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Forwards Draft 1 of 811117 Reg Guide MS-129-4, Anchoring Component & Structural Supports in Concrete. Draft Provides Criteria for Acceptance,Qualification,Design,Installation & Insp for Steel Imbedments Anchored in Concrete
	ML20237A130
Person / Time
Issue date:	12/15/1981
From:	Arlotto G; NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES)
To:	Fraley R; Advisory Committee on Reactor Safeguards
References
	RTR-REGGD-01.XXX, RTR-REGGD-1.XXX, TASK-MS-129-4, TASK-RE IEB-79-02, IEB-79-2, NUDOCS 8712140277
	Download: ML20237A130 (36)
	v • d • e

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SUBJECT:

ORAFT 1 REGULATORY GUIDE MS 129-4 " ANCHORING COMPONENT AND STRUCTURAL I SUPPORTS IN CONCRETE" i Enclosed for the use of the Subcommittee on Regulatory Activities are twenty copies of Draft 1 of the proposed regulatory guide with its Oraft VIS, " Anchoring Component and Structural Supports in Concrete", Task No. MS-129-4, dated November 17, 1981. l This draft guide provides the criteria for acceptance, qualification, design, installation and inspection for steel embedments anchored in concrete. This j draft guide also provides information on the acceptability for NRC licensing j actions of Appendix B, Steel Embedments, to the Code Requirements for Nuclear Safety Related Concrete Structures (ACI 349-.80), published by the American Concrete Institute. Since the draft guide is preliminary, additional staff efforts including review and resolution of public comments will be cessary prior to implementation of a regulatory position. ACRS Subcosnitte osments an recommendations are requested on the proposed position. )J G. ' 4. Arlot Director Div sion of Engineering Technology Off ke of Nuclear Regulstory Research

Enclosures:

1. Draft 1, R.G. Anchoring Component and Structural Supports in Concrete dated 11/17/81 2. Appendix B and Chapter 9 to ACI 349-80 3. Draft Value Impact Statement 4. IEB 79-02 $[j /r7 CONTACT: H. Graves i 443-5860 Task No. MS 129-4 0' k, 1* I cc: See next page o f y nd ~W w

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) i MEMORANDUM FOR: Raymond F. Fraley, Executive Director, ACRS FROM: G. A. Arlotto, Director, Division of Engineering Technology, Office of Nuclear Regulatory Research

SUBJECT:

ORAFT 1 REGULATORY GUIDE MS 129-4 " ANCHORING COMPONENT AND STRUCTURAL SUPPORTS IN CONCRETE" / Enclosed for the use of the Subcommittee on Regulatory Activities are twenty copies of Draft 1 of the proposed regulatory guide with its Draft VIS, " Anchoring Component and Structural Supports in Concrete", Task No. MS-129-4, . dated November 17, 1981. This draft guide provides the criteria for acceptance, qualification, design, installation and inspection for steel embedments anchored in concrete. This draft guide also provides information on the acceptability for NRC licensing actions of Appendix B, Steel Embedments, to the Code Requirements for Nuclear Safety Related Concrete Structures (ACI 349-80), published by the American Concrete Institute. Since the draft guide is preliminary, additional staff efforts including review and resolution of public comments will be necessary prior to implementation of a regulatory position. ACRS Subcommittee coimeents and recommendations are requested on the proposed position. G. A. Arlotto, Director Division of Engineering Technology Office of Nuclear Regulatory Research

Enclosures:

1. Oraft 1, R.G. Anchoring Component and Structural Supports in Concrete dated 11/17/81 2. Appendix B and Chapter 9 to ACI 349-80 3. Oraft Value Impact Statement 4. IEB 79-02 CONTACT: H. Graves 443-5860 Task No. MS 129-4 i cc: See next page FSchroeder DISTRIBUTION I OI GAARLOTTO LCSHA0 WFANDERSON HGRAVES EHILL POR j )l g 83:D

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.s i-Reymond F. Fraley 2 ' cc: .C. P. Tan, NRR; F. Schauer NRR; P. Williams, NRR; M. Hartzman, NRR; R. Bosnak, NRR; J. Fair, IE; R. Shewaaker, IE; H. Wong, IE; R. Baer.'IE MSEB READING MSEB SUBJECT 6 w f 1

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'i EA/dlCTU,0 E I ORAFT REGULATORY GUIDE MS 129-4 ANCHORING COMPONENT AND STRUCTURAL SUPPORTS IN CONCRETE JTLINE A. . INTRODUCTION B. DISCUSSION GENERAL 7 1. GENERAL TYPES OF ANCHORS 8 1.1 STANDARD ANCHORS AND INSERTS 9

1. 2 EXPANSION ANCHORS 10 1.2.1 WEDGE ANCHORS 11 1.2.2 SLEEVE ANCHORS 12 1.2.3 SHELL ANCHORS 13 2.

QUALIFICATION OF ANCHORS 14 2.1 MATERIAL 15 2.2 TESTING 16, 3. DESIGN OF ANCHORS 17 3.1 LOA 05 18 3.2 LOAD COMBINATIONS 19 3.3 STRENGTH REDUCTION FACTORS 20 4. INSTALLATION 21 S. INSPECTION 22 6. ANCHORING IN CONCRETE MASONRY

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i, L... m 1 C. REGULATORY POSITION . 2-1. GENERAL ~ 3 2. QUALIFICATION OF ANCHORS 4 2.1 GENERAL ' 5

2. 2 STANDARD ANCHORS AND INSERTS 6

2.3 PERFORMANCE TESTS FOR EXPANSION ANCHORS 7 3. - DESIGN OF ANCHORS 8 3.1 LOADS 9. 3.2 LOAD COMBINATIONS 10 3.3 STRENGTH REDUCTION FACTORS 11 3.3.1 STANDARD ANCHORS AND INSERTS 12 3.3.2.. EXPANSION ANCHORS 13 4. INSTALLATION 14 4.1 STANDARD ANCHORS AND INSERTS 15 - 4.2 EXPANSION ANCHORS 16 5. INSPECTION 17 6. ANCHORING IN CONCRETE MASONRY 18 D. IMPLEMENTATION l 19 E. REFERENCES i 20 F. VALUE/ IMPACT STATEMENT i eM* tmm ' ' )

y, s', m .1 Anchors used in nuclear power plants'should be able not only to withstand 2 stress' for long periods of time but also compensate for additional stresses as 3-a result of environmental ~ effects. Thus, it is necessary to' carefully. eval-4 usta anchor performance taking into consideration the environment to which 5 they are subjected. ~The need for a careful evaluation of anchors was recog-6 nized by the American Concrete Institute Committee 349. Appendix 8 " Steel '7 Embedments," to ACI 349-80, " Code Requirements for Nuclear Safety Related 8-Concrete Structures," specifically addresses the subject of anchors.. This 9' regulatory guide generally. endorses ACI 349-80, Appendix B, with exceptions in 10 the areas of design by analysis for expansion anchors, strength reduction 11 factors, load combinations,.and installation reqt.frements for expansion 12 anchors.- In addition,' the guide has supplementary recommendations in the '13 areas of static and cyclic performance tests; inservice inspection, and 14 anchors in ansonry walls. 15 This regulatory guida provides recommended criteria for acceptance, 16 qualifications, design, installation, and inspection for load bearing steel 17 embedments anchored in concrete. 18 1. GENERAL TYPES OF ANCHORS 19 The recommendations of this guide apply to the two groups of steel 20 embedments discussed below and as defined in Section B.2 of ACI 349-80, 21 Appendix B. ' 22 1.1 h dard Anchors and Inserts 23 Standard anchors considered in this guide are bolts with heads or nuts or 24 similar studs or bars embedded in concrete at the time of its placement or 25 grouted into formed or drilled holes. 26 Headed stud anchors are u:ually attached to steel plates. The plate i 27 transfers loads to the anchors at the attachment surface. Grouted anchors are 28 designed to transfer loads between the anchor and grout or grout and concrete 29 by tansion or shear. 30 Inserts are predesigned and prefabricated embedments installed prior to 31 concrete placement which are specifically designed for attachment of bolted 32 connections. l 2 ,w . g se. --_____-______m___w

1

1. 2 Expansion Anchors

. 2 Three common types of expansion anchors are wedge, sleeve, and shell. In 3 all three types, expansion is produced forcibly by a specialized and, for the 4 sost part, contro11abisi mechanical process. The mechanism is activated once 5 the expansion anchor is properly installed in the hole drilled in the concrete. 6 1.2.1 Wedae Anchors Wedgeanchorshaveclipsthatareactivatedbytensioningortokueik 7 .8 the nut on the bolt after it is installed in the hole drilled in the concrete. 9 The clips are expanded radially when the wedge part of the bolt.is drawn 10 through them, thus developing the pullout resistance. 11 1.2.2 l Sleeve Anchors ~12 Sleeve anchors consist of an expanding sleeve with clips at one and and a 13 threaded bolt that is drawn up into the sleeve. The clips on sleeve anchors 14 are activated when the nut on the bolt is turned. After the nut is turned a 15 number of times, wedge pullout is countered by the sleeve. 16 1.2.3 Shell Anchors 17 Shell anchors can be self drilling or installed in a hole drilled in 18 concrete. Once the hole is drilled, a short tapered plug is inserted into the 19 drill and, and the plug is hassered,into the hole. The shell expands over the 20 plug as it is driven to its proper depth after which it remains stationary. 21 Once the shell reaches its proper depth, the end that protrudes above the 22 concrete surface is broker. off along a score line. The outer surface of the 23 shell is deformed at the plug and to give resistance to pullout. The shell 24 has internal threads to allow bolting. J 25. 2. QUALIFICATION OF ANCHORS J 26 In qualifying anchors, the requirements of ACI 349-80, Appendix 8, are 27 supplemented in the two general areas outlined below. f. 3 are aw sk..

'r ~ 1 2.1 Material 2 Anchors need to be designed, manufactured, and tested t'o be compatible 3 with the load application, environment, and installation conditions. 4 In general, metal anchors are specified to be made of a material that is i .5 resistant'to corrosive conditions or coated with a protective material. In 6 the case of metal anchors 3 the material sust be stable in the concrete of the 7 support structure and not cause any chemical reactions that could adversely 8 ' affect the concrete or any reinforcement that may be present. '9 2.2 Testing 10 It is recommended that the strength of all' types of anchors be established 11 by tests. Anchors embedded deep enough to develop the ultimate strength of 12 anchor steel, with the embedment. depth determined by the methods of Sec-j 13 tions B.4 and B.5 of ACI 349-80, Appendix B, may not require static tests. 14 However, for deep embedded anchors, cyclic and fatigue load capability needs 15 to be carefully evaluated. For expansion anchors, it is recommended that 16 tests include testing of the anchor expansion mechanism and its ability to 17 transmit'the load to adjacent concrete. Due to the variety of applications j 18 and designs for expansion anchors, a detailed test program is not being 19 specified in this guide. Only the minimum performance criteria are provided. 20 In testing anchors, it is also recommended to determine the capacity of the 21 concrete, thus, tension, shear,'and bearing capacity _of the concrete is 22 defined in accorotnce with applicable Sections of ACI 349-80, Appendix 8. i 23 3. DESIGN OF ANCHORS l 24 The recommendations in regulatory position C.3 of this guide supersede 25 the requirements of ACI 349-80, Appendix B, in the areas of load combinations, i 26 strength reduction factors, and design by analysis. 27 The general procedure for the design of anchors is to (1) determine the j 28 total area of bolts, bars, or studs required for a given configuration of 29 anchors, (2) determine the embedment requirements, (3) check bearing stress on 30 the concrete surface, (4) compute the flexibility effect of base plate, 4

