tests. The purpose of the full-scale tests was to 

identify critical acceleration levels and failure modes of the equipment. The element tests were 

conducted with multiple samples for each element type, and therefore their median capacity and 

the associated variation were able to be determined statistically. The purpose of the element tests 

was to evaluate threshold acceleration levels of parts and to assess median capacities and the 

associated uncertainties. The purpose of the various analyses was to estimate the seismic fragility 

capacities of the equipment based on the element fragility data and numerical models 

representing the appropriate failure modes as determined from the full-scale tests. 

The JNES fragilities were commonly defined in terms of the zero period acceleration (ZPA) at the 

top of the shaking table, and some were reported as the response accelerations/displacements. 

However, all of the generic fragilities in the U.S. SPRA practices are defined in terms of a broad 

frequency 5% damped spectral acceleration (SA) at the base of the component. A reasonable 

relationship between ZPA and SA, SA ≈ 2.4 × ZPA, has been used to convert the JNES fragilities 

for the purpose of comparison (see Section 4.1). 

Specific insights on the JNES equipment fragility tests and the corresponding evaluation results 

are summarized below. It should be emphasized that an analysis of the component anchorage and 

support fragility needs to be performed as a necessary supplement to the equipment fragility data 

for a proper application. 

5.1 Horizontal Shaft Pumps 

The horizontal shaft pump in the full-scale test was a reactor building closed cooling water (RCW) 

pump used in Japan BWR plants, which appears to be very similar to RCW pumps in U.S. 
 88

nuclear plants. Therefore, it is judged that this test result could be used to estimate the median 

fragility of RCW pumps in U.S. plants. The function of the RCW pump was confirmed at a ZPA

of 6.0 g in the full-scale test. The median functional fragilities of the tested RCW pump, a larger 

RCW pump, and a charging injection pump were estimated to be 8.4 g, 8.6 g, and 17.3 g, 

respectively, based on the results of the bearing tests. 

The potentially controlling fragility appears to be slip of the motor on the pump frame. As large 

uncertainties exist for the slip phenomenon, the calculated fragilities were designated as reference

fragilities. The reference fragilities for the tested RCW pump, the larger RCW pump, and the 

charging injection pump were reported to be 6.1 g, 5.3 g, and 2.6 g. A coefficient of friction of 

0.3 was used in the reference slip fragility calculation. The bolt tightening force used in the 

fragility calculation was not reported; however in the large size vertical shaft pump fragility 

analysis, an internal force coefficient was conservatively set to 0.5 in the bolt tensile stress 

calculation. 

For large and critical horizontal pumps such as RCW pumps and Charging High Pressure 

Injection pumps, it has been common U.S. fragility practice to base their fragility estimate on a 

review and scaling of the qualification stress report for the specific pump involved. For lower 

Central and Eastern U.S. (CEUS) seismic regions, and for less critical horizontal pumps, based on 

a screening level spectral acceleration of 1.2 g, the median ZPA capacity of horizontal pumps can 

be estimated to be about 2.0 g, which is much less than the function confirmed ZPA = 6.0 g 

obtained in the JNES RCW pump full-scale test. The JNES tests demonstrate that these screening 

level based fragility estimates are exceedingly conservative for horizontal pumps, and thus 

confirm the judgment that the screening level approach should not be used for risk important 

horizontal pumps. 

5.2 Electrical Panels 

Eight electrical panels were selected for the JNES full-scale tests: 

• Main control board (BWR) 

• Reactor auxiliary control board (PWR) 

• Logic circuit control panel (BWR) 

• Instrumentation rack (BWR) 

• Reactor protection rack (PWR) 

• Reactor control center (PWR) 

• Power center (PWR) 

• 6.9 kV Metal-clad switchgear (BWR). 

The median spectral fragilities for these panels, converted from the JNES test data, range between 

5.5 g and 14.2 g; while the generic median fragilities in the U.S. SPRA practice range between 

2.2 g and 5.1 g. This comparison indicates that generic fragilities commonly used in U.S. SPRAs 

for existing CEUS plants might be conservatively biased by more than a factor of two. The JNES 

test data median fragility levels for electrical components are comparable to the ALWR 

“achievable” fragilities, which are in the range of 8.3 g to 9.8 g. 

However, the natural frequencies for all eight tested electrical components ranged between 21 Hz 

and 44 Hz. Most of these electrical components in U.S. plants exhibit local panel mode 

frequencies in the 4 Hz to 15 Hz range when tested at higher shaking levels. Cabinet response 

amplification factors AFC were reported for representative device mounting locations in the JNES 

tested components to be 1.0 to 2.5; while the recommended median AFC values at the worst 
 89

location for the existing U.S. cabinets range between 2.8 to 4.4. Based both on the natural 

frequency comparisons and the response amplification comparisons, it appears that the JNES 

tested electrical components are much stiffer than most electrical components in existing U.S. 

plants. The JNES reported median fragilities should not be used for U.S. electrical components 

unless it can be shown that the component has stiffnesses similar to those tested by JNES. 

However, they might be representative of electrical components to be used in new U.S. standard 

plants not yet built. 

Electrical element tests included 37 types of devices: 

• 3 protective relays 

• 3 auxiliary relays 

• 1 timing device 

• 12 control equipment devices 

• 4 pressure transmitters 

• 2 magnetic contactors 

• 3 molded case circuit breakers 

• 3 switches 

• 3 air circuit breakers 

• 1 vacuum circuit breaker 

• 1 gas circuit breaker 

• 1 grounded potential transformer. 

Seismic time history tests were conducted up to a ZPA=10g level or slightly higher. All but 8 of 

these 37 types of devices had function confirmed at ZPA levels of about 10g or slightly higher. 

The smallest ZPA at which loss of function occurred for eight types of devices was 2.5 g. 

Additional seismic reinforcement to some of the devices increased the fragility level. With the 

exception of the air and gas circuit breakers, and the grounded potential transformer, all of these 

device fragilities exceed the median fragility level used for similar devices in existing U.S. 

SPRAs. The circuit breaker and transformer capacities are consistent with those used in existing 

U.S. SPRAs. Because the tested devices are identified by manufacturer and model number, the 

JNES electrical equipment device fragility data is a highly valuable resource for future SPRAs. 

5.3 Control Rod Insertion Capability 

JNES performed a full-scale test on a control rod drive mechanism, control rod, and fuel bundle 

assembly representative of 3 and 4 loop PWR plants. The fuel assembly was the 17x17 type. 

The input motion and resulting maximum fuel assembly displacement were 3.2 g (ZPA) and 48 

mm, respectively. The reported computed median fragility for fuel assembly displacement is 77 

mm. The median ZPA fragility for 3 and 4 loop PWR plants is estimated as 3.9 g in this report. 

Based on simulation analysis, the JNES report also reports a median functional limit displacement 

of 66 mm for 2 loop PWR plants with 14x14 type fuel assembly. The median ZPA and 

displacement fragilities are estimated in this report as 3.7 g and 69 mm, respectively. 

JNES also conducted a full-scale test on a control rod drive mechanism, control rod, and fuel 

bundle assembly representative of a BWR5 plant with a high speed scram type control rod drive 

mechanism. JNES estimated that the same fragility estimates were applicable for 80 mil and 120 

mil channel boxes. The input motion and resulting maximum fuel bundle assembly displacement 

were 3.0 g (ZPA) and 83 mm, respectively. JNES estimated the median fragility for the fuel 
 90

bundle displacement was 91 mm. The corresponding median ZPA fragility is estimated as 3.1 g 

to 3.3 g. 

The JNES fragility results are applicable for failure modes associated with fuel assembly 

displacements. Within the U.S., control rod insertion fragilities are generally derived based on a 

detailed review and scaling of NSSS vendor submitted qualification reported results. For PWR 

plants, the derived fragilities are generally controlled by the supports of the control rod drive 

mechanism. The failure modes that have typically been considered to be controlling in U.S. 

fragility assessments for control rod insertion could not have occurred during these tests because 

the entire fuel assembly was supported by very stiff frames in the JNES tests. 

5.4 Large Size Vertical Shaft Pumps 

The large size vertical shaft pump in the full-scale test was a pit barrel type pump in the reactor 

residual heat removal system (RHR). Function was confirmed at an input ZPA of 1.6 g and a 

corresponding response ZPA of 14.0 g at the top of motor, and separately at an input ZPA of 2.8 

g and a corresponding response ZPA of 31 g at the bottom of barrel. The JNES large vertical 

shaft pump test results seem to confirm the reasonableness of the U.S. fragility analysis method 

that determines the pump fragility as the minimum individual fragility capacity of the motor 

mounting bolts, lower motor stand, pump barrel, casing, column, and shaft. 

For low seismic CEUS sites and for less critical vertical pumps, using a screening level of 1.2 g, a 

median ZPA capacity can be estimated to be 2.0 g for the JNES test pump. This value should not 

be used for large critical vertical pumps. Instead, the fragility should be based on pump specific 

analysis. 

 

Similarly as for the large horizontal pumps, the lowest reported fragility is a motor slip reference 

fragility reported in terms of the top of the motor ZPA response. The computed slip reference 

fragility for the tested RHR pump, a high pressure core injection system pump, a component 

cooling seawater pump (PWR), and a component cooling seawater pump (BWR) was 3.6 g, 3.5 g, 

6.2 g, and 2.8 g, respectively. However, a fragility capacity of 14 g at the top of motor was 

achieved in the full-scale test after tightening the anchor bolts, confirming that large uncertainties 

exist for the slip reference fragility. 

Based on the test results of the submerged bearings, the functional fragilities in terms of the 

bottom of barrel were estimated to be 37.1 g for the tested RHR pump, and were between 14.6 g 

and 96.9 g for the other three pumps. For the tested pump, this computed submerged bearing 

functional limit was 20% higher than the highest test level. The functional failure of submerged 

bearings has not been considered in U.S. fragility analyses of vertical pumps. The JNES data on 

bearings should be considered in future U.S. practice; however, the submerged bearing functional 

limit data did not seem to control the pump fragilities. 

5.5 Summary 

The JNES tests make a valuable contribution to the overall state of knowledge of equipment 

fragility levels for use in SPRAs. The JNES fragility capacities were determined based on fullscale component tests and element tests under simulated seismic excitations that were much 

larger than the design basis earthquakes commonly used in previous qualification tests or design 

proving tests. The fragility levels found in the JNES tests are in general much higher than those 

used in current U.S. SPRAs. Additional failure modes, such as relative motor slip on pump frame 

and functional failure of submerged bearings, have been identified for consideration by fragility 

analysts. These test results should be considered by fragility analysts in performing future 
 91

SPRAs. However, caution must be applied to assess the applicability of the results to the specific 

equipment being considered. In particular, an analysis of the component anchorage and support 

fragility needs to be performed as a necessary supplement to the equipment fragility data for a 

proper application. 

