ML17256A705

From kanterella
Jump to navigation Jump to search
App a to Structural Reanalysis Program, Evaluation Rept for NRC SEP Topics II-2.A, 'Severe Weather Phenomena,' III-2, 'Wind & Tornado Loading' & III-7.B, 'Design Codes,Design Criteria & Load Combinations.'
ML17256A705
Person / Time
Site: Ginna Constellation icon.png
Issue date: 03/31/1983
From:
ROCHESTER GAS & ELECTRIC CORP.
To:
Shared Package
ML17256A706 List:
References
TASK-02-02.A, TASK-03-02, TASK-03-07.B, TASK-2-2.A, TASK-3-2, TASK-3-7.B, TASK-RR 2458, NUDOCS 8305310133
Download: ML17256A705 (131)


Text

APPENDIX A to the STRUCTURAL REANALYSIS PROGRAM For The R E GINNA NUCLEAR POWER PLANT

0

'F 1'

TABLE OF CONTENTS Section ~Pa e NOMENCLATURE LIST OF REFERENCES v1

1.0 INTRODUCTION

1.1 . Background Information 1.2 Project Scope and Methodology 1.2.1 Severe Weather and Tornado Loads 1-2 1.2.2 Design Code Changes 1-4 2.0 DETAILED DISCUSSION OF COMPUTER MODELS 2-1 2.1 Buildings Modeled 2-1 2.2 Model Content 2-1 2.3 Model Development 2"3 2.3.1 Define Model Geometry 2-3 2.3.2. Define Structural Analysis Data 2-4 2.3.3 Define Structural Loadings . 2-4 2.3.4 Define Design Parameters 2-5 2.4 Computer Program Description 2-5 2.5 Computer Model 1 and 2 Geometry Plots 2-8

. r 2.6 Load and Load Combinations Tables for Computer Models 1 and 2 2-8 3.0 SEP TOPIC II-2.A SEVERE WEATHER PHENOMENA AND SEP 3-1 TOPIC III-2 WIND AND TORNADO LOADINGS 3.1 General Assumptions 3-1 3.2 Severe Weather Phenomena 3-2 3.2.1 Extreme Snow Loads S'n 3-2 3.3 Wind and Tornado Loads 3-2 3.3.1 Tornado Wind Loads - Ww 3-2 3.3.2 Tornado Differential Pressure - W P

3-3

(: TABLE OF CONTENTS (Cont'd)

Section ~Pa e 3.4 Design Loads 3-4 3.4.1 Dead Load - D 3"4 3.4.2 Live Load L- 3-5 3.4.3 Thermal Effects - To 3-5 3.4.4 Pipe Reactions " Ro 3-5 3.4.5 Wind Load - W 3"5 3 ~4 ~6 Snow Loads Sn 3-6 3.4.7 Load Combinations 3-6 3.5 Evaluation and Results 3-7 3.5.1 Global Systems 3-8 3.5.2 Local Systems 3-22 4.0 SEP TOPIC III-7.B DESIGN CODES, DESIGN CRITERIA~ AND LOAD COMBINATIONS 4-1 4.1 Introduction 4-1 4.2 Evaluation and Results 4-2 4.2.1 Shear Connectors in Composite Beams 4-2 4.2.2 Composite Beams with Steel Deck 4-2 4.2.3 Hybrid Girders 4-3 4.2.4 Compression Elements 4-3 4.2.5 Tension Members 4-4 4.2.6 Coped Beams 4-5 4.2.7 Moment Connections 4-6 4.2.8 Lateral Bracing 4"6 4.2.9 Steel Embedments 4.2.10 Design Criteria and Load Combinations 4-9 4' Summary 4-9

LIST OF FIGURES

~pi ure Title ~Pa e l-l Project Outline 1-3 2-1 Model Coordinate System 2-3 3-1 Computer Model No. 1 Overstressed Members- 3-12 S'n = 100 psf, Wt = 132 mph 3-2 Computer Model No. 1 Overstressed Members- 3-13 S'n = 100 psf, Wt = 188 mph 3-3 Computer Model No. 1 Overstressed Members- 3-14 S'n = 100 psf, Wt = 250 mph 3-4 Tornado Wind Regions 3-27 Panel Location Column Line 3 3-34 Panel Location - Column Line 13, F, H 3-35 Panel Location Column Line'L, lla, M 3-36 Panel Location Column Line 7, A, Q 3-37

LIST OF TABLES Table Title ~Pa e 2-1 Structural Members by Building 2-2 2-2 Computer Model Members by Building 2"2 2-3 Model 1 Independent Loads 2-9 2-4 Model 1 - Load Combinations for Code Check 2-10 2-5 Model 1 Load Combination for Anchorage Check '2-11 2-6 Model 2 . Independent Loads 2-12 2-7 Model 2 Load Combinations for Code Check 2-13 2-8 Model 2 - Load Combination for Anchorage Check 2-14 3-1 Tornado Hazard Probabilities with 95X Confidence 3-3 Limits 3-2 Tornado Differential Pressure at Various Tornado Windspeeds 3-4 Computer Model 1 Primary Member Evaluation 3-10 Computer Model 2 Primary Member Evaluation 3-11 Results of Connection Evaluation 3-18 3-6 Results of Anchorage Evaluation 3"21 3-7 Overstressed Local Members 3-23 3-8 Siding Test Results 3-25 3-9 Siding Panel System Capacities 3-26 3-10 Maximum Allowable Tornado Windspeeds for Various Siding Systems on Vented Structures 3-28 3-11 Maximum Allowable Tornado Windspeeds for Various Siding Systems on Non-Vented Structures 3-28 3-12 Roof Decking Systems Evaluation, 3-31 3-13 Block Wall Description 3-38 Qtcrt /commonwealth 1v

NOMENCLATURE D Dead loads or their related internal moments and forces, including any permanent equipment loads.

L Live loads or their related internal moments and forces, including any movable equipment loads and other loads which vary with intensity and occurrence, such as soil pressure.

T0 Thermal effects and loads during normal operating or shutdown conditions, based on the most critical transient or steady state condition.

Ro - Pipe reactions during normal operating or shutdown conditions, based on the most critical transient or steady state condition.

Sn Design snow load (100 year mean recurrence interval)

W - Loads generated by the design wind specified for the plant.

E - Loads generated by the operating basis earthquake.

E' Loads generated by the safe shutdown earthquake.

w, Loads generated by the design tornado specified for the plant.

Tornado loads include loads due to the tornado wind pressure, but do not include the tornado-created differential pressure.

W P

Tornado created differential pressure loads Sn Extreme snow load

LIST OF REFERENCES

l. American Institute of Steel Construction (AISC) - "Manual of Steel Construction," Eighth Edition " (AISC 1980)
2. Franklin Research Center, Technical Evaluation Report - Wind and Tornado Loading TER"C5257-400, December 2, 1981
3. American National Standards Institute (ANSI) - "Building Code Requirements for Minimum Design Loads in Buildings and Other Structures,"

ANSI A58.1-1982.

4. Letter and attachment from D. Crutchfield, NRC, to L. White, RG&E, dated December 15, 1980 Ginna SEP Topic II-2.A "Severe Weather Phenomena."
5. USNRC Standard Review Plan, NUREG 0800.

Institute (ACI) -

'i 6. American Concrete.

Related Structures," ACI 349-80.

"Code Requirements for Nuclear Safety

7. USNRC Inspection & Enforcement (I&E) Bulletin 80-11 "Masonry Wall Design," May 1980.
8. Rochester Gas & Electric Corporation, Robert Emmett Ginna Nuclear Power Plant Unit No. 1 - "Final Facility Description and Safety Analysis Report."
9. Gilbert/Commonwealth "Fire Protection Evaluation - Robert E. Ginna Nuclear Power Plant Unit 1," GAI Report No. 1936, March 1977.

Qbcrs ICweenwulO

10. Rochester Gas & Electric Corporation, Robert Emmett Ginna Nuclear Power Plant Unit No. 1 "Dedicated Shutdown System Conceptual. Design Summary,"

November, 1981.

11. Code of Federal Regulations (CFR); Title 10 - Energy; Part 100 "Reactor Site Criteria," (10 CFR 100); January 1, 1981.
12. Franklin Research Center, Technical Evaluation Report - Design Codes, Design Criteria and Loading Combinations TER-C5257-322, December 23, 1982
13. Letter and Attachment from D. Crutchfield, NRC, to J. Maier, RGGE, dated April 21, 1982 - "Design Codes, Design Criteria, and Load Combinations."
14. American Institute of Steel Construction (AISC) - "Manual of Steel Construction," Sixth Edition, 1963.
15. American Concrete Institute (ACI) - "Building Code Requirements for.

Reinforced Concrete," ACI 318-63.

16. "Nuclear Safety" - July 1974 - J. McDonald.

INTRODUCTION BACKGROUND INFORMATION Since the 1960's there have been changes and revisions made to the licensing criteria, codes, and regulations to which nuclear power plants are designed. With this in mind the USNRC undertook a program, SEP, to evaluate the design of 11 older plants to a common set of criteria. The Ginna Plant is one of these 11 older plants.

SEP employs current licensing criteria as the common basis for these evaluations.

There are a total of 137 SEP Topical Reports spanning a broad spectrum of safety issues. This report addresses the three following topics as related to the Ginna Plant structures:

o II-2.A SEVERE WEATHER PHENOMENA o III-2 WIND AND TORNADO LOADINGS o III-7.B DESIGN CODES, DESIGN CRITERIA, AND LOAD COMBINATIONS PROJECT SCOPE AND METHODOLOGY To address the SEP topics, the project was divided into two distinct parts as described belo~.'EP Topics II-2.A and III-2 involve loadings that were part of the original design as well as new loadings not considered previously. The plant structures were analyzed and evaluated for these loads by means of computer programs and manual calculations.

b. SEP Topic III-7.B was addressed by reviewing the major code change findings of the USNRC consultants to d'etermine if they 1-1

were relevant to existing structural elements at Ginna. This was done by examination of the construction drawings and, as required, by calculations.

1.2.1 Severe Weather and Tornado Loads For Part a. above, G/C evaluated the anticipated response of the structural steel framing of the plant structures using current design criteria and load combinations for the following loads:

o Dead loads o Live loads o Service loads (including normal operating piping loads) o Wind loads o Tornado loads o Snow loads o Extreme snow loads (including rain surcharge)

This part of the work was broken down into three major activities (see Figure l-l). Activity A concerns modeling and analyzing the plant structures. Activity B concerns evaluating reference documents and developing lists of loads to be applied to the models.

Activity C encompasses all work performed to evaluate and verify the results of the computer analyses and to provide sufficient information upon which to base decisions about the margins of safety inherent in the existing structures and any areas which may require further investigation for possible structural modifications' Qbet /Commonwealth 1-2

PREPARE STRUCTUR'L CREATE INPUT COMPUTER MODEL COMPUTER LOADS RUN DRAWINGS MODELS EXAMINE EVALUATE LIST RESULTS FOR SEP II.2.A SNOW STRUCTURAL LOADS MEMBERS C

EVALUATE SEP III.2 LIST TORNADO LOADS

'XAMINE WIND AND RESULTS FOR SECONDARY MEMBERS COMPILE EXAMINE EVALUATE OVERSTRESSED COMPONENTS RESULTS FOR FINAL REPORT j PRODUCE REPORT EVALUATE LIST RESULTS FOR PLANT DESIGN CONNEC-DWGS. LOADS TIONS SURVEY EXAMINE PLANT LOADS B RESULTS FOR ANCHORGE SELECT DETERMINE COMPILE EVAI.UATE EVALUATE DES. CODE EVALUATE SAFETY . RESULTS SEP III-7.8 FRC REPORT CHANGES CODE SIGNIF. OF FOR FINAL RELEVANT CHANGES CHANGES REPORT TO STUDY PROJECT OUTLINE

A detailed report on the evaluation and findings is presented in Section 3.0.

1.2.2 Desi n Code Chan es SEP Topic III-7.B and the Franklin Research Center (FRC) report TER-C5257-322 (ReE. 13) were used as source documents Eor this part of the evaluation. The FRC report identifies a number of changes to

'esign codes which they regard as having safety significance and which may be applicable to the Ginna Plant. For the purposes of this study, nine changes which involve codes related to the design of steel structures were evaluated and compared to the Ginna Plant design.

The objective of this activity (See D, Figure 1-1), was to determine which of the nine code changes affected aspects of original steel design used at the Ginna Plant. The changes were evaluated to determine their safety significance. Any changes regarded as sign'ificant are further evaluated in this report to provide information on which to base decisions about possible modification of the Ginna structures.

