ML13331B437
| ML13331B437 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 02/17/1981 |
| From: | BECHTEL GROUP, INC. |
| To: | |
| Shared Package | |
| ML13330A216 | List: |
| References | |
| 14000-073, 14000-73, NUDOCS 8102250208 | |
| Download: ML13331B437 (46) | |
Text
SAN ONOFRE NUCLEAR GENERATING STATION UNIT 1 BALANCE OF PLANT STRUCTURES SEISMIC REEVALUATION CRITERIA JOB 14000-073 BECHTEL POWER CORPORATION February 17, 1981 REGULATORY DOCKE FILE copy
TABLE OF CONTENTS Section Page
1.0 INTRODUCTION
AND PROGRAM DESCRIPTION 1
1.1 INTRODUCTION
1 1.2 PROGRAM DESCRIPTION 1
1.2.1 Scope 1
1.2.2 BOPS Approach 2
3.7 SEISMIC DESIGN 3
3.7.1 Seismic Input 3
3.7.1.1 Design Response Spectra 3
3.7.1.2 Design Time History 3
3.7.1.3 Critical Damping Values 3
3.7.1.4 Supporting Media for Seismic Category A Structures 3
3.7.2 Seismic System Analysis 4
3.7.2.1 Seismic Analysis.Methods 4
3.7.2.1.1 Reactor Auxiliary Building 5
3.7.2.1.2 Fuel Storage Building 6
3.7.2.1.3 Control Building 6
3.7.2.1.4 Turbine Building 6
3.7.2.1.5 Turbine Pedestal 6
3.7.2.1.6 Circulating Water System Intake Structure 7
3.7.2.1.7 Ventilation Equipment Building 7
3.7.2.1.8 Seawall 7
3.7.2.2 Natural Frequencies and Response Loads 8
3.7.2.3 Procedures Used for Modeling 8
3.7.2.4 Soil Structure Interaction 8
3.7.2.5 Development of Floor Response Spectra 10 3.7.2.6 Three Components of Earthquake Motion 10 3.7.2.7 Combination of Modal Responses 11 3.7.2.8 Interaction of Non-Seismic Category A Structures with Seismic Category A Structures 11 01
TABLE OF CONTENTS (Cont.)
Section Page 3.7.2.9 Effects of Parameter Variations on Floor Response Spectra 11 3.7.2.10 Use of Constant Vertical Static Factors 11 3.7.2.11 Method Used to Account for Torsional Effects 11 3.7.2.12 Comparison of Responses 12 3.7.2.13 Methods for Seismic Analysis of Dams 12 3.7.2.14 Determination of Seismic Category A Structures Overturning Moments 12 3.7.2.15 Analysis Procedure for Damping 12 3.7.3 Seismic Subsystem Analysis 12 3.7.3.1 Seismic Analysis Methods 12 3.7.3.2 Determination of Number of Earthquake Cycles 13 3.7.3.3 Procedures Used for Modeling 13 3.7.3.4 Basis for Selection of Frequencies 13 3.7.3.5 Use of Equivalent Static Load Methods of Analysis 13 3.7.3.6 Three Components of Earthquake Motion 13 3.7.3.7 Combination of Modal Responses 13 3.7.3.8 Analytical Procedure for Piping 13 3.7.3.9 Multiple Supported Equipment and Components with Distinct Inputs 13 3.7.3.10 Use of Constant Vertical Static Factors 14 3.7.3.11 Torsional Effects of Eccentric Masses 14 3.7.3.12 Buried Seismic Category A Piping Systems and Tunnels 14 3.7-.3.13 Interaction of Other Piping with Seismic Category A Piping 14 3.7.3.14 Seismic Analysis for Reactor Internals 14 3.7.3.15 Analysis Procedure for Damping 14 3.7.3.16 Masonry Wall Subsystems 14 3.7.3.16.1 Analysis Methods for Masonry Wall Subsystems 15 3.7.3.16.2 Basis for Selection of Frequencies 15 3.8.4 STRUCTURES OTHER THAN CONTAINMENT 23 3.8.4.1 Description of Structures 23 11
TABLE OF CONTENTS (Cont.)
Section Page 3.8.4.1.1 Reactor Auxiliary Building 23 3.8.4.1.2 Fuel Storage Building 23 3.8.4.1.3 Control Building 23 3.8.4.1.4 Turbine Building 24 3.8.4.1.5 Turbine Pedestal 24 3.8.4.1.6 Circulating Water System Intake Structure 25 3.8.4.1.7 Ventilation Equipment Building 25 3.8.4.1.8 Seawall 25 3.8.4.2 Applicable Codes, Standards, and Specifications 25 3.8.4.3 Loads and Load Combinations 26 3.8.4.3.1 Normal Loads 26 3.8.4.3.2 Extreme Environmental Loads 28 3.8.4.4 Reevaluation Analysis Procedures 28 3.8.4.5 Structural Acceptance Criteria 29 3.8.4.5.1 Supplemental Structural Acceptance Criteria Concrete and Steel Structures 29 3.8.4.5.2 Supplemental Structural Acceptance Criteria Reinforced Masonry 31 3.8.4.6 Materials and Special Construction Techniques 34 3.8.5 Foundations 36 3.8.5.1 Description of Foundations 36 3.8.5.1.1 Reactor Auxiliary Building Foundation 36 3.8.5.1.2 Fuel Storage Building Foundation 36 3.8.5.1.3 Control Building Foundation 37 3.8.5.1.4 Turbine Building Foundation 37 3.8.5.1.5 Turbine Pedestal Foundation 37 3.8.5.1.6 Circulating Water System Intake Structure Foundation 37 01 Ii
TABLE OF CONTENTS (Cont.)
Section Page 3.8.5.1.7 Ventilation Equipment Building Foundation 37 3.8.5.1.8 Seawall Foundation 37 3.8.5.2 Applicable Codes, Standards, and Specifications 37 3.8.5.3 Loads and Load Combinations 37 3.8.5.4 Reevaluation Analysis Procedures 38 3.8.5.5 Structural Acceptance Criteria 38 3.8.5.6 Materials and Special Construction Techniques 38 4.0 References 39 0
IV
LIST OF TABLES Table Page 3.7-1 DBE Damping Values Used for Seismic Reevaluation 4
3.7-2 Equations for Lumped Structure-Foundation Interaction Analysis 9
3.8-1 Load Combinations for Structures 27 3.8-2
.Acceptance Criteria for Seismic Category A Structures 30 3.8-3 Structural Ductility Ratios for Analysis 32 3.8-4 Allowable Stresses in Reinforced Masonry 33 V
LIST OF FIGURES Figure Pg 3.7-1 Horizontal Ground-Motion Design Response Spectra 17 3.7-2 Effecive Dynamic Modulus for San Onofre Site 18 3.7-3 Modulus and Damping Vs Strain San Mateo Formation Sand 19 3.7-4 Embedment Correction Factor 20 3.7-5 Coefficients for Calculation of Damping and Stiffness Parameters 21 3.7-6 Energy Balance Technique 22 Ii vi
1.0 INTRODUCTION
AND PROGRAM DESCRIPTION
1.1 INTRODUCTION
This document describes the Seismic Reevaluation Program for the San Onofre Nuclear Generating Station, Unit 1 Balance of Plant Structures (BOPS) which is being conducted as a part of the Systematic Evaluation Program (SEP).
As a minimum, all Seismic Category A* structures as defined in section 9.2 of the San Onofre Unit 1 FSAR are subject to seismic reevaluation as part of the BOPS Seismic Reevaluation Program, with the exception of the reactor building, steel containment sphere, sphere enclosure building, and diesel generator building. The reactor building and steel containment were previously reevaluated as reported in reference 1. The sphere enclo sure building and the diesel generator building have been recently added and are independent of the previously existing plant. These structures were designed and constructed in accordance with current seismic design criteria.
The BOPS Seismic Reevaluation Program scope, criteria, and analysis approaches are described in detail in this report. With the exception of section 1, information is presented in accordance with the format of reference 2.
1.2 PROGRAM DESCRIPTION 1.2.1 SCOPE The structures to be reevaluated as part of the BOPS Seismic Reevaluation Program are identified below:
A.
Reactor auxiliary building B.
Fuel storage building C.
Control building D.
Turbine building E.
Turbine pedestal F.
Ventilation equipment building G.
Circulating water system intake structure H.
Seawall
- Seismic Category I structures, as defined by Regulatory Guide 1.29, are identified as "Seismic Category A" within the context of the BOPS Seismic Reevaluation Program in order to maintain consistency with the seismic classification terminology utilized in the original design and construc tion of San Onofre Unit 1.