. a.. 1 1_ (5) check for shear-tension in bolts and concrete for appropriate loads and 2 loading combinations. 3 3.1 Loadr 4 Anchors should be designed to resist all conditions of tension and shear -5 or a combination thereof, taking into consideration the net tensile components ~6 of any bending moments that may result from fixation or partial fixation of 7-column baseplates. 8 3.2 Lead Combinations .9 Codes and specifications such as ACI 349, AISC Manual of Steel 10 Construction, and ASME B&PV do not specify load combinations specifically for ' 11 ' anchors at the present time. These codes and specifications use either the 12 working stress design, stnngth design, stress limits, or the plastic design 13 methods. These methods cannot be applied directly to the design of anchors. 14 The load and load combinations in regulatory positions 3.1 and 3.2 are 15 intended to establish consistency in the design of anchors. 16 3.3 Strength Reduction Factors 17 In general the requirements of Sections B.8 and B.9 of ACI 349-80, ~ 18. Appendix 8, are acceptable for testing standard anchors and inserts. However, 19 because of uncertainties and the lack of sufficient research in this area, 20 additional safety margins are recommended by reducing the applicable strength 21 reduction factors of ACI 549-80, Appendix 8. 22 Tests to detamine the strengths of expansion anchors are generally 23 performed in sound concrete of a specified strength, which may not be repre-24 sentative of the actual application. Thus, it is reasonable to assume that ) '5 the actual holding capacities of expansion anchors will most itkely be less: 2 26 Furthermore, the results of tests performed thus far indicate a scatter of j 27. about 30% to 40% in the ultimate capacities of expansion anchors. Hence, the 28 factors of safety established by IEB 79-02 are considered to be appropriate 29 for use in evaluating expansion anchcrs until the time when the guide 30 recommendations are implemented. 5 1 _ __ _ _

1 The expansion anchor performance criteria are intended to be a guide that 1 2 will guarantee a certain level of confidence in the strength of expansion 3 anchors. If the stated performance criteria are met through adequate testing, 4 the reduced strength reduction factors as recommended in the guide can be used. 5 4. INSTALLATION 6 Tests have shown that the proper installation of anchors is of prime 7 importance ensuring good anchor performance. Factors to be considered in the 8 installation of expansion anchors are hole diameter, embedment, depth, angu-9 1arity, spacing, thread engagement, edge distance, plate bolt hole size, 10 preload and care in grouting. The intentions of the guide are not to specify 11 a detailed program for anchor installation but to ensure that the factors 12 mentioned above are considered. ACI 349-80, Appendix B, is being supplemented 13 by the guide in this area, as noted in regulatory position C.4. In addition, 14 it is necessary to provide a sufficient amount of preload to expansion 15 anchors. The expansion anchor preload is that specified in IEB 79-02. 16 It has been argued that a large amount of preload on expansion anchors 17 (particularly, r> hell anchors) is not necessary. In order to assess the 18 related merit of having a designated amount of preload en expansion anchors, 19 the NRC staff has undertaken a research program to evaluate the effects of 20 various amounts of expansion anchor preload. 21 At present, the results of the. research program are not available. When the 22 research is completed, full consideration will be given to establishing better 23 preload ranges for expansion anchors. For. anchor types other than expansion 24 anchors it is also important that good installation practices be followed. 25 5. INSPECTION 26 An anchor inspection program needs to cover the construction, installation, and 27 inservice conditions of anchors. ACI 349-80, Appendix B, does not include recuire-28 ments for an anchor inspection program, therefore this guide recommends guidelines that will ensure that anchors are properly installed and provide satisfactory service 29 30 throughout the life of the structure. During the construction stage, it is recom-31 mended that anchors be checked to verify that they are of the specified size and type. l 6 1 t

m 1 Items reconeended for inspection during and after the installation stage 2 include those items discussed in Section B.4 of this guide. Inservice 3 inspection requirements for anchors should be consistent with those for 4 component and structural supports. 5 6. ANCHORING IN CONCRETE MASONRY 6 The extensive use of anchors (expansion and others) has led to 7 considerable concern over the behavior of anchors in concrete masonry. This 8 has been addressed in IEB 79-02, but not in ACI 349-80, Appendix B. Manu-9 facturers generally indicate only the load capacities for anchors tested in 10 cast-in place concrete and do not recommend expansion anchors for use in 11 concrete masonry. Until recently, the use of anchors in masonry was not 12 subjected to licensing review. Even though most standards and architect / 13 engineer's specifications prohibit the use of anchors in concrete masonry 14 units (CMUs), a review of licensees' responses to IEB 79-02 indicated the use 15 of anchors in CMUs. 16 The use of anchors was limited in most cases to a small number of piping 17 supports for Seismic Category I piping in a few plants, which raised questions 18 about the anchors' performance and capabilities. The limited amount of data 19 available on static tests performed on anchor bolts installed in concrete 20 block walls indicates that the ultimate capacity of bolts in concrete block 21 walls is lower than that of the same type and sized anchors in cast-in place 22 concrete. It is also expected that, under dynamic loading, the ultimate 23 capacity of anchors will be further reduced. Until standards can be developed 24 on anchoring in masonry, the use of anchors in block walls is not recommended. 2d C. REGULATORY POSITTON 26 The following regulatory' positions describe minimum recommendations to 27 qualify, design, install and inspect steel embedments installed in concrete to 28 support components and structures. They are applicable to the types of 29 anchors discussed in Section B1 of this guide and in Section B.2 of Appendix B 1 30 to ACI 349-80. The procedures and requirements of Appendix B to ACI 349-80 31 are acceptable to the HRC staff as supplemented below. 7

L f-1 1. GENERAL 2 1.1. The concrete' constituents and embedded materials s'hould be compatible 3 with the anticipated a?vironmental conditions to which they will be subjected 4' during the life of the plant. 5. 1.2 Loads and forces on embedments should be properly evaluated to { 6 account for baraplate flexibility and eccentricity of connections, and the-7 dynamic (strain rate and low cycle fatigue) effects of loads and forces. l 8. 1.3. The hardness, saterials, and heat treatment.nf high strength enchor 9 bolt and studs (Fy > 110 ksi) should be carefully controlled to prevent 10- environmental and stress corrosion cracking. 11. 2. QUALIFICATION OF ANCHORS 12 2.1 General i 13 The test'ing requirements defined in ANSI /ASTN E488-76 " Strength of 14 Anchors in Concrete and Masonry Elements" (Reference 5) are acceptable to the 15 NRC staff as a guide for establishing a testing program. Test methods not 16. covered by ANSI / ASTM E488-76 (e.g., combined tension and shear loading) should 17 be established and executed using good engineering judgement. 18 Installation of anchors during performance tests should represent adverse 19 combinatt of variations in instal,1ation parameters. Failure during testing 20 is defined as a slip of indh or more from the original installed position. W 21 '2. 2 Standard Anchors and Inserts 22 The requirements of Sections B.8 and B.9 of ACI 349-80, Appendix B, for 23 testing standard anchors and inserts are acceptable with the following 24. exceptions: 25 1. Instead of the requirements of Section B.4.1, which is referenced in 26 Section B.9, the guidance of regulatory position C.3.2 should be used. 27 2. See regulatory position C.3.3.1 for other exceptions. 8 4

) 1 1 2.3 Performance Tests For Expansion Anchors i 2 Expansion anchors should be tested in accordance with the following: 3 1. A sufficient number of tests of each type and size of expansion 4 anchor should be conducted to detensine the ultimate strength of the anchor 5 for each class of concrete. Tests should include tension, shear, and combined 6 tension-shear loads under static and cyclic loadings. ? 7 2. The ultimate strength for expansion anchors should be based on the 8 static tensile (R ) and shear (R ) strengths. Ultimate strengths should be T 3 9 established for each anchor type and size through an appropriate sampling 10 program. The sampling program and its statistical evaluation should ensure a 11 95% confidence level that the ultimate strength of 95% of the anchors will be 12 equal to or greater than the established ultimate strength. 13 3. Each anchor size and type should be subjected to and meet the cyclic 14 load test conditions described below. For each type of anchor, at least three 15 samples of each size should be tested under tension, shear, and combined 16 tension and shear load conditions. 17 1. Number of cycles and frequency 18 Low - 200 at 5 Hz 19 High - 1,000,000 at 8'O Hz 20 2. Lcw and high-load cyclic tests of approximately equal cycles should 21 be run at the load increments of 0.2R ranging from > 0.0R to 1.0R, where 22 R = ultimate static tensile or shear strength of anchor l l 23 3. Design of Anchors 24 3.1 Loads 25 For the design of the types of anchors considered in regulatory l 26 position C.1.2 of this guide, the requirements specified in Sections B.6, B.7, I I 1 9

1 1 B.8, and li.9 of ACI 349-80,. Appendix B, are acceptable with the following 2 exceptions: -3 '1. Instead of the requirements of Sections B.7.1.1 and 8.7.2 the guidance 4 of regulatory positions 2.3.1, 2.3.2, and 3 should be used. 5 2.- For strength. reduction factors see regulatory position 3.3. l1 6

3. 2 Load Combinations l

7 Reactions on anchors due to individual loads such as. dead, live, thermal, 8 wind, seismic, and accident loads as covered in regulatory postion 3.1 of this 9 guide should be considered. The loading combinations for all types r" anchor 10 design should be in accordance with the following: 11 Loads Definitions, and Nomenclature 12 Loads, definitions, and nomenclature are in accordance with those of f 13 Chapter 9 of ACI 349-80. I 14 Load Combinations for Anchors 15 Normal and Severe Environmental Loads 16 1. D + F + L + H + T, + R, 17 2. D + F + L + H + E, + T,_+ R3 18 3. D + F + L + H + W + T, + R, 19 Normal, Abnormal, and Extreme Environmental Loads 20 4. D + F + L + H + T, + R, + Wt 21 5. D + F + L + H + T, + R,+ 1,5 P, j + Y,) + E,, . 22 6.' D + F + L + H + T, + R, + P, + (Y +Y r 23 3.3 Strength Reduction Factors l 24 3.3.1 Standard Anchors and Inserts 25 The strength reduction factors for standard anchors and inserts of 26 sections B.8 and B.9 of ACI 349-80, Appendix B, are acceptable with the 27 following exceptions: 10 _m_._____

.,o 1 For load combinations 1, 2, and 3 of regulatory position 3.2, the strength 2 reduction factors should be: ~ 3 1. In Section B.8.2; 5 = 0.2. 4 2. In Section B.6.2.1 which is referenced in Section B.9; i = 0.54. 5 3. In Sectica B.6.2.2.1 which is referenced in Section B.9; i = 0.33. 6 For load combinations 4, 5, and 6 of regulatory position 3.2, use strength 7 reduction factors given in appropriate sections of ACI 349-80, Appendix B, 8 except that in Section B.8.2, 9 = 0.33 should be used. 9 3.3.2 Expansion Anchors 10 The following strength reduction factors for all types of expansion 11 anchors are recommended: 12 For load combinations 1, 2, 'and 3 of regulatory position 3.2, 6 = 0.2. (o 4 # 13 For load combinations 4, 5, and 6 of regulatory position 3.2, # = 0.33. (5 4 El l and R as 14 These strength reduction factors are to be applied to RT 3 15 defined in regulatory position C.2.3.1. 16 4. INSTALLATION i l-17 4.1 Standard Anchors and Inserts 18 The requirements of Section 8.10 of ACI 349-80, Appendix B, should be 19 used in the installation of standard, anchors and inserts. 20 4.2 Expansion Anchors 21 Expansion anchors should be preloaded to a load equal to or greater than 22 the maximum allowable load (i.e.,.33R )" T 1 23 5. INSPECTION 24 The following recommendations apply to the types of anchors considered in F.5 regulatory poition C.1.2 of this guide. 26 Anchors should be inspected to verify that they are of the specified size 27 and type. Installation requirements should be consistent with accepted speci-28 fied tolerances and regulatory position 4. Anchor systems that are external 11

m I to the concrete surface should be subject to inservice inspecti,on requirements 2 equivalent to that applicable to a component support or structural member in 3 the load path. 4 6. ANCHORING IN CONCRETE MASONRY 5 The following recommendations apply to the types of anchors considered in 6 regulatory position C.1.2 of this guide. 7 The NRC staff does not recommend the use of anchors to attach seismic 8 category I components or systems to concrete block walls that are seismically 9 qualified, except for extremely low load applications. In locations where it 10 is impossible to avoid the use of anchors the staff recommends bolting through l 11 the block wall. l l 12 0. IMPLEMENTATION 13 This proposes e h has been released to encourage public participation s 14 in its development. wept in those cases in which an applicant proposes an l 15 acceptable alternative method for complying with specified portions of the 16 Commission's regulations, the method to be described in the active guide 17 reflecting public comments will be used in the evaluation of thu following 18 applications that are docketed after the implementation date to be specified 19 in the active guide: 20 L Preliminary Design App'roval (PDA) applications and Preliminary 21 Duplicate Design Approval (PDDA) applications. 22 2. Final Ocsign Approval, Type 2 (FDA-2), applications and Final 23 Duplicate Design Approval, Type 2 (FDDA-2), applications. 24 3. Manufacturing License (ML) applications. 25 4. Construction Permit (Cp) applications except for those portions of Cp 26 applications that reference standard designs (i.e., PDA, FDA-1, FDA-2, PODA, 27 FDOA-1, FDDA-7, or ML) or that reference qualified base plant designs under 28 the replication option. 29 5. This guide is being recommended for n2w plant design; thus the 30 guidance given need not be backfitted to plants operating or under 31 construction. 12