A detailed report on the evaluation and findings is presented in Section 4.0.

Qben/Commonwcal&

1-4

DETAILED DISCUSSION OF COMPUTER MODELS Buildin s Modeled G/C constructed two 3-dimensional computer analysis models to analyze the primary structural members of the structures listed below for the loads specified in Section 3.0. The same computer models were later used to check the structural members for AISC 1980 Code (Ref. 1) compliance. Structural analysis and code checking were done using the computer program GTSTRUDL, which is described later in this appendix. One model, hereafter referred to as Model 1, was used to analyze the Auxiliary Building, Intermediate Building, Facade Structure, Turbine Building, and Control Building which are all interconnected. The other model, hereafter referred to as Model 2, was used to analyze the Screen House which is an isolated structure.

2 2 Model Content For both Models 1 and 2, only the main structural steel framework, required to resist the subject loads, was incorporated. this generally included all of the building columns, the main floor and roof framing members (beams and trusses) attached to the columns, and the vertical and horizontal bracing members. The following items were not included in the models'. girts, purlins, local floor beams, block walls, Service Building, Technical Support Center, AVT Building and SBAFW Building and platforms secondary in nature.

The loads and effects from shielding from these items, where included in the analyses. In Model 1, the stiffening effects of the roofs (steel decking), floors (concrete slabs on steel decking), and the Turbine Building pressurization walls were simulated by finite plate elements. Girts, roof beams, and similar elements required to transmit the loads specified in the SEP topics into the main framework were evaluated separately. The models were terminated at the interface between the steel framework and concrete structures.

Shstt ICannawcsfth 2-1

Table 2-1 defines the approximate number of actual structural steel members which were included in the analysis models'able 2-2 defines the number of computer members used to model the members listed in Table 2-1. Table 2-2 also lists the number of plate elements used to represent the various floors and roofs of the structures'ABLE 2-1 STRUCTURAL MEMBERS BY BUILDING Structural Buildin Model Members Auxiliary 203 Intermediate 202 Facade 450 Turbine 1149 Control 50 Subtotal 2054 Screen House 522

. Total- of Models 1 and 2 2576 TABLE 2-2 COMPUTER MODEL MEMBERS BY BUILDING Buildin Model'oints Members(1) Plate Elements(

Auxiliary 170 279 59 Intermediate 370 377 190 Facade 267 721 0 Turbine 1234 2092 612 Control 83 76 45 Subtotal 2124 3505 906 Screen House 375 766 0 Total of Model 1 and 2 2499 4271 906 (1) Members are structural steel components such'as columns, beams, and bracing.

(2) Plate elements are used to represent the concrete floors and steel roof decking.

2-2

2.3 Model Develo ment After determining vhich structural members should be included in the analysis model, the following steps were taken to develop the model:

2.3.1 Define the Model Geometry:

a. Drawings were generated which described the model geometry.
b. A global coordinate system vas established for the model (see Figure 2-1).
c. Joints (intersections'f model members) vere numbered and their x, y, and z coordinates established with reference to the global coordinate system origin.
d. Locations of model members and plate elements were described by specifying the joints on whiwh they'ere incident (member incidences).
e. . After steps a. through d. were completed and input into the computer analysis database, the model geometry was complete.

Plots of the geometry were generated by the computer to check the model geometry against the model drawings made in step a.

Some plots showing various portions of the model are contained at the end of this section.

PLANT NORTH MODEL COORDINATE SYSTEM FIGURE 2-1 Qbert /Commonwealth 2-3

Define Structural Analysis Data'.

a. Member and finite element physical properties (area, moments of inertia, etc.) and material properties (yield strength, density, modulus of elasticity, etc.) were input.
b. Beta angles, which describe the member local axis orientation with respect to the global axis, were input. This parameter is very important since it orients the strong and weak axies of a member (e.g. specifies if a column web is running north-sourth or east-west).

C ~ Member types (space truss, space frame, plane frame, etc.) were specified to represent the actual member behavior and its connection type. Also, member releases and member eccentricities were input to accurately represent the member connections.

d. Support joints were specified at the interfaces between the structures modeled and the concrete structures, and releases were input to represent support conditions.

With steps a through d input into the computer analysis database all information, except loading information, required to do a stiffness analysis of the structure was input.

2.3.3 Define Structural Loadings:

A description of the loads described below is given in Section 3.0.

a. Structural dead loads (steel, concrete slab, siding, roofing material, etc.) were input as uniform member loads, finite element surface loads or concentrated joint loads. The dead load of structural steel in the model was generated by the computer.

chert /Commonwealth 2-4

b. Service loads (systems and equipment) were determined by field surveys and were input in a manner similar to the dead loads.
c. Live loads shown on the structural drawings were input as finite element surface loads.
d. Snow loads, which are discussed in detail in Section 3.0 were input as finite element surface loads.
e. Wind and tornado loads, which are discussed in detail in Section 3.0 were also input in a manner similar to the dead loads.

The various independent loads and load combinations evaluated for this program are shown in Section 2.6.

2.3.4

~ ~ Define Design Parameters'.

a ~ Additional member physical properties (flange thickness, depth, web thickness, etc.) required for checking the structural steel members for the 1980 AISC Code (Ref. 1) requirements were input.

b. Appropriate parameters used by GTSTRUDL in performing a code check were input.
c. With the data from items a. and b. input, various code checks were made for different loading combinations using the results of the stiffness analysis.

2.4 Com uter Pro ram Descri tion The computer program GTSTRUDLwas used for structural analysis and code checking purposes. GTSTRUDL is a computer aided structural Qbert/Commonwealth 2-5

engineering software system for structural analysis and design process. It is maintained, continuously researched, and developed at the GTICES Systems Laboratory, School of Civil Engineering, Georgia Institute of Technology. The original version of ICES STRUDL-II was conceived, developed, and initially released in 1967 by the Department of Civil Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts.

The 82-02 revision of GTSTRUDL as marketed by Boeing Computer Services Company (BCSC) in Seattle,'Washington was used for the structural analysis and code checking. This version was the most up-to-date version of GTSTRUDL available through BCSC at the time the analysis was performed.

Analytic procedures apply to any combination of framed structure and continuum mechanics problems of arbitrary configuration and composition. Framed structures consist of an assemblage of one-dimensional framework. Force boundary conditions on member ends, and force and displacement boundary conditions at support joints, may be specified implicitly by means of structural type and orientation commands, or explicitly for a member or joint.

Continuum mechanics problems are treated using the finite element method in which the domain of the problem consists of an assemblage of two or three dimensional finite elements, or different shapes, .

connected at a finite number of joints. Over thirty (30) finite elements are available for the solution of plane stress/strain, plate bending, plate bending and stretching, axisymmetric, and three-dimensional solid problems. GTSTRUDL permits elements (members and finite elements) of different types to be mixed in the

.same problem solution, whether they have the same or different number of degrees of freedom per joint.

Properties of member elements may be specified by providing section properties of prismatic or variable section members, naming a section from a pre-established table of properties (such as Qbert /Commonwealth 2-6

"M14X237" or "14MF237"), or specifying flexibil.ity or stiffness matrices for special member elements. Additional conditions for members may be specified such as joint size effects, member end eccentricities from joint centers, location of shear center relative to a member's centroidal axis, etc. Finite element properties may be specified by element type, and either name and thickness, or rigidity matrix. Elastic constants may be specified for members and elements.

External influences resulting from applied forces, temperature, initial strain (fabrication error), or specified joint displacements (support movement) may be considered to act separately or in any combination as independent loading conditions. These applied loads may act on members, elements, and/or joints and may have any arbitrary orientation. Loading combinations (dependent loading conditions) may be defined as consisting of any linear combination of independent and other dependent loading conditions.

GTSTRUDL analysis procedures perform linear small displacement static and dynamic analysis of structures composed of any combination of member and finite elements with the same or variable number of degrees of freedom per joint. In addition, nonlinear geometric and material (large displacement/small strain) static analysis of framed structures may be performed.

GTSTRUDL design procedures include steel design and code checking by the 1969 and AISC 1980 Specifications for member elements. The user is provided the ability to exercise complete control over variety of design constraint conditions, similarity specifications, parameter values, etc. if he so wishes, so that he is able to perform iterative design while carefully controlling the economic and engineering feasibility of the design solution and while maintaining his role as decision maker.

Qbert /CNleOMelllh 2-7

2.5 Com uter Model 1 and 2 Geometr Plots See Sketches A-1 through A-31 2.6 , Load and Load Combinations Table for Com uter Models 1 and 2 See Tables 2-3 through 2-8.

2"8

TABLE 2-3 MODEL NO. 1 INDEPENDENT LOADS LOAD NO. LOAD DESCRIPTION Dead Loads Service Loads Live Loads Design Snow Loads Extreme Snow Loads Design Wind Loads from the North Design Wind Loads from the South Design Wind Loads from the East Design Wind Loads from the West 10 Tornado Winds from the North Tornado Winds from the South 12 Tornado Winds from the East 13 Tornado Winds from the West 14 Differential Pressure Loads Dead Load Due to Floor Beamsl 21 Live Loads Due to Floor Beamsl 22 Service Load Due to Floor Beamsl 23 Design Snow Loads Due to Floor Beamsl 24 Extreme Snow Loads Due to Floor Beamsl 25 Wind Loads from the North Due to Floor Beamsl 26 Wind Loads from the South Due to Floor Beamsl 27 Wind Loads from the East Due to Floor Beamsl 28 Wind Loads from the West Due to Eloor Beamsl 29 Tornado Loads from the North Due to Floor Beamsl 30 Tornado Loads from the South Due to Floor Beamsl 31 Tornado Loads From the East Due to Floor Beamsl 32 Tornado Loads from the West Due to Floor Beamsl 33 Differential Pressure Loads Due to Floor Beamsl 1These loads are applied to perimeter beams in the floors and roofs which do not experience load through the plate elements.

2-9

TABLE 2-4 MODEL NO. 1 LOAD COMBINATIONS FOR STRUCTURAL STEEL CODE CHECKS LOAD NO. LOAD DESCRIPTION 506 Dead Load + Live Load + Design Snow + Design Winds from the North 507 Dead Load + Live Load + Design Snow + Design Winds from the South 508 Dead Load + Live Load + Design Snow + Design Winds from the East 509 Dead Load + Live Load + Design Snow + Design Winds from the West 510 Dead Load + Live Load + Tornado Wind Loads from the North -'50 mph 511 Dead Load + Live Load + Tornado Wind Loads from the South 250 mph 512 Dead Load + Live Load + Tornado Wind Loads from the East " 250 mph 513 Dead Load + Live Load + Tornado Wind Loads from the West 250 mph 519 Dead Load + Live Load + Extreme Snow Loads 100 psf 610 Dead Load + Live Load + Tornado Wind Loads from the North 188 mph 611 Dead Load + Live Load + Tornado Wind Loads from the South " 188 mph 612 Dead Load + Live Load + Tornado Wind Loads from the East 188 mph 613 Dead Load + Live Load + Tornado Wind Loads from the West 188 mph 810 Dead Load + Liue Load + Tornado Wind Loads from the North 132 mph 811 Dead Load + Live Load + Tornado Wind Loads from the South 132 mph 812 Dead Load + Live Load + Tornado Wind Loads from the East " 132 mph 813 Dead Load + Live Load + Tornado Wind Loads from the West 132 mph 999 0.4 psi di ff press 910 DL + LL + 132 mph Wt North + 1/2 (0.4 psi diff press) 911 DL + LL + 132 mph Wt South + 1/2 (0.4 psi diff press) 912 DL + LL + 132 mph Wt East + 1/2 (0.4 psi diff press) 913 DL + LL + 132 mph Wt West + 1/2 (0.4 psi diff press)

Qbere itommonwealth 2-10

TABLE 2-5 MODEL NO. 1 LOAD COMBINATIONS FOR CONCRETE ANCHORAGES LOAD NO. LOAD DESCRIPTION 1000 0.9 Dead Load + 1.7 Design Wind from the North 1001 0.9 Dead Load + 1.7 Design Mind from the South 1002 0.9 Dead Load + 1.7 Design Wind from the East 1003 0.9 Dead Load + 1.7 Design Wind from the West 1005 0.9 Dead Load + 1.0 250 mph Tornado Wind Loads from the North 1006 0.9 Dead Load + 1.0 250 mph Tornado Wind Loads from the South 1007 0.9 Dead Load + 1.0 250 mph Tornado Wind Loads from the East 1008 0.9 Dead Load + 1.0 250 mph Tornado Wind Loads from the West 1009 0.9 Dead Load + 1.0 188 mph Tornado Wind Loads from the North 1010 0.9 Dead Load + 1.0 188 mph Tornado Wind Loads from the South 1011 0.9 Dead Load + 1.0 188 mph Tornado Wind Loads from the East 1012 0.9 Dead Load + 1.0 188 mph Tornado Wind Loads from the West 1017 0.9 Dead Load + 1.0 132 mph Tornado Mind Loads from the North 1018 0.9 Dead Load + 1.0 132'mph Tornado Wind Loads from the South 1019 0.9 Dead Load + 1.0 132 mph Tornado Wind Loads from the East 1020 0.9 Dead Load + 1.0 132 mph Tornado Wind Loads from the West