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During the reevaluation program declassification of portions of these structures may be accomplished by the performance of safety analyses which demonstrate that partial structural failure will not result in unacceptable degradation of the safety-related performance of Seismic Category A struc tures, components, and systems.
1.2.2 BOPS APPROACH The BOPS Seismic Reevaluation Program will utilize the Design Basis Earthquake (DBE) described in subsection 3.7.1.
This reevaluation will consider the occurrence of a DBE in combination with normal plant opera ting loads.
Structures will be reevaluated with respect to their ability to withstand the effects of a DBE without loss of the capability to per form their safety functions.
The criteria and analytical methods employed in the BOPS Seismic Reevaluation Program as described in sections 3.7 and 3.8 will reflect current technology to predict plant response. The analytical methods will include, as appro priate, three ground motion components, three dimensional system models, finite element analysis, and non-linear analysis.
Compliance with stress criteria based upon current code requirements along with consideration of original design codes and quality requirements (as identified in subsection 3.8.4) will represent adequate reevaluation without further analysis.
If the structural response does not comply with such stress criteria, alternate stress criteria based upon further consideration of original design codes, original quality requirements,,and failure probabilities and consequences will be utilized.
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3.7 SEISMIC DESIGN 3.7.1 SEISMIC INPUT 3.7.1.1 Design Response Spectra The design response spectra for horizontal motion for the Design Basis Earthquake (DBE) are presented in figure 3.7-1 for damping values of 2, 4, and 7 percent of critical damping. These spectra correspond to the Housner spectra, as described in Section 9.2 of the San Onofre Unit 1 FSAR, normal ized to 0.67 g. The vertical design response spectra are normalized to 2/3 of the horizontal spectra.
3.7.1.2 Design Time History The horizontal and vertical ground-motion components of the DBE will be developed in accordance with the provisions of the Standard Review Plan (SRP), subsection 3.7.1. The table of frequency intervals used to calcu late the correlation between the design time history and the design response spectra are given in SRP subsection 3.7.1.
Free field time histories to be used in the BOPS Seismic Reevaluation Program will be consistent with the design response spectra which are utilized.
3.7.1.3 Critical Damping Values The damping values given in table 3.7-1 will be used for the seismic analysis of structures unless justification is established for the use of higher damping values. The damping values in the table are identical with the damping values recommended in Regulatory Guide 1.61, with the exception that a damping value for concrete masonary block is also provided. If the actual damping values selected differ from table 3.7-1, the basis for their selection will be documented. Selection of the damping values will be assessed based on the resultant stress level in the structure.
Soil hysteretic and geometric damping are discussed in paragraphs 3.7.1.4 and 3.7.2.4 and reference 3.
3.7.1.4 Supporting Media for Seismic Category A Structures The foundations for the various soil supported structures analyzed in this study are described in section 3.8.5.
The supporting media is a San Mateo Sand deposit which is uniform and extends to a depth of approximately 1000 feet (Reference 5).
As shown in reference 5 the soil shear modulus and material (hysteretic) damping properties are dependent upon confining pressures and induced strains as illustrated in figures 3.7-2 and 3.7-3.
A single average value of Poisson's ratio of 0.35 was developed from dynamic laboratory tests and field geophysical tests (Reference 5).
3
TABLE 3.7-1 DBE DAMPING VALUES USED FOR SEISMIC REEVALUATION DBE Damping Item (Percent of Critical)
Concrete Grade A Masonry Block Cracked 7
Uncracked 5 (a)
Welded Steel Structures 4
Bolted and/or Riveted Steel Structures 7
Reinforced Concrete Structures 7
Prestressed Concrete Structures 5
(a) These values were selected.based upon data in reference 4 and by virtue of the similarity between reinforced grouted masonry and reinforced concrete.
The procedures for how these parameters are used in soil structure inter action analysis were developed from dynamic model tests completed at the site (Reference 10).
The application of these parameters to San Onofre Unit 1 structures is described in reference 3.
3.7.2 SEISMIC SYSTEM ANALYSIS Major Seismic Category A structures that are considered in conjunction with foundation media in forming a soil-structure interaction model are defined as "Seismic Systems".
3.7.2.1 Seismic Analysis Methods In general, the analysis methods utilized in the BOPS Seismic Reevaluation Program will be based upon linear dynamic analysis techniques. These techniques are described in sections 3.1, 3.2, and 4 of Reference 8. The reactor auxiliary building, ventilation equipment building, circulating water system intake structure, and seawall will be analyzed by equivalent static analysis methods.
In instances where the response of the structure is in the inelastic range an appropriate non-linear analysis may be performed. Among the several possible non-linear techniques which may be applied are the inelastic response spectrum, or time history methods. The inelastic spectrum method 4
which may be used is described in detail in Reference 7. The inelastic spectrum will be developed by modifying the spectral ordinates by the appropriate reduction factor, R, which is defined as follows:
R = 1/p for periods greater than 0.5 seconds R = 1/41-1 for periods between 0.125 and 0.5 seconds where p = ductility factor The selection of the minimum number of mass points and the number of degrees-of-freedom per mass point are described in section 3.2 of refer ence 8.
Significant effects such as piping interactions, external structural restraints, and hydrodynamic effects will be included in the analysis.
Methods employed to account for soil structure interaction effects are described in paragraph 3.7.2.4.
The intended analysis methods to be applied to each structural system are described in the following subsections.
3.7.2.1.1 Reactor Auxiliary Building:
The equivalent static coefficient method will be used for the analysis of the structure below grade. The embedded portion of the auxiliary building structure consists of massive reinforced concrete exterior walls and integral interior cross walls and is., therefore, considered rigid in all three directions.
The embedded structure is expected to track the surrounding soil during an earthquake because the weight of the structure was found to be less than the soil it displaces. Consequently, the seismic amplification of the structure is considered insignificant and free field response spectra will be used to analyze substructure elements.
The roof, interior cross-walls, foundation slab and other substructure elements will be analyzed in accordance with the methodology described in section 3.7.3.5.
The analysis of the embedded exterior walls of the structure will consider both static active pressure and dynamic incremental pressure from the soil.
Since these walls are subjected to active or passive pressures the more severe case of the active and passive pressures will be used for the inves tigation of these walls.
The Mononobe-Okabe method will be used to deter mine the incremental soil pressure. Loads will be combined in accordance with the recommendations of reference 3. If the walls of the substructure require more detailed evaluation, a finite element analysis of these walls will be performed, taking into account the soil-structure interaction.
The above grade masonry walls will be analyzed in accordance with sec tion 3.7.3.16.
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3.7.2.1.2 Fuel Storage Building The fuel storage building will be analyzed using a three dimensional finite element analysis.
The proposed model will incorporate characteristics which will include the interaction between the spent fuel. pit and rest of the structure, hydrodynamic effects of the water in the spent fuel pool, and interaction effects between the foundation medium and structure.
Lumped parameters will be used for modeling the foundation medium. The formulation of these parameters will be in accordance with section 3.7.2.4.
The analysis of the masonry wall subsystems and their incorporation into the fuel building system model will be as described in section 3.7.3.16.
3.7.2.1.3 Control Building The control building is a three story structure with unsymmetric arrange ment of shear walls in both plans and elevations.
To determine the dynamic behavior of this complex structure a three-dimensional finite element model will be used.
The reinforced concrete structural walls will be included as plate-type finite elements.
All masonry walls shall be considered as subsystems and analyzed in accordance with section 3.7.3.16.
Inertia and stiffness of the masonry wall subsystems will be taken into account as appropriate. The effects of soil-structure interaction will be represented by linear springs and dampers. The evaluation of these soil-structure interaction parameters will be as described in section 3.7.2.4.
3.7.2.1.4 Turbine Building A three dimensional finite element model of each of the four areas of the turbine building structures will be developed. Since portions of the turbine building are supported by the turbine pedestal mat, the turbine building models will be coupled with a simplified turbine pedestal model.
These models will include lumped soil parameters representing individual and combined footings in accordance with the recommendations of refer ence 3. The masonry block walls will be analyzed in accordance with the provisions of section 3.7.3.16.
The interaction effects between the turbine building and pedestal and the gantry crane will be included and are discussed in more detail in sec tion 3.7.2.1.5.
3.7.2.1.5 Turbine Pedestal The turbine pedestal is a massive reinforced concrete structure approxi mately symmetric in plan. The pedestal supports heavy equipment, unsym metrically placed at the deck level, and a travelling gantry crane. A three dimensional finite element model will be used for the analysis of this structure. The torsional effects due to the unsymmetrically placed masses are appropriately accounted for by using a three dimensional model.