 93

6 REFERENCES 

Bandyopadhyay, K. and C.H. Hofmayer (1986). Seismic Fragility of Nuclear Power Plant 

Components (Phase I), NUREG/CR-4659, Vol. 1, Brookhaven National Laboratory. 

Bandyopadhyay, K., C.H. Hofmayer, M.K. Kassir, and S.E. Pepper (1987). Seismic Fragility of 

Nuclear Power Plant Components (Phase II), Motor Control Center, Switchboard, Panelboard and 

Power Supply, NUREG/CR-4659, Vol. 2, Brookhaven National Laboratory. 

Bandyopadhyay, K., C.H. Hofmayer, M.K. Kassir, and S.E. Pepper (1990). Seismic Fragility of 

Nuclear Power Plant Components (Phase II), Switchgear, I&C Panels (NSSS) and Relays, 

NUREG/CR-4659, Vol. 3, Brookhaven National Laboratory. 

Bandyopadhyay, K., C.H. Hofmayer, M.K. Kassir, and S. Shteyngart(1991). Seismic Fragility of 

Nuclear Power Plant Components (Phase II), A Fragility Handbook on Eighteen Components, 

NUREG/CR-4659, Vol. 4, Brookhaven National Laboratory. 

EPRI NP-6041-SL (1991). A Methodology for Assessment of Nuclear Power Plant Seismic 

Margin, Revision 1, Electric Power Research Institute. 

EPRI TR-016780 (1999). PRA Key Assumptions and Groundrules, Advanced Light Water 

Reactor Utility Requirements Document, Vol. III, Rev. 8, Chapter 1, App. A, Section 3.3.6.6, 

Electric Power Research Institute. 

EPRI 1019200 (2009). Seismic Fragility Application Guide Update, Electric Power Research 

Institute. 

Fujita, T., Y. Sasaki, H. Abe, K. Kuroda, K. Kato, N. Yoshiga, N. Kojima, S. Asakura, and M. 

Nakamaru (1997). “NUPEC project: seismic proving test on reactor shutdown cooling systems – 

(summary of results),” K17/3, Transactions of the 14th International Conference on Structural 

Mechanics in Reactor Technology, SMiRT 14, Lyon, France. 

Holman, G.S., C.K. Chou, G.D. Shipway, and V. Glozman (1987). Component Fragility 

Research Program (Phase I Demonstration Tests), NUREG/CR-4900, Vols. 1 and 2, Lawrence 

Livermore National Laboratory. 

IEEE C37.98 (1984). Seismic Testing of Relays, ANSI/IEEE Standard C37.98-1984, Institute of 

Electrical and Electronic Engineers. 

Iijima, T., H. Abe, and T. Fujita (2004). “Program outline of seismic fragility capacity tests on 

nuclear power plant equipment,” Proceedings of the 12th International Conference on Nuclear 

Engineering, ICONE12, Virginia, USA. 

Iijima, T., H. Abe, and K. Suzuki (2005). “Seismic fragility capacity of equipment – horizontal 

shaft pump test,” Proceedings of the 18th International Conference on Structural Mechanics in 

Reactor Technology, SMiRT 18, Beijing, China. 

Iijima, T., H. Abe, and K. Suzuki (2007). “Seismic fragility capacity of equipment – electric 

panel test,” Transactions of the 19th International Conference on Structural Mechanics in Reactor 

Technology, SMiRT 19, Toronto, Canada. 
 94

Inagaki, M., K. Suzuki, and H. Abe (2006). “Overview of seismic fragility capacity test of PWR 

and BWR control rod insertion systems,” Proceedings of the 14th International Conference on 

Nuclear Engineering, ICONE14, Florida, USA. 

JNES (2009). Fragility Data of Equipment for Nuclear Facilities by Shaking Tests, 08TAIHATV0027 

McGuire, R.K., W.J. Silva, and C.J. Costantino (2001). Technical Basis for Revision of 

Regulatory Guidance on Design Ground Motions: Hazard- and Risk-consistent Ground Motion 

Spectra Guidelines, NUREG/CR-6728, Risk Engineering, Inc. for U.S. Nuclear Regulatory 

Commission, Washington, DC 

Merz, K.L. (1991a). Generic Seismic Ruggedness of Power Plant Equipment, EPRI NP-5223, 

Rev. 1, Electric Power Research Institute, Palo Alto, California. 

Merz, K.L (1991b). Seismic Ruggedness of Relays, EPRI NP-7147, Electric Power Research 

Institute, Palo Alto, California. 

Reed, J.W. and R.P. Kennedy (1994). Methodology for Developing Seismic Fragilities, EPRI TR103959, Electric Power Research Institute, Palo Alto, California. 

Tsai, N.C., G.L. Mochizuki, and G.S. Holman (1989). Component Fragility Research Program 

(Phase II Development of Seismic Fragilities from High-Level Qualification Data), NUREG/CR5470, NCT Engineering, Inc. and Lawrence Livermore National Laboratory. 

Uchiyama, Y. (2008a). Status of Fragility Tests in JNES (slides), July 17. 

Uchiyama, Y. (2008b). Status of JNES Seismic Test Projects After September 2006 (slides), July 

17. 
 A-I

APPENDIX A JNES FRAGILITY DATA OF EQUIPMENT FOR NUCLEAR 

FACILITIES BY SHAKING TESTS 

 
 A-II
Fragility Data of Equipment for Nuclear

Facilities by Shaking Tests

January 2009

Seismic Safety Division/Japan Nuclear Energy Safety Organization

08TAIHATU-0027

A-III
This report is English version of Chapter IV “Development of Fragility Data” excerpted

from the “Report of Fragility Tests of Equipment - Part 3 (Overall evaluation) - in FY

2005”, which was the outcome of the program conducted by Japan Nuclear Energy

Safety Organization (JNES).

A-IV
Table of content

Part-I Introduction

 1. Background of study

 1.1

1.2

Necessity of fragility data of equipment

Fragility capacity evaluation test of equipment and its progress, and

positioning of the report

 2. Evaluation process for fragility capacity of equipment

Part-II Development of fragility data

 1. Outline

 1.1 Outcome of fragility capacity tests for equipment

 1.1.1

1.1.2

1.1.3

1.1.4

Horizontal shaft pump

Electrical equipment

Control rod inserting capability

Large size vertical shaft pump

 2. Evaluation method of fragility capacity

 2.1

2.2

2.3

2.4

Horizontal shaft pump

Electrical equipment

Control rod inserting capability

Large size vertical shaft pump

 3. Fragility data

 3.1

3.2

3.3

3.4

Horizontal shaft pump

Electrical equipment

Control rod inserting capability

Large size vertical shaft pump

 4. Summary

Reference

A-V

A-1

A-3

A-3

A-3

A-5

A-7

A-9

A-10

A-10

A-11

A-12

A-14

A-17

A-17

A-25

A-28

A-33

A-47

A-48

A-55

A-79

A-83

A-93

A-95

Part-I

Introduction

A-1

1. Background of study

1.1 Necessity of fragility test of equipment

In safety assessment of nuclear power installation, probabilistic safety assessment (Seismic

PSA) is studied to probabilistically evaluate possibility of core damage due to the earthquake

movement exceeding the current design basis. Necessity and flow to improve seismic fragility

evaluation is shown in Figure 1-1. In seismic PSA, as shown in the figure, responses of

building and equipment are calculated using the ground movement by earthquake hazard

evaluation, and equipment damage probability evaluation is performed using the above results

and equipment fragility data, and core damage frequency is evaluated by accident sequence

analysis. To evaluate equipment damage probability, fragility data of the equipment, i.e., data

of function limit of equipment, are necessary. Tease data are also important to adequately

grasp seismic margin of equipment.

1.2 Fragility test of equipment in JNES and its progress, and positioning of the report

Fragility data for equipment having large contribution to core damage are one of the

important items in performing seismic PSA. However, the existing knowledge is not enough to

adequately specify fragility capacity for such equipment. Therefore, it is important issue for

performing seismic PSA with high reliability to identify functional limit and damage mode of

equipment by test, and to develop fragility data set.

Regarding objective equipment for fragility test, the following equipment having large

influence were selected, referring seismic PSA trial analysis performed for BWR and PWR

plants in Japan, and tests were performed to obtain fragility data as Part 1 to Part 3 test.

Fragility Test, Part 1: Horizontal shaft pump and electrical equipment

Fragility Test, Part 2: Equipment related to control rod inserting capability (PWR and BWR)

Fragility Test, Part 3: Large size vertical shaft pump

: Overall and comprehensive evaluation of Part 1 to Part 3

In comprehensive evaluation, the results obtained in the tests of Part 1 to Part 3 were

summarized as fragility data set. Supplemental tests were also done at this stage. Major items

of additional tests and evaluation performed in the summarization stage include the followings:

 Comprehensive evaluation of the fragility values obtained in the tests was performed

considering element tests and analytical evaluation of critical portions.

 For the elements of electrical panels and others, in which abnormality occurred at

relatively low acceleration, additional element tests were performed after the elements

were improved.

 Fragility data after improvement were developed by combining the element test results and

response analysis results of equipment body in which the element is installed.

This report is English version of Chapter IV “Development of Fragility Data” excerpted from

the above mentioned comprehensive evaluation report.

Part 1 to Part 3 of Equipment Fragility Test were conducted in FY 2002 to 2005, and then

Part 4 test (valve, tank) and Part 5 test (support structure and fan) were planned from FY 2005

to 2009 as the next object after them from viewpoint of importance on seismic PSA. However,

they are not included in this report.

The JNES reports of this Fragility Test series are listed in reference and English reports

presented at international conferences are attached to this report.

A-3
A-4
2. Evaluation process for equipment fragility capacity

Evaluation process in Part 1 to Part 3 of Fragility Capacity of Equipment is shown in Figure

2-1. In the fragility capacity tests of equipment, the tests are performed for the selected

equipment, and it is examined whether structural damage and/or loss of active function occur,

and if abnormality occurs, detailed analysis is performed for such abnormality. Various types of

abnormality can be expected as abnormality of function, and some of fragility capacity could be

improved by relatively simple measures, depending on such abnormality. Therefore, limits for

maintaining function (acceleration, load, displacement, etc.) are evaluated, confirming how

much fragility could be improved by reinforcement measures if necessary.

For establishment of fragility evaluation method, fragility of equipment is evaluated by

combining seismic response analysis under large input earthquake conditions with fragility

capacity of parts confirmed in the additional element tests. This method is expandable to

equipment which has similar structure that was tested in Part 1 to 3 of this project. Fragility data

of these kinds of equipment were also evaluated in the study of overall and comprehensive

evaluation and included in the data table of this report.