~. 1 Evaluation of existing expansion anchors performed according to IEB 79-02 2 followed by any appropriate modification will be considered to have satisfied 3 the recommendations of this guide. 4 E. REFERENCES 5 1. " Anchorage to Concrete," Research and Development Report No. CEB 75-32, 6 Civil Engineering Branch, Tennessee Valley Authority, Knoxville, Dec. 7 1976, 25 pp. 8 2. McMackin, P. J., Slutter, R. G.; and Fisher, J. W., " Headed Steel Anchors 9 Under Combined Loading," AISC Engineering Journal, 2nd Quarter, 1973, 10 pp. 43-52. 11 3. Bailey, John W., and Burdette, Edwin G., " Edge Effects on Anchorage to 12 Concrete," Civil Engineering Research Series No. 31, The University of 13 Tennessee, Knoxville, Aug, 1977, 21 pp. 14 4. ACI Comittee 318, " Commentary on Building Code Requirements for 15 Reinforced Concrete (ACI 318-71)," American Concrete Institute, Detroit, 16 1971, 96 pp. 17 5. " Standard Test Methods for Strength of Anchors in Concrete and Masonry 18 Elements," (ANSI-ASTM E 488-76),1976 Annual Book of ASTM Standards, 19 Part 18, American Society for Testing and Materials, Philadelphia, 20 pp. 843-851. 21 6. Adams, Robert F., "Some Factors Which Influence the Strength of Bolt 22 Anchors in Concrete," Journal of the American Con' rete Institute, JACIA, c 23 Vol 52, October 1955, pp.131-138. 24 7. Mechanical Fasteners for Concrete, Publication SP-22, American Concrete 25 Institute, 1969. 26 8. Vennedy, T. B., and Crawley, W. 0., " Tests of Anchors for Mass-Concrete 27 Foms," Journal of the American Concr9ta Institute, JACIA, Vol. 52, 28 October 1955, pp. 139-147. 29 9. Reichard, T. W., Carpenter, E. F., and Leyendecker, E. V., " Design Loads 30 for Inserts Embedded in Concrete," U.S. National Bureau of Standards, 31 Bldg. Sci. Ser. 42, May 1972. 32

10. Stowe, R. L., " Pullout Resistance of Reinforcing Bars Embedded in 33 Hardened Concrete," U.S. Army Engineer Waterways Experiment Station 34 Concrete Laboratory, Vicksburg, Miss., June 1974.

35 11. U.S. Nuclear Regulatory Commission, IE Bulletin 79-02, " Pipe Support Base 3G Plate Design Using Concrete Expansion Anchor Bolts", March 1979.

4 1.112. Teledyne Engineering Services, Technical Report TR-3501-1, " General 2 Response:to USNRC IE Bulletin 79-02, Baseplate / Concrete Expansion Anchor .3 Bolts", August 1979. 4

13. American Concreta Institute, " Code Req'uirements for Nuclear Safety Rela ed S'

Concrete Structures -(ACI 349-60)", Appendix B,1980 Supplement. i 6

14. Hanford Engineering Development Laboratory, HEDL TC-1116, " Concrete 7

Expansion Anchor Tests Performed at the Fast Flux Test Facility", August 8 1978. 9

15. Tennessee Valley Authority, Civil Design Standard for Concrete Anchorages 10-05-C5.1.

Rev. 1, August 1976. 14 l i

a 9 h L 1-WORKING PAPER A 0F 2' DRAFT REGULATORY GUIDE MS 129-4 3 ANCHORING COMPONENT AND. STRUCTURAL SUPPORTS IN CONCRETE 1 4 A. INTRODUCTION ( 5 General Design Criteria 1, " Quality Standards and Records," 2, " Design 6 Bases for Protection Against Natural Phenomena,".and 4, "Enviroasental and ,7 Missile Design Bases," of Appendix A, " General Design Critaria for Nuclear 8 Power Plants," to 10 CFR Part 50, " Domestic Licensing of Production and Util-9 ization Facilities" require, in part, that structures, systems, and components 10 important to safety be designed, fabricated, erected, and tested to quality 11 standards commensurate with the importance of the safety functions to be per-12 formed. Appendix B, " Quality Assurance Criteria for Nuclear Power Plants and 13 Fuel Reprocessing Plants," to 10 CFR Part 50 requires, in part, that a quality 14 assurance program be established to control design, procurement, materials, 15' special processes, inspection, and testing. This guide describes a method ~ 16 acceptable to the NRC staff for complying with the Commission's regulations 17 with regard to anchors (steel embedmonts) used for component and structural 18 supports on concrete structures. 19 B. DISCUSSION 20 GENERAL 21 Component supports and structures are fastened to concrete by means of 22 anchors (steel embedments) that transmit forces to the concrete structure by 23 bearing or shear. Recent history of operating reactors has indicated a level 24 of uncertainty regarding the performance of one type of anchoring device, that 1 25 is the expansive type of anchor. Questiens concerning the performance of 26 expansion anchors led to the issuance of an Inspection and Enforcement 27 Bulletin, IEB 79-02, " Pipe Support Base Plate Designs Using Concrete Expansion J 28 Anchor Bolts," in March of 1979. The basic items addressed by IEB 79-02 were 29 the reevaluation of baseplates for fisxibility, safety factors, quality 30 control, and inspection during and after installation of anchors. l { _--_.____m__-.____

6t/dlO6df'E 5 1 WORKING PAPER A. VALUE/ IMPACT STATEMENT FOR ORAFT 2 REGULATORY GUIDE MS 129-4 " ANCHORING COMPONENT AND 3 STRUCTURAL SUPPORTS IN C0" CRETE" 4 1. PROPOSED ACTION 5 1.1 Description e 6 The proposed action vill provide regulatory guidance on reliable methods 7 for qualifying concrete anchors. The proposed action will also provide infor-8 mation on the acceptability for NRC licensing actions of Appendix B " Steel 9 Embedments," of ACI 349-80, " Code Requirectnts for Nuclear Safety Related 10 Concrete Structures," published by the American Concrete Institute. In areas 11 where the referenced code is insufficient for licensing purposes, supplement-IT. ary guidelines will be stated. 13

1. 2 Need for Proposed Action 14 In a typical nuclear power plant various types of anchor devices are used 15 to anchor components and structures in concrete. Since the issuance of an 16 Inspection and Enforcement Bulletin, IEB 79-02, " Pipe Support Base Plate 17 Designs Using Concrete Expansion Anchor Bolts," considerable attention has been 18 focused on the evaluation of the types of expansion anchor devices used for 19 component supports. Review of reports required by IEB 79-02 from licensees 20 and applicants has revealed that current industry practices vary. Also, there 21 is no consistency in the design and installation of such anchors as grouted 22 anchors, embedded plates, or shapes and inserts. Thus, it is the intent of 23 the proposed action to provide a consistent approach for evaluating anchor 24 devices used for componaat and structural supports.

1

1. 3 Value/ Impact of Procesed Action 2

1.3.1 NRC Operations 3 A consistent approach to the evaluation of anchor devices will be benefi-4 cial to NRC license reviewers and will help NRC inspectors to verify Itcensee 5 adherence to licensing requirements and commitments. 6 1.3.2 Other Government Acencies 7 Not applicable. 8 1.3.3 Industry 9 As a result of IEB 79-02, ifcensees are aware of problems in this area. 10 The proposed action will provide guidance to the industry and thus reduce 11 uncertainty as to what is acceptable. No negative impact on the industry is 12 expected. 13 1.3.4 Public 14 The public, including plant operating and maintenance personnel, will 15 benefit from the added assurance of safety provided by properly anchored 16 component supports. 17

1. 4 Decision 18 This proposed action should be undertaken.

19 2. TECHNICAL APFROACH 20 2.1 Technical Alternatives 21 An attempt will be made in the proposed guide to provide a consistent 22 approach in methods to qualify, design, and install anchor devices used for 23 component and structural supports. Public comme.s may indicate equally 24 acceptable technical alternatives. 2

'8 4 1-3. PROCEDURAL APPROACH 2 3.1 Procedural Alternatives 3 Establish guidance and endorse ANSI Standard (ACI 349-80, App. R)'with 4. exceptions in: 10 CFR Part 50 5 Combine with R.G.1.142 " Safety-Related Concrete Structures for .6 7 Nuclear Power Plants (Other than Reactor Vessels and Containments)" NUREG Report 8-Branch Position 9 Separate regulatory guide. 10 11 ,3.2 Discussion of Procedural Alternatives l- - 12 At this time, an amendment to 10 CFR Part 50, the issuance of a NUREG 13 report or a branch position is not practical for use by NRC reviewers, 14 licensees, and applicants. 15 Combination with Regulatory Guide 1.142 is not recommended for the 16 following reasons: ~ 17 1. In anchoring' component supports, separata qualifications for anchor 18 components are needed which are not covered by ACI 349-80, App. 8. 19 2. Load combinations for supports and concrete structures differ. 20 3. Developing a reliable method of qualifying expansion anchors required 21 extra effort and' time, and thus would have delayed the processing of the current 22 revision to Regulatory Guide 1.142. 23 Endorsement of ACI 349-80. App. 8, in a separate regulatory guide is the 24 most straightforward approach to providing infomation and guidance in this 25 area. 26 3.3 Decision on Procedural Approach i 27 A separate regulatory guide should be issued. 1 3 9 e - - - - _ ~ _ - _ _. _ - _ - _ _ - _ _, _ _. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _, _ _ _ _ _ _ _ _ _ _ _ _ _ _

e 1 4. STATUT0i CONSIDERATIONS 2 4.1 NRC Regulatory Authority 3 General Design Criteria 1, 2, and 4, " Quality Standards and Records," 4 " Design basis for protection against natural phenomena," and " Environmental and 5 missile design basis," respectively of Appendix A to 10 CFR Part 50, " Domestic 6 Licensing of Production and Utilization Facilities" require, in part, that 7 structures, systems, and components important to safety be designed, fabri-l 8 cated, erected, and tested to qualify standards commensurate with the impor-9 tance of the safety functions to be performed. Appendix B, " Quality Assurance 10 Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," to 10 CFR 11 Part 50 requires, in part, that a quality assurance program be established to 12 control design, procurement, materials, special processes, inspection, and 13 testing. 14 4.2 Need for NEPA Statement 15 The proposed action is not a major action, as defined by 10 CFR 16 551.5(a)(10), and does not require an environmental impact statement. 17 5. RELATIONSHIP TO OTHER EXISTING OR PROPOSED REGULATIONS OR POLICIES 18 5.1 Relationship with Regulations or Policies of Other Government Agencies 19 This guida does not impact any known regulations or policies of other 20 Government agencies. 21 5.2 Relationship with Other NRC Regulations and Policies 22 The proposed regulatory guide is intended to be used in conjunction with 23 the following NRC documents currently being written or revised: 24 1. Proposed Regulatory Guide " Criteria and Jurisdictional Boundaries for 25 Load Path Members in Component Support Systems" (Task No. SC 114-4). 26 2. Regulatory Guide 1.142, " Safety-Related Concrete Structures fo'r 27 Nuclear Power Plants (Other Than Reactor Vessels and Containments)." 4

__n

Je \\ ~ J L I' 1 5.3 Relationship with National Standards-2 The proposed guide say reference sections of the following national 3' - standards: 4 1. ASME Sections III~and IX 5 2; AISC Steel Building Code i 6 3. ACI 349 7 '4. Oraft ANSI Standard N690 (Nuclear Building Specifications) i-8 - 5. ANSI Standard N45.2 9 6. ANSI / ASTM E488-76 l 10 6.