Additional torsional effects will be considered as described in section 3.7.2.11.
Since the support members are quite thick, clear span 6
dimensions will be used for the beam members in the model. Response spectrum analysis will be used for the structural integrity evaluation.
The base mat will be taken as rigid and a single set of translational and rotational springs and dashpots will be used to represent the foundation medium. These parameters will be developed in accordance with section 3.7.2.4 and reference 3.
To study the dynamic interaction behavior of the turbine building with the turbine pedestal structure, a simplified lumped parameter model of the turbine pedestal will be developed. This model will have similar dynamic characteristics to the three dimensional finite element model.
3.7.2.1.6 Circulating Water System Intake Structure The circulating water system intake structure will be analyzed using an equivalent static method. The intake structure is a fully embedded struc ture and is expected to track the surrounding ground motion. Therefore the seismic amplification of the intake structure is considered insignificant and the ground motion response spectra will be used for the analysis.
The slabs and interior cross-walls will be analyzed in accordance with-the provisions of section 3.7.3.5.
The earth pressure loadings on the exterior embedded walls will be determined in accordance with the recom mendations of reference 3.
3.7.2.1.7 Ventilation Equipment Building.
The ventilation equipment building is a one story masonry structure that is generally symmetrical in plan. The cross walls along with the foundations act like deep beams which makes the structure quite rigid. Therefore the seismic amplification of the ventilation equipment building is considered insignificant and the ground motion response spectra will be used for the analysis. Masonry walls will be considered as part of the structural sys tem and the entire structure will be analyzed using an equivalent static method.
3.7.2.1.8 Seawall This structure consists of a sheet pile wall with a concrete gunite facing, with an average embedment of about 18 feet. The seawall will be analyzed employing equivalent static analysis methods for the Design Basis Earthquake (DBE) and a site specific tsunami as identified in section 2.4.6 of the San Onofre Nuclear Generating Station Units 2 and 3 FSAR. The DBE and tsunami are considered to be sequential, non-simultaneous events with respect to their load inducing effects on the seawall.
The wall will be analyzed for the seismic event first. Any resulting inelastic deformation or residual stresses in the wall will be taken into account during the analysis for tsunami loads.
The hydrostatic and hydrodynamic loading on the seawall will consider the extreme high tide, the tsunami wave, storm surge and a seven foot breaking wave all occuring simultaneously. This condition produces a still water elevation of +15.6 feet MLLW.
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3.7.2.2 Natural Frequencies and Response Loads A summary of natural frequencies, mode shapes, modal responses, and response loads determined by the seismic analyses as well as response spectra at selected plant equipment elevations and equipment support points will be available following completion of structural analysis.
3.7.2.3 Procedures Used for Modeling The procedures to be used for the decoupling of systems and subsystems, the locating of lumped masses for the seismic system analyses, and the modeling of structures for the three component input motion are provided in sec tion 3.2 of reference 8. Decoupling criteria for masonry wall subsystems are discussed in section 3.7.3.16.
Three dimensional finite element models may be employed as discussed in section 3.7.2.1. A detailed description of each finite element model (including the location of mass points) and the number of dynamic degrees of-freedom will be available following completion of seismic system modeling.
3.7.2.4 Soil Structure Interaction Soil-structure interaction, when used, is taken into account by coupling the structural model with the foundation medium. The method used for representing the structure-foundation interaction is the lumped parameter representation. The effect of embedment is always taken into account in the analysis.
The embedment is defined as the vertical distance from the bottom of the structural base slab to the adjacent finished grade.
Appendix H of reference 8 discusses the applicability of the lumped parameter method and its comparison with the finite element method.
In general, the impedances which represent the foundation media are complex functions of the basemat geometry, structure inertia, structural embedment, elastic properties of the foundation medium, and forcing frequencies.
The impedance functions can be approximated by frequency-independent conditions for foundation material with fairly uniform properties.
The impedance func tions can be represented by a mechanical analog composed of equivalent springs and dampers.
The equivalent dampers represent the radiation, or the geometric damping effect of the seismic wave energy away from the structural base and usually predominate over the internal, or hysteretic damping of the foundation medium; the latter is considered to be additive to geometric damping in the lumped parameter representation and is discussed in paragraph 3.7.1.4.
Figure 3-1 in reference 8 shows a schematic lumped parameter model of the structure-foundation system consisting of the foundation impedances. These impedances are represented by the equivalent spring constants and the radiation damping factors for vertical, horizontal, rocking, and torsional seismic excitations. The formulation of these parameters is presented in table 3.7-2 (which is reproduced from reference 3) and is discussed in Section 3.7.1.4.
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Table 3.7-2 EQUATIONS FOR LUMPED STRUCTURE-FOUNDATION INTERACTION ANALYSIS Mode of Vibration Vertical Horizontal Parameters Translation Translation Rocking Torsion Spring Rectangular Gj-(+)
GBL2 16Gr C Constants Footings k =
k = 2(1+v)G/E.
- Ch kr
-v CBr kt 3
Circular k
4GrC 32(1-v)GrC 8Gr 3C k
16Gr3 C Footings v
(1-v) h (7-8v) r 3(1-v) t 3
Geometric Basic 0.288 0.15 0.50 Critical inertia B
(I-V)m B
(7-8v)m B
0V r
Bt t
Ratio V
3p h
321vp r
5 t
5 4re 31vpre 8re pre Equivalent 4
2
[BL
[BL 4 BL3 B4 +L 2)
Footing r=
rV r
4 rLFLB fV 7T 11 3
Radius 6
Effective m, mass of m, mass of I
rrit')oarms Inertia structure and structure and Ir mas moen moment ofieas foundation foundation i nertia of of inertia of structure and structure and foundation about foundation about the rocking axis torsion axis at the base.
1NOTES:
G =shear modulus of foundation soil material p
mass density of foundation soil material
- B
=width of rectangular foundation, parallel to the axis of rocking L =length of rectangular foundation, perpendicular to the axis of rocking r
radius of circular foundation or equivalent radius for rectangular foundation r
effective radius e
r =
p.6r for translation modes e
r E =
.8r for rotational modes C = stress distribution correction factor C Efembedment correction factor (fig. 3.7-4) n inertia correction factor (fig. 3.7-5[an) fPoisson's Ratio of Foundation soil material (0.35)
=
asconstants dependent on geometry of the foundation (Fig. 3.7-5[bJ) (After Richart et al, 1970) 9
3.7.2.5 Development of Floor Response Spectra A multi-mass two or three-dimensional time history analysis method is used to develop floor response spectra, except for the reactor auxiliary building, ventilation equipment building, seawall, and intake structure (see paragraph 3.7.2.1).
The time history method is described in section 4.2 of reference 8.
When the seismic analysis is performed separately for each of the three directions in the case of unsymmetric structures, the ordinates of the floor response spectrum for a given direction will be obtained by combining the ordinates of the three computed floor response spectra for that direction according to the square-root-of-the-sum-of-the-squares (SRSS) criterion.
The resulting response spectrum will then be smoothed and its resonance peaks broadened. In the case of symmetric structures, the floor response spectrum for a given direction will be the single'smoothed floor response spectrum computed for that direction. This procedure is in accordance with Regulatory Guide 1.122, Rev. 1, paragraph C.l.
When the mathematical model of the supporting structure is subjected simul taneously to the action of three spatial components of an earthquake, the computed response spectrum in a given direction with peaks broadened and smoothed will be the floor response spectrum in that direction. This pro cedure is in accordance with Regulatory Guide 1.122, Rev. 1, paragraph C.3.
The floor response spectrum ordinates will be computed at the natural frequencies of the supporting structure and at the frequency intervals given in table 1 of Regulatory Guide 1.122, Rev. 1.
3.7.2.6 Three Components of Earthquake Motion Seismic responses to the three orthogonal earthquake components will be deter mined using time history, response spectrum, or equivalent static analyses.
If the response spectrum method is used, the representative maximum values of the structural responses to each of the three components of earthquake motion will be combined by taking the square-root-of-the-sum-of-the-squares (SRSS) of the maximum representative values of the codirectional responses caused by each of the three components of earthquake motion at a particular point of the structure or the mathematical model.
If the time history analysis method is used two types of analysis will be performed depending upon the complexity of the problem:
A.
When the maximum responses due to each of the three components are calculated separately, the method for combining the three dimensional responses will be the SRSS method applied to the maximum time history responses due to each earthquake component.
B.
If the time history responses from each of the three components of the earthquake motion are calculated by the step-by-step method and combined algebraically at each time step, the maximum response will be obtained from the combined solution. When this method is used, the earthquake motions specified in the three different directions will be statistically independent.