~ /Qmmonwulth 2-11

TABLE 2-6 MODEL NO. 2 INDEPENDENT LOADS LOAD NO. LOAD DESCRIPTION Dead Load Design Snow Load Extreme Snow Load Column Loads Due to Design Wind from the North Column Loads Due to Design Wind from the South Column Loads Due to Design Wind from the East Column Loads Due to Design Wind from the West Roof Loads Due to Design Wind in Any Direction Column Loads Due to Tornado Winds from the North 250 mph 10 Column Loads Due to Tornado Winds from the South 250 mph Column Loads Due to Tornado Winds from the East " 250 mph 12 Column Loads Due to Tornado Minds from the West " 250 mph 13 Roof Loads Due to Tornado Winds from the North or South 14 Roof Loads Due to Tornado Winds from the East or West 15 Tornado Differential Pressure Loads Qbcrc /Commonwealth 2-12

TABLE 2-7 MODEL NO. 2 LOAD COMBINATIONS LOAD NO. LOAD DESCRIPTION 200 Dead Load + Design Snow Load + Design Wind from the North + Roof Loads Due to Design Wind in Any Direction 300 Dead Load + Design Snow Load + Design Wind from the South + Roof Loads Due to Design Wind in Any Direction 400 Dead Load + Design Snow Load + Design Wind from the East + Roof Loads Due to Design Wind in Any Direction 500 Dead Load + Design Snow Load + Design Wind from the West + Roof Loads Due to Design Wind in Any Direction 600 Dead Load + Column Loads Due to Tornado Winds from the North or South 6 250 MPH 700 Dead Load + Column Loads Due to Tornado Winds from the South +

Roof Loads Due to Tornado Winds from the North or South Q 250 MPH 800 Dead Load + Column Loads Due to Tornado Winds from the South +

Roof Loads Due to Tornado Winds from the East or West 6 250 MPH 900 Dead Load + Column Loads Due to Tornado Winds from the West +

Roof Loads Due to Tornado Winds from the East or West 6 250 MPH 1000 Dead Load + Extreme Snow Load Mert ICommomaealth 2-13

TABLE 2-8 MODEL NO. 2 LOAD COMBINATIONS FOR CONCRETr. ANCHORAGES LOAD NO. LOAD DESCRKPTTON 1100 Dead Load + Live Load + Tornado Wind Loads from the North 188 mph 1200 Dead Load + Live Load + Tornado Wind Loads from the South

'188 mph 1300 Dead Load + Live Load + Tornado Wind Loads from the East-188 mph 1400 Dead Load + Live Load + Tornado Wind Loads from the West 188 mph 1900, Dead Load + Live Load + Tornado Wind Loads from the North 132 mph 2000 Dead Load + Live Load + Tornado Wind Loads from the South "

132 mph 2100 Dead Load + Live Load + Tornado Mind Loads from the East "

132 mph, 2200 Dead Load + Live Load + Tornado Wind Loads from the West 132 mph 2300 0.9 Dead Load + 1.7 Wind Loads from the North for Anchorage Evaluation 2400 0 ' Dead Load + 1.7 Wind Loads from the South for Anchorage Evaluation 2500 0.9 Dead Load + 1.7 Wind Loads from the East for Anchorage Evaluation 2600 0.9 Dead Load + 1.7 Wind Loads from the East for Anchorage Evaluation 2700 0.9 Dead Load + 1.0 250 mph Tornado Mind Loads from the North-Anch. Eval.

2800 0-9 Dead Load + 1.0 250 mph Tornado Wind Loads from the South-Anch. Eval.

2900 0.9 Dead Load + 1.0 250 mph Tornado Wind Loads from the East Anch. Eval.

G4ert

/Commonweal'-14

TABLE 2-8 MODEL NO. 2 LOAD COMBINATIONS (Cont'd)

LOAD NO. LOAD DESCRIPTION 3000 0.9 Dead Load + 1.0 250 mph Tornado Wind Loads from the West-Anch. Eval.

3100 0.9 Dead Load + 1.0 188 mph Tornado Wind Loads from the North Anch. Eval.

3200 0.9 Dead Load + 1.0 188 mph Tornado Wind Loads from the South-Anch. Eval.

3300 0.9 Dead Load + 1.0 188 mph Tornado Wind Loads from the East-Anch. Eval.

3400 0.9 Dead Load + 1.0 '188 mph Tornado Wind Loads from the West "

Anch. Eval.

3900 0.9 Dead Load + 1.0 132 mph Tornado Wind Loads from the North-Anch. Eval.

4000 0.9 Dead Load + 1.0 132 mph Tornado Wind Loads from the South "

Anch. Eval.

4100 0.9 Dead Load + 1.0 132 mph Tornado 'Wind Loads from the East-Anch. Eval.

4200 0~9 Dead Load + 1.0 132 mph Tornado Wind Loads from thd West Anch. Eval.

5001 Dead Load + 250 mph Tornado from North + 1/2 (1.5 psi tor.

.dif. press.)

5002 Dead Load + 250 mph Tornado from South + 1/2 (1.5 psi tor.

dif. press.)

5003 Dead Load + 250 mph Tornado from East + 1/2 (1.5 psi tor.

dif. press.)

5004 Dead Load + 250 mph Tornado from West + 1/2 (1.5 psi tor.

dif. press.)

5005 Dead Load + 1.5 psi Tornado diff. pressure 6001 Dead Load + 188 mph Tornado from North + 1/2 (0.8 psi tor.

dif. press.)

2-15

TABLE 2-8 MODEL NO. 2 LOAD COMBINATIONS (Cont'd)

LOAD NO. LOAD DESCRIPTION 6002 Dead Load + 188 mph Tornado from South + 1/2 (0.8 psi tor.

dif. press.)

6003 Dead Load + 188 mph Tornado from East + 1/2 (0.8 psi tor.-

dif. press.)

6004 Dead. Load + 188 mph Tornado from West + 1/2 (0.8 psi tor.

dif. press.)

6005 Dead Load + 0.8 psi Tornado dif. pressure 8001 Dead Load + 132 mph Tornado from North + 1/2 (0.4 psi tor.

dif. press.)

8002 Dead Load + 132 press' mph Tornado from South + 1/2 (0.4 psi tor.

dif. press.)

8003 press' Dead Load + 132 mph Tornado from East + 1/2 (0.4 psi tor.

dif. )

8004 Dead Load + 132 mph Tornado from West + 1/2 (0.4 psi tor.

dif. )

8005 Dead Load + 0.4 psi Tornado dif press.

2-16

ANALYSIS AND RESULTS GENERAL ASSUMPTIONS The following assumptions were made in the analyses and evaluation of the structures:

a. The concrete foundations and structures are adequate to provide supports for the steel framing.
b. Metal siding and roof decking remains attached to the main steel frame for all load conditions.
c. Concrete masonry block walls remain intact for all load conditions.

'. Roofs and floors act SEVERE WEATHER PHENOMENA USNRC SEP as diaphragms in their Topic II-2.A discusses Severe Weather Phenomena.

own planes.

The effects of extreme environmental snow load is the only phenomena described in the topic which has been an issue with the USNRC for the Ginna Structures.

3.2.1 'xtreme Snow Loads - S'n The extreme environmental snow load used for the Ginna plant is 100 psf in accordance with SEP Topic II-2.A.

3.3 WIND AND TORNADO LOADS USNRC SEP Topic III-2 discusses the wind and tornado loadings on the Ginna structures. Wind and tornado parameters for this review are given in SEP Topic II-2.A.

Qbere/Commonwealth 3-1

The USNRC presented, in a report titled 'Wind and Tornado (Ref. 2), the expected values for tornado windspreed Loadings'ER-C5257-400 for the Ginna Station region.

3 ~3 ~ 1 Tornado Wind Loads Ww A design tornado wind of 250 mph with a core radius of 150 ft. to the point of maximum velocity was used as a reference tornado.

Additional windspeeds of 188 mph and 132 mph were also applied to the Ginna Plant structures using procedures provided in ANSI A58.1-1982, (Ref. 3), with the exception of the gust factors since design tornado winds are. based on damage resulting from peak winds'he velocity (V) and velocity pressure (q) were assumed not to vary with height. Wind velocity was converted to wind pressure by the equation q = 0.00256 V For the main wind force resisting systems, the horizontal tornado pressure..profile was positioned on the plant so as to achieve the maximum average pressure over each side. Once this pressure was determined, ANSI A58.1-1982 wind coefficients, Cp, were applied to obtain pressures on the structures. The design pressure, p, equals qCp where q = 0.00256 V For local components and cladding, the tornado pressure equals qGCp qGCpi as defined in the ANSI Code. In the first term, q was determined as described previously (0.00256 V2 where V is the maximum average). However, the tornado pressure profile was positioned to obtain the maximum pressure over the component, not the entire building wall. Because the tributary surface area providing component loading was very small in most cases, the average peak pressure was approximately 160 psf (0.00256 x 250 ) for many components. This pressure was then multiplied by the appropriate local coefficient, GCp, as provided in ANSI A58.1-1982.

The q in the second term of the equation was determined by applying the tornado pressure profile to achieve the maximum average pressure 3-2

on the wall affecting the component or cladding. This pressure was then multiplied by GCpi = +0.25 from the ANSI Code. The total pressure equals qGCp - qGCpi. To eliminate the gust factor from this equation, the two-second gust wind speed, on which a tornado is based, was estimated from a 40 to 60 second fastest~ile wind speed for a 75 mph wind (on which the ANSI coefficients are based) ~ The two-second gust was approximately 1.22 times the fastest~ile wind.

Therefore, the total pressure was obtained by dividing qGCp qGCpi by 1.22 to get the tornado design pressure for local components and cladding.

The preceding pressures can easily be adjusted for any tornado wind by factoring the final design pressure by V /(250) , where V is the desired tornado wind speed.

Table 3-1 shows the basis for choosing design tornado windspeed.

This table was taken from the Texas Tech Report (Ref. 4).

TABLE 3-1 TORNADO HAZARD PROBABILITIES WITH 95X CONFIDENCE LIMITS Hazard Tornado Winds eed MPH Mean Recurrence Probability Expected Lower Upper Interval ( ears) Per Year Value Limit Limit 10,000 1.0 x 104 40 40 46 100,000 1.0 x 10 5 68 40 132 1,000,000 1.0 x 10 6 135 90 188 10,000,000 1.0 x 10 7 172 135 247 The structures were investigated for 250, 188, and 132 mph tornado wind speeds.

Tornado Differential Pressure W P

Differential pressure is caused by a rapid atmospheric pressure drop, and can effect a closed structure. This differential pressure 3-3

varied with the tornado wind speed as shown in Table 3-2 and can be estimated by the equation hp = 0.00512 V (Ref. 16), where V is the translational component of the tornado windspeed.

TABLE 3-2 TORNADO DIFFERENTIAL PRESSURE AT VARIOUS TORNADO WINDSPEEDS Tornado Differential Rate of Pressure Winds eed (MPH) Pressure W ( si) Dro ( si/sec) 250 1.5 0.75 188 0.8 0.35 132 0.4 0.1 3.4 DESIGN LOADS SEP Topic II-2.A, and SEP Topic III-2 are evaluated by means of computer programs.

Since design loads, such as D, L, To, W, Sn, and Ro are part of load combinations which would produce severe environmental loads, they were calculated and included in the computer analyses.

3.4.1 Dead Load D:

Dead loads applied to the computer model elements include the weight of the structure, the weight of permanently supported equipment (such as tanks, pumps, and electrical cab'inets) and systems components (such as piping, cable tray, conduit and ductworks.)

Dead loads were determined from the construction drawings and field inspections. The field inspections were performed to establish the weight of equipment and systems as well as their distributions.

These loads are referred to as service loads in the independent load cases'n the load combinations, service loads are part of the dead loads.

Gi1bert/Commonwealth 3-4

3.4.2

~ Live Load

~

- L:

The live loads used in the evaluation are the uniform live lo'ads as shown on the plant construction drawings.