A-5
A-6
Part-II

Development of Fragility Capacity Data

A-7

1. Outline

In the Program on Equipment Fragility Test, fragility tests for horizontal shaft pump, electrical pannels,

control rod insertion system and large size vertical shaft pump were performed with earthquake motion largely

exceeding the design level, in order to obtain data on realistic fragility capacity of such components, as Part 1

to Part 3 of Equipment Fragility Test. In addition, the issues identified by these tests were studied by

conducting additional tests and analysis, and fragility evaluation method was established based on the

knowledge from these tests and analysis. Evaluation on fragility capacity of similar type equipment was

performed using the method developed.

In this paper, as a summary of Part 1 to Part 3 of Equipment Fragility Test, the results of the Program and

the evaluation method of fragility capacity are described, and fragility capacity data of equipment and their

major parts are summarized.

A-9
1.1 Outcome of Fragility Capacity Tests for Equipment

Outline of Equipment Fragility Test results is described below for horizontal shaft pump, electrical equipment,

control rod insertion system and large size vertical shaft pump.

1.1.1 Horizontal shaft pump

The fragility capacity tests for horizontal shaft pump consisting of two kinds of tests were performed. One

is full-scale equipment test of reactor building closed cooling water (RCW) pump, and another is element

test of bearings and liner rings. The full-scale equipment test was performed with up to the maximum

acceleration of 6×9.8m/s2, using simulated earthquake wave covering design floor response spectra of

horizontal shaft pumps of BWR and PWR plants which are Seismic Class As and A and are important to

safety. The pumps were vibrated in axial and lateral directions under operating and standby conditions

respectively. In the tests, hydraulic characteristics of pump, load acting on bearing, acceleration due to

rotation, water leakage, and strain generated on foundation bolts were measured and observed as well as

seismic response. However, no abnormality was identified in active function and structural strength of the

pump, and no abnormality was also found in disassembling inspection after the test.

In the element tests, in addition to the bearing and liner ring used in horizontal shaft single stage pump

which were tested in the full-scale equipment test, bearings and liner rings used in horizontal shaft

multi-stage pump were also selected for tests. Tests were performed with load corresponding to the seismic

acceleration largely exceeding the one used for the full-scale equipment test. As the result, friction was

generated among balls, inner and outer rings in the thrust direction loading test of deep groove ball bearing,

and plastic flow was generated at white metal on inner side of bearing in the test of radial bearing which is

one of slide bearings. Although such degradation of bearing would not immediately result in shutdown of the

pump, it would cause decrease of bearing operating life. However, it should be noted that such phenomena

were generated under extremely large load conditions greater than 10 to 20×9.8m/s2

 equivalent to

acceleration on pump of actual plant.

Although no abnormality of pump function was identified in full-scale equipment test, degradation was

identified in the element tests, which could result in decrease of operating life of bearing. Pumps related to

safety function of nuclear power plants are required to be continuously operated for a certain period after

occurrence of earthquake, and if operating life of bearing decreases, such requirement could not be

satisfied. Therefore, critical load of the bearing is conservatively specified based on the load which would

generate abnormality to cause decrease of operating life of bearing, or the maximum load under which

function is identified to be maintained. In addition, model of response analysis was developed for horizontal

shaft pump during large input earthquake. Using the earthquake response analysis, seismic force resulting

in the critical load of the bearing was obtained and evaluation method of fragility capacity was developed to

evaluate critical acceleration for active function of horizontal shaft pump. Furthermore, from viewpoint of

structural strength, stress on bolt of pump and motor support and slip of installing portion were evaluated by

simplified static analysis, and critical acceleration of structural strength was calculated.

Section 2.1 describes the evaluation method of fragility capacity of horizontal shaft pump established in

the Part 1 of Equipment Fragility Test, and Section 3.1 shows fragility data of bearing and liner ring obtained

by the element tests, and fragility data of horizontal shaft pump evaluated by applying fragility evaluation

method.

A-10
1.1.2 Electrical equipment

In fragility test of electrical equipment, 8 kinds of representative electrical panels, i.e., a main control

board, a reactor auxiliary control board, a logic circuit control panel, a reactor protection instrumentation

rack, an instrumentation rack, a reactor control center, a power center and a metal-clad switchgear were

selected to be tested for full-scale equipment test, as electrical equipment (panels) important to seismic

PSA. In the full-scale equipment tests, tests were performed with up to the maximum acceleration of

6×9.8m/s2, using simulated earthquake wave covering design floor response spectra of the above electrical

equipment of BWR and PWR plants. In the test, electrical conditions during normal operation were

simulated, and electrical equipment was vibrated in the direction of back and forth and from side to side,

and then electric functional abnormality and structural damage were to be identified. As the results of the

tests, no electrical nor structural abnormality was identified for a main control board, a reactor auxiliary

control board, a logic circuit control panel and an instrumentation rack, and, however, abnormalities in

electrical function or functional abnormalities due to structural damage were generated at electrical parts

contained in a protection instrument rack, a reactor control center, a power center and a metal-clad

switchgear.

In the element tests, based on the investigation of the full-scale test specimen and similar type elements

used in similar panels, about 30 types of parts including relays, control devices, instrument equipment,

electrical equipment and switches were selected from viewpoint of electrical functions and actuating

mechanism, and shaking tests were performed for 3 to 6 specimens of each type in principle. Seismic

response analysis of electrical equipment was performed using simulated earthquake waves developed for

the full-scale equipment test, and response wave at the location mounting the part obtained by the analysis

was used as an input wave. Input acceleration level was specified as about 10×9.8m/s2 at the maximum,

considering response amplification of panel and performance of the shaking table. In the tests, electrical

parts were vibrated in the direction of back and forth and from side to side, under the electric conditions

simulating normal operation, and were also vibrated by sine beat wave, back and forth, from side to side

and vertically as a reference.

As the results of the tests, abnormalities in electrical function were identified in some of relays and control

devices. However, most of other parts had no malfunction even though they were vibrated up to the

performance limit of the shaking table.

It was considered to be necessary to improve fragility data of circuit breaker, because fragility capacity of

breaker became critical for power center and metal-clad switchgear in the Part 1 of Equipment Fragility Test.

Therefore, element test for breaker was performed and fragility data for breaker were reinforced. In addition,

applicability of Bayes analysis was studied as an evaluation method for median value and dispersion

concerning fragility of the parts.

As an evaluation method of fragility of electrical equipment, method to evaluate critical acceleration at

panel foundation was established based on comparison between fragility data obtained by element tests

and response multiplying factor at the location of mounting parts obtained by seismic response analysis of

the panel. Both this critical acceleration of electrical function and critical acceleration of structural strength

specified by stress limit of panel cabinet or anchor bolt were also to be evaluated as fragility capacity of

electrical equipment.

Section 2.2 describes the method to evaluate fragility capacity of electrical equipment established in the

Part 1 of Equipment Fragility Test, and Section 3.2 shows fragility data of electrical parts obtained by the

element tests, and fragility data of electrical equipment evaluated by applying the fragility evaluation method.

A-11
1.1.3 Control rod inserting capability

Regarding control rod of PWR and BWR, control rod inserting capability tests were performed, covering up to

the fuel response largely exceeding the one used in the past tests.

(1) Component related to PWR control rod inserting capability

In the element test for PWR control rod inserting capability, a test vessel containing one fuel assembly

and filled with water was placed on the shaking table, and was vibrated totally. Through this test, vibration

characteristic of fuel assembly in water was obtained for large amplitude region. Based on the test results,

input data for beam element analysis were prepared, and analysis model of fuel assembly response which

can reproduce vibration characteristics (natural frequency, amplitude dependency of damping factor) was

established.

For the full-scale equipment test of PWR control rod insertion system (consisting of control rods, fuel

assembly, control rod drive mechanism, etc.), design conditions of domestic PWR plants were investigated,

and pre-analysis was performed using evaluation method verified by the past tests, and input wave for the

test was developed to make responses of simulated fuel assembly and control rod drive mechanism the

same as ones of actual plant. In the test, it was vibrated by 3.3 times of seismic force due to the extreme

design earthquake ground motion S2, and no abnormality was identified to hinder control rod inserting

function. Relation between displacement of fuel assembly and time delay ratio of control rod insertion was

compared with the past data, and both test results were confirmed to be roughly identical within the fuel

response displacement level of the past test.

Analytical method of control rod inserting capability during large input was established based on these

test results, and reproduction analysis of full-scale equipment test results was performed. Then it was

confirmed by the analysis result that seismic response of major equipment and control rod insertion time

could be simulated. Functional limit was defined considering both structural and insertion aspects, i.e. the

fuel response displacement was defined considering the application limit of evaluation method as functional

limit (fragility capacity). Structural strength of major component is also in this consideration. Median value

and dispersion (logarithmic standard deviation) of fragility were evaluated by performing analytical

evaluation with additional consideration of actual plant conditions such as temperature and flow velocity.

Section 2.3 describes the fragility evaluation method of component related to PWR control rod inserting

capability established in the Part 2 of Equipment Fragility Test, and Section 3.3 shows fragility data of

representative actual plants evaluated by applying the fragility evaluation method.

(2) Component related to BWR control rod inserting capability

In the element test for BWR control rod inserting capability, critical strength tests (material test, buckling

test, load-displacement history test, repeated loading test) were performed for channel box which was main

structural member of fuel assembly, using quasi-dynamic displacement loading facility and critical strength

of fuel assembly was obtained in large amplitude region. It was confirmed that behavior of plastic

deformation at operating temperature of actual plant became larger than the one at room temperature.

Analytical model was developed to reproduce behavior obtained in the element tests.

For the full-scale equipment test of BWR control rod insertion system, design conditions of domestic

BWR plants were investigated, and pre-analysis was performed using the evaluation method verified by the

past tests, and input wave for the test was developed to make responses of simulated fuel assembly the

same level as actual plant. In the test. Vibration tests were performed up to 4 times of seismic input

corresponding to the design limit earthquake S2, and no abnormality was identified to hinder control rod

inserting function. Relation between displacement of fuel assembly and time delay ratio of control rod

insertion was compared with the past data, and both test results were confirmed to be roughly identical

within the response displacement level of the past data.

Analytical method of control rod inserting capability under large input was established based on these test

A-12
results, and reproduction analysis of full-scale equipment test results was performed. It was confirmed by

the analysis result that seismic response of major equipment and control rod insertion time could be

simulated. Then, considering structural strength of related component and application limit of evaluation

method etc., certain fuel response displacement was defined as fragility capacity limit. Median value and

uncertainty dispersion of fragility (logarithmic standard deviation) were evaluated by performing analytical

evaluation with additional consideration of actual plant conditions such as temperature etc.