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The methods described above are in accordance with Regulatory Guide 1.92, Rev. 1, paragraph C.2.
In lieu of the preceding methodology, the combining of the seismic responses to the three orthogonal earthquake components can be calculated by combining 100 percent of the effects due to motion in one particular direction and 40 percent of the effects corresponding to the two directions of motion orthogonal to the principal motion considered.
The structural stability (sliding and overturning) can be calculated in this same manner. This method is in accordance with the recommendations of section 7.7 of reference 7 (see section 3.7.2.14).
3.7.2.7 Combination of Modal Responses The methods used for combining modal responses will be in accordance with the guidelines of Regulatory Guide 1.92 Rev. 1, "Combining Modal Responses and Spatial Components in Seismic Response Analysis."
3.7.2.8 Interaction of Non-Seismic Category A Structures with Seismic Category A Structures This subject is not within the scope of BOPS Seismic Reevaluation Program.
3.7.2.9 Effects of Parameter Variations on Floor Response Spectra To account for variations in the structural frequencies -owing to uncertain ties in such parameters as the material properties of the structure and soil, damping values, soil-structure interaction techniques, and the approximations in the modeling techniques used in seismic analysis, the computed floor response spectra from the floor time-history motions will be smoothed, and peaks associated with each of the structural frequencies will be broadened by a frequency, +Af., where:
1 2
P 1/2 Af. =
(0.05f)
+
I (Af )2 X 0.10f.
n=1 where Af. denotes the variation in jth mode frequency f., due to variation in paramAIer number n, and P is the number of significan parameters con sidered. A value of 0.10f. will be used if the actual computed value of Af. is less than 0.10f. IA lieu of the above procedure, Af. may be taien as 0.15f..
This procedure is in accordance with Regulatory Guide 1.122, Riv. 1, paragraph C.2.
3.7.2.10 Use of Constant Vertical Static Factors Constant vertical load factors are not used for Seismic Category A structures.
3.7.2.11 Method Used to Account for Torsional Effects Torsional effects, if significant, are included in the horizontal models.
Section 3.2 and Appendix C of reference 8 show the technique used to 11
account for torsional effects in lumped parameter models.
In three dimensional finite element models, torsional effects are automatically accounted for. For all structures, an accidental torsional moment based on an eccentricity of 5% of the width of the structure will be added to the calculated torsional moment in accordance with Reference 7.
3.7.2.12 Comparison of Responses It is not anticipated that both time history and response spectrum stress analysis will be performed for any one structure.
3.7.2.13 Methods for Seismic Analysis of Dams Dams are not analyzed in this program.
3.7.2.14 Determination of Seismic Category A Structures Overturning Moments The effects of overturning moments are evaluated by the methods described in section 4.4 of reference 8, which also includes a description of the methods used to compute foundation reactions and to account for vertical earthquake effects.
Codirectional responses are combined using the square-root-of-the-sum-of squares (SRSS) of the applicable maximum codirectional responses as described in section 4.3 of reference 8. The codirectional responses can also be combined using the absolute sum of 100% of the maximum one directional response with 40% of the maximum remaining two directions as described in references (7) and (9) (also see paragraph 3.7.2.6).
3.7.2.15 Analysis Procedure for Damping For a coupled system with different damping and different structural elements, such as would be the case in analysis with coupling between concrete structures and welded steel components, the method to be used for damping is either to:
(a) inspect the mode shapes to determine which modes correspond with a particular structural element and then use the damping associated with that element having predominant motion, or (b) to use one of the damping methods described in paragraph 3.7.2.15 of reference (1).
3.7.3 SEISMIC SUBSYSTEM ANALYSIS Seismic Category A structures not considered as "seismic systems" (see subsection 3.7.2) are defined as "seismic subsystems."
The provisions of subsections 3.7.3.1 through 3.7.3.15 are applicable to non-masonry sub systems, while the provisions of subsections 3.7.3.16 are applicable to masonry subsystems.
3.7.3.1 Seismic Analysis Methods Seismic subsystems consisting of structures will be analyzed using methods similar to those described in paragraph 3.7.2.1 for seismic system analysis-.
In general the analysis methods utilized will be based on linear dynamic analysis techniques, certain examples of which are described in reference 8.
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In instances where the response of a subsystem item would be in the inelastic range, an appropriate non-linear analysis may be performed.
3.7.3.2 Determination of Number of Earthquake Cycles This section is not applicable to the BOPS Seismic Reevaluation Program.
3.7.3.3 Procedures Used for Modeling The techniques and procedures to be employed in the modeling of structural seismic subsystems will be similar to those described in subsection 3.7.2.3 for seismic system analysis.
3.7.3.4 Basis for Selection of Frequencies This section is not applicable to the BOPS Seismic Reevaluation Program.
3.7.3.5 Use of Equivalent Static Load Methods of Analysis The static load equivalent or static analysis method involves the multipli cation of the total weight of the subsystem by the specified seismic accel eration coefficient. The magnitude of the seismic acceleration coefficient is established on the basis of the expected dynamic response characteris tics of the subsystem. Structural subsystems which can be adequately characterized as single-degree-of-freedom systems are considered to have a modal participation factor of one.
Seismic acceleration coefficients for multi-degree of freedom systems which may be in the resonance region of the amplified response spectra curves will be increased by 50 percent to account conservatively for the increased modal participation, unless it can be demonstrated that the effect of higher modes is less than 50%. In the latter case an appropriate increase factor will be used.
3.7.3.6 Three Components of Earthquake Motion Seismic subsystem response to the three components of the earthquake will be determined using either time history or response spectrum analyses. The methods of combination will be in accordance with section 3.7.2.6.
3.7.3.7 Combination of Modal Responses The combination of'modal responses will be in accordance with Regulatory Guide 1.92, Rev. 1.
3.7.3.8 Analytical Procedure for Piping The analysis of piping systems is not included in the scope of the BOPS Seismic Reevaluation Program.
3.7.3.9 Multiple Supported Equipment and Components with Distinct Inputs The DBE-induced differential motion will be evaluated in the seismic analysis of structural components.
13
3.7.3.10 Use of Constant Vertical Static Factors Constant vertical load factors are not used in the seismic reevaluation of safety-related structural subsystems.
3.7.3.11 Torsional Effects of Eccentric Masses This section is not applicable to the BOPS Seismic Reevaluation Program.
3.7.3.12 Buried Seismic Category A Piping Systems and Tunnels The analysis of buried piping systems and tunnels is not included in the scope of the BOPS Seismic Reevaluation Program.
3.7.3.13 Interaction of Other Piping with Seismic Category A Piping The analysis of piping systems is not included in the scope of the BOPS Seismic Reevaluation Program.
3.7.3.14 Seismic Analysis for Reactor Internals The analysis of the reactor internals has been completed as discussed in reference 1.
3.7.3.15 Analysis Procedure for Damping See paragraph 3.7.2.15.
3.7.3.16 Masonry Wall Subsystems The masonry walls at San Onofre Unit 1 are 8" thick hollow core, single wythe, reinforced concrete block, with the exception of the biological shield walls in the control room, which consist of 6" reinforced concrete block.
The masonry walls will be analyzed as seismic subsystems.
In those instances in which the masonry walls perform a structural function the appropriate stiffness and inertia properties of the wall will be incorpo rated into the system model. For nonstructural masonry walls, inertial properties of the wall solely contribute to the structural system response and will be incorporated into the system model. The evaluation of the walls' structural adequacy will also include the local transfer of concen trated loads from a block into the wall.
The damping values given in table 3.7-1 will be used for the seismic analysis for masonry subsystems.
The manner in which the three components of the earthquake and the combi nation of modal responses will be considered in the analysis of the masonry subsystems will be established as appropriate in conjunction with the selec tion of the specific analysis procedure to be employed.
14
3.7.3.16.1 Analysis Methods for Masonry Wall Subsystems Where appropriate, the analysis methods utilized will be based on linear dynamic analysis techniques.
In instances where the response of the struc ture is in the inelastic range an appropriate inelastic analysis technique may be employed. The method used to account for inelastic behavior will be either the energy balance technique or a time history method.
The energy balance technique may be utilized for wall segments which can be idealized as elasto-plastic systems. This technique involves the following steps as the basis for calculations:
(1) Determination of the load and deflection relationship of the structural member being analyzed.
(2) Calculation of the maximum out-of-plane displacement assuming a linear elastic system using the applicable floor response spectra.
(3) Conversion of the maximum out-of-plane displacement to inelastic displacement ductility based on the energy balance technique.
