ML20112C003
| ML20112C003 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 05/20/1996 |
| From: | Doroshuk B, Tilden B, Tucker R BALTIMORE GAS & ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML20112B955 | List: |
| References | |
| NUDOCS 9605240119 | |
| Download: ML20112C003 (100) | |
Text
{{#Wiki_filter:f O Calvert Cliffs NuclearPowerPlant License RenewalProject
' Aging Management Review Report for the Turbine Building Revision 2 --
May, 1996 Prepared by:, Date: 7 R.L. Tucker Reviewed by: Date: B.M. Tilden Approved by: Date: #!26/% B. W. Doroshuk o D A OCK 05 00 17 PDR P
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l l l i p LIFE CYCLE MANAGEMENT O 1 FINAL REPORT l TURBINE BUILDING AGING MANAGEMENT REVIEW RESULTS TABLE OF CONTENTS l SECTION PAGE NUMBER TABLE OF CONTENTS i LIST OF A'ITACHMENTS iii LIST OF APPENDICES iv LIST OF TABLES v LIST OF EFFECTIVE PAGES vi
1.0 INTRODUCTION
1-1 1.1 Turbine Building Description 1-1 1.1.1 Turbine Building LCM Description 1-1 1.1.2 Turbine Building LCM Boundary 1-2 _ 1.1.3 Turbine Building Intended Functions 1-2 1.2 Evaluation Methods 1-3 , 1.3 Turbine Building Specific Definitions 1-3 1.4 Turbine Building Specific References 1-3 1 2.0 STRUCTURAL COMPONENTS WITHIN THE SCOPE OF LICENSE RENEWAL 2-1 l 3.0 STRUCTURAL COMPONENTS PRE-EVALUATION 3-1 i l 1 . gw N/ AGING MANAGEMENT REVIEW RESULTS FINAL REPORT TURBINE BUILDING i REVISION 2
i LIFE CYCLE MANAGEMENT , V'O l l FINAL REPORT ! TURBINE BUILDING AGING MANAGEMENT REVIEW RESULTS TABLE OF CONTENTS SECTION PAGE NUMBER l l 4.0 STRUCTURAL COMPONENTS AGING EFFECTS EVALUATION 4-1 l 4.1 Evaluation 4-1 4.2 Aging Mechanisms 4-1 4.2.1 Potential Aging Mechanisms 4-1 4.2.2 Component Grouping 4-2 4.2.3 Plausible Aging Mechanisms 4-2 4.2.4 Aging Management Program Identification 4-3 4.2.5 Aging Management Recommendations 4-3 O 5.0 PROGRAM EVALUATION 5-1 5.1 Program Adequacy Evaluation 5-1 5.2 Structural Components Subject to Adequate Programs 5-1 5.2.1 Existing Programs 5-1 5.2.2 Modified Existing Programs- 5-2 5.2.3 New Programs 5-2 i
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1 O AGING MANAGEMENT REVIEW RESUL,TS FINAL REPORT TURBINE BUILDING ii REVISION 2
LIFE CYCLE MANAGEMEN" FINAL REPORT ! TURBINE BUILDING AGING MANAGEMENT REVIEW RESULTS TABLE OF CONTENTS SECTION PAGE NUMBER LIST OF A'ITACHMENTS i j Attachment 1 Potential Aging Mechanisms Applicable to Structural Components l Attachment 2 Plausible Aging Mechanisms Applicable to Structural Components l Attachment 3 Structural Components - Aging Mechanism Matrix Codes l l Attachment 4 Summary of Aging Management Review Results Attachment 5 Adequate Program Evaluation i Attachment 6 NOT USED Attachment 7 Walkdown Report - Examination of Auxilicry Feedwater Pump Rooms - l Calvert Cliffs Nuclear Power Plant ; Attachnient 8 Attributes in New Program . i l l l l ~ l l-l l I J t O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT TURBINE BUILDING iii REVISION 2 i I
I LIFE CYCLE MANAGEMENT j FINAL REPORT TURBINE BUILDING AGING MANAGEMENT REVIEW RESULTS TABLE OF CONTENTS l SECTION PAGE NUMBER l LIST OF APPENDICES Appendix A Freeze-Thaw l Appendix B Leaching ofCalcium Hydroxide i Appendix C Aggressive Chemicals l Appendix D Reaction with Aggregates l Appendix E Corrosion in Embedded Steel /Rebar Appendix F Creep l l Appendix G Shrinkage Appendix H Abrasion and Cavitation l - ! Appendix I Cracking ofMasonry Block Walls l Appendix J Settlement l Appendix K Corrosion in Steel Appendix L Corrosion in Liner Appendix M Corrosion in Tendons Appendix N Prestressing Losses l Appendix 0 Weathering Appendix R Elevated Temperature Appendix S Irradiation i Appendix T Fatigue 4 4 O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT TURBINE BUILDING iv REVISION 2 i l
i l l LIFE CYCLE MANAGEMENT UNIT lO FINAL REPORT TURBINE BUILDING AGING MANAGEMENT REVIEW RESULTS l LIST OF TABLES i Table Iitic Page Number 1-1 Turbine Building Specific References 1-4 2-1 Turbine Building Structural Components Within the Scope ofLicense Renewal 2-2 4-1 List of Potential Aging Mechanisms for Turbine Building Structural Components 4-5 4-2 Turbine Building Aging Effects
- Evaluation Summary 4-6 l
l O. ._ I i l l l l l l J P
- O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT TURBINE BUILDING v REVISION 2
LIFE OYCLE MANAGEMENT FINAL REPORT INTAKE STRUCTUREAGING MANAGEMENT REVIEW RESULTS LIST OF EFFECTIVE PAGES Revision Pages Summary of Change 0 All Initial revision prepared using LCM-10S, Revision 1. I All Changes made to reflect disposition of Technical Problem Reports written against Revision 0 and to correct transcription errors between the results and - the final report sections. 2 All Wording changes to make the language in the final report sections more consistent with the language used in the Integrated Plant Assessment Methodology. Also, technical changes regarding the aging management strategy used to address degradation effects associated with corrosion in structural steel, i l { O ^ l l l 1 'S O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT TURBINE BUILDING vi REVISION 2
i 1 l LIFE CYCLE MANAGEMENT O
1.0 INTRODUCTION
1.1 TURBINE BUILDING DESCRIPTION This section describes the scope and boundaries of the Turbine Building as it was evaluated. Section 1.1.1 provides a brief synopsis of the building as described in existing plant documentation. The Turbine Building boundary is defined in Section 1.1.2 to clarify the portions of the structure considered in this evaluation. Section 1.13 is a detailed breakdown of the unique system functions and is provided as a basis for component scoping and the identification of component-specific functions. 1.1.1 Turbine Buildine LCM Descrintion The Turbine Building is an integrated steel structure, with metal siding, supported on reinforced concrete foundations. Included in the Turbine Building are the turbine-generator bays, heater bays, and the turbine-generator concrete pedestals which project through the building to the operating deck at elevation 45 feet. The turbine generator units I and 2 are separated by an expansion joint in the l superstructure. The circulating water intake and discharge conduits are incorporated into the spread footings. h The Turbine Building is a Class 11 structure with the exception of the auxiliary feedwater pump enclosure, which is Ciass I. All of the structural steel columns, beams, and roof trusses of the building have been designed as independent members and in accordance with AISC. The unit I and 2 auxiliary feedwater pump rooms, rooms 603 and 605, contain the auxiliary feedwater pumps; piping and manual valves associated with the main steam system and the auxiliary feedwater system; and cables associated with reactor coolant temperature channels A and B; pressurizer level, channels A and B; steam generator level, channels A and B; and salt water pumps, channels A, B, and C. The rooms also contain the remote hot shutdown control panel, which is considered an alternate means of maintaining the plant in a hot shutdown condition. Piping inside the auxiliary feedwater pump rooms is required to maintain the integrity of the secondary side of the steam generators. 1O t AGING MANAGEMENT REVIEW RESULTS FINAL REPORT TURBINE BUILDING l-1 REVISION 2
LIFE CYCLE MANAGEMENT O 1.1.2 Turbine Building LCM Boundary The auxiliary feedwater pump rooms and their structural components provide support and shelter to safety related and non-safety related equipment inside the Turbine Building. The system boundary addressed by this scoping and evaluation included all auxiliary feedwater pump room structural components serving such functions but did not include commodity items such as pipe supports and snubbers. ! Structural components within this system boundary include supports for the following major device types: Motors (MOTOR)and pumps (PUMP). l l Also included in the system boundary are structural supports for non-safety related i access platforms. During an abnormal event such as a seismic event, failure of these non-safety related components must not adversely affect the operability of other safety related components. 1.13 Turbine Building Intended Functions l A detailed review of the Turbine Building intended functions was completed l _ during the system scoping process described in the BGE Integrated Plant Assessment Methodology. The following system functions for the Turbine l \ Building were identified- as structural intended functions on Table-IS of-
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" Component Level Scoping of Four Site Structures; Intake Structure, Turbine Building. FOST Enclosure, CST Enclosure."
l 1.13.1 Function LR-S-1 l ProvMes structural and/or functional support, or both, to safety related equipment. 1.13.2 Function LR-S-2 Provides shelter / protection to safety related equipment, including radiation shielding for equipment qualification and HELB protection. 1.133 Function LR-S-4 Serves as a missile barrier (internal or external). i l a AGING MANAGEMENT REVIEW RESULTS FINAL REPORT TURBINE BUILDING l-2 REVISION 2 l (
! LIFE CYCLE MANAGEMENT ! t'"\ i (/ 1.13.4 Function LR-S-5 l Provides structural and/or fun 6nal support to non-safety related equipment whose failure could directly prevent satisfactory , accomplishment of any of the required safety related functions. l 1.13.5 Function LR-S-6 Provides a flood protection barrier (intemal flooding event). i 1.13.6 Function LR-S-7 l Provides rated fire barriers to confine or retard a fire from spreading to or from adjacent ereas of the plant. l ! 1.2 EVALUATION METHODS Turbine Building structural components within the scope of license renewal were evaluated in accordance with BGE procedure EN-1-305,3 " Component Aging Management Review Procedure for Structures," Revision 0. The results of these evaluations are summarized in Sections 3.0 through 5.0. 13 TURBINE BUILDING SPECIFIC DEFINITIONS . This section provides the definitions for any specific terms unique to the Turbine Building l component level evaluation. Term Definition l l None N/A 1.4 TURBINE BUILDING SPECIFIC REFERENCES - l References utilized in the completion of the Turbine Building component level evaluation are listed in Table 1-1. Drawings and procedures used as source documents in the evaluation were taken at I the revision level of record at the start of this task which was October 1994. The update performed j in Revisions I and 2 of this report incorporated several TPRs. The update performed in Revision 2 l was performed to address a new strategy in the aging management of corrosion affects on structural steel. Only references affected by Revisions 1 and 2 update have been revised. I
- Revision 0 and Revision I were done to LCM-10S. EN-1-305 is new version of LCM-10S which updated p procedure format and terminology.
, d AGING MANAGEMENT REVIEW RESULTS FINAL REPORT I TURBINE BUILDING l-3 REVISION 2 l
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I LIFE CYCLE MANAGEMENT [ r'- ! Table 1-1 l l Turbine Building Specific References I Document ID. Dupument Title Revision No. Dgg Iygg l UFSAR Calvert Cliffs Nuclear Power Plant Units I and 2, 14 1992 Report 1 Updated Final Safety Analysis Report i Technical Calvert Cliffs Nuclear Power Plant, Units I and 2, 182 9/2783 Report Specification Technical Specification 159 9/2783 i
- CnmM Level Scoping of Four Site Structures, 1 1996 Report
! Intake Structure, Turbine Building. FOST Enclosure CSTEnclosure EPRI RP-2643-27 Class 1 Structures License Renewal Industry Report - 12 S 1 Report NUMARC 90 01 Pressurized Water Reactor Containment Structures I 9S1 Report License RenewalIndustry Report
- Mather, B., "liow to Make Concrete that will be - 11/89 Paper
- irnmune to the effects of freezing and thawing," ACI FallConvention, San Diego ASTM C33-82 " Standard Specification for Concrete Aggregates," - 1982 Spec American Society ofTesting and Materials Civil and Structural Design Criteria for Calvert 0 8/2/91 Guide A)
Cliffs Nuclear Power Plant Unit No. I and 2, by ( I U Bechtel Power Corp. . , _.
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6750<-9 Specification for Furnishing and Delivery of 8 4n0 Spec Concrete - Calvert Cliffs Nuclear Power Plant Unit No. I and 2 ACI 318-63 " Building Code Requirements for Reinforced - 1%3 Code l Concretc." American ConcreteInstitute ACI 201.2R-67
- Guide to Durable Concrete,' American Concrete - 1%7 Std Institute
- "Concretc Manual," U.S. Department of the Interior 8' Edition 1975 Code 1 6750 C-23E Specification for Fumishing and installation of 0 1In3 Spec -
Piezometer - Calvert Cliffs Nuclear Power Plant Unit No. I and 2 ASTM C-28946 ' Potential Reactivity of Aggregates (Chemical - 1966 Code Method)," American Society ofTesting and Materials ASD1 C-29545 " Petrographic Examination of Aggregates for - 1965 Code Concretc," American Society ofTesting and Materials
- Letter from Charles County Sand & Gravel Co. to - 6/30/72 Letter Bechtel Corp.