SUMMARY

AND CONCLUSIONS 11-Guidance on methods of. qualifying anchors aM ar, endorsement of ACI 349-80, 12 App. B, should beLeada.in a separate regulatory guide with certain exceptions 13 and supplements. Consideration will be given to incorporating the proposed 14 guide in Regulatory Guide 1.142 at a later date. 15 7. IMPLEMENTATION o. 16 This guide is recommended for use in reviewing new applications. At 17 present, expansion anchors have been reviewed and accepted in accordance 18 with the criteria of IEB 79-02. Implementation of the' recommendations of this 19 guide, which are at places different from the recommendations of IEB 79-02, does 20 not infer that the present practice is unacceptable. Thus, IEB 79-02 is recom-21 mended for use until the time this guide becomes active. From the above, it 22 is concluded that to backfit these recommendations would be unnecessary.- 23 In addition, it is estimated that there is not a resulting risk reduction 24 that would justify applying the guide recommendation to plants that have already 25 complied with the recommendations of IEB 79-02. L m _m_.._.-._ _____.m______.__._____._m.-____._______--.-

/'. NUCt 1AR SAFETY STRUCTURES CooE 349 75 s (c) All concurrent loada, as specified in Section 9.2. A.4 - Concrete temperatures are considered. A.J.! - The following temperature limitations are for - (d) The coe of thermal expansion may be ~ " ' '"Y ' # I "8 " " d' D 1 taken ss 5.5 x 10' eg F unless other values are temperatures shall not exceed 150 ept for local substantiated by " tests. areas such as around penctrati hich are a!! owed A.J.4 When thermal stress'is gbined with the to, have increased tempe not to exceed 200 F. stress due to other loads to determine a desi' stress, the magnitude of the design stress must not be than A.4.2 - The foll mg temperature limitations are for accident or other4hort term penoJ. The tempera-the magnitude of the stress due to other loadings I unless the following are considered: tures not exceed 350 F for the surface. However. areas are allowed to reach 630 F from steam or (a) The effect of cracking in the tensile zone of wate'P in the event of a pipe failure. flexural members on reduction of the flexural rigi I

and on the redistribution of stress.

- A.4.3 - Highe peratures than those given in Sec-tions A.4.1 and A.4.above may be allowed for con-L (b) The reduction of long term stresses due to creep. crete if tests are provide evaluate the reduction m g l strength and this reduction applied to design (c) Stress combinatio at reduce the magnitude of allowables. Also, evidence shall ivided which the stress due ther loads utilizing actual tem-verifies that the increased temperatures otcause peratures, temperature distributions which act deterioration of the concrete either with or ,out concurrently with the other loads. load. Eddl OsdrA 1 l APPENDIX B - STEEL EMBEDMENTS D B.1 - Scope q ~ D.0 , Notation a = dimension, out to out of bearms edges (see B.I.'1 - This appendix pmvides minimum require-J Fig. B.4-2), in. ments for design and anchorage of steel embedments A, = reduction in projected area, sq. in. used to transmit loads from attachments into reinforced A, = loaded area. sq. in.- concrete structures by means of tension. bearing. A, = maximum area of the portion of the support. shear, friction, or any combination thereof. ing surface that is geonistrically similar to and Tvpical embedment details and concepts as referenced concentric with loaded area, sq. an.- in this appendix are shown in Fig. B.1-1 and B.12. - b = dimension, out to out of taaring edges (see Fig. B.4 2). in. In addition to meeting these requirements considers- ' D = major thread diameter of threaded anchor or tion shall be given to the effect of the forces applied to nominal diameter of anchor. in. the embedment on the behavior of the overall structure. f,. = specified compressive strength of concrete. ' psi B.1.2 - The requirements for the attachment to the f, = minimum specified tensile strength of anchor embedment shall be in accordance with applicable steel, psi codes and are beyond the scope of this appendix. f. = minimum speci6ed yield strength of embed. ment steel psi B.1J - Design limia less conservative than those l h = overall thickness of member, in. speci5cd in this appesiix may be used by the Engineer L, = embedment depth for tensile anchorage if substantiated by experimental or detailed analytical measured from anchorage bearms surface to investigation. concrete surface, in. m = minimum side cover distance from the center D.2 - Definitions of an anchor to the edge of the concrete. (see Ancher head - A nut, washer, plate, stud. or bolt head fof threads per in. or other steel component used to transmit anchor loads I a = t the concrete by bearing. P, = design pullout strength of concrete in tension. Ib Astachmear -The attachment is that structure external U = required strength, to resist factored loads. lb to the surfaces of the embedment which transmits loads 4 = strength reduction factor, dimensiosless to the embedment.

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NUCl.EAM SAFETY STRUCTURES CODE 349.rr i Embedment -The er, bedment is that steel component B.4 - Design ret {uirements for concrete j in contact with the concrete or grout used to transmit j B.4.1 - The design provisions of this appendix are applied loads to the concrete structure.The embedment based on the strength design method.The assumptions. may be fabricated of plates, shapes. bolts, reinforcing principles, and requirements of the Code are applicable bars. shear connectors, expansion anchors, inserts, or for allI ad combinations except as modified herein. any combination thereof. Fy==< ion aseher - A component installed in hardened B.4.2 - Tension concrete for the transfer orloads into structural compo-The design strength of concrete f, for any anchorag nents by direct bearing and/or friction. shall be based on a uniform tensile stress of 44Vr? Croserd Embedmenes - An'embedment located in a acting on an effective stress area which is defined by the formed or drilled hole in hardened concrete utilizing a projected area of stress cones radiating toward the at-i grout to provide load transfer from the embedment to tachment from the bearing edge of the anchors. The effective area is limited by overlapping stress cones, by the concrete. the intersection of the cones with concrete surfaces, by Inserer - Commercially available, predesigned. and the bearing area of anchor heads, and by the overall prefabricated embedmonts installed prior to concrete thickness of the concrete (see Fig. B.41 and B.4 2), placement which are specifically designed for attach-The inclination angle for calculating projected t.reas j ment of bolted connecuons, shall be 45 deg. The e factor shall be taken as 0.65 for an i embedded anchor head unless the anchor head is be-l B.3 - General requirements and loading yond the far face rem, forcement. In such cases a e factor . combinations of 0.85 may be used. B 3.1 -The embedment and surroundtag concrete or BM - Sear grout shall be designed for transmitting to the concrete structure allloeds used in the design of the attachment. The design shear strength of anchors subject to shear shan satisfy me mqdmmenu d Mns BJ.lJ and BJ.2 - Reactions on the embedment due to individual B.6.2.2. loads such as dead. live (including vibratory loads). thermal. seismic. and accident loads shall be consid-B..t.4 - Reit forcement ered. The loading combinations for embedment design (Y shau be in accordance with Section 9.2 of this Code.

- "9 "".enu d Secu.on BJ are not satishd.

reinforcement snail,oc provided to develop the required B.J.3 - Material and testing requirements for embed-strength. Reinforcement requirements shall be in ac. ment steel shall be compatible.with the material and cordance with applicable sections of this Code and testing requirc.sents for the attachment. placed to prevent failure of the concrete in tension. BJ.4 - The design strength of embedment materials B.4J - Bearing may be increased in accordance with Appendix C for B.4.5.1 -The bearing restrictions of Sections 10.16 or embedments subject to impactive and impulsive loads. 18.13 shall apply to the maximum compressive stress BJ.5-De strwnsth of embedments as affected by the under the anchor head for all supporting surfaces where size and grade of steel. spacing. and depth of embed-VAJA,is equal to or less than 2. ment and any concate dimensions which limit or re-B.4[3.2 - Anchor heads other than those specified in strict the transfer oficads from steel to concrete shall be Secuon B.4.5.1 shall meet the requirements of Section considered as defined in Sections B.4, B.5, and B.6. - B.5.1.!(w. BJ.6 - Piartic deformation of the embedment is per-

nitted forimpactive and impulsive loading provided the B.5 - Anchorage requirements strength of the embedment is contmued by the strength BJ.1 - Anchorage design shall be controlled by the of the embedment steel as speci5ed in Section B.S. For these conditions a maximum ductility ratio of 3 may be

s. trength of embedment steel unless otherwise specified in this appen6x.

considend. The definition of ductility ratio shau be as de6ned in Appendtx C. BJ.1.1 -Tension BJ.7 - Shear lugs that meet the requimments of Sec-Steel strength controls when the design strength of the tion B.5.1.2fb) shall be considered effective only when conente 7, as determined in Section B.4.2 exceeds the located in a concrete compression zone developed be-minimum specified tensile strength of the tensile stress tween the embedment and the concrete and transverse component of the embedment steel and full load trans-to the direction of the shear force for a given load fer is accomplished from steel to concrete within the combination. depth of the anchorage by one of the foto wing methods: B.3.3 - A corr.bination of bearms and shear friction (a) A mechanical anchor at the base of the tensile mechanisms shall not be used to develop the required stress components having a minimum gross area of shear strength denned in accordance with Section 9.2. anchor head (including area of the tensile stress com-