The interrelationships between forces, yield points, displacements, and ductility ratios as they apply to the energy balance technique are shown in figure 3.7-6.
Alternatively, a nonlinear time history analysis in which the cracking is modelled by gap elements representing compression only concrete and non linear truss elements representing elasto-plastic reinforcing bars may be performed utilizing time history inputs. Three time histories represen tative of actual earthquakes will be selected to envelope the expected instructure responses. ANSR II, DRAIN-2D or other available computer programs may be employed with this method.
3.7.3.16.2 Basis for Selection of Frequencies The frequency of.the wall subsystem will be calculated assuming one-way action according to the following formula:
f KVEI m e where e
(M t
cr a )
a f
= fundamental frequency K
= a constant dependent upon boundary conditions, span length, and applied load.
E
= modulus of elasticity for masonry = 1000 f' 15
f'
= specified masonry compressive strength m
M
= Uncracked moment capacity cr M
= applied maximum moment on the wall a
I
= moment of inertia of transformed uncracked section t
I
= moment of inertia of the cracked section cr The spectral acceleration will be selected as the maximum value in the interval between 0.85f and 1.15f on the spectrum.
16
FREQUENCY (cps) 100 50 30 20 15 10 7
5 3
2 1.5 1
0.7 0.5 0.3 0.2 0.15 0.1 1007A IIA 0
- 0.
0.01 0.02 0.04 0.06 0.08 0.1 0.2 0.4 0.6 0.8 2
1 1
PERIOD (sec.)
Figure 3.7-1
~HORIZONTAL GROUND-MOTION DESIGN RESPONSE SPECTRA (MAXIMUM ACCELERATION 0.67g) 17
O 60 6.0 k/ft2 CONFINING PRESSURE 50 5.0 k/ft2 40 4.0 k/ft2 C4
~
3.0 k/ft2 2.0 k/ft2 0
20 0
I 10-4 10-3 10-2 10.1 MAJOR PRINCIPAL STRAIN (%)
- a. BASED UPON REFERENCE (10).
Figure 3.7-2 EFFECTIVE DYNAMIC MODULUS (a)
FOR THE SAN ONOFRE SITE 18
600 500 2/3 G =100 Km(am) a
= 2/3 a 400
= OVERBURDEN PRESSURE o
2 UNITS LB/FT 300 U cc o
- 200, LL.
0 a 100 LUj 01 10-5 10-4 10-3 10-2 10-1 MAJOR PRINCIPAL STRAIN, ePERCENT 15:
13 0
11 LU CL.
7 EXTRAPOLATED LU 5
LU cr MEASURED z
3 10-5 10-4 10-3 10-2 10-1 MAJOR PRINCIPAL STRAIN, e, PERCENT
- a. BASED ON REFERENCE (10)
Figure 3.7-3 MODULUS AND DAMPING VS STRAIN (a)
SAN MATEO FORMATION SAND 19
VERTICAL HORIZONTAL 2.0 EMBEDMENT 3600.
10.0 3600 i~
EMBEDMENT 3600 1.5 5.0 1800
[,,.
1 800_o 1.0.
1 I
- 1.
1.
180 0 0
0.5 1.0 1.5 2.0 0
1.0 2.0 h/r h/r ROCKING TWISTING 6
EMBEDMENT 3600 5
10.0 EMBEDMENT 4
3600 3
-C.
5.0 2-1800 5-0 2
400-0
-,a--180~
1~
1.0 0
0.5 1.0 1.5 2.0 0
1.0 2.0 h/r h/r h
RANGE OF DATA POINTS Figure 3.7-4 EMBEDMENT CORRECTION FACTOR 20
1.8 1.7' 1.6 1.5 1.4 1.3 1.2 1.1 1.0 0.1 1.0 10 Br (a) INERTIAL EFFECTS ON ROCKING MODE (??r vs Br 3
1.5 2
-D 1.0 0
ama 0.1 0.2 0.4 0.6 1.0 2
4 6
8 10 LBe (b) COEFFICIENTS @,' h, AND 3r FOR RECTANGULAR FOOTINGS (AFTER FIGURE 10-16, REFERENCE 11) 0Figure 3.7-5 COEFFICIENTS FOR CALCULATIONS OF DAMPING AND STIFFNESS PARAMETERS 21
F I
I AeA
- 1.
- 2. Ae P
Ay Ay
- 3. A p
Ae Figure 3.7-6 ENERGY BALANCE TECHNIQUE 22
3.8.4 STRUCTURES OTHER THAN CONTAINMENT The following section describes the seismic reevaluation of structures as part of the BOPS Seismic Reevaluation Program scope as identified in subsection 1.2.1.
The identified structures will be analyzed to ensure that the DBE will not impair their ability to perform their particular safety-related functions.
3.8.4.1 Description of Structures 3.8.4.1.1 Reactor Auxiliary Building With the exception of the northeast corner, the reactor auxiliary building is a single story, partially embedded, reinforced concrete structure rising to about 6 feet above ground level. The northeast corner of the reactor auxiliary building includes an additional story with roof level varying from 21 to 28 feet above ground level. This second story is constructed of masonry walls, conventionally reinforced concrete walls and slabs, and structural steel floor framing.
The overall dimensions of the reactor auxiliary building are approximately 134 feet by 60 feet. The northeast corner which comprises an additional story is approximately 32 feet by 41 feet.
The enclosed portion of the structure houses the radwaste storage tanks, radwaste processing equipment, and chemical and volume control processing equipment. The roof supports the hydrazine addition subsystem and component cooling water system as well as the recirculation heat exchanger.
3.8.4.1.2 Fuel Storage Building The fuel storage building consists of a reinforced concrete pool supporting a superstructure constructed of reinforced hollow concrete block walls and steel framing. The spent fuel pool is 44 feet, 9 inches high and the superstructure is 23 feet high. The pool structure is partially embedded to a depth of 17 feet on the south side and 22 feet, 9 inches on the other three sides. Adjoining the pool structure on the south side is a three story wing constructed of reinforced hollow concrete block walls and steel framing. The adjoining three-story wing is not embedded and is 51 feet high. The pool structure contains spent fuel storage and handling, spent fuel shipping cask storage and handling, and fuel transfer tube areas.
The adjoining wing contains new fuel storage and handling, a decontamina tion pad, 480v switchgear and Motor Control Center (MCC) Nos. 2 and 3.
The overall plan dimensions of the building are approximately 73-feet long by 48 feet wide; 29 feet of the width is pool structure and the remaining 19 feet is the adjoining structure.
3.8.4.1.3 Control Building The control building is a three-story reinforced concrete structure with a single-story administration office building structurally coupled to the east side. The central portion of the control building (housing the control room and cable spreading room) has only a partial second floor. Structural 23
steel framing is used to support equipment in lieu of a second floor con crete slab. The north and west walls of the control building are 2 feet, 10 inches thick while the remainder of the structural walls vary from 8 inches to 13 inches in thickness. The irregularly shaped building has overall plan dimensions of approximately 110 feet wide and 140 feet long and is approximately 36 feet high. The structure is slightly embedded with grade level varying from elevation +14 feet, 0 inches to elevation +19 feet, 9 inches.
3.8.4.1.4 Turbine Building The turbine building consists of four individual structural systems which surround the turbine pedestal. These four structural systems are known as the turbine building north and south extensions and east and west heater platforms.
The turbine building north extension is a one-story structural steel frame building with a mezzanine. It has approximate plan dimensions of 40 feet by 50 feet with an 8-1/2 inch thick prestressed concrete slab at elevation 42 feet, 0 inch, and a steel grating platform at elevation 30 feet, 0 inch.
One and one half inch wide expansion joints are provided at the juncture between the extension and the turbine generator pedestal (at elevation 42 feet, 0 inch).
The turbine building south extension is a one-story building employing a steel frame system constructed above ground level. The south extension has approximate plan dimensions of 40 feet by 50 feet, with an 8-1/2 inch thick prestressed concrete slab at elevation 42 feet, 0 inches. One and one-half inch wide expansion joints are provided at the junctions of south extension and the turbine generator pedestal (at elevation 42 feet, 0 inches).
One story steel frame heater platforms are on the east and west sides of the turbine building above ground level. Each platform has approximate plan dimensions of 112 feet by 50 feet and supports an 8-1/2 inch thick prestressed concrete slab at elevation 35 feet, 6 inches.