O (') AGING MANAGEMENT REVIEW RESULTS FINAL REPORT TURBINE BUILDING 1-4 REVISION 2 i l 1 l
I l l l l ,e LIFE CYCLE MANAGEMENT
,,,i l V l Table 1-1 Turbine Building Specific References Docunent ID. Docurnent Title Revisinn No. Dalg Igg l - Skoulikidas.T.,Tsakopoulos, A., and Moropoulos, - - Paper l T., " Accelerated Rebar Corrosion When Connected
! to Lightning Conductors and Protection of Rebars with Needles Diodes Using Atnespheric Electricity," in Publication ASTM STP 906,
" Corrosion Effects of Stray Currents and the Techniques for Evaluating Corrosion of Rebars in Concrete" ACI-209R-82 " Prediction of Creep, Shrinkage, and Temperature -
1982 Std Effects in Concrete Structures," American Concrete Institute
- " Design and Control of Concrete Mixtures," !? Edition 1988 Guide Portland Cernent Association IAEA-TECDOC-670
- Pilot Studies on Mar agement of Aging of Nuclear -
10/92 Report Power Plant Components,' Liternational Atomic Energy Agency MN-3100 Painting and Other Protective Coatings - 9/94 Proc TRD-A-1000 Coating Application Performance Standard 8 8/91 Spec 6750-A-24 Specification for Painting cnd Special Coatings 12 10/82 Spec
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6750-C-19 Specification for Furnishing, Detailing, Fabricating, 3 900 Spec j Delivering, and Erecting Structural Steel ( ACI 215R-74 " Consideration for Design of Concrete Structures - 1986 Std
- Subjected to Fatigue Imading,' Arnerican Concrete l Institute ,
I
- " Specification for the Design, Fabrication, and - 1%3 Spec Erection of Structural Steel for Buildings,"
l American Institute of Steel Construction
- Brockengrough, R.L. and "ohnson, B.0, " Steel -
Sn4 Text Design Manual," United States Steel Corporation NUREG-0797 Safety Evaluation Report Related to the Operation - 7/8i SER of Comanche Peak Steam Electric Station, Units I i and 2 1 ! ANSI /ANS-6.4 "Guidelint; m N Nuclear Analysis and Design of - 1985 Code Concrete Radiation Shiciding for Nuclear Power l l Plants," American Nuclear Standard
- Ifilsdorf, ILR., Kropp, J., and Koch,11)., "The -
1978 Paper Effects of Nuclear Radiation on the Mechanical Properties of Concretc," Douglas Mcilenty International Symposium on Concrete and Concrete Structures, American Concrete Institute Publication SP-55 p) t b AGING MANAGEMENT REVIEW RESULTS FINAL REPORT TURBINE BUILDING l-5 REVISION 2
l LIFE CYCLE MANAGEMENT Table 1-1 l l
- Turbine Building Specific References l
Document ID. Docurnent Title Revision No. Dgtg Iygg NUREGCR4652, Naus, DJ.," Concrete C-anaen' Aging and its - 9/86 Paper ORNI/IE10059 Significance Relative to Ufe Extension of Nuclear l l Power Plants," Oak Ridge National taboratory, Oak Ridge,'IN ACI 349-85 " Code Requirements for Nuclear Safety Related - 1985 Code Concrete Structures,' American Concrete Institute 1 i
- EQ Design Manual, Calvert Cliffs Nuclear Power 17 1992 Guide Mut l ASME Section !!!, Division 2 " Code for Concrete Reactor Vessels and - 1986 Code l Containments," American Society of Mechanical i Engineers Boiler and Pressure Vessel Code l
l l 1 V . I l l l I I l I
. Os AGING MANAGEMENT REVIEW RESULTS FINAL REPORT TURBINE BUILDING l-6 REVISION 2 l
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. . - . . _ _ . - - . _ _ _ ~ _ . - _ . - - __ - - .-
LIFE CYCLE MANAGEMENT 2.0 STRUCTURAL COMPONENTS WITHIN THE SCOPE OF LICENSE RENEWAL The Turbine Building components were scoped in accordance with the process described in the BGE Integrated Plant Assessment Methodology. The Turbine Building was scoped using procedure LCM-1IS. The purpose of component scoping is to identify all structural components whose functions are identified in Section 1.13. These structural components are designated as components within the scope of License Renewal. As a result of the scoping,22 structural component types were identified as providing one of the structure's intended functions listed in Section 1.13. A summary of the scoping result is in Table 2-1. ! l l - l I d
. v AGING MANAGEMENT REVIEW RESULTS FINAL REPORT TURBINE BUILDING 2-1 REVISION 2 i
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l LIFE CYCLE MANAGEMENT a
- Table 2-1 Turbine Buildine Structural Comnonents Within the Scone of Licana, Renewal l
STRUCTURAL COMPONENT TYPE INTENDED FUNCTION (S) i Concrete Walls LR-S-1,2,4,6, and 7 l Ground Floor Slab and Equipment Pads LR-S-1,2,4,6, and 7 l Elevated Floor Slabs LR-S-1,2,6, and 7 i Cast-in-Place Anchors /Embedments LR-S-1,2,6, and 7 I Ductbacks LR-S-1 and 2 Grout LR-S-1,2,6, and 7 l Fluid Retaining Walls and Slabs LR-S-1,2,6, and 7 PostInstalled Anchors LR-S-4 awM l Building Siding Clips LR-S-2 l Fire Doors, Jambs, and liardware LR-S-2,6, and 7 Access Doors, Jambs, and Hardware LR-S-2,6, and 7
]
% Caulking and Sealants LR-S-2,6, and 7 d Watertight Doors ,
LR-S-2,6, and 7 , Steel Beams LR-S-1,2, and 7 l Baseplates LR-S-1,2,4,5, and 7 Floor Framing LR-S-1,2, and 7 Steel Bracing LR-S-4 Platform Hangers LR-S-5 Steel Decking LR-S-1,2, and 7 Jet Impingement Barriers LR-S-4 Floor Grating LR-S-5 - Stairs and Ladders LR-S-5 i { I 1 a AGING MANAGEMENT REVIEW RESULTS FINAL REPORT ( TURBINE BUILDING 2-2 REVISION 2
i I LIFE CYCLE MANAGEMENT lV l 1 f3 i 3.0 STRUCTURAL COMPONENTS PRE-EVALUATION Per the BGE Integrated Plant Assessment Methodology, the pre-evaluation task is not conducted on structures. Structural components are assumed to be passive and long-lived and therefore, subject to an aging management review. Consequently, Table 2-1 also represents a list of structural component types subject to aging management review. I l l l l l I t I t l l AGING MANAGEMENT REVIEW RESULTS FINAL REPORT TURBINE BUILDING 3-1 REVISION 2
LIFE CYCLE MANAGEMENT g 4.0 STRUCTURAL COMPONENTS AGING EFFECTS EVALUATION , 4.1 EVALUATION The evaluation of Turbine Building structural components within the scope of license renewal was completed in accordance with BGE procedure EN-1-305, " Component Aging Management Review Procedure for Structures," Revision 0. This procedure evaluated all twenty-two component types identified in Section 2.1. The evaluation accomplished the following: (1) Identified POTENTIAL aging mechanisms for each structural component type. (2) Identified PLAUSIBLE component aging mechanisms for each structural i component type or specific components within the component type based on the_ following:
- environmental conditions
- material of construction
- impact on intended functions O
v (3) Developed attributes for programs to manage the effects of aging from those aging mechanisms identified as PLAUSIBLE. I
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(4) Evaluated program adequacy to demonstrate that the effects of aging will be managed so that the intended function (s) will be maintained for the period of extended operation. These steps are discussed in greater detail in the sections that follow. 4.2 - AGING MECHANISMS 4.2.1 Patan*lal Aoine Mechantema This step of the aging evaluation identifies aging mechanisms that are considered to be POTENTIAL for a given component type. An aging mechanism is considered POTENTIAL for a structural component if the evaluation concludes ' that the aging mechanism could occur in generic applications of the structural component type throughout the plant due to susceptible materials of construction and conducive environmental service conditions. I A comprehensive list of 18 aging mechanisms was developed that may be applicable to structural component types. This was based on the EPRI industry reports prepared for the PWR containment structure and Class I structures. Other references used to prepare this list include the following: AGING MANAGEMENT REVIEW RESULTS FINAL REPORT TURBINE BUILDING 4-1 REVISION 2
IJcE CYCLE MANAGEMENT l O
- NRC NPAR Reports !
- IAEA Reports
- DOE Reports '
The list of aging mechanisms and materials they affect are shown in Table 4-1. ! ne specific description of each is provided in Attachment 1 of procedure EN 305 or is described in detail in Section 1.0 of the corresponding appendices (A through T) in the component aging management review results. t ! Each aging mechanism was evahiated for applicability (i.e., POTENTIAL) to the i structural component type based on its material of construction and the l environmental conditions where the component type could be located. -This ; l approach ensures all the components within a component type will be evaluated if ! the potential of degradation exists. ! The results of the structural component type POTENTIAL scoping of the component list of aging mechanisms are presented in the second column of Table l 4-1. l 1 4.2.2 C .w. - e Gr=-'; i The grouping of stmetural components.which are within the scope of heense renewal is primarily based on their materials and their special functions, if eny, j that contribute to safety, or in the opinion of the evaluator, warrant special ; attention. De components are grouped into four categories: l (1) Concrete (including reinforcing steel) l (2) Structural steel
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(3) Architectural items such as doors, roofing materials, and protective coating j (4) Additional components that may have a unique function in the structure 4.2.3 Plausible Aging Mechanisms The identification of PLAUSIBLE aging mechanisms is accomplished through a careful review of the POTENTIAL aging mechanism list, the development of which is discussed in Section 4.2.1. A potential aging mechanism is considered plausible if when it is allowed to continue without any additional preventative or , mitigative measures, the aging mechanism would result in the Turbine Building structural component not being able to perform its intended function. An aging AGING MANAGEMENT REVIEW RESULTS FINAL REIORT TURBINE BUILDING 4-2 REVISION 2 l
! i I LIFE CYCLE MANAGEMENT i O : t mechanism is also considered plausible if there is insufficient evidence to , conclude that future degradation will have no impact on the intended functions of the Turbine Building structural component. Tha plausibility determmation is made through a careful consideration of all the factors required to allow the aging mechamsm to occur. In particular, the aging mechamsm is scoped for plausibility l on the basis of: l
- Material of construction ;
- Environmental service conditions !
- Design and construction considerations l
- Impact on intended functions l
- Physical conditions of the component ;
i i The results of the aging mechanism plausibility scoping is an aging mechanism component matrix listing the aging mechamsm and its disposition. The aging mechanism matrix developed for each structural component type is included in Attachment 3 in the evaluation results. l Aging mechanisms determined to be PLAUSIBLE are provided specific aging l management recommendations to mitigate the effects of the aging mechanism. l Table 4-2 summarizes the results of the plausibility determination and d recommendations for the Turbine Building. j 4.2.4 Aging Management Program Identification Once plausible aging mechanisms have been identified, the evaluation is l continued to determme whether existing plant programs adequately address the ! effects of aging for the renewal term. If existing programs would not manage the l effects of aging during a renewal term, a one-time inspection could be conducted, l modifications could be made to the programs, or new programs could be initiated l to adequately manage the effects of aging. This evaluation did not include a , l determination of whether recommended changes to existing programs or new i ! program recommendations would actually be implemented or which programs ! would be included in the FSAR Supplement. 4.2.5 AginF Management Recommendations The evaluation of all structural component types in the Turbine Building identified a total of eight (8) aging mechanisms that have the POTENTIAL to degrade these components. A detailed review of the specific component intended functions, material of constmetion and its basis of design and constmetion identified PLAUSIBLE component aging mechanisms as shown in the second column of Table 4-2. In some cases, the conclusion that the aging mechanism is \. AGING MANAGEMENT REVIEW RESULTS FINAL REPORT TURBINE BUILDING 4-3 REVISION 2
l l LIFE CYCLE MANAGEMENT j i l V l l PLAUSIBLE was made because the condition of the component was not available or could not be readily verified due to lack of accessibility. Recommended aging management activities include actions to perform condition j assessment, to verify conditions conducive to degradation do not exist, and to develop inspection and monitoring programs to ensure degradation can be detected and corrective actions can be taken. The following is a summary of the recommendations: (1) Continue visual inspection of coated ' structural steel components in Class 1 portions of the Turbine Building. (2) Develop an age related degradation inspection program for coated surfaces of stmetural steel components that are not readily accessible.
- (3) Sample the water quality of the groundwater using the existing groundwater monitoring wells.
(4) Develop a new program to address the mspection and maintenance of p caulking and sealants in the Turbine Building. V . l O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT l l TURBINE BUILDING 4-4 REVISION 2 l
i l i 1 m LIFE CYCLE MANAGEMENT Table 4-1 l List of Patantial Aelne Macha=leme for Turhina Baildine Structural Camnanante Potential to Affect Aelne Mech ==3== Daecrintion Turhine E 88di==? Materials Affected Freeze-Thaw No Concrete Leaching of Calcium Hydroxide Yes Concrete Aggressive Chemicals Yes Concrete l Reaction with Aggregates Yes Concrete i Corrosion in Embedded Steel /Rebar Yes Steel, Concrete Creep No Concrete Shrinkage No Concrete Abrasion and Cavitation No Concrete ! Cracking of Masonry Block Walls No
- Block Walls i Settlement Yes Structure Corrosion in Steel Yes Steel J
l Corrosion in Liner No* - Steel Liners (Carbon and l Stainless) I Corrosion in Tendons No* Post-tensioning System Prestressing Losses No* Post-tensioning System Weathering Yes Caulking and Sealants l Elevated Temperature No Concrete ! Irradiation No Steel, Concrete Fatigue Yes Steel, Concrete l Affected components do not exist in the Class 1 portion of the Turbine Building. i 1 = O FINAL REPORT AGING MANAGEMENT REVIEW RESULTS TURBINE BUILDING 4-5 REVISION 2
O; O %./ J LIFE CYCLE MANAGEMENT Table 4-2 Turbine Buildina Apina Effects Evaluation Summary STRUCTURAL PLAUSIBLE AGING MECIIANISM COMPONEN13 RECOMMENDATION REMARKS Concrete Walls None None SeejusGr~ain. in Appendices D and T. Ground Hoor Siabs and Aggressive chemicals The ".m.Jun wells, installed during construction, can be restored to Seejustification in Appendices B, C, D, E, J and T. Equipment Pads sample the groundwater for water quality testing. This data can be used Conosien in embedded steel /rebar to evaluate the impact ofchemical attack on the extenor surfaces of exposed w~.a. Elevated Hoor Slabs None I None Seejustifwation in Appendices D and T. Cast-in place Corrosion in steel See e-m.~,iaiuo for
- Steel Deams" Seejustification in Appendices K and T.