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c .t ammm aau wan.;rnuctuwu couk ase.75 m ponent) equal to at least 2.5 times the tensite stress ' > hall not exceed liv.000 psi. The coetlicient of friction i area of the embedment steel. To prevent failure due n shall be 0.9 for concrete or grout placed against as- .E* to lateral bursting forces at an anchor head, the side rnt'ed steel with the contact plane a full plate thickness cover distance m shall not be less than: below the concrete or grout surface: 0.7 for concrete or ) '. grout placed against as. rolled steel with contact plane m=0 Ss coincidental with the concrete surface: 0.5! for grooted 56 V// conditions with the contact plane between grout and unless the requirements of Seedon B.4.4 are met. as rolled steel exterior to the concrete surface. (b) Reinforcing bars with development lengths in ac-n.5.3 - Combined tension and shear cordance with the requirements of Chapter 12. for 8.6.3.1,- For structural shapes and fabricated steel anchor steel composed of reinforcement. ins 4e b shall WesiM fwehe BJ.l.2 - Shear f'anges designed for the tension, compression. and "8' (a) For embedment steel of anchor bolts. studs or bars to control the design shear strength, the side 3.6.3.2 - For bolts, studs, and bars the area of steel cover distance m for shear loading toward a free edge required for tension and shear shall be considered shall not be less than: additive. B.6.4 - The tensile stress area of a threaded stichor ,,p fg ~- Shall be taken as: V 7.5 vf;. unless the requirements of Section B.4.4 are met. 0.7854 D bE'd ~ (b) For shear lugs bearms in the direction of a free edge, the concretc design shear strength shall be de. where D is the major thetad diameter and n is the termined based on a uniform tensile stress of 46v7~ number of thrwads per in. acting on an effective stress area de6ned by project. B.6J-The tensile stress area of Section B.6.4 shall be fag 45 des planes from the beanns edges of the shear applied to all threaded anchors subject to direct tensile lug to the free surface. Bearing area of the shear log and shear stress. If the threads are excluded from the sha!! be excluded from the projected area. The e shearing plane the gross area may be used for deter. -) thetor shall be taken as 0.85, mining the shear stress. BJ.1J ~ For combined tension and shear.' the depth of embedment shall be in accordance with Section B.5.1.1 B.7 - Expansion anchors 4 I and the rainimum edge distance in accordance with Th.is section provides minimum requirements for the Section B.S.I.2(a). design of typical expansion anchors used in nuclear BJ.1.4 - Side cover distance shall not be less than safety related concrete structures and does not restrict m/3. Under no conditions should the edge distance be the use of other expansion anchors provided the expan-less than the concrete cover requirements.for rein-sion anchors are designed and tested in accordance with ( forcement in Section 7.7. the requirements of this section. h B.6 - Design requirements for embedment B.7.1 - Design requirements steel Expansion anchors shall be designed to assure that the B.6.1 - Embedment tasterial sha!! be defined by the design strength of concrete for a given expansion an-Engineer in speci5 cations and design drawings. chor or group of expansion anchors is greater than the strength of the anchor steel except as permitted in Sec. B.6.2-The design strength U for embedrnents shall be tion B.7.2. This requirement shall be met by satisfying based on a maximum steel stress of ef,. The foi-the requirements of Secuens B.7.1.1 or B.7.1.2. lowing values for 4 shall be used: B.7.1.1 - Design by analysis B.6.2.1 - Tension, compression, and bending (a) Tension: The design pullout strength of concrete 4 = 0.9. P, shaR be as defined in Section B.4.2 except that the effective stress area snall be defined by the projected 5.6.2.2 - Shear area of the stress cones radiating toward the concrete 3.6.2.2.1 - Structural shapes and fahrtented steel see-surface from the innarmost expansion contact sur. ($ times and shear lugs fbce between the exansion anchor and the drilled hole. Refer to Fig. B.7-1 for typical details. The de-4 = 0.55. sign pullout strength of concrete shall be equal to or B.6.2.2.2 - The shear. friction provisions of Section greater than the minimum spectfied tensile sternsth 11.7(as herein modified) may be applied to bolts, studs, or average tensile strength if a minimum is not de-and bars using a e of 0.85. The design yield strength /, fined for the expansion anchor. The minimum edge

~. j l. 34600 aClSTANCARD distance shall be twice the requirement of Section B.7.3 - A single expansion anchor used to anchor an I B.5.1.l(a). attachment shall be designed for one-half of the design I strength defined herein. (b) Shear: The design shear strength of expansion anchors subject to shear shall be in accordance with B.7.4 - Testing ( ) g the requirements of Section B.6.2.2 and the minimum B.7 4.1 - Expansion anchors designed in accordance edge distance requirement of Secuan B.S.I.2(ahhall with this appendix shall be tested to verify anchorage strength or to determine the average test failure load. j (c) For combined tension and shear, the depth of Tests shall be conducted by a testing agency other than i embedment shall be in accordance with Section the anchor manufacturer and shad be certified by a q a B.7.1.l(a) and the mimmum edge distance in accor. Professional Ecgineer with full description and details j I dance with Section B.7.1.l(b). of the testing program, procedures, results, and conclu-sions. \\ l B.7.4.2 - The expansion mechanism of the anchor I shall be tested for the installed condition by one of the 8 following methods:- - - - - ' W.*? (a) The mechanism shall be actuated and tested dur-E,N, Y,s. ' j% ing installation by preloading the expansion anchor to j .."y a mmimum value as speciSed by the Engineer. j <r /. ' O i .g.5.- % ?. ,,. - g- (~y (b) A random selection of the installed anchors shall j "'S * % -4 gg, y I be load tested to 100 percent of the required str-ngth. The testing program shall be established by the v. Engm, eer. i Q. jg., /.. 1 B.7.5 - Expansion anchor selection Li! t N -= ..'.n The Engineer shall review the expansion anchor design ~ f featurn. FMhw mades. te<r results, and installation l "]C_$ procedures prior to selecting a specific expansiort an-(' i i l *- chor for an application. Expansion anchors and an-3 chorage mechanisms shall be selected that compernate [ T,,. . 7'. r for tension cracks and maintain required strvngth when w%, N.,"l% / g/. 5j,,/ the expansion anchors are installed in the tension zones \\.3-of concrete members. / (, N i **i. /. -, V T..% i B.8 - Inserts t g,[.* I'y /'.. Concrete inserts shall be specified in accordance with .v--r w c= s s I. Section B.6.1 and tested in accordance with Section i B.7.4.1. B.8.1 - Design requirements I Rg. B.71-7ypical cletails of expansion anchors Design allowables shall be based on actual test data of l tests performed on inserts embedded in concrete. The tesu shall cover the full range of possible loading con-B.7.1.2 - Design by testing Tests shall be conducted to verify that the concrete wiU develop the steel strength of the expansion anchor. B.8.2 -Strength reduction factor Design by test results shall be restricted to tests that are A 6 factor of 0.5 shall be applied to the average test representative of the anchor spacing and load apphea. failure loads in detennining strength requirements. tion. u etn enu B.7.1.3 - Strength reduction factors B.9.1 - Gmuted emWmems M meet me ap%csW The requirements of Section B.6 shall apply except that requirements of Sections B.4. B.5 and B.6. the 6 factors for expansion anchors shall be 0.9 times the values specified in Section B.6.2. B.9.2 - For general grouting purposes the material 8 requirements for cement gmut douM M in acMance B.7.2 - Alternative design requirements with Chapter 3 of this Code. Special grouts used to For expansion anchors that do not meet the require-achieve certain properties such as high strength, low i ment of Section B.7.1. the design strength shall be 0.33 shrinkage. or expansion shall be the responsibility of times the average test failure load. the Engineer and specified in the specifications.

NUC1. EAR SAFETY STRUCTURES CoCE 343 33 g F B.10 - Fabrication and installation pansion of the embedmant which could result in Welding of attachments to large embedments shallbe in detrimental,spalling or cracking of the concrete or ex-accordance with good practice to avoid excessive ex. cessive stress in the embedment anchors. I, APPENDIX C - SPECIAL PROVISIONS FOR IMPULSIVE AND s IMPACTIVE EFFECTS C.0 - Notation pendix.nese loads must be combined with o rloads with Section 9.1 of this C e and in A, = area o are of spirally reinforced column

- - Y N.

.8 of this o the outside diameter of the spi-appendix. Impactive and impulsive etJects are treated measur separately herein because of the nattsre of the effects as j- = area f rectangR ar core of column measured well as the response charactensues of the structural l Ana otst-to-out of hoop, sq m. elements subjected to these loads. j A, = grost area of sectioq, sq in. A, = are; "f tension ret orcement within the C.I.2-The provisions of t appendix apply to those structural elements direc affected by the impactive ' width b, sq in. A', = areaofcompressionrei orcement within the and impulsiveloads and here failure of the structural widt!. b, sq in. \\ elements must be precluded. ? A, = arca of transverse hoop bar (one leg), sq in. g_ g g g "e ma e to n ements less consen = das ce fro e me orrip essi fiber to ,{ p y, neutral axis at ultimate strength, in. y C.I.4-Jtnpactive loads are time-dependent loads duc g(4 4 = effective depth of section (distance f ex. %F treme compressive fiber to centroid of te ile to collision of masses which are associated with finite reinforcement), in, amoc'nts of kinetic energy. Impactive loading may be f,, = specified compressive strength of concrete, defined in terms of time-dependera force or pr:ssure. psi Impactive loads to be considered shall include, but not f, = specified yield strength of'nonprestressed limited to, the following types ofloading: n ps Tornado generated missiles k h = I,, = moment of inertia of cracked sectios s. (b) 'pping pipes nned to gnente /. (c) Aircraft missiles I, = moment of merna of gross concrete section x about centroida.1 axis, neglectir reinforce. (d) Fuel ca%k drop ("I imum unsupported ten of rectangular l. = hoop measured between rpendicular legs C.I.5 - Impulsiv loads are time-dependent loads of the hoop or supple ntary crossties, in, which are not associat with co!!ision of solid masses. = rotational capacity,[ capacity) Impulsive hds to be co 'dered sitallinclude, but not dians r, = re stance (i.e., I be limited to, the following pes of loading: R s. = center to-cen pacing of hoops,in. (a) let impingement 4 p, = ductility [o, dimensionless @ Blast pressure X., = maximu acceptable displacemer:t X, = disp! ment at effective yield point (c) Compartment pressurization = thejfinforcement ratio = A,/bd (d) Pipe-whip restraint reactions p p, = the remforcement ratio = A,,/bd tio of volu'ne of spiral reinforcement t h C.2 - Dynamic strength increase p, = iy total volume af core (out-to-vut of spirals) C.2.1 - Dynamic increase factors (DIF) appropriate {' for the strain rates involved may be applied to statie / C.1.1 - Nuclear safety-related concrete structures material strengths of steel and concrete for purposes of shall be designed for impulsive and impactive loads determining s:ction strength but shall not exceed the f using this Code and the special provisions of this ap-following: 1 i

NuCLEAA sMETY STRUCTURES CooE 346 27 l 8 - Joist construction not m eting the point. Conduus or pic;s snill not irgpatr i limit s of Sections 8.11.1 througn 8.11.3 small significantly the strength of the constructtdfi. be designed as, slabs and beams, g 3, y concrete V, n' ) for the nbs may be ta as 10 percent greater 8.11.5-Removable form 3411 be used and slab thick-than provided ' (acter 11 Shear strengtn may ness shall not be less than 1/17 clear distance be-be increasp use of shear reinforcement or ey tween ribs. nor less than 2 in, wide g'the ends of inc nbs. 8.11.6 - Reinforcement normal to the ribs shal .12-Separate, floor finish provided in the slab as required for flexure, cops' cring 1 - A floor finish shall not be included as cart load concentrations, if any but not lepttfan required of structural member unless ptaced by Section 7.12. monolithic with the floor slab or designed in 8.11.7 - Where ce s or pipes as permitted by Section 6.3 embedced witnin the stab. stab 8.12.2 - All concrete flo dnishes may b6 con / thickness snail be at least 1 in greater tnan the sidered as part of required cove total thickness total overall depth of the conduits or pipes at any for nonstructural considerations. CHAPTER 9 - STRENGTH AND SERVICEABILITY REQUIREMENTS 9.0 - Notation I, = moment of inertia of gross concrete A, = gross area of section, so in. Section about centroidal axis, neglecting A, = area of nonprestressed tension rein, reinforcement t = span length of beam or one-way slab, as forcement, so in. defined in Section 8.7; clear projection et A; = area of compression reinforcement, sq cantilever,in. in. f. = length of clear span in long &cdon of I. I d' = distance from extreme compressren I"U**dY 'U*I'"Ction, measureo face to-fiber to centroid of compression rein. face of supports in stabs without beams forcement,in, a a o ace of en s r er d. = distance from extreme tension fiber to suppods in otmases centroid of tension reinforcement,in, I. = length of clear span in short direction of D = dead loads, or related intemal moments two-way construction measured face to-face and forces of supports in slabs without beams and E, = modulus of elasticity of concrete, psi. keface f beams r mer supp rts in See Section 8.5.1 oder cases l E = load effects of operating basis earthquake L = live loads, or related intemal momers. ~ (OBE), or related internal moments and and forces { forces E., = load effects of safe snutdown -arthquake M, = maximum moment in member at stage deflection is computed { (SSE), orrelated internal moments and forces = caWng meen N Me MM j f' = specified compressive strength of concrete, psi P, - differential pressure load, or related inte-nal = square root of specified compressive moments and forces, generated by a postu. strength of concrete, psi lated pipe break f f, = modulus of rupture of concrete, psi = nominal axial load strength at balanced suam uncons. See SeWon W.12 j f, = specified yield strength of a on-P, = nominal axial load strength at given prestressed reinforcement. psi '#C'" C"Y l F = lateral and vertical pressure ofliquias N re- = factmed adal lead at gNen eccenupy ,i lated internal moments and forces s eP, h = overall thickness of member, in. R. = pipe and equipment reactions, or related {i% H = lateral earth pressure, or remted intemal internal moment. and forces, under thermal moments and forces conditions generated by a postulated pipe f., a moment of inertia of cracked section break and including R., l transformed to concrete R, = pipe and equipment reactions, or related 1, = effective moment of inertia for com-internal moments and forces, during normal { putation of deflection operating or shutdown conditions j f