3.8.4.1.5 Turbine Pedestal The turbine pedestal is a reinforced concrete space frame supported by a 5-foot thick mat foundation. It consists of haunched columns at the four corners of the mat foundation and three haunched intermediate walls. The north columns are 8 feet square; the south columns are 8 feet by 8 feet, 2 inches. Wall thickness varies from 4-1/2 feet to 7 feet. The centerline to centerline distances between columns are:
East -
west:
34 feet, 0 inches North -
south:
135 feet, 6 inches The operating deck consists of an 8-foot thick center section that supports the turbine gantry crane and turbine-generator, which is accommodated 24
through several large openings in the deck, and two cantilevered wings on the east and west sides are 1-foot, 6 inches thick. The top of the deck is at Elevation 42 feet, while the overall height of the structure is approximately 33 feet, 6 inches from the top of the mat foundation.
3.8.4.1.6 Circulating Water System Intake Structure The intake structure is a buried reinforced concrete structure that houses:
(1) the major components of the circulating water system, (2) the safety related salt water cooling pumps which are part of the component cooling water system and, (3) the tsunami gates.
The intake of a 14-foot, 2-inch diameter intake pipe leads to a 12-foot square box culvert to two pump chambers, with a maximum open cross section of 12 feet high by 23 feet wide. The pump well, where the circulating water pumps are installed has a 23-foot high peripheral retaining wall and the pump chamber top slab forms the base of the pump well.
The discharge tunnel cross-section is 10 feet, 8 inches by 12 feet and it leads to the 14-foot, 2-inch diameter outfall tunnel.
Two 12-foot inside diameter, reinforced concrete, pipes extending about 3200 and 2600 feet into the ocean, provide for the intake and discharge of seawater.
3.8.4.1.7 Ventilation Equipment Building The ventilation equipment building is a single-story structure with a roof of steel decking on structural steel roof framing. The roof is supported by peripheral, reinforced, hollow, concrete block walls.
Its plan dimen sions are approximately 44 feet long by 21 feet wide by 20 feet high.
3.8.4.1.8 Seawall The seawall is a cantilevered sheetpile wall which runs along the western boundary of the site.
It is protected with a 2-1/2 inch gunite coating which extends to elevation +4.0 feet on the seaward face and to an eleva tion 1 foot, 0 inches below finished grade on the landward face.
The top and bottom elevations of the wall are +28.0 feet and -8.0 feet respectively.
The finished grade adjacent to the wall varies from +14.5 feet to +17.0 feet.
The stone revetment on the seaward face extends from approximately +5.0 feet to +13.0 feet and is placed at an approximate 1.5:1 slope.
3.8.4.2 Applicable Codes, Standards, and Specifications The following codes, specifications, and project reports constituted the basis for the design, fabrication, and construction of the existing structures.
A.
Uniform Building Code (UBC), 1961 Edition B.
"Manual of Steel Construction," American Institute of Steel Construction (AISC), 1963 Edition.
25
C.
"Building Code Requirements for Reinforced Concrete," ACI Standard 318-63, American Concrete Institute (ACI).
D.
"Specification for the Design of Light Gage, Cold-Formed Steel Structural Members," 1963 Edition, American Iron and Steel Institute (AISI).
E.
"Foundation Investigation at the San Onofre Unit 1 Site,"
Report No. 176, Engineering Department, Southern California Edison Company, Los Angeles, California, October 22, 1963.
Specific sections of the following codes and standards will be employed in the seismic reevaluation of the existing structures (see paragraphs 3.8.4.3 and 3.8.4.5 for application).
A.
Uniform Building Code (UBC), 1979 Edition.
B.
"Specification for the Design, Fabrication, and Erection of Structural Steel for Buildings," American Institute of Steel Construction (AISC), November, 1978.
C.
"Code Requirements for Nuclear Safety Related Concrete Structures,"
ACI Standard 349-76, American Concrete Institute (ACI).
D.
American Society for Testing and Materials (ASTM) Standards.
E.
"Building Code Requirements for Minimum Design Loads in Buildings and Other Structures," ANSI A58.1-1972, American National Standards Institute (ANSI).
F.
"Building Code Requirements for Reinforced Concrete,"
ACI Standard 318-77, American Concrete Institute (ACI).
G.
"Building Code Requirements for Concrete Masonry Structures, (ACI 531-79)," American Concrete Institute (ACI).
3.8.4.3 Loads and Load Combinations The BOPS Seismic Reevaluation Program will consider the occurrence of a DBE during normal plant operation. The loading combinations that will be considered for structures are shown in table 3.8-1.
The normal loads and extreme environmental loads that will be considered are described in the following paragraphs. The loading combinations are consistent with ACI-349-1976 for concrete structures, and the Standard Review Plan section 3.8.4 for steel structures.
3.8.4.3.1 Normal Loads Normal loads are all the loads encountered during normal plant operation.
Normal loads include dead loads (D), live loads (L), lateral and vertical pressure of liquids (F), and lateral earth pressure (H), as well as appropriate thermal operating loads (T ), and pipe reaction loads (R ) as defined in table 3.8-1.
o o
26
TABLE 3.8-1 LOAD COMBINATIONS FOR STRUCTURES Definitions and Nomenclature for Load Combination D = Dead Loads or their related internal moments and forces.
L =
Applicable live loads or their related internal moments and forces.
F =
Lateral and vertical pressure of liquids, or their related internal moments and forces.
H =
Lateral earth pressure, or its related internal moments and forces.
T
=
Thermal effects and loads during normal operating conditions 0
based on the steady state condition.
R
=
Maximum pipe and equipment reactions during normal operating 0
conditions based on the steady-state condition, if not included in the above loads.
E'=
Loads generated by the Design Basis Earthquake (DBE).
Load Combinations for Concrete, Masonry, and Steel Structures D + L + F + H + T + R + E' (a) (b) (c) (d) 0
.0 Load Combination for Overall Structural Effects D + F + H + E' for sliding, overturning, and flotation (a) For the load combinations where D or L reduce the effects of other loads, the corresponding coefficients shall be taken as 0.90 for D and zero for L. The vertical pressure of liquids shall be considered as dead load, with due regard to variation in liquid depth.
(b) Hydrodynamic loads (F) will also be included for the spent fuel storage pool.
(c) T will not be considered when it can be shown that the load
.0 is secondary and self-limiting in nature.
(d) Where applicable, impact effects of moving loads shall be included with the live load L.
27
In the determination of dead loads, where practical and appropriate, the actual as-built data will be used. Otherwise, a uniform load will be estimated for the given area. Where actual dead load data is used it will be collected by means of the following methods:
A.
Use of as-built drawings.
B.
Field investigation, survey, and measurements as appropriate.
C.
Use of final certified vendor drawings.
Live loads shall be based upon actual loadings or table 3 of ANSI A58.1-1972.
Thermal operating loads (T ) and pipe reaction loads (R ) will be con sidered where applicable. o 0
3.8.4.3.2 Extreme Environmental Loads Extreme environmental loads are loads that are credible, but are highly improbable. The extreme environmental loads considered are the Design Basis Earthquake (DBE) loads (E'). The DBE seismic loads will be generated in accordance with the provisions of section 3.7.
In addition, tsunami loads are considered for the sea.wall as discussed in section 3.7.2.1.8.
3.8.4.4 Reevaluation Analysis Procedures The initial analysis procedures to be considered will be based upon elastic analysis techniques. For certain structures and subsystems, an inelastic analysis as discussed in sections 3.7.2.1 and 3.7.3 may be performed in order to demonstrate that the structural response to earthquake excitation will not result in impairment of the safety functions of the structure.
All structures will be analyzed by dynamic analysis techniques with the exception of the reactor auxiliary building, ventilation equipment building, circulating water system intake structure, and seawall. See para graph 3.7.2.1 for a detailed discussion of the dynamic analysis procedures.
The following are the principal computer programs that may be used in the seismic reevaluation and analysis of structures.
A.
Bechtel Structural Analysis Program (BSAP)
B.
Spectra Computer Program (SPECTRA)
C.
Symbolic Matrix Interpretive System Program (SUPER SMIS)
D.
Optimum Concrete Design Program (OPTCON)
E.
Reinforced Concrete Design for Axial Force and Biaxial Bending (BIAX) 28
F.
Generalized Equivalent Modal Damping (GEMD)
G.
Analysis of Nonlinear Structural Response ANSR-II H.
Dynamic Response Analysis for Inelastic Plane Structures (DRAIN-2D)
A description of each computer program, along with information pertaining to the validation and extent of application for each program, is presented in San Onofre Units 2 and 3 FSAR, Appendix 3C, with the exception of ANSR-II and DRAIN-2D. Information pertaining to the validation of these programs, if used, will be available at the conclusion of the structural analysis.