Crane lifted loads are not considered in the evaluation.

3.4.3 Thermal Effects To:

Based on engineering judgement, thermal effects and loads during normal operation or shutdown conditions are assumed to be 2.5 percent of dead load for this program and are included in the independent loads and load combinations as a part of the dead load.

3.4.4 Pi e Reactions - Ro:

Pipe reactions during normal operating or shutdown conditions for main steam and feedwater systems are included in the evaluation.

Based on engineering judgement, other pipe reactions during normal operating or shutdown conditions are assumed to be 2.5 percent of dead load for this program, and are included in the independent load cases and combinations as a part of the dead load.

3 ' ' Wind Load W:

The design wind speed for the Ginna Plant is obtained from Figure 1 of ANSI A58.1-1982 (Ref. 3). This figure shows the fastest~ile windspeed at 33 ft. above grade to be 70 mph with a 50 year recurrence interval. This is modified to a 100 year interval to comply with NUREG-0800 (Ref. 5) by increasing the velocity using an importance factor, I, equal to 1.07. The design wind speed then becomes 75 mph at 33 ft. above ground with a 0.01 annual probability of occurrence.

The main wind force resisting systems are designed using exposure category D in the ANSI Code.

Wind velocity is converted to an equivalent pressure using the procedures described in ANSI. Pressures are then applied, to the analytical model as positive or negative uniform loads. Positive pressures are applied to those surfaces in the direct path of the wind direction while negative pressures are applied to the exterior side walls, exterior leeward walls and roofs.

Components and cladding on structures are evaluated using local pressure coefficients obtained from charts in the ANSI Code.

3.4.6 Snow Loads - Sn:

4 The design snow load for the evaluation of the Ginna Plant structures is based on the ANSI A58.1-1982 (Ref. 3).

' Based upon the ANSI Code, the ground snow area, which has a mean for the Rochester, NY recurrence interval (MRI) of 50 years, is 40 psf. However, the equivalent 100 year snow is obtained by applying an importance factor of 1.2, an exposure factor of 1.0 and a thermal factor of 1.0 to the 50 year snow. This converts to a flat roof snow load of 34 psf for the main plant structures. Using the same approach but using an exposure factor of 0.8 due to its exposed position, the uniform flat roof snow load of the Screen House is computed to be 27 psf. The height of the uniform snow load is taken as the uniform snow load divided by a density of 20 pounds per cubic foot obtained from the ANSI Code.

3.4.7 Load Combinations Since the whole intent of the SEP program is to assess the behavior of the Ginna structure, for load conditions not considered in the 3-6

original design, the following terminology will 'be adopted in evaluating the effects of the load combinations in this study.

1. Severe Load Condition - This load represents the combination of dead load, live load, design snow load and design wind load.

The combination of a 100 year recurrence wind and 100 year recurrence snow represents an event having an annual probability of occurrence in the range of 10 4. Therefore, the combination is referred to as a severe loading condition.

This load condition is not specifically identified in the SEP topics but will be incorporated in this evaluation.

2. Extreme Snow Load This load description represents the combination of dead load, live load, and the extreme snow load, which is the subject of SEP Topic II-2.A.
3. Tornado Load Load combinations that include dead load, live loads and tornado created loads will be referred to as tornado loads. This condition will consider the effects of tornado winds and tornado differential pressure.

EVALUATION AND RESULTS This section discusses the evaluation of the structures and provides the results of this evaluation. It is divided into two parts, Global Systems and Local Systems; Global Systems deals with items which were evaluated either directly by computer Models 1 and 2 or using results obtained from them. Local Systems deals with items that were not part of the computer Models 1 and 2.

3-7

3.5.1 Global S stems

.5.1.1

~ ~ ~ Primary Members Primary members were defined as those members included in computer Models 1 and 2.

The GTSTRUDL computer program was used to check the members for AISC 1980 Code (Ref. 1) compliance. "

This program outputs the results of member code checks and indicates if the member is in full compliance or overstressed per AISC 1980 Code.

+Computer Models 1 and 2 include approximately 4250 members (1800 tons). Table 3-3 and Table 3-4 summarize the results of the study for primary members.

Table 3-3 shows the number and tonnage of overstressed members "

included in Model 1. Load Case 1 shows the impact of extreme snow load, S', and load case 2 shows the effect of design snow and design wind combination, on the Model 1 structures. Loading Cases 3 through 5 show the effect of tornado loads at various speeds. An acceptance criteria of 1.6 S was used for all load cases. The rationale for this is the fact that the probability of occurrence is approximately equal to an SSE, E', probability, and therefore 1.6 S is used as the acceptance criteria.

Figures 3-1 to 3-3 are graphical representations of the influence of each one of the load conditions that are considered for this evaluation. The data shown in anyone cirle represents the amount of overstressed members for that one loading combination. -The results of any two load combination is pr'esented by the intersection of two of the circles, and for influence of the three load conditions by a three circle intersection.

Mbelt ICommonweallh 3-8

Table 3-4 shows the number and tonnage of overstressed members in Model 2, Screen House. Except for the load combination which included the 2SO mph tornado load, the number and tonnage of overstressed members are small.

Prominent modes of overstressing are listed below.'.

Slenderness ratio: Members do not comply with the provisions of AISC 1980 governing slenderness ratio, KL/r.

2. Unbraced length of compression flange: When the wind or tornado suction loads were applied to roof members the resultant load direction changed, resulting in the bottom flange being in compression. Since the bottom flange of roof members are not laterally braced, the allowable bending stress is reduced significantly.
3. Increased 1'oads: Extreme snow, and tornado loads were not considered in the original plant design.

Qbert/Coernonweat&

3-9

LE 3-3 COMPUTER MODEL 1 PRIMARY MEMBER EVALUATION X of Number of X of Tonnage of Overstressed Acceptance Overstressed Overstressed Overstressed Members Loadin Case Criteria Members Members Members 1 ~ D + L + S n (100 psf) 1.6 S 137 3.9X 53 tons 3.2X 2~ D+ L+ Sn + W(3) 1.6 S 160 4.6X 57 tons 3.4X

3. D+ L+ Wt( ) (132 mph) 1.6 S 236 6.8X 79 tons 4.7X
4. D+ L+ (2) (188 mph) 1.6 S 283 8.1X 90 tons 5.4X
5. D+ L+ Wt(2) (250 mph) 1.6 S 485 13.9X 162 tons 9.7X R

K (1) This model includes Turbine Building, Control Room, Intermediate Building, Facade Structure, and Auxiliary Building. It has approximately 3500 members (1666 tons). Local members such as girts and purlins are not included here.

(2) Wt = Ww, or Wt = Wp, or Wt = Ww + 0.5 Wp, whichever is worse.

(3) Includes two (2) loads which have a 100 year mean occurrence interval each. This is in the range of a 10 4 probability.

E 3-4 COMPUTER MODEL 2 PRIMARY MEMBER EVALUATION X of Number of X of Tonnage of Overstressed Acceptance Overstressed Overstressed Overstressed Members Loadin Case Criteria Members Members Members B Wei ht

1. D iL + S'100 psf) 1.6 S 0.5X 0.25 tons 0.2X
2. D + L + Sn + W 1.6 S 1.0X 0.1 tons 0.1X
3. D + L + Wt( ) (132 mph) 1.6 S 24 3 ~ 1X 1.9 tons 1.4X
4. .

D + L + Wt(2) (188 mph) 1.6 S 49 6.3X 3.8 tons 2.8X

5. D + L + Wt( ) (250 mph) 1.6 S 173 23.0X 33.0 tons 25.0X (1) This model includes the Screen House only. It has 766 members (134 tons). Local members such as girts, purlins are not included herein.

(2) Wt Ww> or Wt Wp > or Wt Ww + 0 ~ 5 Wp > whichever is 'orse.

(3) Includes two (2) loads which have a 100 year mean occurrence interval each. This is .in the range of a 10 4 probability.

S'> = 100 psf, Wt = 132mph(3)

O+ L+ S+ W(>)

17 Memb.

10 Tons 11 Memb. 53 Memb.

4Tons 13 Tons 87 Memb.

30 Tons 0 + L + S'(>) 0+ L+ W<(2) 13 Memb. 30 Memb. 88 Memb.

5Tons 14 Tons 24 Tons Number of Overstressed Members = 299 Weight of Overstressed Members = 100 Tons (1) The following buildings are included: Turbine Building, Screen House, Control Building, Facade Structure, Intermediate Building, and AuxiliaryBuilding.

(2) Acceptance Criteria = 1.6S (3) Includes tornado wind load, Wuh and tornado differential pressure load, Wp.

OVERSTRESSEO PRIMARY MEMBERS Local Members (girts and purlins) not included Figure 3-1 3-X2,

S'= 100 psf Wt = 188 mph(3) I D + L+ S+ W(>)

13 Memb.

9 Tons 9 Memb. 57 Memb.

3 Tons 14 Tons 89 Memb.

31 Tons D + L + S'(2) D+ L+ Wt(>)

12 Memb. 31 Memb. 155 IVlemb.

4Tons 15 Tons 34 Tons Number of Overstressed Members = 366 Weight of Overstressed Members = 110 Tons (1) The following buildings are included: Turbine Building, Screen House, Control Building, Facade Structure, Intermediate Building, and Auxiliary Building.

(2) Acceptance Criteria = 1.6 S (3) Includes tornado wind load, Ww, and tornado differential pressure load, WP.

OVERSTRESSED PRIMARY MEMBERS Local Members (girts and purlins) not included Figure 3-2 3-13

S'= 100 psf

=

Wt 250 mph(3)

D+ L+ Sn + W(2) 13 Memb.

9 Tons 8 Memb. 57 Memb.

3 Tons 14 Tons 90 Memb.

31 Tons D+I.+S (2) D+ L+ Wt(>)

12 Memb. 31 Memb. 480 Memb.

4Tons 15 Tons 135 Tons Number of Overstressed Members = 691 Weight of Overstressed Members = 211 Tons (1) The following buildings are included: Turbine Building, Screen House, Control Building, Facade Structure, Intermediate Building, and Auxiliary Building.

(2) Acceptance Criteria = 1.6 S (3) Includes tornado wind load, Ww, and tornado differential pressure load, Wp.

OVERSTRESSED PRIIVIARYMEMBERS Local Members (girts and purlins) not inclu'ded Figure 3-3 3-14

0 3.5.1.2 Connections The evaluation of connections was'ccomplished by first identifying the individual connections included in Models 1 and 2. All attachments of one structural steel member to another, with the exception of column splices, were considered connections.

Approximately 5000 such unique connections were identified.

The use of a statistically random sample of these connections was used to evaluate these connections.

The sample size required to provide a given confidence level is calculated using the hypergeometric as the sample distribution, since sampling is without replacement. The probability density function of the hypergeometric distribution is given by:

p(n,n,k,x) = "......................

(kf LN-k) p)

())

where N = Number of items in the population Number of items in the sample Number of defective items in the population Number of defective items in the sample The probability of finding c or fewer defectives in the sample is:

P(N,n,k,c) = E p(N,n,k,x) ~ ~ ~ ~ ~ ~ (2) x=0 The sample size n is determined by the inequality:

P(N,n,k,c) < 91 . . . . . . . . . . . . . . . . . . . . . . . . (3)

Qbert Io)mmonwes(th 3-15

where 1 - 91 is the required confidence level.

The sample size is a function of the confidence level, the defect rate in the population, and the number of defects in the sample.

The sample sizes used were based on the following values for these parameters:

Confidence level = 95Z Defect rate = 5Z Sample defects = 0 Equation (3) was solved iteratively using these parameters and the population for the given population.

Using the procedure above, a random sample of 60 connections was selected from this population. The sample size of 60 was determined to represent a 95 percent confidence level that the defect rate would not exceed 5 percent for,the entire population, if all 60 of the samples were found to be acceptable.

The 60 random sample connections were then evaluated for 8 different loading combinations; 3 normal type loadings and 5 extreme type loadings. Due to the low probability of occurrence for the extreme loading cases, the allowable stresses for these loadings were increased by a factor of 1.6. The actual values used for the loads were taken from the models output.

The connections were evaluated to the design requirements and allowable stresses given in the AISC 1980 Code (Ref. 1). Truss connections and other axially loaded connections were evaluated manually. Beam-to-column double clip angle connections were Qbert/Commonwealth 3-16

evaluated using a computer program especially developed for this evaluation.

The results of the evaluation are shown in Table 3-5. Most of the overstressed connections shown in this table are clip angles subject to wind induced axial tension loads. Since this type of connection is not normally designed for simultaneous axial and vertical loads, no clearly defined AISC acceptance criteria exists. Therefore, criteria employing combined shear-tension interaction equations were developed especially for this evaluation.