s AC ' TANoARD j S 34s.2s . I l T, = internal moments and forces caused by ther-9.1.1.2 - Severe environmental loads mal effects under accident conditions gener. I h dd i@W W med at-d by a postulated pipe break and includ,g during the piant life including E., and W. N ~ T., = internal moments and forces caused by ther-9.1.1.3 - Extreme environmental loeds mal effects during normal operating or shut. g g g down conditions ble.meludm.g E., and W,. U = required strength to resist factored loads or related internal moments and forces 9.1.1.4 - Abnormal loads w. = unit weight of concrete. Ib per cu ft Those loads genersted by a postulated high-energy pipe W = operating basis wind load (OBW). or related break accident including F,. T. R Y,. Y,. and Y. internal moments and forces W' = loads generated by the design basis tornado 9.1.2 - Members also sh.:ll meet all other requirements (DBT). or related internal moments and of this Code to insure adequate performance at normal forces. These include loads due to tornado load levels. wind pressure, tornado created differential 9.1J - In the der'.3 s for normal loads, consideration pressures, and tornado generated missiles sha!! be given to tne forces due to such effects as j Y, = jet impingement load, or related internal mo-prestressin2 crane loads, vibration, impact, shrinkage. ~ ments and forces, on the structure generated creep, unequal settlement of supports, construction, by a postulated pipe break and testing-Y., = missile impact load, or related internal mo-ments and forces. on the structure generated 9.1.4 -In the determination of earthquake loads, con-by a postulated pipe break, such as pipe whip sideration shall be given to the dynamic response char-acteristics of the concrete structurc and its foundation l', = loads, or related internal moments and forces. on the structure generated by the and surrounding soil. reaction of the broken pipe during a postu. 9.1.5 - The detennination of impulsive and impactive lated break loads, such as the loads associated with missile impact, y, = distance from centroidal axis of gross whipping pipes, jet impingement and coms,artment ccetien..*cg!ceting re!..fetcament, to pic=>arsudun. Shall be condatent with the providuum (), ( extreme fiberin tension of Appendix C. a a ratio of flexural stiffness of beam section to flexural stiffness of a width of slab 9.2 - Required strength bounded laterally by center line of ad-9,;,3_.!he required strength U shall be at least equal jacent panel (if any) on each side W to the greatest of the following: beam. See Chapter 13

1. U = !.4D - 1.4F + 1.7L + 1.7H + 1.7R a.,

= average value of a for all beams on edges

2. U = 1.4 D + 1.4 F,1,7 L - 1.7 H + 1.7 E +

066 of a panel 17 R-J = ratio of clear spans in long to short

3. U = 1.4 D - 1.4 F + 1.7 4 + 1.7 H

1.7 W +

cirect;en of two.way slabs I7A J, = ratio of length of continuous edges to ,f T~-E+L tctat penmeter of a slab panel c, cr f f 5. U = D + F ~ L + H + T..

R.. + W, y

= ratio of the bending moments of factared

6. U = D + F - L + H + T,, - R., + !.25 P.,

7. U = D + F + L

H T., + R.,
1.15 P, +

o = n recuct n a 1or. See Section

3

8. U = D + F - L - H - T.,

R. - 1.0 P,, # 1.0( Y, 9.1 - Generni

+ Y. + Y.) - JAE, ~ 9. U = 1.0$D + 1.05F + 1.3L + 1.3H + 1.05T - 1 I3R-E 9.1.1 - Structures and structural members shall be

10. U = 1.05D - 1.05F + 1.3L + 1.3H + 1.3E +

designed to have design strengths at all v.:tions at least g, l ~ 1.05 7 + !.3R equal to the required strengths calculated for the fac,W tored loads and forces in such combinations as stipu ' L._ ll. U = 1.05D + 1.05F + !.3L + 1.3H + 1.3W + ] 1.05T + 1.3R lated for the following loads combined in accord:rce with the provisions specified in Section 9.2. 9.2. - Where the structural effects of differential set-I i 9.1.1.1 - Normal loads tlement creep or shrinkage may be significant, they ) shall be included with the dead load D in Load Combi-l Those loads which are encountered during normal plant nations 4 tbrough I1. Estimation of these effects shall operation and shutdown including D. L. F. H. T,. and be based on a realistic assessment of such effects eccur-R. ring in service. { { \\ __-________a

Nuct. EAR SAFETY STRUCTURES CooE 549-23 j a 9.2.3 - Fcr ths Load Combinations in Section 911. For oth;r remforced memb;rs. e mry b3 l where any load reduces the effects of other loads, the increased sinearly to 0.90 as oP. decreases corresponding coefficient for that 10: _ hall be taken as from 0.10f; A, or o p.. whichever is 0.9 if it can be demonstrated that the load is always smaller, to zero. ) present or occurs simultaneously with the other fonds. (c) Shear and torsion. . 0.85 Otherwise, the coefficient for that load shall be taken as zero. (e) Bearing on concrete (See also Section 18.13).. .0.70 9.2.4 Where appliccble impact effects of movm.g loads shall be included with the live load L. (f) Flexure in plain concrete... .0.65 9.2.5 - In Load Combinations 6. 7. and 8. the maximum values off. T,,. R.,. Y,. Y,. and Y including 9.3.3-Development longths specified m Chapter 12 oo not require a o-factor. an appropriate dynamic load factor, shall be used unless an appropriate time. history analysis is performed to justify otherwise. 9.4 - Design strength for reinforcement 916-Load combinations 5,7 and 3 shall be satisfied Designs shall not be based on a yield strength of rein. first without the tornado missile load in 5. and without forcement f, in excess of 60.000 psi, except for Y, Y,. and Y.,,in 7 and 8. When considering these con. prestressing tendons. centrated loads, local sections strengths and stresses 9.5 - Control of deflections may be exceeded provided there will be no loss of

ntended function of any safety related systems. For 9.5.1 - General additional requirements related to impulsive and im.

9.5.1.1 - Deflection limits pactive effects, icfe-to Appendix C. 9.2.7 -If resistance to other extreme environmental Reinforced concrete members subject to flexure shall l loads such as extreme floods is specified for the plant. be designed to have adequate stiffness to limit deflec-then an additional load combination shall be included tions or any deformations which may adversely affect with the additional extreme environmental load sub. the strength and serviceability of structural and stituted for W, in Load Combination 5 of Section 9.2,1. nonstructural elements. { k.h One.way construction, two.way construction and 9.3 - Cesign strength shored cor:posite construction shall satisfy the minimum thickness requirements specified in this i 9.3.1 - Design strength provided by a member, chapter. Prestressed concrete and unshored composite its connections to other members, and its cross construction shall satisfy the deflection limits indicated sections, in terms of flexure, axial load, shear, in Table 9.5(a). Lesser thicknesses may be used ifit is and torsion, shall be taken as the nominal determined by computation that the resulting deflec. strength calculated in accordance with require-tions will not adversely affect strength and ser. ments and assumptions of this Code, multiplied viceability, j t by a strength reduction factor p. When deflection limits more stringent than those 9.3.2-Strength reduction factor o snall be as specified in Table 9.5(a) are required to insure the follows: proper functioning of certain nonstructural systems, the minimum thicknesses specified in Tables 9.5(b) and (a) Flexure, with or without axial tension. 0.90 9.5(c) shall not apply and the members shall be sized such that the calculated deflections are within the re. (b) Axial tension. .... 0.90 quired limits. h (c) Axial compression. with or without flexure: 9.5.1.2 - leading conditions 5 Members with spiral remforcement When deflection computations are performed, these I conforming to Section 10.9.1 . 0.75 Computations shall be based on the loading conditioa l Other reinforced members . 0.70 entical for f!cxure. l exce;:t that for low values of axial load. 9.5.1.3 - Factored load computations may be increased in accordance with the foltrwing: The deflection limits specified in this chapter are for unf ctored loads. Deflections may De computed by 'y For members in which f, does not exceed factored load analysis and divided by a factor y to 60,000 psi. with symmetne reinforce-obtain the deflections corresponding to unfactored ment, and with (h f -d,)lh not less than loads. Unless other. vise determir.ed by computation. i 0.70. o may be increased linearly to 0.90 the factor y shall be as follows: as eP, decreases from 0.10f; A, to (a) For load combinations I through 3. y = 1.5 zero. i

7 t:. ' :.,.no.as. Act sTasecano 'i i . (b') For load combinations 4 through 8. y = 1.0 The long-time deflection shall be determined in accor. ~i dance with Sections 9.5.2.3. 9.5.3.5. or 9.5.4.2. but may (c) For load combinations 9 through 11. y = 1.2. be reduced to the amount of long. time deflection that 9.5.1.4 - Deflections to be coesidered occurs after the attachment of the ' nonstructural ele-g *. 4' ments or the leveling of equipment. This amount of When minimum thickness requirements are satisfied. a long-time deflection shall be determined on the basis of deflection equal to the limits given in Table 9.5(a) may ac densimering damining to the time deh be consuieved for the design of nonstructural elements. th ohb @ to h Wg con-When calculations are performed. the sum of the long-sidered. time deflection due to all appropriate sustained loads. 9J.2 -- Oneway h (noeW) and the immediate elastic deflection due to all appropri-ate nonsustained loads shall be considered. Due con-9J.2.1 - Minimum twelr-ss stipulatsd in Table 9.5(b) sideration shall be given to the effective moment of shall apply for one-way construction unless computa-inertia at each of these stages. tion of deflection indscates a lesser thickness may be used without adverse effects. TAtl.E 9.5(aHAXIMUM DEFLECTIONS FOR UNFACTORFD LOADS 95.2.2-Where deflections are to be comouted. de' lections that occur immediately on application j l oeding eg e 3's Type number Beams stabs' of load shall be computed by usual methods or 1 (sectios 9.2.1) formutas for elastic deflections, considering 1 I Eq. (t). (2), and (a) u400 us20 effects of cracking and reinforcement on member 2 l Eq. (4) and (5) t/250 t/200 stiffness. f .rertw wor a sneu n.,wi e er i 9.5.2.3 - Unless stiffness values are obtamed by a more comprehensive analysis, immediate deflection shall be computed with the modulus of elasticity E. for - TABLE 9.5(b)--MINIMUM THICKNESS OF BEAMS OR concrete as speciSed in Section 8.5.1 and with the ef-ONE.WAY CONSTRUCTIC N UNLESS DEFLECTIONS Afs2 CO: IPUTED fecuve moment of inertia as follows. but not greater thanI,. . o,i. =t nas n,.w9 ! Simply contin-I contin-Castr. )- ] M, $ 3 gE.$3 Me=her ', supported uous { uous lever q M. )l 7,. g_jqM )l 7,. g9,7) 4,, Soud one- ~ way con-t/t2 i/15 l/19 t/5 s*.ruction Beams or '

h*

nbbed I t/10 t/13 t/16 t/4 -[le (9.g) one-way I y slabs t trMJ,'.' "r.'7a'7"r#e "%nE' '"n'" 27c.""N.!7 Tin'*lorm""al and Tr"n**,"##tr47a",'fndf,W".Ns*l#fn"Eu.,n,iusiira.ii f, = '.5VT (9-9) Y*'0.*0 sn nium m nu tante.n. 4 ny 3r.,soegen j ne insenn.a 'or any n w r construeo snau not >,. i When the values of V are obtained from factored load analysis, these values shall be divided by the factor y as specified in Section 9.5.1.3 TABLE 9.Ste) MINIMUM THICXNESS OF TWO.WAY Where the computation of deflection is to be based on CONSTRUCTION UNLESS REFLECTIONS ARE L. the deflection calculated by an analysis using I, may COMPUTED be used. if the deflection thus calculated is increased by i stiaimum thickness. A a factor of /,//,. l Support. Edge ~Rauo of cles'r span in 9.S.2.4-For continuous scans. etfective moment q -b eondition continuity lo,ng.to-short direction of inertia may be taken as the average of values j i e = 1.0 .: = 10 obtained from Ea. (9 7) for the critical positive and i .. a. 2.0 A. = 0 i 1./22 1./25 negative moment sections.