3.8.4.5 Structural Acceptance Criteria The limiting values of stress, strain, and gross deformations are established by the following general criteria:
A.
To maintain the structural integrity as required to achieve its Seismic Category A safety function when subjected to the DBE load combination.
B.
To prevent structural deformations from impairing the safety function of Seismic Category A systems and equipment.
The acceptance criteria for non-critical portions of Seismic Category A structures will be the demonstration that their response or collapse will not impair the integrity or function of Seismic Category A structures, systems, or components.
Where justified, actual material properties and increased allowable stresses may be utilized. Justification may include in-situ tests, material tests performed during the original construction, or reference to technical literature.
If inelastic ductile behavior is accounted for in the analysis of a struc tural member, an evaluation will be made to insure that non-ductile failure modes do not govern the behavior of the member.
Acceptance criteria presented herein (section 3.8.4.5) are based on current code requirements and consideration of original design codes and quality requirements. Compliance with such criteria will represent adequate reevaluation without further analysis. If the structural response does not comply with such criteria, alternate acceptance criteria based upon further consideration of original design codes, original quality requirements and failure probabilities and consequences will be utilized.
3.8.4.5.1 Supplemental Structural Acceptance Criteria - Concrete and Steel Structures When a linear elastic analysis is used, the specific acceptance criteria stated in table 3.8-2 will be employed for the critical portions of Seismic Category A structures.
29
TABLE 3.8-2 ACCEPTANCE CRITERIA FOR SEISMIC CATEGORY A STRUCTURES DEFINITIONS AND NOMENCLATURE FOR ACCEPTANCE CRITERIA U =
For concrete structures, U is the required section strength to resist the design loads based on the streg 5 h design methods as described in ACI Standard 349-76.
For masonry blockwall structures, U is the required section strength to resist the design loads based on the working stress methods described in ACI Standard 531-79 and the allowable stresses described in subsection 3.8.4.5.2.
S =
For structural steel structures, S is the required section strength based on elastic design methods and the allowable stresses defined in Part 1 of the AISC "Specification for the Design, Fabrication, and Erectto of Structural Steel for Buildings."
November 1, 1978.
Y =
For structural steel, Y is the section strength required to resist design loads based on plastic design methods described in Part 2 of the AISC "Specification for the Design, Fabrication, and riction of Structural Steel for Buildings,"
November 1, 1978.
ACCEPTANCE CRITERIA FOR THE CRITICAL PORTIONS OF THE CATEGORY A CONCRETE AND MASONRY STRUCTURES The strength design method and working stress method will be used for concrete and masonary structures, respectively, and the following acceptance criteria will be considered:
U>D+F L+H+ +R+E (b)
U > D + F + L + H + T + R + E'(b 0
0 ACCEPTANCE CRITER A)FOR THE CRITICAL PORTIONS OF CATEGORY A STEEL STRUCTURES If the Elastic Working Stress Design Method is used, the following acceptance criteria will be considered:
1.6S > D + F + L + H + T + R + E'(b) 0 0
If an inelastic analysis is performed, typical values of ductility ratios for use in the analysis are given in table 3.8-3. These values are for the overall structural response of steel and concrete structures and are based upon recommendations in references 12 and 13 and are also discussed in reference 14.
The values given in table 3.8-3 are generally equivalent to those recommended in reference 7 for structures that can deform inelasti cally to a moderate extent without unacceptable loss of function.
30
TABLE 3.8-2 (Cont.)
ACCEPTANCE CRITERIA FOR OVERALL STRUCTURAL EFFECTS Following is the acceptance criteria against overturning, sliding and flotation.
Minimum Factors of Safety Loading Combination Against Overturning Against Sliding Against Flotation D + F + H + E' 1.1 1.1 1.1
- a.
Where justified, actual material properties and/or increased allowable stresses will be utilized based upon in-situ tests, material tests performed during the original construction, or reference to generic information.
- b.
T and R will be neglected when it can be shown that they are 0
0 secondary and self-limiting in nature.
- c.
If plastic design methods are used, the following acceptance criteria will be considered:
0.9Y > D + L + F + H + T + R + E' 0
0 3.8.4.5.2 Supplemental Structural Acceptance Criteria Reinforced Masonry When a linear elastic analysis, based on the working stress procedures described in ACI Standard 531-79, is used, the specific acceptance criteria stated in table 3.8-2 will be employed for the critical portions of Seismic Category A structures. The reinforced masonry allowable stresses for this method are provided in table 3.8-4. These tabulated values are based on the allowable stresses for inspected masonry as given in table 10.1 of ACI Standard 531-79 and have been increased by the factors shown in table 3.8-4.
The increase factors account for the extreme environmental loading condi tion which is being evaluated. The increase in allowable stresses for masonry in conjunction with extreme environmental loading conditions is consistent with the methodology employed for evaluating other structural materials (i.e. reinforced concrete and structural steel) under the same loading conditions; namely, that the allowable levels of stress are set closer to the materials' elastic limit than those values used for normal loading conditions.
If an inelastic analysis is performed using the inelastic spectrum or energy balance techniques, as described is section 3.7.2.1 and 3.7.3.16.1 respec tively, the typical values of ductility ratios associated with these methods are given in table 3.8-3. These ductility ratios are based upon test data summarized in reference 4.
31
TABLE 3.8-3 STRUCTURAL DUCTILITY RATIOS FOR ANALYSIS(a)(b)(c)
Ductility Ratio (p)
Without Moment With Moment(d)
Resisting Resisting Material Structure Type Frame Frame 1
HORIZONTAL EXCITATION Concrete Frame 3.0 3.0 Shear Wall 1.3 1.3 Steel Braced Frame 2.0 3.0 Moment Resisting Frame 3.0 Masonry Frame 3.0 3.0 Shear Wall 1.3 1.3 2
VERTICAL EXCITATION All structures 1.2
- a. Ductility ratio (p) is defined as the ratio of maximum member deformation to the member deformation at yield.
- b. Damping ratio for the various types of structures is given in Table 3.7-1.
- c. Note these ductility ratios assume the existence of adequate connections. All connections will be checked for adequacy prior to utilizing these ductility ratios.
- d. The frame moment capacity shall be equal to or greater than 25% of seismic shear.
32
Table 3.8-4 ALLOWABLE STRESSES IN REINFORCED MASONRY Allowable Maximum Increase Factor Description (psi)
(psi)
Over ACI 531-79 Stresses Compressive (1)
Axial 0.44f' 2000 2.0 m
Flexural 0.85f' 3000 2.6 m
Bearing On full area 0.62f' 2250 2.5 m
On one-third area 0.95f' 3000 2.5 or less Shear Flexural members(2 )
1.7 f'
75 1.5 m
Shear Walls( 3,4 )
Masonry Takes Shear M/Vd > 1 1.5 V 56 1.67 M/Vd = 0 3.4 123 1.67 m
Reinforcement Takes Shear M/Vd > 1 2.5 f 125 1.67 m
M/Vd = 0 3.4 f' 180 1.67 m
Reinforcement Bond Plain Bars 80 Deformed Bars 186 Tension Grade 40 0.9F y
Grade 60 0.9F y
33
Table 3.8-4 ALLOWABLE STRESSES IN REINFORCED MASONRY (Continued)
Allowable Maximum Increase Factor Description (psi)
(psi)
Over ACI 531-79 Stresses Joint Wire 0.9F y Compression 0.9F y (1) These values shall be multiplied by (1 -
) 3 if the wall has a significant vertical load.
(2) This stress shall be evaluated using the area determined to be in flexural compression.
(3) Net bedded area shall be used with these stresses.
(4) For M/Vd values between 0 and 1 interpolation shall be made between the values given for 0 and 1.
If an inelastic time-history analysis is performed to evaluate masonry structures then an appropriate acceptance criteria will be developed.
3.8.4.6 Materials and Special Construction Techniques Basic materials used in the construction of structures identified in subsection 1.2.1 and their specified minimum design strengths are pre sented below.
A.
Concrete(a) 2
- 1.
Slabs on grade, building f'c (lb/in. )
and equipment foundations
- = 2,500 2
- 2.
Supported floor slabs, f'c (lb/in. )
beams, walls, retaining
= 3,000 walls, turbine pedestal foundation, intake struc ture, shielding concrete
- 3.
Prestressed decks, cir-f'c (lb/in. 2 culating water system
= 4,000 gates, turbine pedestal superstructure 2
- 4.
Grout f'c (lb/in.2
= 2,000 34
- 5.
Hollow concrete block UBC-63 f'm (lb/in. 2 masonry, Grade A ASTM C-90
= 1,350 2
- 6.