Anchors /E- '- - - - - - Ductbanks None None Secjustifwation in Appendix D. Fluid Retaining Walls and Stabs None None Seejustification in Appendix D. Post 4nstaHed Anchors Corrosion in steel See -. .~,asiun for" Steel Beams" SeejustiScation in Appendix K. Building SidingClips Corrosion in steel See .-m.~.&aion for
- Steel Beams
- Seejustification in Appendix K.
Fire Doors, Jambs, and liardware Corrosion in steel See . - - -- - taion for " Steel Beams" Seejustificationin AppendixK. Access Doors, Jambs, and Corrosion in steci See r-- - - t-ion for"Stect Beams" Seejustification in Appendix K. Ilardware i Caulking and Scalmts Weathering Caulking and scalants which perform a fire barrier function will be Seejustificationin AppendixO. addressed by the Appendix R Program. For caulking and scalants which perform an intended funrtion other than fire barrier, an inspection and maintenance program which wiD identify &y eaaini and ensure corrective action is taken before the component losses its ability to perfarn hs intended function will be developed. The resolution to issue Report iR1995-01698 will form the basis for this pmgnun. Watertight Doors Conosion in steel Seeir - -- = %- for" Steel Beams
- Seejustification in Appendix K.
AGING MANAGEMENT REVIEW RESULTS , FINAL REPORT TURBINE BUILDING , 4-6 REVISION 2
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LIFE CYCLE MANAGEMENT Table 4-2 Turbine Builrlino Apina Effects Evaluation Sn=marv STRUCTURAL PLAUSIBLE AGING MECIIANIS31 COSIPONENTS RECOMMENDATION REMARKS Seejustificalion in Appendix K. Steel Beams Corrosion in stee! protective coating. For accessible areas, signifu: ant coating my-.. , an&or the presence of corrosion will be identified, an issue report written, and corrective action tsh:n through the following existing site programs. PEG-7, System WallEdoims Qle2-100, Issue Reportiig MN-3-100, Prntective Co6e p: gen. For those structural steel cornponents not readily accessible, significant coating degradation and/or the presence ofcorrosion will be detennined utilizing an age related ap.idiv.. inspection. Baseplates Corrosion in steel See -...~.1.&-i for
- Steel Beams
- Seejustification in Appendix K.
I Hoar Framing Corrosionin steel See -...~h$ for " Steel Beams
- Seejustification in Appendix K.
Steel Bracing Corrosion in steel See i-. .~.1.&m for
- Steel Beams
- Secjustification in Appendix K.
Platform llangers Conosion in steel Seer - m-- trion for" Steel Beams
- Seejustification in Appendix K.
Steel Decking Corrosion in steel See e - - - : :L- for" Steel Beams
- SeeMr~.A.h in Appendix K.
Jet Impingement Barriers Corrosion in steel See r- - 2 :'-- for" Steel Beams" Seejustification in Appendix K. Hoor Grating Corrosion in steel See .-...m. " &m for ' Steel TJeams* Secjustification in Appendix K. Stairs and Ladders Corrosion in steel See recommendation for
- Steel Beams
- Secjustification in Appendix K.
AGING MANAGEMENT REVIEW RESULTS , FINAL REPORT TURBINE BUILDING , 24-7 REVISION 2
l \ l l l LIFE CYCLE MANAGEMENT U 5.0 PROGRAM EVALUATION 5.1 PROGRAM ADEQUACY EVALUATION Program adequacy evaluations were completed in accordance with EN-1-305, Revision 0, for those programs or aging management alternatives developed to address PLAUSIBLE l component aging mechanisms. The evaluation of programs or aging management alternatives considered the following criteria as a means of establishing the adequacy of specific CCNPP programs: l
- 1. Adequate programs must ensure management of the affects of aging for those structural components subject to plausible aging mechanisms.
- 2. Adequate programs must contain acceptance criteria against which the need for corrective action will be evaluated, and ensure that timely corrective action will be taken when these acceptance criteria are not met.
l l
- 3. Adequate programs must be implemented by the facility operating procedures and l reviewed by the onsite review committee.
l The results of the program adequacy evaluations are provided in Section 5.2. 5.2 STRUCTURAL COMPONENTS SUBJECT TO ADEQUATE PROGRAMS l I - I 5.2.1 Existing Programs The program evaluation task reviewed all existing CCNPP programs that were established to monitor, inspect, and repair Turbine Building structural components ! that are degraded by identitled plausible aging mechanisms. i The Appendix R Program, implemented through procedure STP-F-592-1/2 for f penetration fire barrier inspection, is adequate to manage the effects of aging for caulking and sealants which function as fire barriers without any modification. . PEG-7 in conbination with QL-2-100 and MN-3-100 for identifying, documenting, and correcting significant coating degradation are adequate for managing the ! effects of corrosion in accessible steel components. 'O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT TURBINE BUILDING 5-1 REVISION 2
. - . . - . . . - -..=__ - _- -. ._ -~. . . . s LIFE CYCLE MANAGEMENT 5.2.2 Madified Fula*1== Proer=== This section provides the summary results for those structural components that were determined to have an existing CCNPP Program / Activity that with modification would become an adequate program to manage the effects of aging during the renewal period. The evaluation started from evaluating structural component types and applicable aging mechanisms and has focused to specific components or locations. No modified existing programs were identified to manage the effects of aging into the licecse renewal period. 5.2.3 New Proer=== This section provides the summary results for those structural components that were determined to require a new CCNPP Program / Activity be created as an adequate program to manage the affects of aging during the renewal period. Components that can be managed by the creation of such a new program include the following: Ground floor slab: An investigative program to test the water quality of the groundwater should be developed to determine if there is any possibility of aggressive chemical attack on the Turbine Building ground floor slab. -- Caulkino and Sealants: A periodic inspection and maintenance program should be developed for components not covered by the Appendix R Inspection Program. The resolution to issue Report IR1995-01698 will address the requirements for the inspection and maintenance of caulking and scalants not covered by the Appendix R Program. ; Non-accessible Structural Steel: An age related degradation inspection, as defined in the BGE Integrated Plant Assessment Methodology, should be conducted for - structural steel components that are not readily accessible. The ARDI Program - must provide requirements for identification of a representative sample of components for inspection, the inspection sample size, appropriate inspection techniques, and requirements for reporting of results and corrective actions. AGING MANAGEMENT REVIEW RESULTS FINAL REPORT TURBINE BUILDING 5-2 REVISION 2
LIFE CYCLE MANAGEMENT List of Attachments and Appendices For the Turbine Building Aging Management Review Total Papes 3 Attachment 1, Potential Aging Mechanisms Applicable to Structural Components 3 Attachment 2, Plausible Aging Mechanisms Applicable to Structural Components 3 Attachment 3, Structural Components Aging Mechanism Matrix Codes ! 3 Attachment 4, Summary of Aging Management Review Results 9 Attachment 5, Adequate Program Evaluation 0 Attachment 6,Not Used 4 Attachment 7, Walkdown Report - Examination of Auxiliary Feedwater Pump Room 6 Attachment 8, Attributes in New Program I Appendices S l Appendix A - Freeze-Thaw 6 l Appendix B - Leaching of Calcium Hydroxide 4 Appendix C- Aggressive Chemicals 6 t A Appendix D - Reactions with Aggregates ( ) 5 w Appendix E - Corrosion of Embedded Steel /Rebar . 3 Appendix F - Creep 3 Appendix G - Shrinkage 2 Appendix H - Abrasion and Cavitation 3 Appendix I - Cracking of Masonry Block Walls 4 Appendix J - Settlement 5 Appendix K - Corrosion of Steel 3 , Appendix L - Corrosion of Liner 2 i Appendix M - Corrosion of Tendons 2 4 Appendix N - Prestress Losses 3 Appendix 0 - Weathering 0 f Appendix P -Not Used 0 Appendix Q - Not Used 3 Appendix R - Elevated Temperature 3 Appendix S -Irradiation 8 Appendix T- Fatigue
- O FINAL REPORT AGING MANAGEMENT REVIEW RESULTS REVISION 2 TURBINE BUILDING
.--..s o a-+ - e s ~.,a < w +:- e a -- s s 1 j
i i r i 1 i 4 I 4 Attachment 1 I Potential Aging Mechanisms Applicable to Structural Components ; t i f i i
- i. .
9 i , h i a 4 i
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Sheet I of._3_
.1
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% ) (m) v ATTACHMENT 1: POTENTIAL AGING MECHANISMS APPLICABLE TO STRUCTURAL COMPONENTS REVISION: ? DATE: 5/7/96 STRUCTURE NAME: Turbine Building SYSTEM NUMBER: . - _ Sheet 2_ of 3 REMARKS STRUCTURAL POTENTIAL AGING MECHANISMS APPLICABLE TO CONCRETE / ARCH. COMPONENTS COMPONENTS A B C D E F G H I J K O R S T
- - 4 - - - -
NA - - - - - 4 Functions LR-S-1, 2, 4, 6, 7 Concrete Watts - 4 4 4 4 NA 4 - - - - 4 Functions LR-S-1, 2, 4, 6, 7 Ground Floor Slabs & Equip. Pads - - - -
- 4 - - - - NA - - - - -
4 Functions LR-S-1, 2, 6, 7 Elevated Floor Slabs - -
- - - - - - - NA - 4 - - - 4 Functions G-S-1,2,6,7 Csst4n-Place Anchors / Embed. -
- 4 - - - - NA - - - - - - Functions LR-S-1,2 Duct Banks - -
- - - - - - NA - - - - - - Fui c;v. .5 LR-S-1, 2, 6, 7 Grout - -
4 NA - - - - - - Functions LR-S-1,2,6,7 Fluid Retaining Watts & Stabs - - - - - - - NA - 4 - - - - Functions m-S-4,5 Post-Installed Anchors - - - Building Siding Clips - - - - - - - - NA - 4 - - - - Function W-S-2 NA - 4 - - - - Fune".,ons LR-S-2, 6, 7 Firs Doors, Jambs, Hardware - - - - - - - - NA Y - - - - Functions LR-S-2,6,7 Access Doors, Jambs, Hardware - - - - - - - - -
- - NA - - 4 - - - Functions W-S-2,6,7 Caulking and Sealants - - - - - -
Watertight Doors - - - - - - - - NA - 4 - - - - Functions LR-S-2,6,7 Legend: A Freeze-thaw G Shrinkage M Corrosion in tendons S Irradiation B Leaching of calcium hydroxide H Abrasion and cavitation N Prestressing losses T Fatigue C Aggress % c.hemicals I Cracking of masonry block walls O Weathering U (Not Used) D Reaction with aggregates J Settlement P (Not Used) V (Not Used) E Corrosion in embedded steel /rebar K Corrosion in steel Q (Not Used) NA Not applicable F Creep ,L Corrosion in Liner R Elevated temperature - Not potential
O 0 (~ O L.) ATTACHMENT 1: POTENTIAL AGING MECHANISMS APPLICABLE TO STRUCTURAL COMPONENTS REVISION: 2 DATE: 5/7/96 STRUCTURE NAME: Turbine Building SYSTEM NUMBER: _- Sheet 3_ of 3 REMARKS STRUCTURAL POTENTIAL AGING MECHANISMS APPLICABLE TO STEEL COMPONENTS COMPONENTS K L M N R S T 4 NA NA NA - - 4 Functions LR-S-1,2,7 Steel Beams NA NA NA 4 Functions LR-S-1,2,4. 5,7 BIseplates i - - Floor Framing i NA NA NA - - 4 Functions LR-S-1,2,7 4 NA NA NA - 4 Function LR-S-4 Brscing - Fistform Hangers 4 NA NA NA - - 4 Function LR-S-5 NA NA 4 Functions LR-S-1,2,7 Decking 4 NA - - ht Impingement Barriers 4 NA NA NA - - - Function LR-S-4 Floor Grating i NA NA NA - - - Function LR-S-5 4 NA NA NA - - - Function LR-S-5 Stairs & Ladders t Legend: A Freeze-thaw G Shrinkage M Corrosion in tendons S trradiation B Leaching of calcium hydroxide H Abrasion and cavitation N Prestressing losses T Fatigue C Aggressive chemicals l Cracking of masonry block watts O Weathering U (Not Used) D Reaction with aggregates J Settlement P (Not Used) V (Not Used) E Corrosion in embedded steel /rebar K Corrosion in steel Q (Not Usedl NA Not applicable F Creep ,L Corrosion in Liner R Elevated temperature . Not potential
= - _ - - - . O Attachment 2 Plausible Aging Mechanisms Applicable to Stiuctural Components O o see ,,, I i
V V C) t ATTACHMENT 2: PLAUSIBLE AGING MECHANISMS APPLICABLE TO STRUCTURAL COMPONENTS REVISION: 2 DATE: 5/7/96 STRUCTURE NAME: Turbine Buildina SYSTEM NUMBER: _ - _ Sheet 2_ of 3 REMARKS STRUCTURAL PLAUStBLE AGING MECHANISMS APPLICABLE TO CONCRETE / ARCH. COMPONENTS ! COMPONENTS A B C D E F G H I J K O R S T 102 - - - NA - - - - - 104 Functions LR-S-1, 2, 4, 6, 7 Concrete Watts - - - - Ground Floor Stabs & Equip. Pads - 101 PA 102 PB - - - NA 103 - - - - 104 Functions m-S-1, 2, 4, 6, 7 Elevated Floor Stabs - - - 102 - - - - NA - - - - - 104 Functions LR-S-1,2,6,7 Cast-in-Place Anchors / Embed. - - - - - - - - NA - PC - - - 104 Functions LR-S-1,2,6,7 Duct Banks - - - 102 - - - - NA - - - - - - Functions LR-S-1,2 NA - - - - - - Functions LR-S-1,2,6,7 Grout - - - - - - Fluid Retaining Walls & Slabs - - - 102 - - - - NA - - - - - - Functions M-S-1, 2, 6, 7 Post-Installed Anchors - - - - - - - - NA - PC - - - - Functions LR-S-4,5 Building Siding Clips - - - - - - - - NA - PC - - - - Function LR-S-2 Firs Doors, Jamos, Hardware - - - - - - - - NA - PC - - - - Functions LR-S-2,6,7 Access Doors, Jambs, Hardware - - - - - - - - NA - PC - - - - Functions LR-S-2,6,7 Courking and Sealants - - - - - - - - NA - - PD - - - Functions LR-S-2, 6, 7 Watertight Doors - - - - - - - - NA - PC - - - - Functions LR-S-2,6,7 Legend: A Freeze-thaw G Shrinkage M Corrosion in tendons S Irradiation B Leaching of calcium hydroxide H Abrasion and cavitation N Prestressing losses T Fatigue C Aggressive chemicals I Cracking of masonry block walls O Weathering U (Not Used) D Reaction with aggregates J Settlement P (Not Used) V (Not Used) E Corrosion in embedded steet/rebar K Corrosion in steel Q (Not Used) NA Not applicable F Creep L Corrosion in Liner R Elevsted temperature - Not potential
O O v V J ATTACHMENT 2: PLAUSIBLE AGING MECHANISMS APPLICABLE TO STRUCTURAL COMPONENTS REVISION: 2 DATE: 5/7/96 STRUCTURE NAME: Turbine Buildino SYSTEM NUMBER: __ -- Sheet 3_ of 3 REMARKS STRUCTURAL PLAUSIBLE AGING MECHANISMS APPLICABLE TO STEEL COMPONENTS COMPONENTS K L M N R S T Steel Beams PC NA NA NA - - 104 Functions LR-S-1,2,7 Baseplates PC NA NA NA - - 104 , Functions LR-S-1, 2, 4, 5, 7 Floor Framing PC NA NA NA - - 104 Functions LR-S-1,2,7 Brecing PC NA NA NA - - 104 i Function LR-S-4 Ptr.tform Hangers PC NA NA NA - - 104 . Function LR-S-5 Decking PC NA NA NA - - 104 Functions LR-S-1,2,7 ht Impingement Barriers PC NA NA NA - - - Function LR-S-4 Floor Grating PC NA NA NA - - - Function LR-S-5 Sttirs & Ladders PC NA NA NA - - - Function LR-S-5 l Legend: A Freeze-thaw G Shrinkage M Corrosion in tendons S trradiation B Leaching of calcium hydroxide H Abrasion and cavitation N Prestressing losses T Fatigue C Aggressive chemicals I Cracking of masonry block walls O Weathering U (Not Used) D Reaction with aggregates J Settlement P (Not Used) V (Not Used) E Corrosion in embedded steet/rebar K Corrosion in steel Q (Not Used) NA Not applicable F Creep L Corrosion in Liner i R Elevated temperature - Not potential
1 l f 1 1 I l l i l l l
- i I
l Attachment 3 ) l l Structural Components ; i Aging Mechanism Matrix Codes l l 2 i i l
~
1 l l t I i i Sheet 1 of_3._
.. . - .. . = . . _ - - _ .. . _ . .