s. = 1 t.m L/30

.. as 1.0 8

d. = 0 1./19 1./21 9.5.2.5 - Unless values are obtained by a more com-t./:S prehensive analysis, additional long. time deflection for i

p.. t i

4.f:2 3 " n niu .w.n in ini sani..n.n n. un.e.tirwi-for non. ticxural members shall be obtained by multiplying the / UlEE47."'."OJ7'* I'c"E"no"OrJe'/.".u "p,",8 immediate deflectirm caused by the sustained load con-f I?a*rI"irIf n'II.'/In"In'."'s.U.."lan"$'rlE"pY.% i,7"e/a",*a sidered, computed in accordance with Section 9.5.2.3. j TU,"n *l, *.* * #" ""' ' '" * '"'""""" ""' * ""' ** " t in.. g.giennem os any two.wo con.iruoi n in n nos 6. in. [2 - 1.2 (A'./Aa] as 0.6 l

NUCL.A3 SAFETY STRucTU2tLS CoDt! W1 ?J.2.5 - Denection computed in accordance with mulas for ciastic reflections, and tha moment ofinTrtia i Sections 9.5.2.2 through 9.5.2.5 shall not exceed limits of the gross concrete section may be used for uncracked sections. When members are cracked. a bitincar stipulated in the design specification. moment-curvature method shall be used. l. as provided ) 9.5.3 - Two-wa. construeden (nonprestressedi n Eq. H may be used for this purpose. v 9.5.3.1 - For two-way construction, the minimum 9.5.4.2 - Additional long-time camber and deflection thickness stipulated in Table 9.5(c) shall apply unless of prestressed concrete members shall be computed the computation of deflection indicates that lesser taking into account stresses and strain in concrete and thickness may be used without adverse effects. steel under sustained load and inc!uding effects of ercep 9.5.3.2 - For slabs without beams but with drop and shrinkage of concrete and re!axation of steel. panels extending in each direction from center line of 9.5.4.3 - Deflection computed in accordanc: with support a distance not less than 1/6 the span length in Sections 9.5.4.1 and 9.5.4.2 shall not exceed limits that direction measured center-to-center of supports, stipulated in Table 9.5(a) and a projection below the slab at least 1/4 the slab , thickness beyond the drop. thickness required by Table 9.5J - Composite construction 9.5(c) may be reduced by 10 pertent. 9J.5.1 - Shored construction 9.5.3.3 - At discontinuous edges, an edge beam shall If compos te Gexural members are supported during be provided with a stifTness ratio a not less than 0.80: or construction so that. after removal of temporary sup-the minimum thickness required by Table 9.5(c) or Sec-ports. dead load is resisted by the full composite sec. tion 9.5.3.2. shall be meressed by at least 10 percent m tion, the composite member may be considered equiv-the panel with a discontinuous edge. alent to a monolithically cast member for computation 9.5.3.4 - Computa lon of immediate deflecdon of deflection. For nonprestressed members considered equivalent to a monolithically cast member. the values Where deflections are to be computed. those which given in Table 9.5N. or Tabic 9.5(c) as appropriate. occur immediately on application ofload shall be com-shall apply. If deflection is computed account should puted by the usual methods or formulas for elastic de-be taken of curvatures resulting from differential Cections and as specified m this chapter. These com-shrinkage of precast and cast-in-place components, and putations shall also take into account the size and shape of axial creep efecu in a prestressed concrete member. 3 + t of the panel, the conditions of the support, and the reure of reau.h.t the pauel edges. For auch com. 9.5.5.2 - 1*=hered - - Men putations, the modulus of elasticity. E. of the concrete If the thickness of a nonprestressed precast flexural shall be as specified m Section 8.5.1. The effective member meets the requirements of Table 9.5(b) or moment of, erna shall satisfy the provisions of Seenon Table 9.5(c), as appropriate, deflection need not be m 9.5.2.3; other values may be used if they result m pre-computed. If the thickness of a nonprestressed com-dictions of deflection m reasonable agreement with the posite member meets the requirements of Table 9.5(b) results of comprehensive tests. or Table 9.5(c), as appropriate, deflection occurring j i 9.5.3.5 - Computation of long-time deflections after the member becomes composite need not be com-puted. but the long time deflection of the precast ( i Unless values are obtained by a more comprehensive" member should be investiga ed for magnitude and du. l analysis or test, the addiuonal long-time deflection for ration ofload prior to begmning of effective composite normalweighttwo way construction shallbe computed action. in accordance with Section 9.5.2.3. 9.5.5J - DeGection computed in accordance with 9JJ.6 --- ADowable de&cdon Sections 9.5.5.1 and 9.5.5.2 shall not exceed limits The deflection computed in accordance with Sections stipulated in Table 9.5(a). i i 9.5.3.4 and 9.5.3.5 shall not exceed the limits stipulated 9.5.6 - Walls l in the design specification. Walls subjected to tra.nverse loads shall also satisfy the 4 ~ _.mamed com construedoa l requirements as specified in this chapter fe'r nonpre-l 9.5.4.1 - For flexural memberi designed in accordance stressed one way or nonprestressed two-way, pre-with provisions of Chapter 18, immediate camber and stressed construction, or composite construction, as deflection shall be computed by usual methods or for-appropriate.

e m wre 4 UNiiED FtATES !!!"? "r.: fr?? i i.d.i.Eu REGULAT00 Cf. :-:5530N t.c: sri:n ":.: .TFICE 0F IH.iPECT10H AND E!JORCEMENT 7908220136 !.*ASHIli3 TON, D. C. 20555 November 8,1979 IE Bulletin No. 79-02 (Revision 2) PIPE SUPPOP.T BASE PLATE DESIGNS USING CONCRETE EXPANSION ANCHOR BOLTS DescH ption of Circumstances: Inspection experiences and the review of licensee response have' identified 'several R2 areas where the Eu11atin intant has not been adequately addressed by licensees., R2 ' Revision No. 2 of the Bulletin is intended to clarify the intent of the Bulletin R2 and establish the NRC positions on minimum factors of safety, anchor bolt preload, R2 and the expected date of completion for certain Bulletin actions. R2 j Since the issuanca of IE Bulletin No. 79-02 on Jiarch 8,1979, IE inspection R1 expeHance'and many inquiries from licensees indicate that additional informa-R1 tion and clarificatica is needed. This revision is intended to serve that R1 purpose. None of the requirements of the original Bulletin have been deleted, R1 and the'due date for ce=pletion of the requestad actions-(July 6,1979) hs. R1 not been changed. The following text supersedes the text of Bulletin No. 79-M. R1 Changes from the original text are identified by RI and R2 in the margin. The R1 - purpcsa of this avision is to identify acceptabla ways of satisfying the Bulletin R1 s requirements. R1 .I While perfoming inservice inspections dudng a March-April 1978 refueling outage at Millstone Unit 1, structural failures of piping supports for safety equipment were observed by the licensee. Subsequent licensee inspections of undunaged supports showed a large percentage of the concrete anchor bolts were' not tightened prcperly. Deficiency reports, in accordance with 10 CFR 50.55(e), filed by Long Island Lightine Company on Shoreham Unit 1, indicate,that design of base plates using rigid plate assumpticas has resulted in underestimation of loads on some anchor . bolts. Initial investigation indicated that nearly fifty percent of the base plates could not be assumed to behave as rigid plates. In addition, licensee inspection of anchor bolt installations at Shoreham bas shown over fifty percent of the bolt installations to be deficient. Ver. dor Inspection Audits by NRC at Architect Engineering firms' have shown a wide range of design practices and installation procedures which have been employed for the use of concrete expansion anchors. The current trends in the industry are toward mere rig:rous controis and veHfication of the installation of the bolts. 'The data availabla on dynamic testing of the concrete expansion anchors show fatigue failures can occur at loads substantially below the bolt static L F.1 anc F.2 - Identifies those additions or revisions to IE Bulletin Nc. 79-02 h p nq4Wgg

4 ,o v.. IE D.11v.ir.!.:. 72 '.': b,. t::.Lt.. ,,, 1/,7

' : n."

. z. ; 0 capacities due to enterial i=::erfections or notch type stress risers. The data also show low cycle cynamic failures at loads.below the bolt static. capacities . cue to joint slippage. In the review of anchor bolt installation practices, three facilities-(Trojan, 1 .Duane Arnold, and Zimmer) have~ been identified which use expansion anchor bolts { in concrete block walls to attach Seismic Category I piping supports. Testing I results of anchor bolts in concrete block w&11s performed at FFTF indicate signi-I ficantly lower ultimate capacities than for those in concrete. An Information ( Notice will be issued which provides additional details on the deficiencies '( identified at Trojan.- f In the review of responses to the Bulletin, we have become aware that licensees - '1 may not have-included review of. piping supports with concreta expansion anchor i bolts which did not use base plates. Such supports use structural steel members ( (angle or channel.) attached directly to the concrete by expansion anchor bolts, -{ with the piping attached to tne structural-steel member. The adequacy of the 1 anchor belt design and installation should be verified to satisfy the intent of 1 the Bulletin. i Action to be Taken by Licensees and Permit Holders: This Bulletin addresses those pipe support base plates that use concreta expansion anchor bolts in Seismic Category I systems as defined by Regulatory Guide L29 " Seismic Design Classification" lievision 1. dated August 1973 or as defined in the applicable.FSAR. For older plants where Seismic Category I-requirements did not exist at the time of licensing. it' must be shown that piping supports for - safety related systems, as defined in the Final Safety Analysis Report, meet design requirteer.ts. 'The revision is not intended to penalize licensees who have already completed some of the Bullatin requirements. In those instances in which a licensee has com-plated action en a specific itam and the Bulletin revision provides more conser-vative guidance, the licensee should explain the adequacy of the action already performed. It should be reiterated that the purpose of the Bulletin actions , are to assure operability of Seismic Category I piping systems in the event of a seismic event. L Verify that pipe support base plate 'flexibilit[ Gas accounted for'in the cal-culation of anchor bolt loads. In lieu of supporting analysis justifying ~ the assumption of rigidity, the base plates should be considered flexible if the unstiffened distance between the member welded to the plate and the edge of the base plate is greater than twice the thickness of the. plate. It is recognized that this criterion is conservative. Less conservative accep- .ance c~iteria cust be justified and the justification submitted as part of the response to the Bulletin. If the base plate is detemined to be flexible, than recalculate the bolt loads using an appropriate analysis. If possible, this is to be done prior to testing of anchor bolts. These calculated bolt loads'are referred to hereafter as the bolt design loads. A description of the analytical medel used to verify that pipe support base pla:e flexibility is acccunted for in the calculation of anchor bolt loads is to be submitted witn your respense to the Bulletin. t l _