Regarding BWR control rod inserting capability, effects of vertical earthquake ground motion exceeding

gravity acceleration had not been confirmed only by the existing knowledge. Therefore, analytical

investigation of the effect of vertical excitation was performed for the effects on control rod insertion time and

up-lift of fuel assembly, and outlook that effects of vertical earthquake ground motion on control rod inserting

capability are small was obtained.

Section 2.3 describes the fragility evaluation method of component related to BWR control rod inserting

capability established in the Part 2 of Equipment Fragility Test, and Section 3.3 shows fragility data of

representative actual plants evaluated by applying the fragility evaluation method.

A-13
1.1.4 Large size vertical shaft pump

In the fragility capacity test of large size vertical shaft pump, full-scale equipment test for pit barrel type

pump of reactor residual heat removal system (RHR) and element test for submerged bearing, liner ring

(austenite stainless steel), and thrust bearing, which are parts important to rotating function, were

performed.

In full-scale equipment test, specimen was excited horizontally and vertically under the normal operating

conditions and shutdown conditions of the pump respectively, using simulated earthquake wave enveloping

design floor response spectra for large size vertical shaft pumps of BWR and PWR plants, in order to

confirm function of pump. Test procedure and specimen of the full-scale equipment test are shown in Figure

1.1.4-1 and 2. As the results of the horizontal vibration test (fragility test (A) and (B) ). It was confirmed that

motor mounting bolt was yielded at 12.0×9.8m/s2 of response acceleration at the top of motor (motor

function of motor itself was maintained even at 14.0×9.8m/s2 of response acceleration at the top of motor),

and that barrel was yielded at 31.0×9.8m/s2 of response acceleration at the bottom end of the barrel.

Regarding non-linear response behavior caused by clearance of barrel support, relation between change of

clearance (diametric clearance: 4.0 mm, 2.0 mm and 1.0 mm) and non-linear response was confirmed. As

the results of vertical vibration tests (Step 3 and 4 of fragility capacity test (A)), it was confirmed that function

of the pump was maintained even at 31.0×9.8m/s2 of response acceleration at the bottom end of barrel and

12.0×9.8m/s2 of response acceleration at the top of motor. No abnormality was also identified in operation

and disassembling inspection after the test. The results of the full-scale equipment test are shown in Table

1.4-1.

These results confirmed that pump function was maintained even at the response acceleration in

horizontal direction which widely exceeded the function-confirmed response acceleration (bottom end of

barrel column: 10.0×9.8 m/s2, top of motor (portion of bearing): 2.5×9.8 m/s2; JEAG4601) of each portion of

vertical shaft pump obtained by Utilities Joint Research Study on Maintaining Function of Active

Component during Earthquake (ACT Joint Research) conducted from FY 1980 to FY 1982, aiming at

confirmation of maintaining function of active component during earthquake.

In the element test, specimen was vibrated with the load corresponding to the extremely greater seismic

load than one in the full-scale equipment test, in order to confirm whether function of the part itself is lost,

and to obtain dynamic characteristics (spring constant, damping factor, PV value (index for seizure limit of

material: product of contact surface pressure P and slip speed V between two surfaces) ) As the test results,

it was confirmed for submerged bearing that rotating function of bearing was maintained with the surface

pressure which was at least 5 times of allowable surface pressure considered in the design of actual plant

(abnormality such as deformation, which was considered to be pre-indication of function limit, occurred after

the maximum vibration for rubber and resin bearings among submerged bearings, and rotating function

was, however, maintained.). For liner ring, it was confirmed that rotating function was maintained even

under the maximum vibrating load of about 17.0 kN (equivalent to 3 times of S2; S2 is the wave enveloping

design floor responses of BWR/PWR (ZPA: 1.24×9.8m/s2) ). For slide bearing among thrust bearings, up-lift

analysis was performed using spring constant of bearing itself obtained by the test. Based on the analysis

result, vertical acceleration of 1.3 to 1.5×9.8m/s2is evaluated as the acceleration where the bearing load

reaches to the maximum load in element test or the acceleration where collision between liner ring and

impeller occurs. The latter is conservatively defined as uplift limit of vertical pump shaft. The evaluated

acceleration correspond to about six times of S2 which is vertical ground motion (ZPA : 0.22x9.8m/s2)

tentatively used in the Improvement and Standardization Program.

Simulation analysis was performed for the full-scale equipment test using the above test results, and

simplified evaluation method (equivalent linear analysis and impulse response analysis method) capable of

fragility evaluation for large size vertical shaft pump of actual plant was established.

Section 2.4 describes the fragility evaluation method of large size vertical shaft pump of actual plant

established in the Part 3 of Equipment Fragility Test, and Section 3.4 shows fragility data of bearings, liner

rings and thrust bearings obtained by the element tests, and fragility data of representative pump of actual

plants evaluated by applying the fragility evaluation method.

A-14
Barrel Column Motor

Maintaining or Loss of Function

Structure for

r moto g mountin

6000 8000

Motor Portion Pump Portion

2. Evaluation method of fragility capacity

2.1 Horizontal shaft pump

             









               



               





       



           

  



 

 

 





                 



  









  

             

  

 





  



 

A-17


             



  



              

















             

 





         





 

 

 



















  

 

               







 

A-18




 



            



            























 





 







 





             



 

              





 

 

                

  



A-19










 



 









             





 







 



 



           

 





          



          

 

A-20




 



















































A-21
 

A-22
2 1

c1



















 

A-23
























 













 





 





A-24
2.2 Electrical equipment



 



           







            



 

 

 A=m/km

             

   k          

           



 



           



    

 



             







            

 



 

A-25


 

                

           

         



 







           





A-26


     

m  k

k

A m



    k 

      









 m 







mounting position

of panel

Critical part

Typical model used for

evaluation (Protection

instrument rack)

A-27
2.3. Control rod inserting capability

  











           







            



 

           





  

              

            







              



             

  

          



          











A-28
            



 



            



          













          

             



A-29
 











           

              







         







             

           



            







              



             



       

             





            

          

           

             



A-30


              





             







             





A-31










    



 

     

 

     



 

     





















Prescribed Scram Time(

(: Prescribed time in safety evaluation: 1.62 sec. (75% insertion time).

Exceeding it does not directly result in a problem.











A-32
2.4 Large size horizontal shaft pump

 

               



















              

             



















 













 

 

















 



 









A-33


  







 























 



 





 



A-34




 



    

















              

              

 





















 













[Method to specify equivalent linear stiffness]



       

 

A-35


 

C

KcKb

Kb

y







     





        

     



 

:

:: C

KcKb

Kb

yXXc

 

Xc

X

C

KcKb

Kb



 



            





 



 





















   



 





A-36




 









         



              



 







  

               



[Impulse response analysis method]

 







            

  

VMVMtF 2211

21

, MM   



21

,VV   

 

  

 

          









 





 

A-37










 













A-38


 





  







          

         





 















         

 



 









 





 







  



 



   



 



  













 



 



 

A-39
 

 




            

            

           



 



 

















         

 

           

          



   

          

          

             







           

      Japanese Industrial Standards(    



   













  

            

















 

A-41
 



 

              



 

        



 

  

       31        



      

              



 

  



           



            

        



 

   

       31       

              



             



  



 

     



           

  



  





 

           



 





A-42






 

           











 



              

           















               





         

            



             

 

 



             





              



     



















A-43
 

            



                 





















A-44


           



            

           



        

              







        



 

            

  

Figure 2.4-5 Two mass model for vertical direction response analysis of vertical shaft pump

A-45

3. Fragility data









           



             

         

             

   

          

          

          





           



 

A-47
3.1 Horizontal shaft pump



 



  

 

 











 

A-48
Table 3.1-2 Summary Table of Fragility Data (1/3)



 











       

 

 

 

 

 













 





 







  

    



    

    



    



  





  



  

 





















 

 















 































 



 

A-49
Table 3.1-2 Summary Table of Fragility Data (2/3)



 











      



  









 



  







 

 















 

































 







 

 

 









A-50
Table 3.1-2 Summary Table of Fragility Data (3/3)



 











      



  









 



  







 

 















 

































 





 

 

 

 

 

 









 

























A-51
Table 3.1-3 Summary Table of Fragility Data (1/2)



 







      

 

































      



      



      



  





 



















   

  

   

 







   

   

   

 







 

 

 

























  





 



















 

 

 







 

 

 







           





A-52
Table 3.1-3 Summary Table of Fragility Data (2/2)



 







      













 







 

     

     

     



 

 

































































   

   

   

   

 





   

   

   

   

 

 























 

 



 































 

















   

   

   

 



 













A-53
Table 3.1-4 Summary Table of Fragility Data



 







       











 







 

    

    

    

    

    

    



 













 















 



















   

    

   

   

    

   

   

    

   

   

    

   

   

    

   

   

    

   

 

A-54
3.2 Electrical equipment

               





  





















 



 

 

 

 

 





 

A-55
Table 3.2-2 Summary Table of Fragility Data (1/8))





















        

  







  





 





















  





  





 



















 







   











 







    







 

 





 



A-56
Table 3.2-2 Summary Table of Fragility Data (2/8)





















       

  





  

























   



   



 



















 







    





























   















 





A-57
Table 3.2-2 Summary Table of Fragility Data (3/8)















 







       

  







  

























 





 









 



















 







    































    

























 

A-58
Table 3.2-2 Summary Table of Fragility Data (4/8)





















      

  





  

























 

   

 



   



 



















 







    































   









 





































A-59
Table 3.2-2 Summary Table of Fragility Data (5/8)





 











 



        



  







  

























   





  



 

















 







  





























    









 

















 







 













A-60
Table 3.2-2 Summary Table of Fragility Data (6/8)













 



 



      

  





   

  







  

























   



   



 



















 







   



















    









 











A-61
Table 3.2-2 Summary Table of Fragility Data (7/8)























      

  







  

























  

 

















 

 





 







 



 



















 







   























    

















 













A-62
Table 3.2-2 Summary Table of Fragility Data (8/8)















 





      

  







  































  

        



        



 







 

  



 





















 







   



















    









 





 





 



A-63
Table 3.2-3 Summary Table of Fragility Data (1/3)













      

   

 



    

    

    

    

    

    

   

 



    





































   

   



   

 

  

  











 







  

 

  

  

  

  

  





  

 

  

  

  

  

  









  

 

  

   



  

 

  

   



  

 

















   

  

   



  

 

  

  









 







  

 



  



A-64
Table 3.2-3 Summary Table of Fragility Data (2/3)

      

 



    





































   

   

   

   

   





   

 

  

  

  

  

  









  

 

   

    



   

 

  

   



  

 

 







   

  

  

  

  

  





  

 

  

  

  

  

  









  

 

  

   



  

 

   

    



