Developing Computer Program VDAS and Seismic Analysis in Nuclear Power Plant using GTSTRUDL

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Developing Computer Program VDAS and Seismic
Analysis in Nuclear Power Plant using GTSTRUDL

• 2003. 06
• YoonHo Nam, PE

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CONTENTS

• 1. About KOPEC and Nuclear Power Plant in Korea
• 2. Seismic Analysis in Nuclear Power Plant
• 3. Developing Computer Program VDAS
• 4. Conclusion

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1. About KOPEC and Nuclear Power Plant in Korea

• KOPEC(Korea Power Engineering Company) has been
  designing nuclear power plants and fossil power
  plants as an Architectural Engineer. It performs
  technical central role in the power industry by
  supporting all the necessary information on
  engineering, procurement, construction management
  start-up and maintenance.
• KOPEC has established its firm position in the
  domestic power industry by continuous investment
  and effort since its founding in 1975.
• KOPEC designed 11 NPPs and has been designing 8
  NPPs in Korea.

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1. About KOPEC and Nuclear Power Plant in Korea

• The Characteristics of Korean Standard Nuclear
  Power Plant(KSNP)

TGB
PAB
RCB
FHB
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1. About KOPEC and Nuclear Power Plant in Korea

• Layout of Korean Standard Nuclear Power
  plant(KSNP)

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CONTENTS

• 2. Seismic Analysis in Nuclear Power Plant

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2. Seismic Analysis in NPP

• The Analysis Method and Results of Seismic
  Analysis in NPP
• Analysis Method Response Spectrum Analysis and
  Time History Analysis
• Analysis Results
• FRS(Floor Response Spectrum)
• 3-Directions(NS, EW, VT) FRSs of each floor level
  are required.
• FRS provide to equipment vender for designing
  seismic qualification of Equipment.
• FRS use to design of sub-structures or sub-system
• PVRC Damping Response Spectrum is used to analyze
  safety-related Safety Related Piping System
• Seismic Forces and Displacement
• To design Shear Walls using Results of Seismic
  Forces and Moment on Shear Walls
• To design Beams, Slabs and Columns using Results
  of Seismic Displacement

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2. Seismic Analysis in NPP

• Seismic Input motions
• The ground input motion for seismic analysis is
  defined either by the Design Ground Response
  Spectra (DGRS) or by the artificial synthetic
  acceleration time histories.
• The peak ground accelerations of artificial time
  histories are 0.10g and 0.20g for horizontal and
  vertical shall be applied, respectively, for
  Operating Basis Earthquake (OBE) and Safe
  Shutdown Earthquake(SSE).
• The DGRS which comply with USNRC RG. 1.60
  requirements for both OBE and SSE are applied for
  the response spectrum analysis that is to obtain
  seismic forces for the design of structural
  members.
• The artificial time histories are used in the
  analyses to develop floor response spectra. A set
  of input acceleration time histories for three
  orthogonal directions is generated.

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2. Seismic Analysis in NPP

• Creating Artificial Time Histories by SRP 3.7.1
• A set of acceleration time histories composed of
  two horizontal components (east-west and
  north-south) and one vertical component is
  artificially generated by a numerical simulation
  method.
• Duration 24 sec, Time Step 0.005 sec, Peak
  Acceleration 0.2g
• Regulatory Requirement Check for creating
  artificial time histories
• Design Response Spectra Enveloping Requirement
• Power Spectral Density Function Requirement

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2. Seismic Analysis in NPP
Creating Artificial Time Histories by SRP 3.7.1

• Each acceleration time history has a 24 second
  duration with approximately 9 seconds of
  strong-motion and is defined at a time step of
  0.005 second.
• These parameters meet the requirements given in
  USNRC SRP Section 3.7.1 which states that a time
  history is required to have the total time
  duration between 10 seconds and 25 seconds with a
  stationary phase strong-motion duration between 6
  seconds and 15 seconds.