O l ATTACHMENT 3 l STRUCTURAL COMPONENTS- AGING MECHANISM MATRIX CODES REVISION: 2 DATE: 5/7/96 l l l STRUCTURE NAME: Turbine Building i SYSTEM NUMBER: - Sheet 2 of 3 I CODE JUSTIFICATION REMARKS i 101 See Appendix B l 102 See Appendix D l 103 See Appendix J i 104 See Appendix T l l l
- O
i f3 V i ATTACHMENT 3 l STRUCTURAL COMPONENTS - AGING MECHANISM MATRIX CODES l REVISION: 2 DATE: 5D/96 STRUCTURE NAME: Turbine Building l SYSTEM NUMBER: - Sheet 3 of 3 l CODE JUSTIFICATION REMARKS 1 PA See Appendix C l PB See Appendix E ! PC See Appendix K PD See Appendix 0 i !O I l l O . l
i !,O i i i j. ! Attachment 4 4 2 Summary of Aging Management Review Results O . Sheet 1 of__3_ O
O O O Attachment 4
SUMMARY
OF AGING MANAGEMENT REVIEW RESULTS REVISION:._2_ DATE: Sn/96 STRUCTURE / SYSTEM NUMBER- - STRUCTURE NAME: Turbine Building COMPONENTS AFFECTED AGING MECIIANISM CONCRETE STEEL ARCH PROGRAM / COMMENT Freeze-Thaw None None None Not Needed Leaching ofCa(OH)2 None None None Not Needed Aggressive Chemicals Ground Floor Slab None None None existing. Need to investigate water quality ofgroundwater. Reaction with Aggregates None None None NotNeeded Corrosion of Embedded Ground Floor Slab None None None existing. Need to investigate Steel /Rebar water quality of groundwater. Creep None None None Not Needed Shrinkage None None None Not Needed Abrasion / Cavitation None Nope None NotNeeded Cracking of Masonry Block None None None Masonry block walls do not exist in the Walls Class 1 portion of the turbine building. Settlement None None None Not Needed Corrosion in Steel None All carbon steel None PEG-7,QL-2-100,MN-3-100,ARDI. components Corrosion in Liner None None None Steel liners do not exist in the Class I portion ofthe turbine building Corrosion in Tendons None None None Ihhsd tendons do not exist in the Sheet 2.of.2
r t\ f%
'vl Attachment 4
SUMMARY
OF AGING MANAGEMENT REVIEW RESULTS REVISION:_2_ DATE: Sn/96 STRUCTURE / SYSTEM NUMBER: - STRUCTURE NAME: Turbine Building COMPONENTS AFFECTED AGING MECilANISM CONCRETE STEEL ARCH PROGRAM / COMMENT Class I portion of the turbine building Prestressing Losses None None None Prestressed tendons do not exist in the Class I portion of the turbine building Weathering None None Caulking and Appendix R Program for components Sealants with fire protection function. For non-Appendix R components, develop an inspection and maintenance program to identify degradation and ensure corrective action is taken. The resolution to Issue Report IR1995-01698 to fonn the basis of this program. Elevated Temperature None None None Not Needed Irradiation None None None Not Needed Fatigue None None None Not Needed S Sheet 3_ ofl
i O Attachment 5 Adequate Program Evaluation O - O O Sheet _1 of_1 j
I l l O Q Attachment 5 I l l ADEQUATE PROGRAM EVALUATION REVISION:_2_ DATE: 5/7/96 l STRUCTURE / SYSTEM NUMBER: STRUCTURE NAME:_Iprbine Building STRUCTURAL COMPONENT DESCRIPTION: All accessible steel surfaces AGING MECIIANISM DESCRIPTION: Corrosion of steel l CCNPP PA or Task ID: MN-3-100. PEG-7. OL-2-100 l Criteria 1: Adequate programs must ensure mitigation of the effects of agre related degradation for the SSCs within the scope oflicense renewal. DISCOVERY DESCRIPTION / BASIS:
- 1. Is there a frequency interval in the PA or Task? I YES X NO _ 1 O
gj Basis: System Engineer Walkdowns as directed by PEG-7 are conducted neriodically as ! mandated by system performance. olant coerating conditions. or as required by olant- - - management. Walkdowns can be iob soecific or outage related but otherwise tvolcally occur on a monthly basis.
- 2. Is the frequency interval consistent with. industry standards, industry experience, experience unique to Calvert Cliffs, or vendors' recommendations? J YES ._X_ NO_
Basis: The PEG-7 walkdown frecuency is consistent with industry standards and can be . modified as necessary to reflect unioue olant ooerating conditions soecific to CCNPP.
- 3. Will the PA or Task be applicable to all structural components under the same component type?
YES_X_ NO_ Basis: All coated surfaces in areas that are " reasonably accessible" are visually insnected during the PEG-7 activity. l l l l Sheet .2_. of _.2.
i l l [] G Attachment 5 - Adequate Program Evaluation (continued) l ! REVISION:_l_ DATE: 5/7/96 AGING MECHANISM DESCRIPTION: Corrosion of steel [ CCNPP PA or TASK ID: MN-3-100. PEG-7. OI 2-100 Criteria 2: l Adequate programs must contain acceptance criteria against which the need for i corrective action will be evaluated, and ensure that timely corrective action will be taken when these acceptance criteria are not met. ASSESSMENT / ANALYSIS / CORRECTIVE ACTION DESCRIPTION / BASIS:
- 1. Does the PA or Task have an action or alert value or condition parameter to determine the need for corrective action?
YES_X_ NO __ Basis: There is no auantitative alert value to determine the need for corrective action. PEG-7 allows for degraded coatings to be documented on a checklist which is then used to orioritize corrective actions. MN-3-100 soecifies approoriate technical orocedures for corrective action based on the coatings service level. IN Does the action value or condition provide sufficient indication of degradation to ensure that D) 2. there will not be a functional failure prior to the next PA or Task? YES _X_ NO _ Basis: Conditions adverse to anality and functionality. indications of cauioment stress or abuse. safety or fire ha7ards. and general housekeening deficiencies are noted during PEG-7 system walkdowns conducted monthly. Structural degradation occurs at a sufficiently slow rate such that monthly insoections would detect degradation before loss of function could occun
- 3. Will the action value or condition parameter remain the same during the renewal period ?
YES _X_ NO _ Basis: The corrective actions and condition parameters prescribed in MN-3-100 are based on insoection of the surface condition of the oainted comoonent. This anoroach does not need to be revised during the renewal neriod. O O Sheet _3_ of _9_ l
r l
. Attachment 5 - Adequate Program Evaluation (continued)
REVISION:_ 2__ DATE: 5/7/96 AGING MECHANISM DESCRIPTION: Corrosion of steel CCNPP PA or TASK ID: MN-3-100. PEG-7. OI 2-100
- 4. Does the PA or Task ensure that corrective action is taken?
YES .X_ NO _ Basis: PEG-7 reauires deficiencies to be documented on a system walkdown report. Conditions adverse to anality will result in the initiation of an Issue Reoort oer OI,2-100 squirements. MN-3-100 invokes the noorooriate technical orocedure to ensure crocer anolication and that a analified orotective coating is used.
- 5. Does the PA or Task ensure that the corrective action is appropriately scheduled?
YES_X_ NO __ l Basis: OL-2-100 assigns a due date for corrective action to occur. The comotetion date is i driven by engineering iudgment based on the condition of the degraded coating and its p contribution to the comoonent's intended function. l l l l l l l l Sheet 4_ of _.2.
4 l Attachment 5 - Adequate Program Evaluation (continued) REVISION:_2_._ DATE: 5/7/96 AGING MECIIANISM DESCRIPTION: Corrosion of steel CCNPP PA or TASK ID: MN-3-100. PEG-7. OI,2-100 Criteria 3: Adequate programs must be implemented by the facility operating procedures and reviewed by the onsite review committee. CONFIRMATION / DOCUMENTATION DESCRIPTION / BASIS:
- 1. Does the PA or Task have a review / approval process?
- YES X. NO _
Basis: The crocedure reauires signatures from approoriate levels of supervision (i.e.. POSRC. Manager of Calvert Cliffs Nuclear Power Plant. and GSOA) after it is submitted by the resnonsible engineer.
- 2. Does the PA or Task have a change / revision process?
YES_X. NO _ V Basis: The " Record of-Revisions and Changes" of the nrocedure documents the changes to the
~
nrocedure. i ) i s O Sheet _i_ of 9_
-- = _ . _. _- . _ _- _ ,_ .. /N Attachment 5 i )
V i ADEQUATE PROGRAM EVALUATION l REVISION: _2_ , DATE: 5/7/96 STRUCTURE / SYSTEM NUMBER: None STRUCTURE NAME: Turbine Building STRUCTURAL COMPONENT DESCRIPTION: Caulking and Sealants AGING MECHANISM DESCRIPTION: Weatherine CCNPP PA or Task ID: STP-F-592-1/2 Criteria 1: Adequate programs must ensure mitigation of the effects of age-related degradation for the SSCs identified as within the scope oflicense renewal. DISCOVERY DESCRIPTION / BASIS:
- 1. Is there a frequency interval in the PA or Task?
YES .2L_ NO _ O) ( - Basis: Both the Unit 1 and Unit 2 procedures are implemented in accordance with the freauency intervals soecified in olant Technical Soecification Section 4.7.12. --
- 2. Is the frequency interval consistent with industry standards, industry experience, experience unique to Calvert Cliffs, or vendors' recommendations?
YES _2L_ NO _ Basis: The frequency interval is consistent with that commonly used in the industrv for surveillance of fire barrier penetration seals. The frequency interval has been nooroved lagssociation with the imolementation of the CCNPP Annendix R Program. .
- 3. Will the PA or Task be applicable to all structural components under the same component type?
YES .2L NO __ Basis: The orocedure is anolicable to fire barrier eenetration seals including electrical conduit and cable tray penetration seals. HVAC duct oenetration seals. and mechanical pine oenetration seals. The orocedure also covers insocction of the fire resistivity of rated walls. ceilines. and floors. Data sheets are orovided with the orocedure to identify the fire areas requiring insoection. A
- (v)
! Sheet J_ of _2.