~ ~.. . 7I-02. b.;4r 5,1575 a.k i r.d 7 l' 8 -t. i'een nr:ed that the schedule for anal tical work on base plate C f*6Exicility for some facilities extends beyond the Bulletin r:perting tice C fraca of July 6, IS73. For those facilities for which an anchor bolt R;' testing program is mquired (i.e., sufficient QC documentation does not R' exist), the a.chor bolt testing program should not be delayed. R* 2. Varify that the concrete expansion anchor bolts have the following minimum factor of safety between the bolt design load and the bolt ultimate cape-city da ersined free static load tests (e.g. anchor belt manufacturer's) whi:h si=ula.a tne a:tual cenditons of installation (i.e., type of con-creta and i.s st.rangth prcperties): a. Four - Fcr vedge and sleeve type anchor bolts, ~ b. Five - For shall type anchor bo.lts. l The bolt ulticata capacity should account for the effects of shear-tension R1 interaction. cinimum edge distance and proper bolt spacing. R1 If the cinium factor of safety of four for wedge type anchor bolts and R2 five for shall type anchors can not be shown then justification must be R1 provided. The Ea11stin factors of safety were intended for the maximum R2 support ica: including the SSE. The NRC has not yet been provided adequate R2 justificatica trat lower factors of safety are acceptable on a long tem R2 basis. Lcwer factors of saf,ety are allowed on an intaris basis by the R2 provisiens of Supplement No. I to IE Bulletin No. 79-02. The use of R2 redu:ed factors of safety in the factored load approach of ACI 349-76 has R2-not yet been accepted by the NRC. R2-3. . Describe the design requirements if applicable for anchor bolts to with stand cyclic 1sads (e.g. seismic loads and high cycle operating loads). Verify frcm axisting QC (ccucentation that design requirements have been met fer ma:t ancnor bolt in the following areas: (a) Cyclic leads have been considered (e.g. anchor bolt preload is equal to or greatar than bolt design load). In the case of the shall type, assure that it is not in contact'with the back of the support plate l prior to preload testing. ).g (b) Specified design size and type is correctly ins'talled (e.g. proper L sabed= ant dapth). If sufficient de:u=entation does not exist, then initiate a testing program that vill assure that sinint: design requirements have been met with respect to sub-ite".s (a) and'(b) abow. A sampling technique is acceptable. One acceptable technique is to randomly select and test one anchor bolt in each base plate (i.e. some supports may have more than one base plate). The j test shecid provide verifi:ation of sub-items (a) and (b) above. If the test fails, all ether bolts on that base plate should be similarly tested. In any ever.:, T.he test ;- gram should assure that each Seismic Catsgary I system vill sarf:r: its intended fun: tion. i ,4v e

m K *,. '......... ~. m hovemeer 6, 19h . F63 4 of.7 i k'. Tha prafarrcf tut c.athed to demonstrate thu *aolt preload has been accom- 'R1 plished is u ing.z direct pull (tensile test) equal to or greater than R1' casign load.. Recognizing this method may be difficult due to accessibility R1

- in so a areas en alternative test method such as torque testing may be _

R1 used. fIf tcrque testing is used it adst be shown and substantiated that R1 a correlation between torque and tension exists. If manufacturer's data R1 for the specific bolt used is not available, or is not used, then site R1 specific data aust be developed by qualification tests. 'R1 Bolt test values of one-fourth (wedge type) or one-fifth (shall type) of R1 ! bolt ultimate capacity may be used in lieu of individually calculated bolt R1 1 design loads where the test value can be shown to be conservative. R1 The purpose of Bulletin No. 79-02 and this revision is to assure the R1 operability of each seismic Category I piping' system. In all cases an R1 evaluation to confirm system operability must be performed. If a base plate R1 or anchor belt failure rate f s identified at one unit of a multi-unit site R1 l which threatens operability of safety related piping systems of that unit, R1 y continued operation.of the remaining units at that site must be immediately R1 evaluated and reported to the NRC. The evaluation must consider the generic - R1 l applicability of the identified failures. R1 Appendix A cascribes two sampling methods for testing that can be used. Al l Other sampling methods may he-used but must be justified. Those options R1 . may be selected on a system by system basis. ~ R1 Justification for omitting certain bolts from sample testing which are in R1 I.. high radiation areas during an outage must be based on other testing or R1 i analysis.which substantiates operability of the affected system. R1 l Ecits which are found during the testing program not to be preloaded to R1 a lead equal to or greater than bolt design load must be properly pre-- R1 loaded er it must be shown that the lack of preloading is not detrimento1 R1 ! to cyclic loading capability. Those licensees that have not verified anchor R2 bolt preload are not required to go back and establish preload.

However, P.2 additional information should be submi,tted which demonstrates the effects R2 of preload en the anchor bolt ultimate capacity under dynamic loading.

R2 If it can be established that a tension load sn.q y of the bolts does not R1 exist for all loading cases then no 'preload or testi,ng of the bolts is .R1 required. R1 i If anchor bolt testing is done prior to completion cf the analytical work R1 on base plate flexibility, the bolt testing must be performed to at least R1 j-the original calculated bolt load. For testing purposes factors may be R1 used to conservatively estimate t's potential increase in the calculated R1 bolt load due to base plate flexibility. After completion of the analytical R1 l work on the base plates the conservatism of these factors must be' verified. R1 L L L

V. .............. 7 L - L:.

,;;;a a L,

page ; cf - ?cr base plate :Up; orts using expansion anchors, but raised fic: the C su ;orting surface with grout placed under the base plate, for. testing ( purposes it must be verified that leveling nuts were not used. If leveling ( nuts were used, than they must be backed off such that they are not in-t con.act with the base plate before applying tension.or torcue testing. I Eulletin No. 79-02. requires verification by inspection that bolts are { prererly installed and are of the specified size and type.. Parametars ( which should be included are embedment depth, thread engagement, plate ( bolt hole size, bolt spacing, edge distance to the side of a concrete ' I sa:bar and full expansion of the shall for shall type anchor bolts. ( If piping systans 21/2-inch in ' diameter or less were computar analyzed 1 then they must be treated the same as the larger piping. If a chart I analysis method was used and this method can be shown to be highly con-i servative, than the proper installation of the base plate and anchor bolts should be verified. by a sampling inspection. The parameters inspected i should include those described in the preceding paragraph. If small diasater piping.is not inspected, then justification of system operability _ must be provided. 5. Jetereine the extent that expansion anchor bolts were used in concrete block (casonry)' walls tc attach pi. ping supports in Seismic Category 1 systems (or safety relatad systems as defined by Revision 1 of IE Bulletin No. 79-02). If expansion anchor bolts were used in concrete block walls: l i a. Previde a list of the systems involved, with the number of supports type of anchor bolt, line size, and whether these supports are acces-sible during normal plant operation. c. Describe in detail any casign consideration used to account for this type of installation. c. Previde a detailed evaluation of the capability of the supports, including the anchor bolts, and block wall to meet the dasign loads. The evaluation must describe how the allowable loads on anchor bolts in ccacrate block walls were det'armined and also what analytical method was used to determine the integrity chthe block walls under the imposed loads. Also describe the acceptance ePiteria, including the ntzerical values, used to perform this evaluation. Review the defician- 'cies idantified in the Information Notice on the pipe supports and walls at Trojan to determine if a similar situation exists at your facility with rega-d to supports using anchor bolts in concrete block walls. d. D* scribe the esults of testing of anchor bolts in concrete block l walls and your plans and schedule for any further action. 1 E. Datarcir.e tf.e extant that pipe supports with expansien anchor bolts used structural steel shapes !~nstead of base plates. The systems ano ifnes

i .l*'} .Vmin !.o. 79-02, !4"c:/.. : o,.1E

i:r 2

'v,.. ~ i A l revie ed must be consistent with the criteria of IE Eulletin No. 79-02, R2 l Revision 1. If expansion anchor bolts were used as described above, verify R2 ~ ' that the anchor bolt and structural steel shapes in these supports were R2 included in the actions performed for the Bulletin. If these supports R2 cannot.be verified to have been included in the Bulletin actions: R

a..

Provide.a list of the systems invol'.ed, with the nuchar of supports, R ', - ~ type of anchur bolt, line size, and whether the supports are acces-R '. l sible during normal plant operation. C l 4 b. Provide r rietailed evaluation' of the adequacy of the anchor bolt. design R2 and inst C.ation. The evaluation should address the assumed distribu-R2 i i tion of loads on the anchor bolts. The evaluation can be based on R2.1 l the results of previous' anchor bolt testing and/or analysis which R2 I substantiates operability of the affected systam. R2 i c. Describe 'your plans and schedule for any further action necessary to~ R2 j assure the affected systacs meet Technical Specifications operability R2 R2 ; requirements in the event of an SSE. l s. Fcr those licensees that'have had no extended outages to perform the testing R2 of the inaccessible ancher bolts, the testing of anchor bolts in acces-RI f sible areas is expected to be completed by November 15, 1979. The testing R *. of the inaccessible anchor bolts should be completed by the next extended R2 { For those licensees 7 hat have completed the anchor bolt testing R2 ' ) t outage. In inaccessible areas, the testing in accessible areas should continue R2 L as rapidly as possible, but no longer than March 1,1980. The analysis. R2 i fcr the Bulletin items covering base piste flexibility and factors of R2. o safety should be completed by November 15, 1979. Provide a schedule R2 that details the completion dates for IE Bulletin No. 79-02, Revision 2, R2. ite:s 1,.2, and 4. R2 j l S. Maintain documentation of'any sampling inspection of anchor bolts required R2 1 by item 4-on site and available for NRC inspection. All holders of R2 i cperating licenses for power reactor facilities are requested to complete R2 i itees 5, 6, and 7 within 30 days of the date of issuance of Revision No. 2. R2 1 Also describe any instances not previously reported, in which you did not R2 I caet the ravised (R2) sections. of itams 2 and 4 and, if necessary, your R2 l plans and schedule for resolution. 1teport inYt'ti,ng within 30 days of the R2 i data of this revision issuance, to the Director of'the appropriate Regional R2 1 Office, c mpletion of your review. For action not yet complete, a final R2 ! re: ort is to be submitted upon completion of your action. A copy of R2 ycur report (s) should be sent to the United States Nuclear Regulatnry R1 Coc=ission, Office of Inspection and Enforcement, Division of Reactor R1 ! 0,.eratione Inspection, Washington, D. C. 20555. These reporting reqdire-R1 cents do n'ot preclude nor sucstitute for the applicable requirements to R1 ;, - re.c-t as set ferth in the regulations and license. R1 ; f. All helders of construction permits for power reactor facilities are recuest-R2 ed to cceplete items 5 and 6 for installed pipe supports within 60 days of R2 data cf issuance of Revision No. 2. For pipe supports whien nave not yet R2 ;' l 4 m. 2.m_______.

n. _: u f

l.,
m

.r

i bliesin No. 71-0?

..:;:.:2.r.?, Ci i:h r.

q. 7 :.' *

.r been installed, document your action to assure thct ite=s 1 tnrc-Th 5 vill ' P.2 . be-satisified.. V.aintain documentation of. these actions on site - available R2 1 for NRC inspection. Repsrt in writing.within 60 days of date of issuance'of R2 Revision No. 2, to the Director of the appropriate NRC Regional Office, cour-R2 i plation of 'your review and. describe any instances not previously repo-ted, R2 in which you did not meet the revised (R2) sections of itans 2 and 4 and, if R2-hacessary, your plans and schedule for resolution. A copy of your report R2 .l should be sent to the United States Nuclear Regulatory Commission, Office R2 l of-Inspection and Enforensen, Division of Reactor Construction Inspection, R2 Washington, D.C.. 20EE5. R2 Approved by GAO (RG072); clearance expires 7/31/80. Approval was given under a ~ blanket clearance specifically for identified generic problems. Enciosures: 1. Appendix A R1 ' 2. Recently Issued IE Bulletins 1 m l y l ' ~ ~ ) e e 4 6 e e.e. e 9

l; .; s.

T ~S?IX !.

6 5;,:'.? LING METHODS ) Ita: 4 of this Eu11stin states that fo,r anchor bolt testing p0rposes a st=pling g prograr is acceptzbie. Two sampling methods are discussed below, but other reth:ds tzy be used if justified. Test one bolt on each plata a$s originally recommended in Bulletin No. 79-02. a. If tne test fails, all other bolts on that base plate should De similarly tested. A hign failure rate should be the basis for increased testing. c. Randomly select and test a statistical sa=ple of the bolts to provide a 85 - percent confidence level that less than 5 percent defective anchors are installed in any one seismic Category I systam. The sampling program should be done on a systan by system basis.. e

e e

e 4 %*b = e ._}}

ML20237A130

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