North-South Direction
East-West Direction
Vertical Direction
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2. Seismic Analysis in NPP
Design Response Spectra Enveloping Requirement
Each calculated spectrum of the design time
history is considered to envelop the design
response spectrum when no more than five points
fall below, and no more than 10 percent below,
the design response spectrum.
- Response Spectrum of Artificial Time
History - Response Spectrum of US/NRC Reg.
Guide 1.60
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2. Seismic Analysis in NPP
Power Spectral Density Function Requirement
The generated PSD function is greater than a
target PSD function throughout the frequency
range of significance.
PSDF for Artificial Time History
Target PSDF by SRP 3.7.1
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2. Seismic Analysis in NPP

• Seismic Analysis Model
• Mathematical Lumped Mass Stick Model is composed
  from actual Structures
• 3D FE full Model is used comparison of Dynamic
  Characteristics with Beam Stick Model
• Developing Seismic Mathematical Lumped Mass Stick
  Model
• Calculating Lumped Mass(mass and mass inertia)
  and Stick Section properties(Area Moment of
  inertia, etc) from structures(Wall, Column, Slab)
  and equipment.
• To consider torsional effect mass center and
  stiffness center is connected by rigid link.

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2. Seismic Analysis in NPP

• Code and Standards
• USNRC Regulatory Guide 1.60, "Design Response
  Spectra for Seismic Design of Nuclear Power
  Plants (10/73)
• USNRC Regulatory Guide 1.61, "Damping Values for
  Seismic Design of Nuclear Power Plants
• USNRC Regulatory Guide 1.92, "Combining Modal
  Responses and Spatial Components in Seismic
  Response Analysis (12/74)
• USNRC Regulatory Guide 1.122, "Development of
  Floor Design Response Spectra for Seismic Design
  of Floor-Supported Equipment or Components
  (9/76)
• USNRC Standard Review Plan 3.7.1, "Seismic Design
  Parameters
• USNRC Standard Review Plan 3.7.2, "Seismic System
  Analysis
• ASCE Standard 4-86, "Seismic Analysis of
  Safety-Related Nuclear Structures and Commentary
  on Standard for Seismic Analysis of
  Safety-Related Nuclear Structures," ASCE, Sep.
  1986.

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2. Seismic Analysis in NPP
Typical Horizontal seismic model of Auxiliary
Building
Stiffness Center Mass Center Massless Corner
Node Vertical Stick Rigid Beam Constraint Beam
Aux. Bldg. Level 1 GA
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2. Seismic Analysis in NPP
Dynamic Characteristic Tuning
Creating Beam-Stick Model
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CONTENTS

• 3. Developing Computer Program VDAS

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3. Developing Computer Program VDAS

• Procedure of Seismic Analysis in NPP and
  Developing Method of Pre/Post processor VDAS
  using GTSTRUDL

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3. Developing Computer Program VDAS

• The Starting Menu of VDAS

Starting form of VDAS
Post-Processor Menu
Pre-Processor Menu
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3. Developing Computer Program VDAS

• Inputting Structural Element Menu

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3. Developing Computer Program VDAS

• Creating Lumped Mass Stick Model using Data Base

VDAS -gt Model Menu (Calc. of Geometry)
Mass Properties
Vertical Stick Properties
Stick Model (AUX Bldg.)
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3. Developing Computer Program VDAS

• Creating GTSTRUDL Input File from DB

VDAS-gt Model Menu (Create GT STRUDL Input)
GTSTRUDL Input File (Including THA, RSA)
GTSTRUDL input file creation Window
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3. Developing Computer Program VDAS

• Used GTSTRUDL Command
• Constraint mass center joint and corner node
• TYPE RIGID SOLID
• Calculate Modal Damping with Mass Matrix Define
  the damping properties with material
  characteristics P/C 5, R/C 7, Piping 3,
  Water 0.5
• INERTIA OF JOINTS WEIGHT WITH DAMPING RATIO
• RESPONSE DAMPING INPUT 0.0 STIFFNESS 0.0 MASS 1.0
• COMPUTE MODAL DAMPING RATIOS
• Response Spectrum Analysis
• PERFORM RESPONSE SPECTRUM ANALYSIS
• COMPUTE RESPONSE SPECTRUM DISPLACEMENTS MODAL
  COMBINATIONS DSM RMS
• LIST RESPONSE SPECTRUM DISP
• Transient Time History Analysis
• PERFORM TRANSIENT ANALYSIS
• CREATE RESPONSE SPECTRUM ACCELERATION VS
  FREQUENCY FILE 'RHO-001X'

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3. Developing Computer Program VDAS