1 , Attachment 5 - Adequate Program Evaluation (continued) REVISION:_2_ DATE: 5/7/96 AGING MECHANISM DESCRIPTION: Weatherine CCNPP PA or TASK ID: STP-F-592-1/2 l Criteria 2: Adequate programs must contain acceptance criteria against which the need for j corrective action will be evaluated, and ensure that timely corrective action will be taken when these acceptance criteria are not met. l 1 ASSESSMENT / ANALYSIS / CORRECTIVE ACTION DESCRIPTION / BASIS:
- 1. Does the PA or Task have an action or alert value or condition parameter to determine the need for corrective action?
YES .X_ NO __ Basis: Acceptance criteria is orovided for each tyoe of oenetration in Attachment A to the Unit I and Unit 2 orocedures. The accentance criteria orovides the basis for determining the need for corrective action. p 2. Does the action value or condition provide sufficient indication of degradation to ensure that
'( there will not be a functional failure prior to the next PA or Task?
l YES _X_ NO __ Basis: The orocedures in both units mandate visual insoection of the oenetration Hre barriers for indications of degradation or. damage. The criteria imolemented in the Calvert Cliffs ! nenetration fire barrier surveillance orocedures will ensure the Gre barriers perform their l intended functions at all times. This reauirement is imolemented in accordance with the i reauirements of Anoendix R and CCNPP Technical Sneci6 cations. l l 1
- 3. Will the action value or condition parameter remain the same during the renewal period ? !
, YES_X_ NO_ 1 l Basis: Since the surveillance orocedures and the acceptance criteria in the orocedures are to ensure the availability and the reliability of the fire barrier oenetration seals. this accentance criteria should not be changed during the renewal neriod. I Sheet l_ of _2_ I t l
[ Attachment 5 - Adequate Program Evaluation (continued) REVISION:_.2__ DATE: 5/7/96 AGING MECHANISM DESCRIPTION: Weatherine l l CCNPP PA or TASK ID: STP-F-592-1/2
- 4. Does the PA or Task ensure that corrective action is taken?
l YES X_. NO _ Basis: In accordance with Sections 5.4. 7.1. and Attachment B of the orocedures for both units. any insoection results determined to be unsetisfactory will be reoorted to the Shift Suoervisor for nossible Tech Soec reauired action and to the Fire Protection System Engineer or Fire Protection Engineer for investigation and corrective action.
- 5. Does the PA or Task ensure that the corrective action is appropriately scheduled?
YES _X__ NO _ Basis: All corrective actions must meet reporting reauirements soecified in Technical Soecification 4.7.12 of both Units 1 and 2. 1 ! A m l l l l i
+ 'h t') Sheet .fL of _9_
- . . . . . - . . . . _ _ ~ . . _ _ _ _ _ _ - - . - - . _ - - .- __
1 l 1 i O d Attachment 5 - Adequate Program Evaluation (continued) REVISION:__2__ DATE: 5/7/96 , AGING MECHANISM DESCRIPTION: Weatherine CCNPP PA or TASKID: STP-F-592-1/2 l Criteria 3: Adequate programs must be implemented by the facility operating procedures and j reviewed by the onsite review committee. ! CONFIRMATION / DOCUMENTATION DESCRIPTION / BASIS: i
- 1. Does the PA or Task have a review / approval process?
YES_X_ NO _ i Basis: This procedure has a review /anoroval nrocess ner EN-4-104. l 2. Does the PA or Task have a change / revision process? i YES .X_ NO _ Basis: This procedure has a change / revision orocess ner EN-4-104.
'I t
i O Sheet _9_ of _2.
O Attachment 7 . Walkdown Report Examination of Auxiliary Feedwater Pump Rooms Calvert Cliffs Nuclear Power Plant O . O Sheet 1 of _i
^** ca-
!O *7 l Examination of Auxiliary Feedwater Pump Rooms Calvert Cliffs Nuclear Power Plant l October 27,1994 Date ofInmeetion: October 27,1994 i
Participants:
Lloyd Philpot G/C David Knepper G/C Patrick McCarraher G/C 1 Summarv: An inspection of the Auxiliary Feedwater Pump Rooms located inside the Turbine Building wa performed to support the Component Evaluation and Program Evaluation of the Turbine Building. Prior to the inspection a checklist was developed to establish those characteristics indicative of specific aging mechanisms. The interior and exterior of the pump rooms were inspected. A U Results:
~
The inspection checidist and correspording findings are included o'n the following
~
n pages. This information will be used as input to the turbine building evaluation as needed. l V l Sheet _2_. of _4_
O O O Attachment 7 LCM INSPECTION CHECKLIST AUXILIARY FEEDWATER PUMP ROOMS Appendix Aoine Mechanien Characteristic Comments A Freeze-thaw Scaling, cracking, spalling No scaling, cracking, or spalling was observed B Imching of calcium hydroxide Leachate No leachate was observed C Aggressive chemicals Spills, discoloration No aggressive chenucals were observed in the auxiliary feedwater Pump rmms. D Reaction with aggregates Map cracking No map cracking was observd E Corrosion in embedded steel /rebar Cracking, rust staining, spalling No cracking, staining, or spalling was observed F Creep NA Creep is not a potential aging mechanism for this structure G Shrinkage , KA Shrmkage is not a potential aging mechanism for this structure H Abrasion and cavitation NA 'Ihis aging ird suii is not applicable to the auxiliary feedwater pump rooms I Cracking of masonry block walls N'A 'Ihis aging ird.2e ke . is not applicable to the auxiliary feedwater pump rooms J Settlement Cracking No cracking or other evidence of settlement was observed K Corrosion in steel Rust Minor areas of rust were found, however a periodic maintenance Sheet _3_ of _4_ 1
O O O Attachment 7 LCM INSPECTION CHECKLIST AUXILIARY FEEDWATER PUMP ROOMS Appendix Aging Mechanism Characteristic Comments program could be used to control this aging mechanian L Corrosion in liner NA This aging mechanian is not applicable to the auxiliary feedwater pump rooms M Corrosion in tendons NA His aging mechamsm is not applicable to the auxiliary feedwater pump rooms N Prestressing losses NA His aging mechamsm is not applicable to the auxiliary feedwater pump rooms O Weathering NA This aging mechanism is not applicable to concrete in the auxiliary feedwater Pump rmms R Elevated temperatures Heat sources Only minor heat generating sources were observed in the pump rooms S Irradiation Radiation No monitored radiation sources were observed inside the pump rooms T Fatigue Vibrating equipment The auxiliary feedwater pump rooms contain vibrating equipment. Fatigue caused by this equipment was - considered in the original design of the structure. No cracking or spalling of the concrete around the base of this equipment was observed Sheet 4 of_4_
1 l I Attachment 8 l l Attributes in New Program l i i 1 I I l 1 Sheet 1 off i
q Attachment 8 (continued) ATTRIBUTES IN NEW PROGRAM , REVISION:_2_ DATE: 5/7/96 STRUCTURE / SYSTEM NUMBER: None STRUCTURE NAME: Turbine Building STRUCTURAL COMPONENT DESCRIPTION: Ground Floor Slab AGING MECHANISM DESCRIPTION: Aggressive Chemicals APPLICABLE APPENDIX: Anoendix C BACKGROUND: The intended function of the turbine building's ground floor slab is to provide supoort. orotection. and shelter to safetv-related and non-safety related eauinment inside the turbine building. Chemical anack is olausible if the chemistry of the groundwater has become significantiv more aggressive than was originally anticioated. RECOMMENDED A ATIRIBUTES: Since decradation of the below crade nortion of the turbine buildine around floor slab would be olausible only if tlie water chemistry has become more aggressive. the oroposed orogram will begin with investigative tasks followed by - - -- corrective action if necessarv. The recommended anoroach is:
- 1. Restore the groundwater observation wells installed during initial clant construction for samnling puroose.
- 2. Secure samnles of the groundwater for water chemistrv testing. If the water chemistry meets the original design reauirements (Cl ions < 500 com. SQlons
< 1500 oomi no further action is necessarv.
- 3. If the water chemistry tests conclude that the concrete comoonents are being degraded by chemical agents. the levels of chemical concentration will need to be assessed to determine the aoorooriate corrective action.
BASIS: Because of the design and construction of the turbine building ground floor slab. and the knowledge of the water chemistrv during the design of the olant. it is unlikely that chemical attack to concrete is a maior concern. ( L Sheet _.2_ of ti
l C ( Attachment 8 (continued) i ATTRIBUTES IN NEW PROGRAM J l REVISION:_2__ DATE: 5/7/96 STRUCTURE / SYSTEM NUMBER: None STRUCTURE NAME: Turbine Buildine ; l STRUCTURAL COMPONENT DESCRIPTION: Ground Floor Slab AGING MECHANISM DESCRIPTION:Corrosien of Embedded Steel /Rebar l APPLICABLE APPENDIX: Anoendix C
- BACKGROUND
- The intended function of the turbine building's ground floor slab is to provide supoort. nrotection. and shelter to safetv-related and non-safety related cauinment inside the turbine building Corrosion of embedded steel /rebar in the j ground floor slab is clausible if the chemistry of the aroundwater has become l l significantiv more aggressive than was originally anticinated. i l
I RECOMMENDED l p ATTRIBUTES: Since degradation of the below crade nortion of the turbine building ground floor slab would be olausible only if the water chemistry has become more l aggressive. the oroposed orogram will begin with investigative teks followed by - - - - corrective action if necessarv. 'llie recommended anoroach is.
- 1. Restore the groundwater observation wells installed during initial olant construction for samoling puroose.
l
- 2. Secure samoles of the croundwater for water chemistry testine. If the water
~
l chemistrv meets the original design requirements ( oH > 4.0. Cl ions < 500 l oom. and SO4 ions < 1500 nom 1. no further action is necessarv. l
- 3. If the water chemistry tests conclude that the concrete comoonents are being l
decraded by chemical acents. the levels of chemical concentration will need to be assessed to determine the noorooriate corrective action. l- BASIS: Because of the desien and construction of the turbine buildine around floor slab. l and the knowledge of the water chemistrv during the design of the plant. it is unlikely that corrosion of embedded steel /rebar in the ground floor slab is a major concern. l l D V i Sheet _1. of _fi_ l
i Attachment 8 (continued) l l ATTRIBUTESIN NEW PROGRAM REVISION:_ 2__ DATE:. 5/7/96
. STRUCTURE / SYSTEM NUMBER: None.
L STRUCTURE NAME: Turbine Buildina STRUCTURAL COMPONENT DESCRIPTION: Caulking and halanta AGING MECHANISM: Waatherina APPLICABLE APPENDIX: Anoendix 0 l BACKGROUND: ne intended functions of caniking and cealants are to nrovide shelter and protection to safety related eanipment (includh g HRIR and radiation protection) inside the Turbine Buildina. He canikina and cealante have an additional intended fimetion to nrovide a flood orotective barrier for internal floodina events. The canikina and scalants are comnnnents which are tvolcally reolaced l on condition. However insnections in the plant revealed that an inanection program was reanired to adenuatelv mannae the aging of these comoonents. Note: The caulking and scalants which require a new proc. ram to manage their aging do not nerform the intended function of a fire barrier. Caulking and sealants which perform a fire barrier function are managed under an existing program. RECOMMENDED l ATfRIBUTES: The management program for the caulking and cealants is recommended to be develooed in association with the resolution to Issue Report IR1995-01698. The grogram must mannae the aging of the caulking and sealants in the Turbine Buildina which suonort intended functions of the structure. The recommended anoroaches are:
- 1. Identify all non-Apoendix R caulking and cealants locations that suonort the structure's intendad functions.
- 2. Develoo an insnection animaintenanrdLorogram which will identify degradation and ensure corrective action is taken before the comoonent loses the ability to nerform its intended function. The program should concentrate on caulkina and cealants located in exterior walls and in interior walls and floors where NFI R and flooding functions an:.pfrformed.
l \ l h f Sheet _.4.._ of.fL
. . . ._. - _-. .. . - . - - - . ~ _ - . . - . - - . - . - . - . . - .
l I l( . Attachment 8 (continued) i REVISION:_ 2__ DATE: 5/7/96
- STRUCTURAL COMPONENT DESCRIPTION
- Can1 king and Sealanta i
l AGING MECHANISM: Weatherine APPLICABLE APPENDIX: Annendix O , BASIS: The manmoement nrogram for the canikina and emalante is recommendaA to be , develoned in association with the resolution to issue Renort IR1995-01698. The i==na renort identified ioints in the Auxiliary Building which showed signs of denradation. This concern is also annlicable to the Turbine Buildina. Resolution of this issue renort will ensure develonment of an ar,ina mannaement nronram for canikina and walants in the Turbine Buildino such that these comonnents will be able to nerform their intended functions both during the current license neriod and the neriod of extendad onerations. t W
# h f
t I { I l Sheet _i_ of.fi_ I
l l (9 G' Attachment 8 (continued) ATTRIBUTES IN NEW PROGRAM l REVISION: _2._._ DATE: 5/7/96 STRUCTURE / SYSTEM NUMBER: None STRUCTURENAME: Turbine Buildin_g STRUCTURAL COMPONENT DESCRIPTION: Non-accessible structural steel ARDM DESCRIPTION: Corrosion of Steel APPLICABLE APPENDIX: Appendix K BACKGROUND: Safety related structural steel in the Turbine Building is covered with an appronriate nrotective coating. Corrosion of structural steel can only occur if these nrotective coatings have been degraded. Aging management of degraded coatine conditions on accessible structural steel in the Turbine Building is
~
accomnlished through the combination of existing plant nrograms. However. structural steel comnonents not readily accessible reauire additional acing manacement.