   

 

 







  





 





A-65
Table 3.2-3 Summary Table of Fragility Data (3/3)

      

 



    





































  

  

  

  

  





  

 

  

  

  

  

  









  

 

  

   



  

 

  

   



  

 

 







  

  

  

  

  

  





  

 

  

  

  

  

  









  

 

  

   



  

 

  

   



  

 

 







  







A-66
Table 3.2-4 Summary Table of Fragility Data (1/2)



  







       

   

 

    

    

    

    

   

   

   

 

  

 

  

 

    

    

  

  

 



    





































  

   



  

 

  

  



  







  

 

  

   



  

 

  

   

  

   

   



  







   

 

  

   



  

 

  

  

 











  

 

  

   



  

 

  

  

 











  

 



  



A-67
Table 3.2-4 Summary Table of Fragility Data (2/2)

       

 



    





































  

   



  

 

  

  

  







  

 

  

   



  

 

  

  



  







  

 

  

   



  

 

  

  

  







  

 

  

   



  

 

  

  



  







  

 

  

   



  

 

  

  



  







  

 

  

   



  

 

  

  













  

 

  

   



  

 

  

  



  







  

 

   

   

  



  

 

   



 



A-68
Table 3.2-5 Summary Table of Fragility Data













      

 



    





































  

  

  





  

 

  

  

  







 







  

 



    

  

 

   

  

   



  

 

  

  







 







  

 

  

   



  

 

  

  







 







  

 







   

 



    

    



    



   

A-69
Table 3.2-6 Summary Table of Fragility Data (1/3)













      

   

 

    

 

   

    

    

    

 



  

 







































  

  

  

  

  





  

 

  

  

  

  

  









  

 

   

    



   

 

  

   



  

 













   

  

  

  

  

  





  

 

  

  

  

  

  









  

 

  

   



  

 

  

   



  

 















  



 



A-70
Table 3.2-6 Summary Table of Fragility Data (2/3)

      

 



  

  







































  

  

  

  

  





  

 

  

  

  

  

  









  

 

  

   



  

 

  

   



  

 



 







  

  

  

  

  

  





  

 

  

  

  

  

  









  

 

  

   



  

 

  

   



  

 



 







  







A-71
Table 3.2-6 Summary Table of Fragility Data (3/3)

      

 



  

  







































  

  

  

  

  





  

 

  

  

  

  

  









  

 

  

   



  

 

  

   



  

 



 







  







A-72
Table 3.2-7 Summary Table of Fragility Data (1/2)













      

 



    





































  

  

  

  

  





  

 

  

  

  

  

  









  

 

  

   



  

 

  

   



  

 

 









   

  

  

  

  

  





  

 

  

  

  

  

  









  

 

  

   



  

 

  

   



  

 















  





 

   

 

    

    

    

A-73
Table 3.2-7 Summary Table of Fragility Data(2/2)

      

 



  

  







































  

  

  

  

  





  

 

  

  

  

  

  









  

 

  

   



  

 

  

   



  

 

 









  







A-74
Table3.2-8 Summary Table of Fragility Data



 







      

   

 

    

    

    

    

    

  

  





 

 



    







































    

 

 

    

 

     





 

    

 

     









 

     



      





 

 

     



     

 

 

    



 



   

  

 

 





 





    



     

 

 

     



    







 

 

    





 



 

A-75
Element test result and evaluation of gas circuit breaker with reinforcement







  



  







      

 

  

















 

   

   

 







   



  









  



 













 

  



A-76
              

















 

   

   





    

  

  

           

   

  

  

 





         

             

            



              





            







    



  

  

  



















  

  

   



A-77
                       

           







  



    







               

  



           





  



  



A-78
3.3 Control rod inserting capability









  



 



 



 





 















A-79
Table 3.3-2 Summary Table of Fragility Data (3 Loop and 4 Loop of PWR)



 











      





 











      

 

  

  

  

 

  

   





 



 









   









 









   







A-80
Table 3.3-4 Summary Table of Fragility Data (BWR, 100 mil channel box)



 













      





 













      



  

  

   







 









   











  













  









  







A-81

3.4 Large size vertical shaft pump





 

 















 



 









 





 



  

A-83
Table 3.4-2 Summary Table of Horizontal Fragility Data of Pump (1/4)



 









 

      





















 





   

 

 



   

 

 



 

  

  























 















































 









 

















































 



              



  



 

 

 

 

 









 



  

A-84
Table 3.4-2 Summary Table of Horizontal Fragility Data of Pump (2/4)



 









 

      



 











  







































































































 





 

 

 

 

 









 



   

A-85
Table 3.4-2 Summary Table of Horizontal Fragility Data of Pump (3/4)



 











      

 



 















 





















































































































 





 

 

 

 

 



























A-86
Table 3.4-2 Summary Table of Horizontal Fragility Data of Pump (4/4)



 











      



 

 















 



























































































 































 





 

 

 

 

 









 



  

A-87
Table 3.4-3 Summary Table of Vertical Fragility Data of Pump (1/2)



 











 

       































 



  

 

 



 



   







 



 







  









  







  





 





  



 

 

 

 

 









 



  

A-88
Table 3.4-3 Summary Table of Vertical Fragility Data of Pump (2/2)



 













      

 



































    



    







 

    



     



























  



A-89
Table 3.4-4 Summary Table of Horizontal Fragility Data of Equipment (1/2)



 







      

































 



       



       







      



       



       





 

 



















 

 

 

 

 







   

   







    

   

   







    

   

  

   





   

  

   

   



   









  

   

   





   



















 

 



















A-90
Table 3.4-4 Summary Table of Horizontal Fragility Data of Equipment (2/2)



 







      





















 

     

     



 









 



















 



















   

    

   

   

    

   

 

A-91
Table 3.4-5 Summary Table of Vertical Fragility Data of Equipment



 







      





















 







 

     

     



 









 













 

  

 

 

  

 

 



A-92
4. Summary

(1) Horizontal shaft pump

As fragility evaluation method for horizontal shaft pump, fragility evaluation method was

established to obtain seismic force which reaches to critical load of bearing by seismic

response analysis of horizontal shaft pump during large input earthquake, and to evaluate

critical acceleration of active function. Regarding critical load of bearing, critical load and

dispersion for fragility evaluation were developed according to the types of bearing,

based on the element test results of bearing. Furthermore, mount bolts of motor and

pump was evaluated by simplified static analysis from viewpoint of structural strength,

and critical acceleration of structural strength was evaluated.

Critical accelerations of active function were evaluated for full-scale specimens (RCW

pump), similar types of horizontal shaft single stage pump and multi stage pump.

Accelerations obtained from the above evaluation exceeded function-confirmed

acceleration (6×9.8m/s2) of actual equipment test.

(2) Electrical equipment

Regarding electrical equipment, fragility evaluation method was established to evaluate

critical acceleration of electrical function for electrical equipment (panel) based on

response multiplying factor of panel by analysis and function critical acceleration by parts

tests. Regarding function critical accelerations of parts, median value and dispersion of

fragility were developed based on the parts test results. From viewpoint of structural

strength, stress evaluation was performed for cabinet body using response analysis of

electrical equipment, and critical accelerations of structural strength were evaluated.

Critical accelerations of electrical function and critical accelerations of structural

strength were evaluated for 8 type panel specimens and similar types of electrical panels.

The results of evaluation revealed that electrical function is controlled by electrical fragility

capacity for all electrical equipment, and fragility capacity obtained from the above

evaluation results exceeded fragility capacity (3.6×9.8m/s2) used in the past seismic PSA.

(3) Control rod inserting capability

(i) PWR control rod inserting capability

Regarding PWR control rod inserting capability, structural fragility capacity and limit

of control rod inserting capability were investigated by using analysis method, of which

adequacy was verified by simulation analysis of actual equipment test. Seismic

response analysis and strength analysis of fuel assembly, control rod drive

mechanism and in-core structure for actual representative plant (4 loop) and plant

other than representative (2 loop) were performed, and based on such evaluation

results, fragility evaluation was performed.

As the results of fragility evaluation for actual representative plant (4 loop), fragility

capacity was decided by excess response displacement of fuel assembly, and

calculated median value of fragility capacity (77 mm) exceeded the median value of

fragility (fuel response displacement: 36 mm) used in the past seismic PSA.

A-93
(ii) BWR control rod inserting capability

Regarding BWR control rod inserting capability, fragility capacity of equipment and

limit of control rod inserting capability were investigated by using analysis method, of

which adequacy was verified by simulation analysis of full-scale equipment test.

Seismic response analysis and strength analysis of fuel assembly and in-core

structure for standard plant (channel box type: 100 mil) and plant other than standard

(channel box type: 80 mil and 120 mil) were performed, and based on such evaluation

results, fragility evaluation was performed.

As the results of fragility evaluation for actual plant (channel box type: 100 mil),

fragility capacity was decided by excess response displacement of fuel assembly, and

calculated median value of fragility capacity (91 mm) exceeded the median value of

fragility (fuel response displacement: 82 mm) used in the past seismic PSA.

(4) Large size vertical shaft pump

As fragility evaluation method for large size vertical shaft pump, seismic force, under

which mounting bolts and barrel reached to yield, and seismic force, under which

submerged bearing reached to function-confirmed PV value (index for seizing limit of

material: product of contact surface pressure, P, by slip velocity between 2 surfaces, V),

were obtained by seismic response analysis of large vertical shaft pump during

earthquake, and fragility evaluation method was established to evaluate critical

acceleration of active function. For active function limit of submerged bearing and liner

ring, function-confirmed PV values were developed for fragility evaluation respectively

based on element test results.

Evaluations of critical acceleration of active function for pit barrel type pumps (long

size; full-scale test specimen, short size), vertical mixed flow pump (PWR, BWR) were

performed. As the result, it was found that vertical mixed flow pump (BWR) has smallest

fragility value, and median value of it is 14.6×9.8m/s2

 for response acceleration at column

bottom and 4.3×9.8m/s2 for response acceleration at motor top. These values exceed the

function-confirmed horizontal response accelerations in former studynote 1, i.e.,

10.0×9.8m/s2 and 2.5×9.8m/s2 respectively, which were obtained in the past study.