3-17

TABLE 3-5 RESULTS OF CONNECTIONS EVALUATION TOTAL NUMBER OF CONNECTIONS CHECKED = 60(

Sam le Results Population Defect Acceptance Acceptable Overstressed Rate at 95X Total Number of Load Case Criteria Connections Connections Confidence Level Defective Connections

1. D + L + S'n 1.6 S 58 11X 548 2e D + L + Sn + W 1 ~6 S 58 11X 548
3. D + L + Wt (132 mph)(2) 1.6 S 57 13X 647
4. D + L + Wt (188 mph)(2) 1.6 S 52 23X 1145 D + L + Wt (250 mph)(2) 1.6 S 16 39X 1942 (1) Total population of connections for Computer Model 1 and Model 2 is 4980.

(2) Wt = W>> or Wt = Wp, or Wt = Ww + 0.5 W>> whichever is worse.

3.5.1.3 Anchorages The computer models of the plant structures (Models 1 and 2) contain 219 supports. These supports consist of column and beam/truss anchorages.

Using a statistical approach similar to that used for the connections, 53 randomly selected supports were chosen from the population of 219 supports.

The capacity of each support was checked, using the current code allowables against the applied support reactions from the computer output.

The following elements were reviewed:

a. The capability of the column to base plate connection to transfer applied loads.
b. The capacity of the anchor bolt in shear plus tension compared to applied loads.

C ~ The ultimate capacity of the concrete based on the embedment depth, spacing of bolts and edge distance, as defined by ACI 349-80 (Ref. 6), Appendix B, was calculated. If the requirements of ACI 349-80 were met, the anchorage was considered acceptable. If ACI 349"80 requirements were not met, but the applied loads were less than the ultimate concrete capacity, the anchorage was still considered acceptable. If the applied loads were greater than the ultimate concrete capacity, the anchorage was considered overstressed.

In other words, a support was not considered overstressed just for not meeting the "ductile failure" requirements of ACI 349-80.

3-19

Support reaction load summary sheets were prepared, from the computer output, for the 53 support anchorages. The reactions from the load combinations for dead load plus wind load from various directions and dead load plus the tornado loads from various directions were used in the comparison with anchorage capacities.

The evaluation of support anchorages for extreme snow load condition is not required since the effects only increase the downward reactions which are not the'controlling load combinations for the design of supports or anchorages.

The results of the load/capacity comparison for the 53 anchorages are shown in Table 3-6. This table shows the number of overstressed anchorages for the various elements and load combinations. The last column in Table 3-6 is a statistical projection of the expected percentage of overstressed anchorages in the total population.

3-20

0 TABLE 3-6 RESULTS OF ANCHORAGE EVALUATION TOTAL NUMBER OF ANCHORAGES EVALUATED = 53 Sam le Results Defect Rate Acceptance Acceptable Overstressed at 95X I. ANCHOR BOLT SIZE Load Case 0 'D + 1.7 W Y 48 5 18X 0.9D + 1.0 132 Wt Y 48 5 18X 0.9D + 1.0 188 Wt Y 35 18 50X 0.9D + 1.0 250 Wt Y(1) 22 31 75X II'OLUMN TO BASE PLANT CONNECTION Load Case 0.9D + 1 ~0 W 1.6 S 53 0 5X 0.9D + 1 ' 132 W 1.6 S 50 3 13X 0.9D + 1.0 188 Wt 1.6 S 45 8 27X 0.9D + 1.0 250 Wt 1.6 S 34 19 53X III. CONCRETE CAPACITY Load Case 0.9D + 1.7 W 48 5 18X 0.9D + 1.0 132 Wt U 49 4 16X 0 'D + 1.0 188 Wt U 49 9 30X 0.9D + 1.0 250 Wt U(2) 37 16 46X Total Population of Anchorages = 219 (1) Y = Strength of steel embedment per ACI 349 Appendix B (2) U = Concrete strength per ACI 349 Qbert/Commonwealth 3-21

3.5.2.1 Local Members Local members were defined as girts and purlins only. Local floor beams were not investigated in this evaluation.

Girts and purlins were analyzed and checked for AISC 1980 Code (Ref. 1) compliance using the GTSTRUDL computer program. A total of 70 typical members were investigated. This represents 1050 members or approximately 95 percent of the girts and purlins.

Snow and extreme snow loads were calculated as described in Section 3.0. Local wind and tornado loads were determined in accordance with ANSI A58.1-1982 (Ref. 3). Wind and tornado load requirements of ANSI A58.1-1982 on local members, such as girts and purlins, are

- much more severe than wind and tornado load requirements on the overall structure. Local loads determined per ANSI 58.1-1982 were two to three times higher than the loads for the overall structures.

Results of local member evaluations are shown in Table 3-7. It was assumed that local panels, i'.e., siding and roof decking would stay in place to transfer the loads to the girts, and purlins under positive pressure loads.

Overstressing for tornado loads was due to upward loads (suction) on the purlins and leeward loads (suction) on the girts. For both the purlins and girts, the unbraced length of the compression flange is equal to the full member length for suction loads only.

3-22

TABLE 3-7 OVERSTRESSED LOCAL MEMBERS(1)

(GIRTS, PURLINS)

Number of X of Tonnage of Acceptance Overstressed Overstressed Overstressed Loadin Case Criteria Members Members , Members 1 ~ D + Sn (100 psf ) 1.6 S 21

2. D + Wt (132 mph) ( 1.6 S 640 61X 139
3. D + Wt (188 mph)(2) 1.6 S 805 77X . 179 4~ D + Wt (250 mph)( 1.6 S 983 94X 204 (1) The following buildings are included: Screen House, Diesel Generator Building, Turbine Building, Control Room, Facade Structure, Intermediate Building, Auxiliary Building. A total of 1050 members were evaluated.

This represents approximately 95 percent of all the girts and purlins.

(2 ) Tornado loads on the roofs are upward.

Wt Ww~ or Wt Wp, or Wt w + 0.5 Wp whichever is worse.

3-23

3.5.2.2 Metal Siding Systems The three types of siding that exist at the Ginna Plant, as manufactured by the E. G. Smith Corporation, are the "B" panel system, ribwall, and shadowall. The ribwall panel system is located on the middle portion of the four sides of the facade structure while the corners of the facade consist of the shadowall panels.

The rest of the plant is convered by the "B" panel system.

In order to determine the various siding capacities a test procedure was developed and a test program was implemented. Pittsburg Testing Laboratory was contracted to do the tests. A two-span test model having 7 ft. spans with C 12 x 20.7 supports was used. The spans were loaded uniformly to represent tornado wind loading by means of a vaccum chamber. The test configuration and siding installation was based on the plant siding construction drawings with a field verification being made at the plant to insure that the test material was installed the same as the 'existing plant condition.

An engineering comparison was made between the two-span test condition and the three or more span conditions typically existing I

at the plant. Using this analysis and the method of failure that was observed during testing, it was determined that no adjustment to the test values was required for them to accurately represent the plant conditions.

A total of six tests wer'e performed on each panel system. The six tests consisted of three positive and three negative pressure loadings ~ The positive tests represented a wind load from the .

outside of the structure while the negative tests represented pressure from the inside of the structure or a suction from the outside. Each panel system was tested to failure. Failure was defined as loss of function of the siding resulting from tearing or failure of any or all the panel connectors. The test failure loads and the method of failure are shown i'n Table 3-8 and in Attachment D to the RG6E Report (Pittsburg Testing Laboratory Report "Uniform Qbcrt/Commonweslth 3-24

TABLE 3-8 SIDING TEST RESULTS Initial Buckling Failure Failure*

S stem Load ( sf) ~Load ( sf) Load (MPH) Failure Mode Ribwall + 75-85 156-180 246+ Edge Tore &

Lifted Ribwall 80-92 90-115 187+ Pulled Pulled Through Through at at Center Fastener Support (no buckling)

Shadowall + 60-70 180-187 265+ Edge Tore at Maximum Machine Capacity Shadowall 67-74 91-92 188 Pulled Pulled Through Through at at Center Fastener Support (no buckling) u"B"u System + 65-75 125 220 Mainly Fastener Pulled Through.

Some Fasteners Sheared.

IIBll Sy p50%+ 80-95 176+ Fasteners Pulled Through Conversion of pressure loading in PSF to velocity loading in MPH by V =

This value does not indicate the application of wind speeds to buildings.

~ Deflection curves are linear up to maximum reading (at 50 PSF)

Stclt I CtNIIMIIWSII!h 3-25

Load Test on Wall Panels" ). Load vs. deflection curves for each test panel are also shown in Attachment D.

Using the minimum tested capacities as the field condition capacity, the ultimate siding loads are as shown in Table 3-9 below.

TABLE 3-9 SIDING PANEL SYSTEM CAPACITIES Loading Pressure Corresponding Sidin S stem ~Load in Velocit Ca acit "B" Panel System positive 125 psf 221 MPH negative 80 psf 176 MPH Ribwall positive 156 psf 246 MPH negative 90 psf 187 MPH Shadowall positive 180 psf 265 MPH negative 91 psf 188 MPH Based on the minimum capacities of the tested panels the equivalent tornado winds were established. In ANSI A58.2-1982 local pressure coefficients are*prescribed for various locations on a building.

Figure 3-4 shows these regions. The pressure coefficients were modified to eliminate the gust factor effect. Siding capacities were essentially equated to the modified pressure coefficients times the square of the velocity. The equivalent tornado velocity in miles per hour was then achieved.

In order to determine the tornado wind speed Wt capacities were calculated with and without differential pressure effects as shown in this equation.

Wt Ww or Wt Wp or Wt Ww + 0 5 Wp Tables 3-10 and 3-11 show the actual tornado wind speeds that different areas of the plant can resist assuming vented and non-vented structures.

Qbert/Couth 3-26

<V Ag m

C C ln Q 0 0 Ul Ul 22O~

aaa QJ QJ aaa CC a 20 42 40

~<r I 0

Z I

I I

&M Ga~ ICOemeWCSIO

TABLE 3-10 MAXIMUM ALLOWABLE TORNADO WINDSPEEDS FOR VARIOUS SIDING SYSTEMS ON VENTED STRUCTURES

'Ne ative Sidin S stem Positive R~eion 1 ~Re ion 2 ~Re ion 3 ~Re ion 4 (mph) (mph) (mph) (mph) (mph)

Ribwall (Facade) 267 187 150 129 Shadowall (Facade) 287 188 151 129 "B" System (Turbine Bldg. 6 High Aux. Bldg.) 239 176 141 121 "B" System (All Others) 220 169 161 TABLE 3-11 MAXIMUM ALLOWABLE TORNADO WINDSPEEDS FOR VARIOUS SIDING SYSTEMS ON NON-VENTED STRUCTURES Ne ative Sidin S stem Positive R~eion 1

~Re ion 2 ~Re ion 3 'R~eion 4 (mph) (mph) (mph) (mph) (mph)

Ribwall (Facade) 267 187 150 129 Shadowall (Facade) 287 188 151 129 "B" System (Turbine Bldg. 6 High Aux. Bldg.) 239+ 138 119 106 "B" System (All Others) 220+ 135 130

  • Note Regions 1 to 4 correspond to various Regions defined in ANSI A58.1-1982 Qleoloanmonecee 3-28

e As seen from the Maximum Allowable Tornado Wind Speed, on vented structures, that with modifications to Regions 3 and 4, the plant could resist tornado wind speeds of up to 160 MPH.

When looking at the building exteriors as non-vented structures it can be seen that Regions 2, 3, and 4 fail at varying wind speeds.

This in itself provides an existing venting'echanism.

Modifications to increase capacities for the "B" panel system are relatively minor and require the installation of additional fasteners. For the ribwall and shadowall, both of which are used only on the facade structure, modifications would be of no benefit.

3-29

3.S.2.3 Roof Decking Systems In the evaluation of the Ginna structures for the subject SEP topics, loads were input assuming that the roof decking would ~emain intact. A study was made to determine whether the decking system would support the subject loads as installed, or if it would require modifications to do so.

The roof decking system used at Ginna is made from ribbed sheet steel which is welded to structural roof steel. The decking generally covers two or more spans. The decking is covered with a built up type roof material.

The load carrying capability of the decking system is dependent on the strength of the decking and also on the strength of the connection of the decking to the structure.

The capacity of the decking was determined using the section properties recommended by the manufacturer, and the yield strength of the material as the bending strength of the section.