,~
RECOMMENDED (')\ ATTRIBUTES -An age related degradation inspection (A RDn program as described in the BGE Integrated Plant Assessment Methodology should be imnlemented to address corrosion of non-accessible structural steel comnonents which support the intended functions of the Turbine Building. The ARDI Program must consist of the following:
- 1. Identification of non-accessible locations.
- 1. Selection of renresentative structural steel comnonents for insnection.
- 2. Develonment of an insnection samnle size.
- 3. Use of Annronriate insnection techniaues.
- 4. Reauirements for renorting of results and corrective actions if aging concerns are identified.
BASIS: The ARDI Program will ensure that degraded conditions due to corrosion of j steel are identified and corrected such that non-accessible structural steel ! camponents of the Turbine Building will be canable of nerforming their intended '\ p) v functions under all design conditions reonired by the current licensing basis. i Sheet _.fi._ of.fi.
l 9 b APPENDIX A- FREEZE-THAW 1.0 MECHANISM DESCRIPTIONI Repeated cycles of freezing and thawing can alt l component. The freeze-thaw phenomenon occurs when water freezes l concrete's pores, creating hydraulic pressure. This pressure either increa size of the cavity or forces water out of the cavity into surrounding voids. Freeze-thaw damage is characterized by scaling, cracking, and spalling. Sc or surface flaking occurs in the presence of moisture and is aggravated by the of deicing salts. Cracks or spalling occurs when voids are already filled with water, and freezing causes pressure to increase, in extreme cases of freez damage, the cover over reinforcing steel is reduced, and the reinfo eventually exposed to accelerated corrosion. expansive effects of the resulting corrosion products, thereby wea concrete's resistance to further attack by aggressive environments. To minimize the adverse effects of freeze-thaw, three factors must be co l' in the design and placement of concrete:2 The cement paste must have an entrained air system with an appropriate void spacing factor. The aggmgate must be of a sufficiently high quality to resist scaling. The in-place concrete must be' allowed to mature sufficiently befo exposure to cyclic freezing and thawing.
. As shown in Figure A-1, the optimal air content range extends from 3 to based on the nominal size of coarse aggregate.3 2.0 EVALUATION 2.1 Conditions According to Specification ASTM C33-82, " Standard Specification for Aggregates,"4 the CCNPP site is located in the geograph weathering conditions.
Criteria,"5 the frost penetration depth is 20 to 22 inches. l O Revision 2 , m A-1 50/96 l
i Freeze-Thaw 2.2 Potential Aging Mechanism Determination l All Class 1 portions of.the turbine building are located within the structure. Therefore, freeze-thaw is not a potential aging mecharusm. l i 2.3 Impact onIntended Functions Since freeze-thaw is not a potential aging mechanism, it will not affect the intended functions of any safety related structural component located inside the turbine building. 2.4 Design and Construction Considerations CCNPP concrete design specification No. 6750-C-96 specifies: 9.3.1 The Portland cement concrete furnished, unless otherwise specifed herein, shall conform to ASTM C-94 Specipcationfor Ready Mix Concrete, ACI 318-63 Building Code Requirements for Reinforced Concrete, ACI 301-66 Standard Specipcations for Structural Concrete for Building, and ACI Manual of Concrete . Inspection. 10.1.2.2 All aggregate shall conform to ASTM Designation C33.
~' Section 10.1.16 of ASTM Designation C33-67 specifies thap ,
Procedures for making freezing an'd thawing tests of concrete are described in ASTM Method C290, "Testfor Resistance of Concrete < Specimens to Rapid Freezing and Thawing in Water," and in ASTM l
~
Method C291, " Resistance of Concrete Specimens to Rapid Freezing in Air and Thawing in Water." Both ASTM Methods C290 and C291 cover the method for determining the resistance of concrete specimens to rapidly repeated cycles of freezing and thawing in the laboratory. , Design specification No. 6750-C-9 for CCNPP also specifies: , 10.4.2.1 The Subcontractor shall specify the air entraining agent he l proposes to use. It shall be in accordance with ASTM C-260, capable of entraining 3-S% air, be completely water soluble, and be completely dissolved when it enters the batch. The Subcontractor shall give 30 days advance notice of the type of AEA he proposes to \ use. j ACI 3187 and its relevant ACI standards and ASTM specifications provide the physical property requirements of aggregate and air-entraining admixtures, chemical and physical requirements of air-entraining cements, and proportioning ,'p of concrete including containing entrained air to maxunize the concrete resistance to freeze-thaw action. e A-2 Revision 2 S/7R6 l
1 i l Freeze-Thaw 2.5 Plausibility Detennination 1 Not applicable. 2.6 Existing Programs Not applicable. i
3.0 CONCLUSION
I 1 The CCNPP site is located in the geographic region subject to severe weathermg ; conditions, however, concrete structural components located inside the turbine building are not exposed to freeze-thaw cycles. Freeze-thaw is not a plausible aging mechanism for the structural components of the turbine building. l 4.0 RECOMMENDATION Freeze-thaw is not a plausible aging mechanism for any concrete structural components of the turbine building. No further evalue. tion or recommendation is required. i s
5.0 REFERENCES
- 1. " Class I Structures License Rene[ val Industry Report," EPRI's Project RP-2643-27, December 1991. ;
- 2. Mather, B., "How to Make Concrete that Will Be Inunune to the Effects ,
of Freezing and Thawing " ACI Fall Convention, San Diego, November l 1989. l
- 3. " Design and Control of Concrete Mixtures," Portland Cement Association,13th Edition.
- 4. " Standard Specification for Concrete Aggregates," American Society of Testing and Materials, ASTM C33-82.
- 5. Civil and Structural Design Criteria for Calvert Cliffs Nuclear Power Plant Unit No.1 and 2, by Bechtel Power Corporation, Revision 0, August 2,1991.
- 6. " Specification for Furnishing and Delivery of Concrete - Calvert Cliffs Nuclear Power Plant Unit No.1 and 2," CCNPP's Design Specification No. 6750-C-9, Revision 8, April 1970.
- 7. " Building Code Requirements for Reinforced Concrete," American Concrete Institute, ACI 318-63.
U S/7/96 m A-3 Revision 2
j 1 i t
- Freeze-Thaw 4
i 1 Espension,peeeent i O.20 . Feemse-thew cycess: 300 oj g Speciamens: 5 x 3 at1%
) '
concente prisms Cement: Type I,517 sb per cv yd OJ S - Sawmp: 2 -3 3n. { i t ! CJ 4 - I
\ .
Q.12, -
- 7 k
-w --we .se,e e '
O.lO - L -{A l I I aOe - l -8A A ' f i OAlps - l k l*
\ !
\
1 O.04 - ! 4
.- ~
OD2 - --
)
t i 1 i e i
; 00 2 4. 6 8 to 12 14
. Alr content, peecent 2
l 1 i J 4 1 4 Figure A-1 Relationship between Air Content Aggregate Size and Concrete Expansion i (Reference 3) 4, i 1 I i 5/7/96 m A-4 Revision 2 d J
.. - -. _~ - . . _. .
l l t APPENDIX B - LEACHING OF CALCIUM HYDROXIDE l d[ % l 1.0 MECHANISM DESCRIPTION 2 Water, either from rain or melting snow, that contains small amounts of calcium ions can readily dissolve calcium compounds in concrete when it passes through cracks, inadequately prepared construction joints, or areas inadequately consolidated during placing. The most readily soluble calcium compound is , calcium hydroxide (lime). The aggressiveness or affinity of water to leach calcium hydroxide depends on its dissolved salt content and its temperature. Since leaching occun when water passes through the concrete, structums that are subject to flowing liquid, ponding, or hydraulic pressure are more susceptible to degradation by leaching than those structures that water merely passes over. Leaching of calcium hydroxide is visible on concrete surfaces that have dried. The leachate is almost colorless until carbon dioxide is absorbed and the material dries as a white deposit. The white deposit is a product of water, free lime from the concrete, and carbon dioxide that has been absorbed from the air. When calcium hydroxide is leached away, other cementitious constituents become exposed to chemical decomposition, eventually leaving behind silica and alumina gels with little or no strength. Leaching over a long period of time increases the porosity and permeability of concrete, making it more susceptible to p other forms of aggressive attack and reducing the strength of concrete. Leaching Q also lowers the pH of concrete and threatens the integrity of the exterior protective oxide film of rebar ~ Resistance to leaching and efflorescence can be enhanced by using concrete with low permeability. A dense concrete with a suitable cement content that has been well cured is less susceptible to calcium hydroxide loss from percolating water because ofits low permeability and low absorption rate. The design attributes to enhance water-tightness include low water-to-cement ratio, smaller coarse aggregate, long curing periods, entrained air, and thorough consolidation.3 Figure B-1 shows the impact on permeability due to water-to-cement ratio and curing time. 2.0 EVALUATION 2.1 Conditions The underside of the turbine building ground floor slab could be in contact with underground water. A permanent dewatering system wa!. installed during construction to maintain a stable groundwater table at El.10'-0". The bottom of the ground floor slab is at El.10'-0". A waterproof membrane was installed under the gmund floor slab to prevent contact with the groundwater, however the condition of this membrane could not be ascertained during an October 27,1994 inspection of the auxiliary feedwater pump rooms. l 1 (h , b W7/96 m B-1 Revision 2
}
Leaching of Calcium Hydroxide 2.2 Potential Aging Mechanism Detennination teaching of calcium hydroxide is a potential aging meclumism for the following structural component of the turbine building because it could be exposed to flowing liquid, ponding, or hydraulic pressure: Ground floor slab Functions LR-S 1,2,4,6, and 7 where: LR-S-1: Provides structural and/or functional support (s) for safety-related equipment. LR-S-2: Provides shelter / protection for safety-related equipment. l LR-S-4: Serves as a missile barrier (internal or external). LR-S-6: Provides flood protection barrier (internal flooding event). LR-S-7: Provides rated fire barriers to confine or retard a fire from i spreading to or from adjacent areas of the plant. O b Leaching of calcium hydroxide is not a potential aging mechanism for other structural components of the turbine building be~cause they are located'inside th'e turbine building. 2.3 Impact on Intended Functions If the effects ofleaching of calcium hydroxide were not considered in the original ; design or are allowed to degrade the above structural component unmitigated for an extended period of time, this aging mechanism could affect all the intended functions of the component listed in Section 2.2. 2.4 Design and Construction Considerations Leaching attack can be muumized by providing a low-permeability concrete mix design during construction. CCNPP concrete design specification No. 67S0-C-94 specifies: 9.3.1 The Portland cement concrete furnished, unless othenvise specified herein, shall conform to ASTM C-94 Specipcation for Ready Mix Concrete, ACI 318-63 Building Code Requirements for Reinforced Concrete, ACI 301-66 Standard Specifcations for Structural Concrete for Building, and ACI Manual of Concrete inspection. 12.1 Concrete Quality O 5f7/96 m B-2 Revision 2
Leaching of Calcium Hydroxide 12.1.1.1 Portland cernent shall conform to ASTM Designation C-94-67, Alternate No.1 and ACI301-66. l 12.1.2.1 Concrete shall rneet thefollowing requirements: l Nominal 28-Day Simnp nt Simnp Maxinunn Class Strength Pokt of Tolerance Aggregate Use andlocation (ps0 Placement (in.) Size (k.) 1 A.1 2,000 4 11 W4 in. ElectricalDuct Encasement &l.ean Concrete Back)ill A-2 2,000 4 t1 1-% in. Electrical Duct Encasement & Lean Concrete Back)Ill B-1 3,000 3 t% W4 in. Strucural Concrete Walls & Slabs less than 12* thick & Congested Rebar B-2 3,000 3 1% 1-H in. Turbine Pedestal & other Structural Concrete B Grout 3,000 - - N4 Construction Joints C-1 4,000 3 t% 3/4 in. Walls & Slabs less than 12* thick &
., , , , Congested Rgbar C-2 4,000 2 t% i-% in. Containment Base Slab and Other Structural Concrete C-3 4,000 3 t% 3/8 in. Stair Treads High Density 4,000 High Density Concretefor Nuclear Concrete Shielding. Use Where Directed.
C Grout 4,000 - - N4 Containment hints D-1 5,000 3 1% W4 in. Walls and Slabsless than 12* thick and Congested Rebar D-2 S,000 2 1% 1-% in. Containment Walls and Dome and , Other Structural Concrete l D Grout 5,000 - - N4 Construction joints j i Dry Pack 4,000 0 - N4 As Directed Tremie 4.000 6 W4 in. As Directed Concrete AA 1,000 S t2 1-% in. Earth Alternate i AAA 1,000 5 12 3/4 in. Earth Alternate I i l 12.1.5 Mix Design i o O l I S/7&6 n B-3 Revision 2
l Leaching of Calcium Hydroxide l 12.1.S.1 The Constructor shall retain an approved Testing Laboratory, at his own cost, to design and test initial concrete mixes. The initial mixes shall be designed in accordance with ACI I Standards 613 and 301 to produce a required strength of 15 percent over speciped strength for reinforced concrete at 28 days and 2S percent over specifed strengthfor post-tes.sioned concrete at 28 days for each class of concrete with slump and maximum sizes of l aggregate as specifed in the Classifcation Table (Section 12.1.2). 12.1.S.2 The Constructor shallfurnish the Subcontractor with mix designs one month prior to the manufacture of concrete. Furnishing mix designs shall not relieve the Subcontractor of his responstbility for compliance with the provisions of the Specifcation. Where necessary, the Constructor shall increase or decrease cementfactors as deemed necessaryfor design mixes using statistical methods desenhed in the ACI 214-6Sfor the particular class of concrete. An increase in the water-ccment ratio of a mix design or a decrease in its cement quantity shall constitute a new mix design and the provisions of Section 12.1.S.1 of this Specifcation sha!! apply. Calcium chloride shall not be used.