Note 1: Function-confirmed horizontal response accelerations for each portion of large size vertical

shaft pump (RHR pit barrel type pump) which were obtained in the Utilities Research, “Study

on Maintaining Function of Active Component during Earthquake (ACT Joint Study)”

performed from 1980 to 1982, in order to confirm maintenance of function during earthquake

for active component. (Study summary is described in JEAG4601-1991)

A-94
Reference

- JNES report (2006), 06 KIKOHO 0003, “Overall and comprehensive evaluation report of

Equipment Fragility Test, Part 1 to Part 3” (in Japanese)

- JNES report (2005), 05 KIKOHO 0002, “Fragility Test, Part 1 : Horizontal shaft pump and

electrical equipment” (in Japanese)

- JNES report (2004), 04 KIKOHO 0003, “Fragility Test, Part 1 : Horizontal shaft pump and

electrical equipment” (in Japanese)

- JNES report (2006), 06 KIKOHO 0001, “Fragility Test, Part 2 : PWR control rod inserting

capability” (in Japanese)

- JNES report (2006), 06 KIKOHO 0014, “Fragility Test, Part 2 : BWR control rod inserting

capability” (in Japanese)

- JNES report (2005), 05 KIKOHO 0005, “Fragility Test, Part 2 : PWR and BWR control rod

inserting capability”

- JNES report (2006), 06 KIKOHO 0002, “Fragility Test, Part 3 : Large size vertical shaft

pump” (in Japanese)

- JNES report (2005), 05 KIKOHO 0004, “Fragility Test, Part 3 : Large size vertical shaft

pump” (in Japanese)

- JNES report (2004), 04 KIKOHO 0004, “Fragility Test, Part 3 : Large size vertical shaft

pump” (in Japanese)

A-95

B-1 

APPENDIX B ELECTRICAL PANEL TEST RESPONSE SPECTRA 

This appendix describes response spectra used in the JNES electrical panel tests and the electrical 

device tests. Response spectra for the horizontal shaft pump tests, the vertical shaft pump tests, 

and the control rod driven mechanism (CRDM) insertion capability tests are included in Section 3. 

These spectra were developed based on recorded time histories in the tests, or determined by 

analyses. JNES provided these spectra to NRC/BNL through its annotated fragility reports, 

which are in Japanese. 

The annotations and labels in these spectra in this appendix are created based on the JNES 

annotations. The unit for the spectral acceleration in a spectrum plot may be g, gal (cm/s2), or 

m/s2, as being consistent with the unit in the corresponding original spectrum plot in the JNES 

fragility reports. Similarly, the horizontal axis can be period (s) or frequency (Hz). The damping 

ratio for a response spectrum and the level of excitation are also indicated in the spectrum plots. 

The damping ratio for the electrical panels and the electrical devices is 4%. Other information 

useful in identifying the spectra is also presented as annotations or included in the captions. 

The response spectra for the electrical panels and devices will be described in two sections of this 

appendix. The first section includes the spectra for the tests reported in September 2003. The 

zero period accelerations (ZPA) of these spectra are 5 g or smaller. The second section includes 

the spectra for the tests reported in July 2004 that have higher input ZPAs. 
B-2 

B.1 Response Spectra Reported in September 2003 

These spectra were extracted from the JNES annotated fragility report dated September 2003. 

The title of that report in English is “Report on Seismic Reliability Proving Test, Vol. 2 – 

Equipment Fragility Vol. 1 (Horizontal Shaft Pump, Electrical Panels and Their Components).” 

A total of 36 figures are included in this section. 

For device tests (i.e., component tests in JNES’s annotation), the input motions were developed 

based on analysis of the panels instead of recorded data in the tests, because the device tests were 

scheduled before the full scale panel tests. For a device that was installed in a tested panel, the 

input motion was the predicted response time history at its installation point; otherwise, the input 

motion was obtained from prior analysis of similar panels that included the subject device. The 

analytical input motions were further filtered by removing long period (< 8 Hz) components to 

consider the shaking table characteristics so that high acceleration was achieved in the concerned 

frequency range. The spectra for devices included in this section were extracted from Appendix 

C of the above mentioned proving test report. 

 
B-3 

B.1.1 Reactor Control Center 

Figure B-1 Reactor Control Center Test – Child Table RS – 5 g (Side to Side) 

Figure B-2 Reactor Control Center Test – Base Plate RS – 5 g (Side to Side) 

Period (s) 

Target for Child Table 

Child Table Response

Spectral Acceleration (m/s

2) 

5 g Excitation Level 

Damping: 4% 

Period (s) 

Target for Child Table 

Base Plate Response 

Spectral Acceleration (m/s

2) 

5 g Excitation Level 

Damping: 4% 
B-4 

Figure B-3 Reactor Control Center Test – Panel RS at the Installation Point of Magnetic 

Contactor – 5 g (Side to Side) 

Figure B-4 Reactor Control Center Test – Child Table RS – 5 g (Back to Forth) 

Period (s) 

Target for Child Table 

Panel Response 

Spectral Acceleration (m/s

2) 

5 g Excitation Level 

Damping: 4% 

Period (s) 

Target for Child Table 

Child Table Response

Spectral Acceleration (m/s

2) 

5 g Excitation Level 

Damping: 4% 
B-5 

Figure B-5 Reactor Control Center Test – Base Plate RS – 5 g (Back to Forth) 

Figure B-6 Reactor Control Center Test – Panel RS at the Installation Point of Magnetic 

Contactor – 5 g (Back and Forth) 

Period (s) 

Target for Child Table 

Base Plate Response 

Spectral Acceleration (m/s

2) 

5 g Excitation Level 

Damping: 4% 

Period (s) 

Target for Child Table 

Panel Response 

Spectral Acceleration (m/s

2) 

5 g Excitation Level 

Damping: 4% 
B-6 

B.1.2 Power Center 

Figure B-7 Power Center Test – Child Table RS – 4 g (Side to Side) 

Figure B-8 Power Center Test – Base Plate RS – 4 g (Side to Side) 

Period (s) 

Target for Child Table 

Child Table Response

Spectral Acceleration (m/s

2) 

4 g Excitation Level 

Damping: 4% 

Period (s) 

Target for Child Table 

Base Plate Response 

Spectral Acceleration (m/s

2) 

4 g Excitation Level 

Damping: 4% 
B-7 

Figure B-9 Power Center Test – Panel RS at the Installation Point of the Ratio Differential Relay 

– 4 g (Side to Side) 

Figure B-10 Power Center Test – Child Table RS – 3 g (Back and Forth) 

Period (s) 

Target for Child Table 

Panel Response 

Spectral Acceleration (m/s

2) 

4 g Excitation Level 

Damping: 4% 

Period (s) 

Target for Child Table 

Child Table Response

Spectral Acceleration (m/s

2) 

3 g Excitation Level 

Damping: 4% 
B-8 

Figure B-11 Power Center Test – Base Plate RS – 3 g (Back and Forth) 

Figure B-12 Power Center Test – Panel RS at the Installation Point of the Ratio Differential Relay 

– 3 g (Back and Forth) 

Period (s) 

Target for Child Table 

Base Plate Response 

Spectral Acceleration (m/s

2) 

5 g Excitation Level 

Damping: 4% 

Period (s) 

Target for Child Table 

Panel Response

Spectral Acceleration (m/s

2) 

3 g Excitation Level 

Damping: 4%
B-9 

B.1.3 Device Tests 

Figure B-13 Ratio Differential Relay (MELCO TUB-2-D) 

Figure B-14 Over Current Relay (MELCO CO-18-D) 

Period (s) 

Filtered (HPF 10 Hz + LPF 16 Hz)

Original

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s) 

Filtered (HPF 10 Hz + LPF 16 Hz)

Original

Back and Forth Side to Side 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s) 

Thick Line: Filtered (HPF 11 Hz + LPF 16 Hz) 

Thin Line: Original 

Back and Forth Side to Side 

Thick Line: Filtered (HPF 11 Hz + LPF 16 Hz) 

Thin Line: Original 
B-10 

Figure B-15 Auxiliary Relay (MELCO NRD-81) 

Figure B-16 Comparator Card (MELCO HALN) 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s) 

Back and Forth Side to Side 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s) 

Back and Forth Side to Side 

Thick Line: Filtered (HPF 11 Hz + LPF 17 Hz) 

Thin Line: Original 

Thick Line: Filtered (HPF 11 Hz + LPF 17 Hz) 

Thin Line: Original
B-11 

Figure B-17 AC Controller Card (MELCO HASN) 

Figure B-18 Power Supply Equipment (MELCO -) 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g)

Period (s) 

Thick Line: Filtered (HPF 11 Hz + LPF 17 Hz) 

Thin Line: Original

Back and Forth Side to Side 

Thick Line: Filtered (HPF 11 Hz + LPF 17 Hz) 

Thin Line: Original

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s) 

Thick Line: Filtered (HPF 11 Hz + LPF 17 Hz) 

Thin Line: Original 

Back and Forth Side to Side 

Thick Line: Filtered (HPF 11 Hz + LPF 17 Hz) 

Thin Line: Original 
B-12 

Figure B-19 Magnetic Contactor (MELCO MSO-A80) 

Figure B-20 Breaker for Wiring (MELCO NF-100-SH) 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s) 

Back and Forth Side to Side 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s) 

Back and Forth Side to Side 
B-13 

Figure B-21 Module Switch (MELCO SSA-SD3-53) 

Figure B-22 Over Current Relay (Toshiba VCR520) and Auxiliary Relay (Toshiba UP3A) 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s) 

Back and Forth Side to Side 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g)

Period (s) 

Thick Line: Filtered (HPF 10 Hz)

Thin Line: Original 

Back and Forth Side to Side 

Thick Line: Filtered (HPF 10 Hz)

Thin Line: Original
B-14 

Figure B-23 Controller (Toshiba TOSMAP) 

Figure B-24 I/O Unit (Toshiba TOSMAP) 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% 

Period (s) 

Spectral Acceleration (g) 

Back and Forth Side to Side 

Thick Line: Filtered (HPF 10 Hz)

Thin Line: Original 

Thick Line: Filtered (HPF 10 Hz)

Thin Line: Original 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s)

Back and Forth Side to Side 

Thick Line: Filtered (HPF 10 Hz)

Thin Line: Original

Thick Line: Filtered (HPF 11 Hz)

Thin Line: Original
B-15 

Figure B-25 Power Supply Equipment (Toshiba TFV) 

Figure B-26 Differential Pressure Transmitter (Toshiba AP3107) 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s)

Back and Forth Side to Side 

Thick Line: Filtered (HPF 10 Hz) 

Thin Line: Original 

Thick Line: Filtered (HPF 10 Hz) 

Thin Line: Original 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s)

Back and Forth Side to Side 

Thick Line: Filtered (HPF 10 Hz)

Thin Line: Original

Thick Line: Filtered (HPF 10 Hz)

Thin Line: Original
B-16 

Figure B-27 Magnetic Contactor (Toshiba C-20J, T-20J) and Breaker for Wiring (Toshiba SH100) 

Figure B-28 Auxiliary Relay (HITACHI MY4Z), Timer (HITACHI H3M), and Breaker for 

Wiring (HITACHI F type) 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% 

Damping: 4% 

Spectral Acceleration (g) 

Period (s) 