Fully grouted, hollow UBC-63 f'm (lb/in. )
block masonry, ASTM C-90
= 1,500 Grade A 2
- 7.
Mortar for concrete ASTM C270 f'm (lb/in. )
block
= 2000 B.
Reinforcing steel(b) 2
- 1.
Intermediate ASTM A15 f (lb/in. )
Grade No. 2
=40,000 size round bars 2
- 2.
No. 3 thru 11 ASTM A15 f (lb/in. )
ASTM A305
=Y40,000 2
- 3.
No. 14 and 18 ASTM A408 f (lb/in. )
-40,000
- 4.
Welded Wire Mesh 2
10 gage and larger ASTM A185 fy (lb/in. )
65,000. 2 11 gage and smaller ASTM A185 fy (lb/in. )
=56,000 2
- 5.
Prestressed tendons ASTM f
(lb/in.2 A421-59T
=P240,000 Type BA C.
Structural steel ASTM A36 fy (lb/in.2
= 36,000 D.
Miscellaneous steel
- 1.
High-strength bolts
> 1-1/8 inch ASTM A325 fy (lb/in.2
= 81,000 2
< 1 inch ASTM A325 fy (lb/in.2
= 92,000
- 2.
High-strength anchor ASTM A193, fy (lb/in.2 bolts Grade B7
= 105,000
- 3.
Anchor bolts ASTM A307, fy (lb/in. 2 Grade A
= 36,000 35
2
- 4.
Stainless Steel plates ASTM A167 f (lb/in.2 Type 304
=Y30,000 2
ASTM 240 f (lb/in. )
Type 304L
=Y25,000 2
ASTM A276 fy (lb/in. )
Type 304
= 30,000
- 5.
Insert plates ASTM A36 fy (lb/in. 2
= 36,000
- a.
f'c = specified compressive strength of concrete at 28 days f'm = specified compressive strength of masonry block at 28 days f'm = specified compressive strength of mortar at 28 days 0
- b.
fy = specified yield strength of steel fpu = ultimate strength of prestressed tendons The structures listed in subsection 1.2.1 were built of reinforced concrete, reinforced concrete block masonry (with special inspection), and/or structural steel, using methods common to heavy industrial construction.
3.8.5 FOUNDATIONS 3.8.5.1 Description of Foundations All structures are supported on mats or footings bearing on undisturbed San Mateo sand unless noted otherwise in the description of the structures.
Resistance to lateral forces is provided either by friction between the bottom of the mat or footing and the soil or by passive resistance.
3.8.5.1.1 Reactor Auxiliary Building Foundation The auxiliary building foundation is a reinforced concrete mat, 2 feet, 4 inches thick, 134 feet, 4 inches long and 60 feet, 2 inches wide, bearing directly on the San Mateo formation. The general bottom elevation of the basemat in the radwaste holdup tank area is at elevation -4 feet, 4 inches and the remainder of the area is at elevation 2 feet, 8 inches.
3.8.5.1.2 Fuel Storage Building Foundation The spent fuel pool foundation is a reinforced concrete slab, 5 feet, 9 inches thick, 73 feet, 4 inches long by 23 feet wide, bearing directly on the San Mateo formation. The southern adjoining wing walls are sup ported by 1-foot, 6-inch wide, 8-inch thick continuous reinforced concrete footings; steel columns are supported by approximately 4-foot square, 1-foot, 6-inch thick reinforced concrete spread footings, bearing directly on the San Mateo formation.
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3.8.5.1.3 Control Building Foundation The control building foundation consists of continuous reinforced concrete wall footings and some individual column spread footings, bearing directly on the San Mateo formation. Footing width varies from 1 foot, 8 inches to 8 feet, 10 inches, and its thickness varies from 1 to 2 feet.
3.8.5.1.4 Turbine Building Foundation The turbine building foundation consists of column spread and combined footings, bearing directly on the San Mateo formation. Footing width varies from 3 feet to 5 feet, while footing thickness varies from 2 feet, 6 inches to 5 feet. Elevation of top of footing varies from elevation 6 feet to elevation 17 feet, 7 inches.
3.8.5.1.5 Turbine Pedestal Foundation The turbine pedestal foundation is a 147-foot long by approximately 47-foot wide by 5-foot thick reinforced concrete mat resting directly on San Mateo formation at elevation 3 feet, 6 inches (grade is at elevation 14 feet). A 12.5-foot by 20-foot circulating water discharge culvert, built monolithically with the mat, passes through from underneath the mat at the south end.
3.8.5.1.6 Circulating Water System Intake Structure Foundation The intake structure foundation is a reinforced concrete slab, 3 feet, 4 inches thick, 136 feet, 3-1/2 inches long with a varying width, bearing directly on the San Mateo formation.
3.8.5.1.7 Ventilation Equipment Building Foundation The external walls of the ventilation equipment building are supported by a 1-foot, 6-inch wide, 8-inch thick continuously reinforced concrete foot ing, resting directly on the San Mateo formation.
3.8.5.1.8 Seawall Foundation The seawall is a sheet pile structure that is laterally supported by San Mateo sand.
3.8.5.2 Applicable Codes, Standards, and Specifications The applicable codes, standards, and specifications, used in the structural design, fabrication, and construction of foundations, and the applicable codes, standards, and specifications to be used in the seismic reevaluation of foundations are discussed in paragraph 3.8.4.2.
3.8.5.3 Loads and Load Combinations Foundation loads and loading combinations for structures are discussed in paragraph 3.8.4.3.
37
3.8.5.4 Reevaluation Analysis Procedures Reevaluation analysis procedures, including computer programs to be employed in the reevaluation of foundations are discussed in paragraph 3.8.4.4.
3.8.5.5 Structural Acceptance Criteria The structural acceptance criteria for foundations of structures will be the same as that which is discussed in paragraph 3.8.4.5.
A minimum factor of safety of 1.1 against overturning and sliding is maintained for all structures.
3.8.5.6 Materials and Special Construction Techniques The foundations are built of reinforced concrete using conventional methods for heavy industrial construction. Materials utilized in the construction of foundations are discussed in paragraph 3.8.4.6.
38
4.0 REFERENCES
- 1. "Seismic Reevaluation and Modification, San Onofre Nuclear Generating Station, Unit 1, NRC Docket 50-206," April 29, 1977.
- 2. "Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants, LWR Edition," Regulatory Guide 1.70, Revision 3, USNRC, November 1978.
- 3. Woodward-Clyde Consultants, Balance of Plant (BOP) SONGS Unit 1 Soil Structure Interaction Methodology Report, Revision 1, Orange, California, July 1978.
- 4. Computech Engineering Services, Seminar Notes, A State-of-the-art Review Masonry Design Criteria, Berkeley, California, June 1980.
- 5. "Material Property Studies, San Onofre Nuclear Generating Station,"
San Onofre Nuclear Generating Station Units 2 and 3 PSAR, Amendment 11 Attachment A3 to Appendix 2E, March 13, 1972.
- 6. Seed, H., and Whitman, R., "Design of Earth Retaining Structures for Dynamic Loads," Proceedings of ASCE specialty conference on Lateral Stresses in the Ground and Design of Earth Retaining Structure, 1970.
- 7. Newmark, N. M. and Hall, W. J., Development of Criteria for Seismic Review of Selected Nuclear Power Plants, NUREG/CR-0098, USNRC, May 1978.
- 8. Hadjian, A. H., et. al., Design Guide C-2.44, Seismic Analyses of Structures.and Equipment for Nuclear Power Plants.
- 9. "Combination of Co-directional Responses Due to Three Earthquake Input Components by the Component Factor Method," Seismic Committee News letter No. 6, Bechtel Power Corporation, Los Angeles, California, July 1, 1976.
- 10.
"Soil-Structure Interaction Parameters", San Onofre Nuclear Generating Station, Units 2 and 3 FSAR, Appendix 3.7C.
- 11.
Richart, F. E., Jr., Hall, J. R., and Woods, R. D., Vibration of Soil and Foundations, Prentice-Hall, Inc., Englewood, New Jersey, 1970.
- 12.
Newmark, N. M., and Haltiwanger, J. D., Air Force Design Manual AFSWC-DR-62-138, prepared by the University of Illinois for Air Force Special Weapons Center, Kirtland Air Force Base, N. M., 1962.
- 13.
Hsiu, F. J., and Hanson, R. D., "Inelastic Seismic Response of a Turbine Building," 4th SMIRT Conference, August 1977.
- 14. Hadjian, A. H., et. al., Design Guide C-2.33, Simplified Inelastic Seismic Design of Non-Safety Related Structures.
39