Table 3-12 compares the calculated capacity of the decking with the SEP loads evaluated in this program. The decking was determined to be strong enough to resist the upward suction loads from a 132 mph tornado for all buildings listed. For the 100 psf extreme environmental snow loads the roof decking was found to be adequate to support the loads for all buildings except the Diesel .Generator Building.

The metal roof decking was welded to the structural roof steel. The weld used for the purpose of decking attachment was a puddle or plug type weld. The AISC 1980 Code (Ref. 1) does not permit tension perpendicular to the faying surfaces for plug welds. Therefore these connections cannot be used to resist uplift loads. The uplift capacity of the connections cannot be calculated with any degree of confidence without further investigation andlor testing.

Qbert /Commonwealth 3-30

TABLE 3-12 ROOF DECKING SYSTEMS EVALUATION(1)

Extreme Loads(3)

S'n Building Number of Spans Decking Capacity (100 psf) Wt (250 mph) Wt (188 mph) Wt (132 mph)

Turbine +144 +100 -252 "139 -69 Intermediate +173 +100 -216 -115 -58 a173 +100 -216 -115 -58 al91 +100 -216 -115 -58 Auxiliary +107 +100 -275 "152 -76 al34 +100 "275 -152 -76 I

Diesel Generator +83 +100 -280 -155 -77 Screen House F117 +100 -283 -157 -78 al34 -283 -157 -78

'100 al57 +100 -283 -157 -78 (1) All loads and capacities are given in pounds per square foot (psf).

(2) Decking capacity is calculated at first yield.

(3) Extreme environmental load, S'n, does not include drifting. Tornado load, Wt, includes tornado wind load, Wwf and tornado differential pressure load, Wp + means loads are acting downward, - means loads are acting upward.

3.5.2.4

~ ~ 'Concrete Masonry Block Walls The concrete block walls that exist at the Ginna Plant are constructed of unreinforced concrete masonry block except for walls in the Control and Containment Buildings which are reinforced.

For the Structural Reanalysis Program, the exterior walls were considered as deadweight and were assumed to transfer the tornado wind loads into the steel structure. The interior block walls were assumed to contribute only their dead weight to the structure. No structural stiffness was considered. Because the exterior shell was assumed to remain intact, the interior walls were not considered to be subjected to tornado ~inds.

As part of the structural reanalysis, all the walls that could see direct tornado winds were investigated and their capacities to resist various wind speeds calculated. Wind speed capacities were calculated using ACI-539-79 inspected values with a 1.6 overstress factor consistent with an extreme environmental events Exterior block walls are identified in Figures 3-5 through 3-8.

These walls were shown as panels. A panel represents a portion of a complete wall that was isolated for an engineering analysis. An actual block wall in the plant consists of a number of panels for this investigation. For the analysis it was assumed that each wall panel had adequate boundary supports to resist lateral translation.

As a result of the analysis, 15 panels were capable of resisting a 132 MPH tornado using conventional stress analysis.

In addition to conventional stress analysis a "stability criteria" was investigated., "Stability criteria" can be explained as the ability of a masonry wall to resist additional levels of loading after cracking has occurred. Various factors such as height/thickness ratio, self weight, overburden weight and support 3-32

stiffness must be present to enable the stability criteria to be applicable to that wall panel.

All of the exterior block walls listed in Table 3-13 were examined.

A wind, capacity was calculated for each panel, using accepted stress analyses. These walls were also investigated to see 'if the stability criteria would be applicable.

Of the 66 exterior walls, 15 of these are capable of resisting a 132 mph tornado with 22 more potentially qualifying for 132 mph with the inclusion of static stability factors such as overburden and support stiffness. 33 of these walls will not withstand a 132 mph tornado, 9 based on the wall stresses and 22 based on the support stiffness.

Engineering was also done to eliminate block walls required to resist a tornado based on one or both of the following:

1) elimination of walls in areas of the plant where it has been determined that secondary failure of members is acceptable and
2) protection of the single shutdown train areas only.

To the degree of wind speed selected concrete block walls required to resist tornado winds would need boundary type modifications as a minimum. Above this, if the wall would not qualify using the stability criteria then modifications would be required to the wall and/or the supporting structures.

Gilbet. ICammonweslth 3"33

~ W ~ FACADE 4-6l I--3 TURBINE BLDG. j 4 51 j INTERMEDIATE AUX.

3-9I . 3-10l . 3-111 . 3-12l BLDG SERVICE 4-31 . 3-6l BLDG (IN FRONT}

3-2'I'-12'I' 2-11'I' 2-10'I' 2-9'I' 8'I COLUMN LINE 3 - WEST ELEVATION Figure 3-5

TURBINE BLDG TSCECD8 3 3a 3b FACADE (in front)

CONTROL BLDG 4-3I ~

LINL<" V6 TURBINE BLDG BEYOND 1-3C 4-8l 1-2T (EW) I.INL<6 4-Zl COLUMN LINE 13 - EAST ELEVATION CONTAINMENT 11 INTER-10 MEDIATE BLDG TURBINE BLDG CONTROL BLDG COLUMN LINE H - SOUTH ELEVATION j 1-3T l COLUMN LINE F -SOUTH ELEVATION Figure 3-6

Sa AUXILIARYBLDG.

AUXILIARYBLDG.

'1

~ 3-3A . 3-4A ~ ~3-1A

~ ~ ~

~

3-7A

~

~ 3 6A

~Line I

34A 8a COLUMN LINE L - NORTH ELEVATION COLUMN LINE 11a - EAST ELEVATION 4d 4a ROOF AUXILIARY ROOF INTERMEDIATE 4-13I(B) ~ 4-13I(A) 4-13C(NS)

INTERMEDIATE BLDG COLUMN LINE M - NORTH ELEVATION Figure 3-7

F, FACADE 4-12I

~ ~ ~

~ ~

(EW)

FACADE I

. 4-11I ROOF I%I%I r ~ ~ ~ ~~ ~

TURBINE 4-10I BLDG TURBINE 2-12I ROOF BLDG INTERMEDIATE BLDG INTERMEDIATE BLDG COLUMN LINE 7 - EAST ELEVATION COLUMN LINE A - EAST ELEVATION Sa 11a AUXILIARYBLDG.

SERVICE BLDG. (IN FRONT) PUMP BLDG. (IN FRONT)

~ ~ ~~ ~ ~ ~ ~

~ ~ ~ ~ ~I

~ ~ ~ ~

3-13 A ~ 3-12A ~ 3-11 A ~ 3-10 J

3-14A COLUMN LINE Q - SOUTH ELEVATION Figure 3-8

LEVEI.

3 3

3

'MALL NO.

II A

12 A

13 A

14 15 A

FLOOR AND BI.DG.

Aux.

271'Wo Aux.

271'-0o Aux.

271'Wu Aux.

271-Oo Aux.

278'Ho I

of col. Q MAI.I.

LOCATION

'-l-l/2" of col. Q (7A to 6A)

I'"l-l/2o sooth (6A to 5A)

I'-l-l/2o sooth of col. Q (5A to 4A)

I'-l-l/2" so>>th of col.

I '-l-l/2o of col.

Q Q

sooth south DIREGFION E-M E-M E-M E-M E-M 24 I.FNGIN

'-IUo 26'-10o 26'-10o 5'

21'"I>)"

211 281 NF

'5 TABLE IQ)r 10'>-101-72 211'o 281' 281'5 IU'-IUI-12 10'-I>)1-12 211 '

10'11'n II '-4o>

o 281'-101-72 278'-4" tn 289'-8" 3-13 BLOCK HALL DESCRIPTIOM RFFERENGE DRAMING 0-102-54

'o 0-102-54 D- 102-54 0-102-54 0-101-72 0-102-54 Ml DIN>>F Mhl.l. AND NAYERIAL 4" cnnc.

blnck 4o conc.

b lock 4" conc.

b I nc4 4" cnoc.

block 4" conc.

block MAI.I.

USAGE Scpar.

Scpsr.

Scpar.

Sepal Fire Scpar.

80-11 FIX H

H N

H N

SUIEI.DED SD SB DY V

HPN 75 120 60 Sheet AREA SF 250 270 270 50 248 1 of REMARKS 10 3

3 8

9 A

Aux.

271'Wo Aux.

271'-0o I '-l-l of col. Q

/2".

(IOA to 9A)

I'-l-l/2o south of col .

(9A tn Bh) so>>t h E-M E-M 24 '

25'-8" 281'5 281'>-101-72 IO'11'n IU'-IUI 271'o D-102-54 "72 I>-IU2-54 4" conc.

block 4" cnnc.

blnc4 Scpar.

Scpar.

Y Y

Fl'8 Fl'8 85 240 250

TABLE 3-13 Sheet 2 of 10

. BLOCK WALL DESCRIPTION LEVEL MALI.

NO.

IO A

6 A

FLOOR AND BLDG.

Aux..

27l '-0u Aux.

27)'-0u of Col. O MALI.

I.U<'ATIUH I '-I-I/2" south (SA to 7A)

I '-3-I /2u cast of IIA DIREC1'IUN E-M N-S 32 I.EH<:I'N

'-4u 38'O'7I '-IOI-72 IU'1I 28 I Nl'I<alp

'n

'n A/F.

REFERFH<X DRAWING I 0 I-12 0-102-54 0-IU2-57 Ml Dl'N UF MAI.I. AND HAYERIAI.

4u conc.

block 8"

'lock conc.

MAI.I.

USA(E Scpar.

S<!par.

80-I I FIX

'I N

SNIEI.DED FPB BY partial V

Hl'N 75 60

/

AREA SF 320 380 REHARKS (I'-7-I/2u north '28I of col. I. tn I'-Ou south of col. N)

Aux ~

27l 'Wu I '-5-1/2u of IIA cast H-S 24'U'1l28I'-IOI-12 'n 0- l02-51 4u c<u<c.

b I ock Scpar. H 75 240 Conc. ual I facing (4'-8-I/4u north of col. Hi to I'-7-I/2u south of cnl. O) 4 Aux.

27I'-Ou I'-5-l/2u of col. L north E-M 30' IU'1I '-IUI-72 to 0-l02-57 4u conc.

block Scpar. H 75 600 par't.

enact 'Mall (9A - IOA<) 28I facing 3 5 Aux.

21l '-0u I '"3-! /2u north of col. I.

E-M 7' Iu'1l '-IUI-72

'o 0- I02-57 Bu cnuc.

block Sopor. N 60 70 Part.

conc ~ ual I (IOA " IIA) 28 I facing I '-3-l/2" north 35' 8" conc.

3 I Aux.

27I'Wu of col. L E-M 281'-IOI-012 IO'7I'o D-I 02-51 b I nck Scpar. N 60 350 (8A to 9A)

e TABLE 3-13 Sheet 3 of 10 BLOCK WALL DESCRIPTION FLOOR h/K Wl DI'll OF WAI.L AND WA I.L RfitERENIX WAI.I. AttD Whl.l. 80-11 SIIIKI.DED V ARCh LEVEL NO. BLOC. 1.0t'ATION DIRKCfION Lfitlt I'l ItfiltXIY DRAWlttC HAIERIAI. USACE FIX BY Ht'll SF REIIARKS 2

A Aux.

271 On I '-5-1/2" north of col ~ L K-W 4'-10-1/2" 15'-!01-072 D-102-57 4" conc.

block Separ. 150 70 Conc. ual I faci>>8 (I '-7-1/2" uest of Bh t>>

6'-6>> ucst of Bh) 3 h>>x. 6 2. ucdt N-8 2'-8-1/2" 13'-B-I/2" 0-101-072 8" conc. Separ. N 150 40 Exterior A 271 On of BA D-I02-57 bl>>ck Chcekuall (I'-3-l/2" north of col. I. to north of col L)

~

16 Aux. 6>> ucst of tl-S 47 ~ 3>> II'-4" 0-101-72 12" dnl ict Fire Y SB 145 535 Sce ualls A 278'Hn col. 3 278'-4" to D-I)1-03 c>>nc. block Scpar. on Line 3 289'-8>> 0-102-55 Inter. 9" north of 26'-0" 4 13 I(A) 317'ol ~ N K-W I0 ~

317'n 127' OM IOI 112 12>> conc.

hl >>c k Separ. N 90 260 inter. 9>> north of 12" conc.