• Execution GTSTRUDL

Execution Window of GTSTRUDL
VDAS-gt Processor Menu (Execute GTSTRUDL)
File Open
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3. Developing Computer Program VDAS

• Mode Shape for Lumped Stick Model

GTSTRUDL Modeler (Input Model)
GTSTRUDL Modeler (1st Mode Shape)
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3. Developing Computer Program VDAS

• The automatically generated input file by VDAS
  contained coutput command, so the output files
  automatically created by GTSTRUDL consist of 3
  extension names(eig, mod, frs).
• The eig output contained mode shape, eigen
  vector, eigen solution. VDAS summarize eigen
  analysis results from GTSTRUDL output.
• The mod output contained modal displacement of
  mass joints. Itll be used for calculating shear
  wall forces and moments.
• The frs output contained Response Spectrum(RS)
  with various damping values and Response Time
  History(TH) of each joints. VDAS separates
  GTSTRUDL output file each RS and TH files. If
  GTSTRUDL output have 10 joints RS and TH results,
  VDAS create 10 RS files and 10 TH files for
  creating widening Response Spectrum.

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3. Developing Computer Program VDAS
GTSTRUDL output
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3. Developing Computer Program VDAS
GTSTRUDL Output
VDAS output
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3. Developing Computer Program VDAS

• Calculation Shear Forces and Moments of Shear
  wall using Data Base with GTSTRUDL output

VDAS-gtProcessor Menu (Calculate Shear wall force)
The Result of Shear Force and Moment of Shear
Wall Shear wall ID 009 Shear Force
9378k(OBE),14987k(SSE) Moment 1325482
k-ft(OBE), 2139512 k-ft(SSE)
Layout of Shear Wall in Aux. Bldg.
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3. Developing Computer Program VDAS

• Enveloping Response Spectrum from GTSTRDUL results

VDAS-gt Processor Menu (Make Response Spectrum)
Calculating Maximum Response Spectrum at each
frequency from 5 Joints
Enveloping Response Spectrum
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3. Developing Computer Program VDAS

• Widening Response Spectrum from enveloping RS

Widening FRS
VDAS-gt Processor Menu (Make Response Spectrum)

• VDAS generates Widening Response Spectrum from
  enveloping by US/NRC Reg. Guide 1.122
  Development of Floor Design Response spectra for
  Seismic Design of floor supported Equipment or
  Components
• Default value of Widen Factor is 15 of each side
  of peak value, and User can define the
  value(050)

Unwidening FRS
Widening Response Spectrum
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3. Developing Computer Program VDAS

• PVRC Damping Response Spectrum from enveloping RS

2 Damping FRS
VDAS-gt Processor Menu (Make Response Spectrum)
PVRC Damping FRS

• VDAS generates PVRC Damping Response Spectrum by
  ASME BPV Code case N411-1 Alternative Damping
  Values for Response Spectra Analysis of Piping
• It used 5 Damping FRS for 20 to 33Hz and 2
  Damping FRS for 0 to 10Hz and interpolated 2 and
  5 damping FRS for 10 to 20Hz.
• PVRC Damping Response Spectrum is also widened
  for Piping design.

5 Damping FRS
PVRC Damping Response Spectrum
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3. Developing Computer Program VDAS

• Displaying and Plotting FRS

VDAS-gt RSG Menu (Draw/Print)

• VDAS displays the set of Response Spectra using
  Batch Files.
• When user makes batch file for enveloping
  response spectrum, VDAS automatically generates
  batch files for Widening and PVRC damping
  response spectrum

Example of Batch File
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3. Developing Computer Program VDAS
Generated Widening Batch File
Generated PVRC Batch File
Enveloping Batch File
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CONTENTS

• 4. Conclusion

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4. Conclusion

• The GTSTRUDL is satisfied the for use of seismic
  analysis in NPP with various regulations and code
  requirements.
• The pre/post processor program VDAS has special
  features as below
• Easily creating for seismic lumped mass stick
  model and GTSTRUDL input file using MS-ACCESS
  Data base.
• Automatic execution GTSTRUDL
• Enveloping/Widening Response Spectrum for
  designing sub-structure
• Making PVRC Damping Response Spectrum for
  analyzing Piping Stress
• Distributing Shear wall Force and Moment for
  designing shear wall