/~~N
(
) 2.5 Plausibility Detennination Based on the discussion in Section 2/1, tlie turbine building ground floor slab is located at the designed underground water table and may be subjected to some hydraulic pressure. However, as discussed in Section 2.4, concrete used for the ground floor slab was des,igned in accordance with ACI 3185 and its relevant ACI standards and ASTM specMcations to maxunize resistance to leaching of calcium -
hydroxide. A walkdown of the auxiliary feedwater pump rooms conducted October 27,1994 observed only slight traces of leaching on concrete surfaces and were judged to have no adverse impact on the integrity of these components. Therefore, leaching of calcium hydroxide is not a plausible aging mechanism for the auxiliary feedwater pump room ground floor slab. . 2.6 Existing Pacgrams There are no existing programs at CCNPP that are designed specifically to identify or to repair damage to concrete due to leaching of calcium hydroxide. Since leaching of calcium hydroxide is not a plausible aging mechanism that could degrade the safety related structural components of the turbine building, no management program is necessary.
3.0 CONCLUSION
Although the turbine building ground floor slab could be subjected to hydraulic
'( pressure due to underground water, the concrete mix was designed for low permeability and high compressive strength which provide the best protection Sm96 m B-4 Revision 2
l F 'i Leaching of Calcium Hydroxide b against leaching. Therefore, leaching of calcium hydroxide is not a plausible aging mechanism for any concrete structural components of the turbine building. This ; condusion is supported by an October 27,1994 walkdown inspection during ; which only minor traces of leaching were detected. ! l l ! 4.0 RECOMMENDATION i 1 l leaching of calcium hydroxide is not a plausible aging mechanism for any I concrete structural components of the turbine building. No further evaluation or recornmendation is required, l , i
5.0 REFERENCES
l 1
- 1. " Class I Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991. l l
- 2. "
Design and Control of Concrete Mixtures," Portland Cement Association, Thirteenth Edition. i
- 3. " Guide to Durable Concrete," American Concrete Institute, if'
- x. ACI-20 2R-67.
I
- 4. " Specification for Furnishing and Delivery of Concrete - Calvert Cliffs l Nuclear Power Plant Unit No.1 and 2," CCNPP's Design Specification l No. 6750-C-9, Revision 8, April 1970.
l
- 5. " Building Code Requirements for Reinforced Concrete," American Concrete Institute, ACI 318-63.
l 1 i I l b V 5/7/96 a B-5 Revision 2
_ -. . _ ~ _ _ - . . . . .. - . .. . = .. ._ . l l i Leaching of Calcium Hydroxide 1 l L = < r m, a.s x.o \
)
8emi .ir-emetedsmarear RW:1e4en,esamms e : 2o,.s e.s l
)
?*** l ae cs4 l
0 a t r sa as e.<i.d .e e swine w . .. r. Figure B-1 Effect of Water-Cement Ratio j and Curing Duration on Permeability i ( Reference 2) l lO i 97/96 a B+6 Revision 2 l
a- --, J l APPENDIX C - AGGRESSIVE CHEMICALS
]-
l l 1.0 MECHANISM DESCRIPTION 2 Concrete, being highly alkaline (pH > 12.5), is vulnerable to degradation l by strong acids. Acid attack can increase porosity and permeability of concrete, reduce its alkaline nature at the surface of the attack, reduce strength, and render the concrete subject to further deterioration. Portland cement concrete is not acid-resistant, although varying degrees of resistance can be achieved depending on the materials used and the attention to placing, consolidating, and curing. No Portland cement concrete, regardless of its composition, will withstand exposure to highly acidic fluids for long periods. Below grade, sulfate solutions of sodium, potassium, and magnesium I sometimes found in groundwater may attack concrete, often in combination with chlorides. The exposed surfaces of structures located l near industrial plants are vulnerable to industrial pollution from the sulfur-based acid rain and are subject to deterioration. Sulfate attack produces significant expansive stresses within the concrete, leading to
. cracking, spalling, and strength loss. Once established, these conditions l
k allow further exposure.to. aggressive chemicals. Groundwater chemicals can also damage foundation concrete. A dense concrete with low permeability may provide an acceptable degree of protection against mild i acid attack. Any factors that tend to improve the compressive strength of I the concrete will have a beneficial effect on low permeability. Therefore, the better the quality of the constituent material, the less permeable the concrete. Low water-to-cement ratio, smaller aggregate, long curing period, entrained air, and thorough consolidation all contribute to watertightness. Concrete thus constructed has a low permeability and effective protection against sulfate and chloride attack. Minimum degradation threshold limits for concrete have been established at 500 ppm chloride or 1,500 ppm l l sulfates. The use of an appropriate cement type (e.g., ASTM C150, Type II) and pozzolan (e.g., fly ash) also increases sulfate resistance. t l u) 5/7/96 m C-1 Revision 2
( Aggressive Chemicals 2.0 EVALUATION 2.1 Conditions There are no aggressive chemicals stored inside the Class 1 portion of the turbine building. Therefore, none of the internal structural components are exposed to the risk of aggressive chemicals. ! There is no heavy industry near the CCNPP site that could release aggressive chemicals to the atmosphere. However, extemal concrete is exposed to an environment containing chloride ions due to the plant's proximity to the Chesapeake Bay. The below-grade exterior surface of the auxiliary feedwater pump rooms could he exposed to groundwater on a more or less continuous basis. A passive dewatering system, installed during construction, maintains a j stable groundwater level at El. +10.0 ft (UFSAR 2.7.3.2), which is just at the l ground floor slab's bottom surface. A waterproof membrane installed in l , the subgrade below the ground floor slab, protects the underside of the (m) _ slab, however, there is no way to inspect this membrane. 2.2 Potential Aging Mechanism Determination Attack by aggressive chemicals is a potential aging mechanism for the following concrete structural component of the turbine building because it is exposed to outside environment: Ground floor slab Functions LR-S-1,2,4,6, and 7
~
where: LR-S-1: Provides structural and/or functional support (s) for safety-related equipment. LR-S-2: Provides shelter / protection for safety-related equipment. LR-S-4: Serves as a missile barrier (internal or external). LR-S-6: Provides flood protection barrier (internal flooding event). s LR-S-7: Provides rated fire barriers to confine or retard a fire from spreading to or from adjacent areas of the plant. 5/7/96 E C-2 Revision 2
l l \ i l t Aggressive Chemicals l Other concrete structural components are located inside the turbine ] building; therefore, attack by aggressive chemicals is not a potential aging mechanism. 2.3 Impact on Intended Functions If the effects of attack by aggressive chemicals were not considered in the original design or are allowed to degrade the above structural component unmitigated for an extended period of time, this aging mechanism could affect all the intended functions of the component listed in Section 2.2. 2.4 Design and Construction Considerations The turbine building was constructed with concrete that complies with CCNPP's design specification No. 6750-C-92 to assure low permeability. Another design consideration was the use of a waterproof membrane to protect the ground floor slab concrete, however, the. condition of the A membrane could not be ascertained. These properties provide the best V protection against chemical attacks. 2.5 Plausibility Determination Based on the discussion in Sections 2.1 and 2.4, attack by aggressive chemicals is not a ' plausible aging mechanism for the structural components located inside the Class 1 portion of the turbine building. Because the chemical composition of the groundwater is unknown, attack by aggressive chemicals to the below-grade portion of the turbine building ~ is a plausible aging mechanism. 2.6 Existing Programs There are no existing programs at CCNPP that are designed specifically to identify or to repair damage to concrete due to aggressive chemicals. Since attack by aggressive chemicals is not a plausible aging mechanism for concrete components inside the turbine building, no management program is needed for these components. : I lO S/7/96 E C-3 Revision 2 } _ .i
Aggressive Chemicals i
3.0 CONCLUSION
There are no aggressive chemicals stored in the Class 1 portion of the turbine building. The concrete components inside the turbine building are constructed of high quality, low permeability concrete. Attack by aggressive chemicals to concrete located inside the Class I portion of the turbine building is not plausible. The bottom of the ground floor slab is located at the groundwater level and may be exposed to groundwater. Because the quality of the groundwater is not known, degradation due to l aggressive chemicals is plausible for the turbine building ground floor ' slab. 4.0 RECOMMENDATION During initial plant construction, groundwater observation wells were l installed to monitor the fluctuation of the groundwater table, and samples were taken for groundwater quality testing.8 Although the wells are still g- in place, the monitoring activities have been discontinued. It is s recommended that the groundwater quality be tested using these wells. This data can be used to evaluate the effects of chemical attacks on the underside of the turbine building's grotmd floor slab. l l
5.0 REFERENCES
- 1. " Class I Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991.
- 2. " Specification for Fumishing and Delivery of Concrete - Calvert Cliffs Nuclear Power Plant Unit No.1 and 2," CCNPP's Design l
Specification No. 6750-C-9, Revision 8, April 1970.
- 3. " Specification for Furnishing and Installation of Piezometers -
Calvert Cliffs Nuclear Power Plant Unit No.1 and 2," CCNPP's Design Specification No. 6750-C-23E, Revision 0, November 1973. i S/7/96 m C-4 Revision 2
l l l !UO APPENDIX D - REACTIONS WITH AGGREGATES 1.0 MECHANISM DESCRIPTION 1 l ! Certain mineral constituents of all aggregates react with chemical compounds that compose the Portland cement, most notably alkalis. Alkalis may also be introduced from admixtures, salt-contaminated I aggregates, and penetration by seawater or solutions of deicing salt. However, it is only when the expansive reaction products become extensive and cause cracking of concrete that aggregate reactivity is considered a deleterious reaction. l Three principal deleterious reactions between aggregates and alkalis have I been identified as alkali-aggregate, cement-aggregate, and expansive alkali-carbonate reactions. l l Alkali-aggregate reaction, more properly designated as alkali-silica ! reaction, involves aggregates that contain silica and alkaline solutions. All silica minerals have the potential to react with alkaline solution, but the degree of reaction and ultimate damage incurred can vary significantly. 1 , b.) Alkali-silica reaction can cause expansion and severe cracking of concrete I V _ structures. Reactive materials in the presence of potassium, sodium, and calcium oxides derived from the cement react to form solids, which can expand upon exposure to water. Cement-aggregate reaction occurs when the alkalis in cement and some siliceous constituents of the aggregates react. This reaction is complicated by environmental conditions that produce high concrete shrinkage and alkali concentrations on the surface due to drying. Sand-gravel aggregates from some river systems in the Midwestern United States have been involved in deteriorated concrete attributable to this reaction. ; l Expansive alkali-carbonate reaction occurs between certain carbonate aggregates and alkalis, and produces expansion and cracking. Certain limestone aggregates, usually dolomitic, have been reported as reactive. 1 Aggregates that react with alkalis can cause expansion of varying severity, j even to the extent of producing cracking of the concrete and resulting loss ! of strength and durability if the expansion is severe. The cracking is irregular and has been referred to as map cracking. l Moisture must be available for chemical reactions between aggregates and alkalis to occur. Consequently, areas that are either consistently wet or b 5/7/96 E D-1 Revision 2
1 Reactions with Aggregates alternately wet and dry are susceptible to deterioration given the presence of potentially reactive aggregates. The deleterious effects of reactive aggregates are best avoided by using aggregates from sources that have a proven record of service. If such records are unavailable, aggregates should be examined petrographically to identify potentially reactive constituents. Chemical reactions of aggregates for both fast and slow reaction rates were recognized as early as 1940. The method to identify the reactive constituents in concrete i aggregates was first published in ASTM C-289, " Potential Reactivity of l Aggregates (Chemical Method)"2 and ASTM C-295, " Petrographic Examination of Aggregates for Concrete"3 in 1952 and 1954, respectively. Both standards provide guidance for selecting aggregates and cements to avoid alkali-aggregate reactions. 2.0 EVALUATION 2.1 Conditions es U The aggregates used in the concrete of the CCNPP turbine building came from sites in Charles County, Maryland 4, which is not in the geographic l regions known to yield aggregates suspected of or known to cause aggregate reaction. 2.2 Potential Aging Mechanism Determination Reaction with aggregates is a potential aging mechanism for the following concrete structural components if reactive aggregates were used in the concrete structure construction: Concrete walls Functions LR-S-1,2,4,6,7 Ground floor slab Functions LR-S-1,2,4,6,7 and equipment pads Elevated floor slabs Functions LR-S-1,2,6,7 Ductbanks Functions LR-S-1,2 Fluid retaining floors Functions LR-S-1,2,6,7 and slabs O 5/7/96 E D-2 Revision 2
I Reactions with Aggregates where: LR-S-1: Provides structural and/or functional support (s) for safety-related equipment. LR-S-2: Provides shelter / protection for safety-related equipment. LR-S-4: Serves as a missile barrier (internal or external). LR-S-6: Provides flood protection barrier (internal flooding event). 1 LR-S-7: Provides rated fire barriers to confine or retard a fire from spreading to or from adjacent areas of the plant. i 2.3 Impact on Intended Functions l If the effects of reaction with aggregates were not considered in the original design or are allowed to degrade the above structural components p), unmitigated for an extended period of time, this aging mechanism could affect all the intended functionrof components listed in Section 2.2. 2.4 Design and Construction Considerations j i All aggregates used in' construction of the CCNPP turbine building were investigated, tested, and examined based on the following specifications: CCNPP's design specification No. 6750-C-95 specifies: 10.1.1.1 Cement shall be Portland cement, Type il conforming to ASTM Designation C-150, . . . The cement shall not contain more than 0.60 percent by weight of alkalies calculated as Na2O plus 0.658 K20. Only one brand of j cement shall be usedfor all work. . . . 15.2.3.1 The Bidder, at his expense, shall retain an approved independent testing laboratory to sample and test aggregates and the aggregate source in accordance with methods as specyied in ASTM Designation C-33. Acceptability of aggregate and source shall be based on thefollowing ASTM tests: n S/7/96 E D-3 Revision 2
p - Reactions with Aggregates V Method of Test ASTM Designation l ... ... Potential Reactivity C-289 15.2.3.4 Upon award of the subcontract, the i Subcontractor shall submit for petrographic analysis, in accordance with ASTM Designation C-295, a 5-pound sample of quarried material, or if alluvial, 2-1/2 pounds each of sand and coarse material which has been certiped as sampled at the proposed aggregate source by an approved testing laboratory. 15.2.3.6 . . . Aggregates will be tested during the ; progress of the work. . . .Thefollowing user tests will be performed on every 4,000 tans of aggregates delivered to thejobsite:
. Method of Test ASTM Designation Potential Reactivity C-289 Both ASTM C289 and C295 provide guidance for selecting aggregates and cements to avoid alkali-aggregate reactions, and both standards were i specified for use in CCNPP's concrete specification. The aggregates used in the turbine building concrete were specifically investigated, tested, and
( examined in accordance with the ASTM specifications to determine l potential for reactivity with alkalis. l. ! 2.5 Plausibility Determination i Based on the discussion in Section 2.4, the aggregates used in CCNPP's turbine building concrete were specifically investigated, tested, and l examined in accordance with the pertinent ASTM specifications to ! minimize the potential for reactivity with alkalis. For this reason, reactions with aggregates will not degrade any concrete components of the turbme building and will have no adverse impact on the intended functions of these concrete structural components. Therefore, reaction with aggregates is not a plausible aging mechanism for any concrete structural components of the CCNPP turbine building. This conclusion is supported by an 5/7/96 E D-4 Revision 2
l l l
/ Reactions with Aggregates I
l October 27, 1994 walkdown inspection report that documented no indication of concrete damage due to this mechanism. , i < 2.6 Existing Programs There are no existing programs at CCNPP that are designed specifically to identify or to repair damage incurred by reaction with aggregates. Since ; reaction with aggregates is not a plausible aging mechanism that could degrade the turbine building structural components, no management program is necessary.