4 13 l(B) 317'ol. N fi-W I 8 ~ OH 327'-101-112 IO 317'o On hl ock Separ. N 90 180 4 13 I(C) 317'-8 Inter. On line 48 3 II 127'-Illl-112 10'-0" 317'>>

12" cnnc.

block Scpar. N s 150 60

0 TABLE 3- 13 Sheet 4 of 10 BLOCK WA'LL DESCRIPTION FLOOR A/b WIDIH Ol WAI.L AHD WA I.I. REIEREHCE Whl.l. AHD Whl.l. 80-11 SIIIEI.DED V AREA LEVEL NO. BLDG. LOCATION DIRECf IOH I.EHCI'll Hl'. IGIT DRAWING NATERIAL USACE FIX DY NPH SF REHARKS I 13 Inter. I'-0-1/2" vest H S 25 Sn 24'-8". 0-001-022 12" Fire Y SR 70 630 I 253 Su of col 3 253'-8" tn 0-101-72 Separ.

(F6 to II) 278'-4" I 15 Inter. I'-0-1/2" vest N-S 24'-3" 17

~ hll D-OOI.022 12" Fire Y SD 65 420 I 253'-8u of cnl. 3 253'-8" to D-101-72 concrete Scpar.

(J - H) 271 '-0" block Envi ron-'l I.'n t s I Control I 16 Inter. I '-0-1/2" vest N-S . 24'-3" I 7

~ 4l ~

0-001-022 12" Fire 70 420 I 253'-8u of col. 3 253 Sn to D-IOI-72 concrete Scpar.

(K - J) 271 '-0" block Envi ron-4l ncntal Control I 17 Inter. I'-O-l/2" vest N-S 24 ~

3

~ I I7~ 4 I

~

D-001-022 12" Fire Y SS 85 420 I 253 Su of col 3 253'-8" to D-101-72 concrete Separ.

(N - K) 271'-0" block Environ-mental.

Control I IS Inter. I'-O-l/2" vest H-S 24l-3" 17

~ /l ~

0-001-022 12". Fire 150+ 190 I 253'-8u of col. 3 253'-8" to 0-101-72 concrete Separ.

(N- N) 271

~ Oll block Environ-ncntal Control I 8 Turb. I '-0-1/2" vest N-S 24 ~

3 II 17'-6" D.DUI-II I 2ll Fire H SA . 85 425 T 253'-6" of col. 3 253'-6" tn concrete Separ.

(F - F.) 271'-0" block

5 TABLE 3-13 Sheet 5 of 10 BLOCK WALL DESCRIPTIOH FLOOR A/L Ml I)Ill l)l.

MALL AHD MALL Rl Ft,R) t>>t MAI I Altl) MAI.I. SO-I I Sl)IEI.I)FI) V AREA LEVEL HO. SLDG. I.UCATIUtl DIRECTION LEtNTN Ilt'. I QI F I)RANINO HATER I Al. NSACE FIX SY HPN SF REHAIIRS I 9 Turb. I'W-I/2o vest N-S 24'-3" I7 6 0 UUI II I2o f>re N SS 85 425 T 253'-6o of col. 3 253'-6" to concrete Scpar.

(E - D) 211'-0" bluck I IO Turb. I '-O-l/2" vest tl-S 24'-3o t 7'-6" I>-OOI-I I I2" Fire tl SH 85 425 T 253'-6" of col. 3 253'-6o tn < our re> e Separ.

(0 - C) 27I'-0o block I I6 Turb. I '-0-I/2" vest H-S 2( ~

3

~<

I 7 '6" I)-OUI - I I Fire tl SS 85 425 T '253'-6u of col 3 253'-6" tn Separ.

2)I '-0"

~

(c - 8) 465 I '-0-I/2o vest 26'-6o 6< ~ OUI-II Sopor. H SS 65

~

I7 Turb. N-S I7 I)

T 253'-6o of col. 3 253'-6o to (8 - A) 271'-0" 2 IO I

Inter.

278'-4u I'-O-l/2o vest of col. 3 N-8 25'-So 20')-IUI 2 78'4" to

-12 12" concrete Fire Separ.

Y SS EI.

bclov 287 60 5IO (0 - F6) 298 ~

(u bl ock 2 l4 Inter. I '-0-I/2" vest N-8 22 Oo I) IOI 12 l2" Fire N SS belov 65 550 I 27l'-0o of col. 3 21I Ov >0 c o ) ) c r <' e Separ. El. 287 (H - X) 293'-0" block 2 I5 I

Inter.

27I '-Ou I '-I/2" of co'I ~ 3 vea t N-S l2'-3o 22'-ll" 27I'-0" to D-lnl-72 I 2" coocr<!I e Fire Separ.

Y SS EI.

belov 281 l45 270 (N-H) 293'.0" block

TABLE 3-13 Sheet 6 of 10 BLOCK WALL DESCRIPTION FLOOR Nittrn Or

'NAI.I. AND WAIL urFEREIIGE HALL AttI> HALL Bo-I I SNIEI.DEo v AREA LEVEL NO. BLDG. I.OCAT ION Dl REGF ION I.EHGrtt Ilt'. I(PIT DRANIHG ttAYERIAL USAGE FIX BY NPII SF RENARKS 2 IS Inter. I 'W-I/2<<west N-S 25

~

0 II 22 I)-IOI-72 I 2" Fire Y Stt below 65 ~ 550 I 21l'W<<of cnl. 3 27l'-0<< to

'-0" concrete Separ. F I. 287 293 block 2 l9 Inter. I'-0-I/2<< west N-8 25 ~ OI~ D-IOI-72 I2" Separ. tt SB below 85 480 I 27l '-0<<of cnl. 3 22'7I'-0" to c I I II c r << t o E I. 281 291'-0" block 2 7 Turb. I'-O-l/2" west N-S 1 I IB'-6<< D-OOI-2l l2" Fire tt SB I50t l30 T 27l'-0<< of col. 3 21I'-0" to concrete Scpar.

(F) 289'-6" block 8 Turb. I '-O-I/2<<west N-S l7'-3" IB'-6" D OOI 2I I2<< Scpar. tt 85 320 I T 271'W<< of col. 3 211'-0<< to co<<crete (E) 289'-6<< block I

g 2 9 Turb. I '-O-l/2" west N-S 24 '-3" IS'-6" D-OOI-2l I 2<< Separ. tt 85 450 T 27I 0<< of col. 3 271'-0" to co<<crete (8 - O) 289'-6<< block 2 IO Turb. I '-0-I/2<<west N-8 ~ 31 ~ IA'<< 0-OOI 2I I2" Sepal' N 85 450 T 21l'%<<of col. 3 271'-0" to concrete (O - C) 289'-6" block 2 II Turb. I '-0-I/2" west H-S 27 e 3oe IS '6" I)-OUI -2 I I 2<< Separ. H 85 450 T 27l'W<<of cnl. 3 211'-0<< to concrete (c 8) 289'-6" block

TABLE 3-13 Sheet 7 of 10 BLOCK MALL DESCRIPTION FLOOR A/F Wl illtl tft MALL AND MALI. REFEICKtICE MAI.L ANI) MAI.I. 80-11 SIIIKI.DED V AREA SLDC. LOCATION Dl RECTION I.Et tell ll IIE IIXIT l>RAMINC IIATEIIIAI. USAGE FIX SY tll'll SF RKtIARXS LEVEI NO.

2 12 Turb. I'-0-1/2n vest NS 276n IS'-6" 0-001-21 12n Separ. N 85 510 T 271'-0n of col. 3 271'-0" to concrete (8 - A) 289'-6" block 9 Inter. I'W-I/2w vest N-S 24i'-3" 28'8n 0-012-02 12" Scpar. N 70 695 I 293'-0" of col. 3 293'-On to cuncrcte (3 - it) '121'-8" blnck 3 10 Inter. I 'W-I/2n west N-S 24'-3n 28'-8" I)-012-02 12" Scpar. N 70 695 I 293'Ww of col. 3 291'-0" tn rcwicrctc (R - 3) 321'-8n block 3 II Inter. I '-0-1/2" west N-S ~ 3H 28'-8" D-OI 2-02 12" Scpar N 70 695 Cia I 293 OH of col ~ 3 293'-0" to ronrrcte I - 321'-8" blnck (N R) 3 12 Inter. I'W-I/2n west N-S 12'-3" 28'-IV'-012-02 - 12" Scpar. N 145 350 I 293'-0" of cnl. 3 293'-Un to conc rcte (N - N) 321 '-8" block 3 6 Inter. I'-0-1/2n vest N-8 25 '-8". I lc-0" 0-012-02 12" Separ. T'DI. below 85 185 I 298'-4n of col. 3 298 4n to concrete E 289 (N - F6) 315'-4" hlnck 3 2 Inter.

I(P) 315'-4" of col.

(0 - F6)'-S I '-0-1/2n 3

vest 25'-8n 23'-8" 3(5'-4" to 3'l9'On D-012-02 D-101-112 12n cuncretc block Separ. N 70 605

TABLE 3-13 Sheet 8 Of 10 BLOCK WALL DESCRIPTION FL(X)R A/F. ((I DT(( I)F WAI,L AND NA I.I. 8('.I ( RKN(28 ((AI.I. AND MAI.I. 80-11 SIIIKI.DED V AREA LKVEI NO. BLDG. I.UCATION Dl RYGP IUN I.YN(<T(l IIE I(2('I'RAHING HA'I KR I A I. USAGE F IX 8T I(PN SF REI(ARKS 2 Turb. vali 3 N-S 124'-6" 2'-6<<D-101-71 12" Parapet N 150s 310 T 289'-6<< col. 3 289'-6" to <'uncrcte 292'-0<< bl ock 25'-0<<0-101-72 3 I I 253'f Inter. I (F

'W-I/2<<vest col.

- F6) 3 N-S 2I

~ 8< ~

253'-u" 278'-0<<

co 12" c<<ncrete block Scpar. N SD 70 640 I'-0-1/2" 2

I 253'f Inter.

(F col.

F6) 3 vest N-S ~

8 << 20 278'<<

298'-0<<

0 t ~<

0-101-72 12<<

concrete block S<'.par. N SD Partial 70 510 I'-O-l/2<< '-8<< '-0" 3

I 253'f Inter.

(F col.

- F6) 3 uest N-S 21 I 7 298'-U<< t<<

315 'U<<

0-101-112 12" concrete block Separ. N 85 420 I'-0-1/2" 4

I 253'f Inter.

(F col.

- F6) 3 vest N-S 21< 8<< 24 <-0<"

315'-0"to 319'-0" D-101-112 12" ro<n blnck rote Srpar N 70 640

'W-I/2<<vest 5

I 253'f Inter. I (F

col.

- F6) 3 N-S 21'-8<< 14'-0"

.339'-0" to 3$ 3'-0<<

0 IOI 112 12<<

co<<crete block Separ. N 85 29$

6 'nter.

253-O-l/2<< ueat N-S 21'-8" 14'-0" 0-101-112 8<< Sopor. N 60 29$

I of cnl. 3 ')51'" to c<<ncrrte (F - F6) 1(07'0" block

TABLE 3-13 Sheet 9 of 10 BLOCK WALI. DESCRIPTION F(.OOR A/8 Wl l(TN ((F WAI.I. AND WA 1.1. RKI'ERKNCE 'WAI I. AND WA(.I. 80-11 SNIK(.(RKD V AREA IXVEL NO. B(.DC. LOCATION DIRECTION I.KNCI'll ((K((a(T DRAWING WATER(A(. USACE FIX BY NPN SF RKHARKS I I Turb. I '-5-1/4" east N-S 27'-6" 17'-6" D-IO(-004 12" conc. Fire ND TSC 65 530 T 253'-6" of col. 13 25'I'-6" tn D-OOI-I I block Separ.

(A - 8) 271'-0" I 2 Turb. I '-6-3/8" north E-W 4'-I" 17'-6" 0-181-004 12" conc. Fire NO TSC 150< 70 T 253'-6" of col . 8 253'-6" to '-OOI-II block Separ.

(e col. 13) 7 71

~ Oii I 3 Turb. I '-S-I/4" east N-S 20'-3" II '-I" D-001-0(l 12" cnnc. Separ. NO TSC 150< 225 T 253'-6" of col. 13 259'-ll" (0 block (E 13 - F 13) 271'-0" 3 Control I '-5-1/4" east N-S 38

~

2 iI 4 ~ 2<< 0-105-012 12" conc. Ester. NO Belou 150s 160 4J C 253'-8" of col. 13 266'-4" to bl. rein- Wall Grade 7 I 270'-6" force<l c

Conc. brin<<

266'-4" 3 2 Turb. I'-8" south K-W 25'-9" IS'-6" D-001-21 12" conc. Separ. N 150< 310 T 271'-0" of col. F 271'-0" to block (I I - IO) 289'-6" 3 I Turb. I'-8" south F.-W 25 -9N

~

14'-10" 0-101-71 12" conc. 85 390 T 289'-6" of col. F 289'-6" (n block (10 - I I) 304< '-4"

TABLE 3-13 Sheet 10 of 10 BLOCK WALL DESCRIPTION FI.(k)R h/8 Wl I)l'0 I)F WAI.I. ANU WA I.I, RKFKHKNUK WAI.). ANI) Whl.l. HU-I I Sl)II'.I.I)KU V AREA I.EVEL NU. 8).UG. I.l)Cu'ri)kl I))AKUI'l<kl I.KNWI'll 0)".I<kll I)NAMIN)) HA'IEHIA). I)SAQ'. FIX HY N)'ll SF AKNAHHS 2 l2 Inter. 3-3/8" east N-S 32'U" 21 ~

I ~s

')-IUI-72 I 2" ccn)c. Sr)sar. 80 1 278'-4" of enl. 70 21I'"

is'

)c> hie)ck N

to 79U I r ss l50)

I n) <) ) as< sl.