Back and Forth Side to Side 

Thick Line: Filtered (HPF 10 Hz)

Thin Line: Original 

Thick Line: Filtered (HPF 10 Hz)

Thin Line: Original

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s) 

Side to Side Back and Forth 

Thick Line: Original 

Dashed Line: Filtered (BPF 10-50 Hz)

Thick Line: Original 

Dashed Line: Filtered (BPF 10-50 Hz)
B-17 

Figure B-29 Flat Display (HITACHI 18” type) 

Figure B-30 Controller Display (HITACHI 18” type) 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s) 

Side to Side Back and Forth 

Thick Line: Original 

Dashed Line: Filtered (BPF 10-50 Hz)

Thick Line: Original 

Dashed Line: Filtered (BPF 10-50 Hz)

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s) 

Side to Side Back and Forth 

Thick Line: Original 

Dashed Line: Filtered (BPF 10-50 Hz)

Thick Line: Original 

Dashed Line: Filtered (BPF 10-50 Hz)
B-18 

Figure B-31 Differential Pressure Transmitter (HITACHI EDR-N6) 

Figure B-32 Pressure Transmitter (HITACHI EPR-N6) 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s) 

Side to Side Back and Forth 

Thick Line: Original 

Dashed Line: Filtered (BPF 10-50 Hz) Thick Line: Original 

Dashed Line: Filtered (BPF 10-50 Hz)

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s) 

Side to Side Back and Forth 

Thick Line: Original 

Dashed Line: Filtered (BPF 10-50 Hz) Thick Line: Original 

Dashed Line: Filtered (BPF 10-50 Hz)
B-19 

Figure B-33 Cam Type Switch (HITACHI MS type) and Key Switch (HITACHI ACSNK type) 

Figure B-34 Test Module (S9186AW), Power Supply Module (S9016AW), and Monitor Module 

(S9146AW), All Produced by Yokogawa Electric Co. 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s) 

Side to Side Back and Forth 

Thick Line: Original 

Dashed Line: Filtered (BPF 10.5-50 Hz) 

Thick Line: Original 

Dashed Line: Filtered (BPF 10.5-50 Hz)

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s) 

Back and Forth Side to Side 

Thin Line: Original 

Thick Line: Filtered (HPF 11 Hz + LPF 17 Hz)

Thin Line: Original 

Thick Line: Filtered (HPF 11 Hz + LPF 17 Hz)
B-20 

Figure B-35 Power Supply Module (S9980UD), Produced by Yokogawa Electric Co. 

Figure B-36 Differential Pressure Transmitter (UNE13), Produced by Yokogawa Electric Co. 

 

Period (s) 

Spectral Acceleration (g) 

Damping: 4% Damping: 4% Spectral Acceleration (g) 

Period (s) 

Back and Forth Side to Side 

Thin Line: Original 

Thick Line: Filtered (HPF 11 Hz + LPF 17 Hz)

Thin Line: Original 

Thick Line: Filtered (HPF 11 Hz + LPF 18 Hz)

Period (s) 

Spectral Acceleration (g) 

Damping: 4% 

Back and Forth / Side to side 

This test was implemented later as reported in July 

2004. 
B-21 

B.2 Response Spectra Reported in July 2004 

These spectra were extracted from the JNES annotated fragility report dated July 2004. The title 

of that report in English is “Seismic Proving Test – Equipment Fragility Vol. 1 (Horizontal Shaft 

Pump and Electric Panels).” A total of 42 figures are included in this section. 

In the full scale tests of the electrical panels, the target spectrum was developed by enveloping 

Japanese PWR and BWR spectra. The synthesized input time history was adjusted by filtering 

out long period components (period > 0.14 s). 

For device tests, both time histories obtained from the full scale panel/rack tests and time histories 

obtained from analysis were used. 
B-22 

B.2.1 Main Control Board 

Figure B-37 Main Control Board Test – Base Plate RS – 6 g 

Period (s) 

Target Spectrum 

Base Plate Response

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 

Target Spectrum 

Base Plate Response 6 g Excitation Level 

Damping: 4% 

Spectral Acceleration (g) 

Period (s) 

(A) Side to Side Direction 

(B) Back and Forth Direction 
B-23 

Figure B-38 Reactor Auxiliary Panel – Base Plate RS – 6g 

Period (s) 

Base Plate Response 

Target Spectrum 

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 

6 g Excitation Level 

Damping: 4% 

Spectral Acceleration (g) 

Period (s) 

(A) Side to Side Direction 

(B) Back and Forth Direction 

Base Plate Response 

Target Spectrum 
B-24 

Figure B-39 Reactor Auxiliary Panel Sensor Location 

Figure B-40 Reactor Auxiliary Panel – Panel RS – 6 g (Side to Side) 

Period (s) 

Base Plate Response 

Response at A16 

Response at A18 

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 

Acc (X, Y, Z) 

Acc (X, Y) 

Strain 
B-25 

Figure B-41 Reactor Auxiliary Panel – Panel RS – 6 g (Back and Forth) 

 

Period (s) 

Base Plate Response 

Response at A16 

Response at A18 

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 
B-26 

B.2.2 Logic Control Panel 

Figure B-42 Logic Control Panel – Base Plate RS – 6 g 

Period (s) 

Input (Original) 

Base Plate Response 

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 

Input (Original) 

Base Plate Response 

6 g Excitation Level 

Damping: 4% 

Spectral Acceleration (g) 

Period (s) 

(A) Back and Forth Direction 

(B) Side to Side Direction 
B-27 

Figure B-43 Logic Control Panel – Panel RS – 6 g (Side to Side) 

Figure B-44 Logic Control Panel – Panel RS – 6 g (Back and Forth) 

Period (s) 

Base Plate 

Frame top, right side 

Power Supply Unit Location 

I/O Unit Location

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 

Period (s) 

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 

Base Plate 

Frame top, right side 

Power Supply Unit Location 

I/O Unit Location
B-28 

B.2.3 Protection Instrument Rack 

Figure B-45 Protection Instrument Rack – Base Plate RS – 6 g 

Period (s) 

Base Plate Response 

Target Spectrum 

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 

6 g Excitation Level 

Damping: 4% 

Spectral Acceleration (g) 

Period (s) 

(A) Side to Side Direction 

(B) Back and Forth Direction 

Base Plate Response 

Target Spectrum 
B-29 

Figure B-46 Protection Instrument Rack – Rack RS – 4 g (Side to Side) 

Figure B-47 Protection Instrument Rack – Rack RS – 4 g (Back and Forth) 

Period (s) 

Base Plate Response 

Frame top, left side R1 

Power Supply Unit Locate R17

Spectral Acceleration (g) 

4 g Excitation Level 

Damping: 4% 

Frame top, left side 

R1

Period (s) 

Spectral Acceleration (g) 

4 g Excitation Level 

Damping: 4% 

Base Plate Response 

Frame top, left side R1 

Power Supply Unit Locate R17

Frame top, left side 

R1
B-30 

The AC controller card installed in the Protection Instrument Rack malfunctioned at a 4 g input 

excitation in the side to side direction, which resulted in a 7.62 g at the installation point of the 

AC controller card. The component tests reported in September 2003 utilized analytical 

responses. The AC controller card was re-tested using the recorded response of the full scale 

Protection Instrument Rack. The following two RS’s were for the investigation of the function 

limit capacity of the AC controller card. 

Figure B-48 AC Controller Card – 7 g Excitation (Non-malfunction) 

Figure B-49 AC Controller Card – 7.1 g Excitation (Malfunction) 

Period (s) 

HPF: No, LPF: No 

Spectral Acceleration (g) 

7 g Excitation Level 

Damping: 4% 

Max

Period (s) 

HPF: No, LPF: No

Spectral Acceleration (g) 

7.1 g Excitation Level 

Damping: 4% 

Max
B-31 

B.2.4 Instrument Rack 

Figure B-50 Instrument Rack – Base Plate RS – 6 g 

Period (s) 

Target Spectrum 

Base Plate Response

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 

Target Spectrum 

Base Plate Response 6 g Excitation Level 

Damping: 4% 

Spectral Acceleration (g) 

Period (s) 

(A) Side to Side Direction 

(B) Back and Forth Direction 
B-32 

B.2.5 Reactor Control Center 

Figure B-51 Reactor Control Center – Base Plate RS – 6 g 

Period (s) 

Base Plate Response 

Target Spectrum 

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 

6 g Excitation Level 

Damping: 4% 

Spectral Acceleration (g) 

Period (s) 

(A) Side to Side Direction 

(B) Back and Forth Direction 

Base Plate Response 

Target Spectrum 
B-33 

Figure B-52 Reactor Control Center – Panel RS – 6 g (Side to Side) 

Figure B-53 Reactor Control Center – Panel RS – 6 g (Back and Forth) 

Period (s) 

Dotted: Base Plate 

Thick: Top-Left of Panel 

Thin: Installation Point of Relay Unit 

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 

Period (s) 

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 

Dotted: Base Plate 

Thick: Top-Left of Panel 

Thin: Installation Point of Relay Unit 
B-34 

B.2.6 Power Center 

Several devices in the Power Center malfunctioned in the 6 g excitation test. 

Figure B-54 Power Center – Base Plate RS – 6 g 

Period (s) 

Base Plate Response 

Target Spectrum 

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 

6 g Excitation Level 

Damping: 4% 

Spectral Acceleration (g) 

Period (s) 

(A) Side to Side Direction 

(B) Back and Forth Direction 

Base Plate Response 

Target Spectrum 
B-35 

Figure B-55 Power Center – Panel RS – 6 g (Side to Side) 

Figure B-56 Power Center – Panel RS – 6 g (Back and Forth) 

Period (s) 

Dotted: Base Plate 

Thick: Top-Left of Panel 

Thin: Installation Point of Feed Breaker 

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 

Period (s) 

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 

Dotted: Base Plate 

Thick: Top-Left of Panel 

Thin: Installation Point of Feed Breaker 
B-36 

Figure B-57 RS of Ratio Differential Relay (TUB-2-D), Malfunctioned in 6 g Full Scale Power 

Center Test (Back and Forth, 10.9 g) 

Period (s) 

Solid: 10.9 g Component Test 

Dotted: 6 g Full Scale Test 

Spectral Acceleration (g) 

10.9 g Excitation Level 

Damping: 4%
B-37 

B.2.7 Metalclad Switchgear 

Several devices installed in the Metalclad Switchgear malfunctioned in the 6 g full scale panel 

test. 