Sle< ~

I 7

I 3IA'3 Inter. Line 0 to lF>)

E-W 2I I)9')-IUI-I 2I

'IH' c~

)2 l2" Ale)rk

<<<so<'. Sc par, - 8 80 45U Inter. 8' 4 8 I 339'3  !.ine F6 to lh)

K-W r ~

15.)')"

I I9 ) c>

IUI "112 l2" rsn)r.

bl ~ >c:k Separ. Y ) I 50 I IO 9

I Inter.

353'3 Line F6 to lh)

F.-W 8 'hc ')- l67

'5)'

cl IUI-II 2 A" hl c)ck ccn>r. Sc'par. H '10 I I0 c

s 4 IO Inter. Linc lh H-S '8" Ir ~ I)-IUI-II2 12" r<)>>c .

I 339'F6 to F) 2I I I')' cl l>lc)rk Scpar. N 15 3IU I~

II Inter. '-A" rc>cl<'c'Iaf I 353'F6 Line lh to F) 0-S 2I

)61')-IUI-I lr

'5)'c>

I2 )2" hl ~ >c:k 0 65 3'I 0 4 l2 I 36I'3 Inter. Line lh t<) 3A)

I -W 8'<sl61')- I I c>

IUI "I I 2 )2" I> I nrk

<<cn)<<. Sel>a<'l ~ I 5U 50

4.0 SEP TOPIC III-7.B DESIGN CODES DESIGN CRITERIA AND LOAD COMBINATIONS

4.1 INTRODUCTION

This section contains results of the evaluation of design code changes identified by SEP Topic III-7.B, as potentially affecting the margin of safety, with respect to code allowable limits, of the plant's structural design.

The evaluation was based on the major findings of a code comparison review performed for the USNRC by FRC and documented in TER-C5257-322 (Ref. 12) which is an attachment to the USNRC letter dated 4/21'/82 (Ref 13). Only. the design code changes which affect the structural steel elements and anchorages to concrete for the plant structures listed in Section 2.0 and the Diesel Generator Building were addressed. Design code, design criteria, and loading combinations changes, which affect only concrete structures, were not evaluated in this report.

Design criteria and load combination changes which affect structural steel members 'of the plant are addressed in Section 4.2.10 The design code changes that are addressed herein are those which the USNRC deemed to potentially degrade the percieved margin of safety. They are listed in the FRC report on pages 57, 58, and 62.

The structural elements which are to be examined are also listed on pages 71 and 72 of the same FRC report.

An evaluation of code changes was performed for all eight major findings of the AISC 1963 (Ref. 14) vs. AISC 1980 (Ref. 1) Code comparison and one major finding of ACI 318-63 (Ref. 15) vs ACI 349-'80 (Ref. 6) Code comparison.

4-1

Where code comparisons used the computer model output, only the normal operating loads and load combinations were used. It should be noted that the effects of seismic loads are not a part of the code comparison or this report.

4.2 EUAULATION AND RESULTS This section contains a brief description of each code change, the approach used Eor evaluating the change, and the results found.

4.2.1 Shear Connectors in Composite Beams The code, change which required this evaluation involved new requirements added in the AISC 1980 Code (Ref. 1) subsection 1.11.4 as compared with AISC 1963 Code (Ref. 14) Subsection 1.11.4.

The code change affects the distribution, diameter and sp'acing of shear connectors in composite beams.

The approach used Eor this evaluation was to review the calculations and the construction drawings Eor the use of shear connectors for composite beams.

The resul'ts of the above review showed no use of shear connectors for composite design on the plant structures reviewed, and therefore no change to the margin of safety of the Ginna Plant.

4.2.2 Composite Beams with Steel Deck This evaluation is required due to the addition of a new subsection 1.11.5 to the AISC 1980 Code. The code addition defines requirements Eor composite beams where a formed steel deck is used Eor support of the concrete slab.

4-2

' The approach and decking.

used for this evaluation was to review tPe calculations the construction drawings for composite beams with steel The results of the review determined that the main beams and girders on the Turbine Building Operating Floor Elev. 289'-6" and located between all columns, had shear connectors attached to the top flange. The concrete slab was supported by steel decking.

Selected beams were analyzed for the loads shown on the drawings.

The results of the analysis showed that composite design was not required for these beams and it is surmised that the shear connectors were added to provide lateral support for the top flange.

Therefore the code change has no effect on the margin of safety of the Ginna Plant.

4.2.3 H brid Girders This evaluation was required due to the addition of a new requirement by the AISC 1980 Code (Ref. 1) to subsection 1.10.6 which did not appear in the AISC 1963 Code (Ref. 14). This new requirement limits the maximum stress in the flange of a hybrid girder.

The approach used for this evaluation was to review the construction drawings and specifications for the existence of hybrid girders.

The results of the review showed no use of hybrid girders on the plant structures. Therefore this code change does not affect the margin of safety of the Ginna Plant.

4.2.4 Com ression Elements This evaluation is based on a revision to Subsection 1.9.1 of the AISC 1963 Code by new provisions in Subsection 1.9.1.2 and Appendix C of the AISC 1980 Code.

~ /Commonwealth 4-3

These new provisions revise the approach for designing certain unstiffened compression elements which exceed the width to thickness ratios prescribed in the codes.

From the results of Case Study 10 in the FRC report (Ref. 12), it was concluded that only Tee sections in compression need to be reviewed as the AISC 1963 Code (Ref. 14) is more conservative for other members in compression.

The approach used for this evaluation was to review the members in the structural model of the plant described in Section 2.0 to determine where Tee sections were used and if they were subject to compression, under the normal operating load combinations evaluated in this report.

The results of the computer output review showed none of the Tee sections failing the code check for normal load combinations with the member in compression.

It is therefore concluded that for normaL load combinations, the margin of safety for, members affected by this code change is stiLL acceptable.

4.2.5 Tension Members This evaluation was necessary because of a new requirement in the AISC 1980 Code (Ref. 1) added in Subsection 1.14.2.2.

Th'is code addition defines the requirements for the design of axially loaded tension members where the load is transmitted by bo'its or rivets through some but not all of the cross section of the member.

/commonweslth 4"4

A generic review of the two codes was performed to compare a design example using the formulas and allowables for each. The results showed that the AISC 1963 Code provided a more conservative design.

It is therefore concluded that this code change does not decrease

, the margin of safety of the Ginna Plant.

A new requirement was added in the AISC 1980 Code (Ref. 1) requiring that beam end connections, where the top flange is coped, be checked Eor a tearing failure, "block shear capacity", along a plane through the Easteners.

The method used to evaluate this code change was to completely revie~ all steel fabrication drawings Eor major members with bolted connections and coped top Elanges. Girts, platform steel, stair stringers .and miscellaneous steel were not included as these members are lightly loaded and shear, is not a concern.

The drawing review turned up 452 coped beams with 335 difEerent erection marks. From this total a random selection of 55 beams was statistically chosen Eor evaluation of the code change effects. The statistical evaluation method is described in Section 3.

The evaluation consisted of calculating the block shear capacity of each of the beams selected and comparing this capacity against either the loads shown on the construction drawings, the shear capacity of the connection bolts or the reaction based on the maximum allowable load for the beam span.

In all cases the block shear capacity was higher than these other controlling reactions'-5

It is therefore concluded that, using a statistical approach at a 95 percent confidence level, no more than 5 percent of the population of coped beams may have capacities controlled by this code change.

4.2 ' Moment Connections A new requirement was added in the AISC 1980 Code (Ref. 1) in Subsections 1.15.5.2, 1.15.5.3, and 1.15.5.4. These subsections define the requirements for column web stiffeners where moment connected members frame into columns.

The construction and Eabrication drawings were thoroughly reviewed for the use of moment type connections. This survey found that only some roof beams in the Screen'ouse were designed and detailed as moment connections.

These connections were then checked against the AISC 1980 Code and it was determined that, based on the member sizes, details, and original applied loads, no column web stiffeners are required.

It is therefore concluded that the code change does not affect the margin of safety of the Ginna Plant Eor the structures reviewed.

4.2.8 Lateral Bracin The AISC 1963 Code (Ref. 14) Section 2.8 has been revised by AISC 1980 Code Section 2.9. This code change revises the formulas Eor determining the maximum spacing for lateral supports of members designed using plastic design methods.

This code change was evaluated by a review of the existing available calculations and the Ginna FSAR (Ref. 8). No evidence was found of plastic design methods being used.

Stet/Co ywtltlh 4-6

It is therefore concluded that this code change does not affect the margin of safety of the Ginna Plant for the structures reviewed.

4.2.9 Steel Embedments This code change involves the use of the ACI 349-80 Code (Ref. 6)

Appendix B for the design of steel embedments in concrete structures. The ACI 318-63 Code (Ref. 15), used in the original design did not specifically address the design of steel embedments'.

It was up to the individual designer to provide an embedment which satisfied the allowable stresses in the code. Working stress design was the method used Eor determining loads and stresses.

The Latest ACI Code requires the use of ultimate .strength design which includes the use of factored Loads and Larger allowable stresses. This difference alone would make direct comparison of the margins of safety difficult.

There are many other diEferences in the methods and details that the designer would use Eor a given embedment and a given code, but the main difference is the requirement of ACI 349-80 Code Appendix B that the anchorage design be controlled by the ultimate strength oE the embedment steel. Concrete strength of the anchorage must not control no matter what actual loads are applied to the anchorage.

Unless the designers were fully cognizant oE the requirements of ACI 349 during the actual design it is unlikely that all anchorages would satisfy this code requirement, since it allows only a ductile (steel) failure of the anchorage irrespective of the calculated or actual applied loads.

Due to these difficulties in direct comparison of the two codes it was decided to statistically select a random number of anchorages for evaluation against the ACI 349-80 Code.

Gilbert IConvnonetalO 4-7

From a total population of 194 columns, 51 columns were selected for evaluation. Of the 51 columns selected, 46 had anchorage into concrete.

The approach taken for this evaluation was to analyze the column anchorage to determine if it met the ductile failure and other requirements, including minimum edge distances, embedment depth, anchor size, etc. of the ACI 349-80 Code (Ref. 6). If the code requirements were met, it is concluded that the margin of safety for the anchorage is acceptable.

If the requirements were not met then the ultimate concrete capacity of the anchorage or the .allowable steel capacity whichever was less, using the ACI 349-80 Code as the basis, was compared to the applied factored loads. Only normal design loads using current load combinations were used in'the comparison. IE the concrete or steel, capacity, whichever controls, was still greater than the applied loads the anchorage was deemed to have an acceptable margin of safety.

The results of the evaluation Eor this code change are as follows:

a. Of the 46 column anchorages evaluated, a total of 22 did not meet the ACI 349-&0 Code.
b. Of the 22 that did not meet the code, a total of 5 anchorages were unacceptable Eor the applied loads.

The result of this design code evaluation, using a is that at a 95 percent confidence level, statistical'rojection, no more than 21 percent of the population of 194 column anchorages would have unacceptable margins of safety for normal load combinations.

GlltlftlC0 owlSllh 4-8

4.2.10

~ ~ Desi n Criteria

~

and Load Combinations The term design criteria as used in the FRC report (Ref. 12) is synomous with design codes. In any case the design code/criteria and applicable load combinations used for the SEP Topics addressed in this report, were all taken from current codes and standards.

All structural evaluations performed for the two computer models were done to current criteria.

4.3

SUMMARY

The results of the design code change evaluations showed that the eight AISC code changes either are not applicable to Ginna or had little if any effect on the margin of safety of existing structural elements.

The one ACI code change evaluated showed that at a 95 percent confidence level, no more than 21 percent of the population of 194 anchorages would be overstressed for the applied normal loads.

@bert /CommonwulO 4-9