Figure B-58 Metalclad Switchgear – Base Plate RS – 6 g 

Period (s) 

Target Spectrum 

Base Plate Response

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 

Target Spectrum 

Base Plate Response 

6 g Excitation Level 

Damping: 4% 

Spectral Acceleration (g) 

Period (s) 

(A) Back and Forth Direction 

(B) Side to Side Direction 
B-38 

Figure B-59 Metalclad Switchgear – Panel RS – 3 g (Side to Side) 

Figure B-60 Metalclad Switchgear – Panel RS – 3 g (Back and Forth) 

Period (s) 

Thin (lower): Base Plate 

Thin: Door position at upper left of Metalclad 

Thick: Top-Left of Metalclad Frame 

Spectral Acceleration (g) 

3 g Excitation Level 

Damping: 4% 

Period (s) 

Spectral Acceleration (g) 

3 g Excitation Level 

Damping: 4% 

Thin (lower) Base Plate 

Thin: Door position at upper left of Metalclad 

Thick: Top-Left of Metalclad Frame 
B-39 

B.2.8 Device Tests 

Figure B-61 RS at Installation Points for Test Module (MHI S9166AW), Power Supply Module 

(MHI S9016AW), and Monitor Module (MHI S9146AW) 

Period (s) 

Thin: Analysis 

Thick: Full scale test

Spectral Acceleration (g) 

Damping: 4% 

Damping: 4% 

Spectral Acceleration (g) 

Period (s) 

(A) Side to Side Direction 

(B) Back and Forth Direction Thin: Analysis 

Thick: Full scale test
B-40 

Figure B-62 RS at Installation Points for Power Supply Equipment (MHI S9980UD) and Diode 

Unit (S9154UT) 

Period (s) 

Thin: Analysis 

Thick: Full scale test

Spectral Acceleration (g) 

Damping: 4% 

Damping: 4% 

Spectral Acceleration (g) 

Period (s) 

(A) Side to Side Direction 

(B) Back and Forth Direction Thin: Analysis 

Thick: Full scale test 
B-41 

Figure B-63 RS for Differential Pressure Transmitter (MHI UNE13) 

Period (s) 

Spectral Acceleration (g) 

1. Damping: 4% 

2. Synthesized input 

wave that envelopes 

Japanese PWR and 

BWR design spectra 

for electric panels 

3. HPF 6.7 Hz (0.15 S) 
B-42 

Figure B-64 RS of Recorded Time History for Feed Breaker (DS-416) in Power Center – 5 g 

Figure B-65 RS of Recorded Time History for Feed Breaker (DS-416) in Power Center – 6 g 

Period (s) 

Spectral Acceleration (g) 

5 g Excitation Level 

Damping: 4% 

Max

Period (s) 

Spectral Acceleration (g) 

6 g Excitation Level 

Damping: 4% 

Max
B-43 

Figure B-66 RS for Feed Breaker (DS-416) in Power Center – Malfunction 

Figure B-67 RS for Feed Breaker (DS-416) in Power Center – Normal Function 

Period (s) 

Dotted: Feed Breaker Response

Thick: Shaking Table 

Spectral Acceleration (g) 

5 g Excitation Level 

Damping: 4% 

Period (s) 

Dotted: Feed Breaker Response

Thick: Shaking Table 

Spectral Acceleration (g) 

5 g Excitation Level 

Damping: 4% 
B-44 

Figure B-68 RS for Feed Breaker (DS-416) in Power Center 

Figure B-69 RS for Feed Breaker (DS-416) in Power Center 

Period (s) 

BPF: 8 Hz + 30 Hz 

Spectral Acceleration (g) 

Damping: 4% 

Max

Period (s) 

BPF: 9 Hz + 30 Hz 

Spectral Acceleration (g) 

Damping: 4% 

Max
B-45 

Figure B-70 Test Module (MHI S9166AW), Power Supply Module (MHI S9016AW), and 

Monitor Module (MHI S9146AW) – Recorded Wave 10 g (Side to Side) 

Figure B-71 Test Module (MHI S9166AW), Power Supply Module (MHI S9016AW), and 

Monitor Module (MHI S9146AW) – Recorded Wave 10 g (Back and Forth) 

Period (s) 

Thick: Shaking Table 

Thin: Target 

Spectral Acceleration (g) 

10 g Recorded Wave 

Damping: 4% 

HPF: 10 Hz 

LPF: None

Period (s) 

Thick: Shaking Table 

Thin: Target 

Spectral Acceleration (g) 

10 g Recorded Wave 

Damping: 4% 

HPF: 10 Hz 

LPF: None
B-46 

Figure B-72 Test Module (MHI S9166AW), Power Supply Module (MHI S9016AW), and 

Monitor Module (MHI S9146AW) – Predicted Wave 10 g (Side to Side) 

Figure B-73 Power Supply Equipment (MHI S9980UD) and Diode Unit (MHI S9154UT) – 

Recorded Wave 10 g (Side to Side) 

Period (s) 

Thick: Shaking Table 

Thin: Target 

Spectral Acceleration (g) 

10 g Predicted Wave 

Damping: 4% 

HPF: 11 Hz 

LPF: 13 Hz

Period (s) 

Thick: Shaking Table 

Thin: Target 

Spectral Acceleration (g) 

10 g Recorded Wave 

Damping: 4% 

HPF: 11 Hz 

LPF: None
B-47 

Figure B-74 Power Supply Equipment (MHI S9980UD) and Diode Unit (MHI S9154UT) – 

Recorded Wave 10 g (Back and Forth) 

Figure B-75 Power Supply Equipment (MHI S9980UD) and Diode Unit (MHI S9154UT) – 

Predicted Wave 10 g (Side to Side) 

Period (s) 

Thick: Shaking Table 

Thin: Target 

Spectral Acceleration (g) 

10 g Recorded Wave 

Damping: 4% 

HPF: 11 Hz 

LPF: None

Period (s) 

Thick: Shaking Table 

Thin: Target 

Spectral Acceleration (g) 

10 g Predicted Wave 

Damping: 4% 

HPF: 11 Hz 

LPF: 20 Hz
B-48 

Figure B-76 Power Supply Equipment (MHI S9980UD) and Diode Unit (MHI S9154UT) – 

Predicted Wave 10 g (Back and Forth) 

Figure B-77 Differential Pressure Transmitter (MHI UNE13) – Recorded Wave 10 g (Side to 

Side) 

Period (s) 

Thick: Shaking Table 

Thin: Target 

Spectral Acceleration (g) 

10 g Predicted Wave 

Damping: 4% 

HPF: 11 Hz 

LPF: 20 Hz

Period (s) 

Thick: Shaking Table 

Thin: Target 

Spectral Acceleration (g) 

10 g Recorded Wave 

Damping: 4% 

HPF: 11 Hz 

LPF: None
B-49 

Figure B-78 Differential Pressure Transmitter (MHI UNE13) – Recorded Wave 10 g (Back and 

Forth) 

Period (s) 

Thick: Shaking Table 

Thin: Target 

Spectral Acceleration (g) 

10 g Recorded Wave 

Damping: 4% 

HPF: 11 Hz 

LPF: None

 NRC FORM 335 U.S. NUCLEAR REGULATORY COMMISSION

 (9-2004) 

 NRCMD 3.7

BIBLIOGRAPHIC DATA SHEET

(See instructions on the reverse)

1. REPORT NUMBER 

(Assigned by NRC, Add Vol., Supp., 

Rev., and Addendum Numbers, if any.) 

NUREG/CR-7040 

BNL-NUREG-94629-2011

 2. TITLE AND SUBTITLE 

Evaluation of JNES Equipment Fragility Tests for Use in Seismic Probabilistic Risk 

Assessments for U.S. Nuclear Power Plants

3. DATE REPORT PUBLISHED

MONTH 

 April

YEAR 

2011

4. FIN OR GRANT NUMBER 

JCN: N-6076/N-6998

 5. AUTHOR(S) 

 R. Kennedy (RPK Structural Mechanics Consulting) 

 J. Nie and C. Hofmayer (Brookhaven National Laboratory)

6. TYPE OF REPORT 

Technical

7. PERIOD COVERED (Inclusive Dates) 

 8. PERFORMING ORGANIZATION - NAME AND ADDRESS (If NRC, provide Division, Office or Region, U.S. Nuclear Regulatory Commission, and mailing address; if contractor, 

provide name and mailing address.) 

RPK Structural Mechanics Consulting Nuclear Science and Technology Department 

28625 Mountain Meadow Road Brookhaven National Laboratory 

Escondido, CA 92026 P.O. Box 5000 

Upton, NY 11973-5000

 9. SPONSORING ORGANIZATION - NAME AND ADDRESS (If NRC, type "Same as above"; if contractor, provide NRC Division, Office or Region, U.S. Nuclear Regulatory Commission, 

and mailing address.) 

Division of Engineering 

Office of Nuclear Regulatory Research 

U.S. Nuclear Regulatory Research 

Washington, DC 20555-0001

 10. SUPPLEMENTARY NOTES 

Syed Ali, NRC Project Manager

 11. ABSTRACT (200 words or less) 

The Japan Nuclear Energy Safety Organization (JNES) is conducting a multi-year equipment fragility test program to 

obtain realistic equipment fragility capacities for use in the seismic probabilistic risk assessments (SPRAs) of nuclear 

power plants (NPPs) in Japan. This test program started in 2002 and is planned to continue until 2012. This program 

consists of the test of a series of safety significant equipment, which are scheduled in two phases. Phase I includes 

large horizontal shaft pumps, large vertical shaft pumps, electrical panels, and control rod insertion capability and 

Phase II includes fans, valves, tanks, support structures, and overhead cranes. As part of collaborative efforts 

between the United States and Japan on seismic issues, the U.S. Nuclear Regulatory Commission (NRC) and 

Brookhaven National Laboratory (BNL) participated in this program by evaluating the results of the JNES equipment 

fragility tests. The goal of this research effort was to compare the JNES fragility results with the fragility data typically 

used in current U.S. SPRAs and assess the impact that the new test results may have on current SPRAs and how 

this data can be utilized for future SPRAs. This report summarizes the BNL evaluation of the JNES equipment 

fragility test data and provides insights on the applicability and application of this data in U.S. SPRA practices.

 12. KEY WORDS/DESCRIPTORS (List words or phrases that will assist researchers in locating the report.) 

Seismic equipment fragility, full-scale shaking table testing, seismic margin, seismic 

probabilistic risk assessment, design certification (DC) application, combined license (COL) 

application, high confidence low probability of failure (HCLPF) capacity, large horizontal shaft 

pump, large vertical shaft pump, electrical panel, control rod insertion, fans, valves, tanks, 

support structures, and overhead cranes

13. AVAILABILITY STATEMENT 

unlimite

14. SECURITY CLASSIFICATION d

(This Page)

unclassified 

(This Report)

unclassified

15. NUMBER OF PAGES 

16. PRICE

NRC FORM 335 (9-2004) PRINTED ON RECYCLED PAPER