3.0 CONCLUSION
Since the potential effects of aggregate reactions on all concrete components were well known and understood, measures to avoid using l reactive aggregates were implemented for CCNPP in design specification No. 6750-C-9. The aggregates used in the turbine building concrete were specifically investigated, tested, and examined in accordance with i applicable ASTM specifications to minimize any reactivity of aggregates with alkalis. This conclusion is' supported by an October 27,1994 -* walkdown inspection during which no trace of reactions with aggregates l was detected. l
\
I 4.0 RECOMMENDATION ' Reaction with aggregates is not a plausible aging mechanism for any concrete component of the CCNPP turbine building and requires no
~
further evaluation or recommendation.
5.0 REFERENCES
- 1. " Class I Structures License RenewalIndustry Report," EPRI's Project RP-2643-27, December 1991.
l ! 1 l 2. " Potential Reactivity of Aggregates (Chemi:al Method)," American j l Society of Testing and Materials, ASTM C-289-66.
- 3. " Petrographic Examinahon of Aggregates for Concrete," American Society of Testing and Materials, ASTM C-295-65.
V 5/7/96 E D-5 Revision 2 l
Reactions with Aggregates l
- 4. Letter from Charles County Sand & Gravel Co., Inc. to Bechtel Corporation, June 30,1972.
- 5. " Specification for Furnishing and Delivery of Concrete - Calvert Cliffs -
Nuclear Power Plant Unit No. I and No. 2," Design Specification No. 6750-C-9, Revision 8, April 1970. l O _ i O 5/7/96 E D-6 Revision 2
i. l 1 APPENDIX E - CORROSION OF EMBEDDED STEEL /REBAR 1.0 MECHANISM DESCRIITION2 l The environments that induce corrosion of reinforcing steel, embedded steel, and cast-in-place anchor bolts are similar. Therefore, this appendix ; is applicable to all structural components that are either part of or comprise these three component types. Concrete's high alkalinity (pH > 12.5) provides an environment around embedded steel /rebar and protects them from corrosion. If the pH is lowered (e.g., to 10 or less), corrosion may occur. However, the corrosion rate is stillinsignificant until a pH of 4.0 is reached. A reduction in pH can be caused by the teaching of alkaline products through cracks, the entry of acidic materials, or carbonation. Chlorides can be present in constituent i ! materials of the original concrete mix (i.e., cement, aggregates, admixtures, l and water), or they may be introduced environmentally. The severity of j corrosion is influenced by the properties and type of cement and aggregates as well as the concrete moisture content. Galvanized decking and galvanized embedments are used in some j _ structures. Since galvanmng materialis not considered a dissimilar metal, its application will not aggravate corrosion of the structure. l Studies have also been conducted to determine the effects of stray l electrical currents on reinforcing steel. Lightning conductors exchange electrons with the atmosphere and, if connected to reinforcing steel, may accelerate the corrosion process. However, while stray electrical currents can aggravate active corrosion, they are not age-related2 Corrosion products have a volume greater than the original metal. The . presence of corrosion products on embedded steel or rebar subjects the concrete to tensile stress that eventually causes hairline cracking, rust staining, spalling, and more severe cracking. These actions will expose more embedded steel /rebar to a potentially corrosive environment and cause further deterioration in the concrete. A loss of bond between the concrete and embedded steel /rebar will eventually occur, along with a reduction in steel cross section. Rebar corrosion can cause deterioration of l concrete from a series of hairline cracking, rust staining, spalling, and more severe cracking. These conditions can ultimately impair structural
- integrity.
!O S/7/96 E E-1 Revision 2 l l l
l Corrosion of Embedded Steel /Robar I 1 l The degree to which concrete will provide satisfactory protection for embedded steel /rebar depends in most instances on the quality of the concrete and the depth of concrete cover over the steel. The permeability l i of the concrete is also a major factor affecting corrosion resistance. l Concrete of low permeability contains less water under a given exposure l and, hence, is more likely to have lower electrical conductivity and better resistance to corrosion. Such concrete also resists absorption of salts and their penetration.into the embedded steel and provides a barrier to oxygen, an essential element of the corrosion process. Low water-to-cement ratios and adequate air entrainment increase resistance to water penetration and thereby provide greater resistance to corrosion. l 2.0 EVALUATION At CCNPP, embedded steel has been used in composite structural members or as anchorages of concrete surface attachments. Reinforcing steel (rebar) and cast-in-place anchors are both treated as embedded steel in the evaluation of corrosion effects, because the environment and the l ,Q technical basis for their corrosion induction are similar. The base plates under the columns or those used as part of attachments to the concrete-surface are treated as structural steel, and the evaluation of their corrosion effects is addressed in Appendix K. 2.1 Conditions i There is no significant inventory of aggressive chemicals stored inside the Class 1 portion of the turbine building. Therefore, the turbine building's interior surface and all internal structural components are not exposed to i the risk of aggressive chemicals. The primary area of concem is the below-grade exterior surface which l could be exposed to groundwater on a more or less continuous basis. A passive dewatering system, installed during construction, maintains a stable groundwater level at El. +10.0 ft (UFSAR 2.7.3.2), which is just at the ground floor slab's bottom surface. A waterproof membrane installed in j the subgrade below the ground floor slab, protects the underside of the slab, however, there is no way to inspect this membrane. l l i S/7/96 E E-2 Revision 2
l l 1 3 Corrosion of Embedded Steel /Robar 9 i I
- 2.2 Potential Aging Mechanism Determination
- Corrosion of embedded steel /rebar is a potential aging mechanism for the j following structural component of the turbine building because it is
- exposed to the outside environment and could be subjected to corrosive attack
- l
] i - Ground floor slab Functions LR-S-1,2,4,6,7 I j where: l LR-S-1: Provides structural and/or functional support (s) for' safety-related equipment. , LR-S-2: Provides shelter / protection for safety-related equipment. [ i , l LR-S-4: Serves as a missile barrier (internal or external). LR-S-6: Provides flood protection barrier (internal flooding 4 event). , LR-S-7: Provides rated fire torriers to confine'or retard a fire j from spreading or from adjacent areas of the plant. j ,i Other concrete structural components are located inside .the turbine j building; therefore, corrosion of embedded steel /rebar is not a potential j aging mechanism. T 2.3 Impact on Intended Functions ? i If the effects of corrosion of embedded steel /rebar were not considered in j the original design or are allowed to degrade the above structural . component unmitigated for an extended period of time, this aging mechanism could affect all the intended functions of the component listed in Section 2.2. i 4 ) S/7/96 E E-3 Revision 2
f Corrosiors of Embedded Steel /Rebar _ 2.4 Design and Construction Considerations The turbine building was constructed with concrete that complies with CCNPP's design specification No. 6750-C-93, which adhems to the relevant ACI Codes and ASTM specifications for a concrete structure of low permeability. Also proper concrete covers wem specified in accordance with ACI 318 Code to effectively prohibit exposure of embedded steel /rebar to the corrosive environment. Another design consideration was the use of a waterproof membrane to protect the underside of the ground floor slab. 2.5 Plausibility Determination Based on the discussion in Sections 2.1 and 2.4, corrosion is not a plausible aging mechanism for embedded steel /rebar in the above-grade portion of the turbine building, As discussed in Section 2.1, only the below-grade portion of the ground O floor slab could be exposed to an aggressive environment on a continuous basis and could be susceptible to . embedded steel /rebar corrosion.'- Because the chemical quality of the underground water is not known, corrosion of embedded steel /rebar is a plausible aging mechanism for the below-grade portion of the turbine building.
?6 Existing Programs There are no existing programs at CCNPP that are designed specifically to identify or to repair damage of the concrete structure due to corrosion of embedded steel /rebar.
3.0 CONCLUSION
Based on the discussions in Sections 2.1 c.nd 2.4, corrosion of embedded steel /rebar is not a plausible aging mechanism for concrete components located inside the turbine building. No further evaluation is required for these concrete structural components. Because the quality of the groundwater is not known, corrosion of embedded steel /rebar is a plausible aging mechanism for the below-grade portion of the ground floor slab. O S/7/96 E E-4 Revision 2
Corrosion of Embedded Steel /Robar 4.0 RECOMMENDATION During initial plant construction, groundwater observation wells were installed to monitor the fluctuation of the groundwater table, and samples were taken for groundwater quality testing.5 Although the wells are still in place, the monitoring activities have been discontinued. It is recommended that the groundwater quality be tested using these wells. This data can N used to evaluate the effects of chemical attacks on the underside of the turbine building's ground floor slab.
5.0 REFERENCES
- 1. " Class I Structures License Renewal Industry Report," .EPRI's Project RP-2643-27, December 1991.
- 2. Skoulikidas, T., Tsakopoulos, A., and Moropoulos, T.,
p " Accelerated Rebar Corrosion When Connected to Lightning y/ Conductors and Protection of Rebars with Needle Diodes Using Atmosphere Electricity," in ' Publication - ASTM -STP 906,
" Corrosion Effect of Stray Currents and the Techniques for Evaluating Corrosion of Rebars in Concrete."
- 3. " Specification'for Fumishing and Delivery of Concrete - Calvert Cliffs Nuclear Power Plant Unit No.1 and 2," CCNPP's Design Specification No. 6750-C-9, Revision 8, April 1970.
- 4. "Calvert Cliffs Nuclear Power Plant, Units 1 and 2, Updated Final Safety Analysis Report (UFSAR)," Baltimore Gas and Electric Co.
- 5. " Specification for Fumishing and Installation of Piezometers -
Calvert Cliffs Nuclear Power Plant Unit No.1 and 2," CCNPP's Design Specification No. 6750-C-23E, Revision 0, November 1973. O 5/7/96 m E-5 Revision 2
1 APPENDlX F - CREEP f]~~' I I 1.0 MECHANISM DESCRIPTION 1 l l l Creep is defined as the time-dependent increase of strain in hardened concrete that has been subjected to sustained stress. The sustained stress results from the dead load and live load of the structure and from temperature effects. Creep deformation is a function of loading history, environment, and material properties of the concrete. The time-dependent deformation of concrete under compressive load consists of strain resulting from progressive cracking at the aggregate-cement paste interface, from moisture exchange with the atmosphere, and from moisture movement within the concrete. ! The effects of temperatures on creep are not linear. At 122 'F, creep strain is about two to three times as great as at room temperature (68 - 75 *F.) But from 122 'F to 212 'F, creep strain continues to increase four to six times that experienced at room temperatures. While little is known about creep rate beyond 212 *F, the maximum creep rate may have occurred between 122 'F and 176 'F.2 Creep is not visible because micrxracking occurs at the aggregate cement-paste interface. The deformation resulting from cracking.and from - - moisture exchange with the atmosphere is not recoverable. Creep - deformation can generally be characterized as follows: Increased water-to-cement ratio results in increased creep i magnitude, i I Increased aggregate-to-cement ratio results in increased creep i magnitude for a given volume of concrete. Creep deformation is approximately proportional to the applied load for a level not exceeding about 40% to 60% of the ultimate strength of concrete. l Concrete age at application of load affects creep (i.e., the older the concrete, the less the creep). j I Creep increases with increased temperature. < l Aggregate with a high modulus of elasticity and low porosity will l
- mininuze creep.
O S/7/96 E F- 1 Revision 2 l l
Creep ! ( Creep-induced concrete cracks are typically not large enough to result in concrete deterioration or in exposure of the reinforcing steel to environmental stressors. Cracks of this magnitude do not reduce the concrete's compressive strength. Creep is significant when new concrete is subjected to load and decreases exponentially with time. Any degradation is noticeable in the first few years of plant life. According to ACI 209R-82,2 78% of creep occurs within the first year,93% within 10 years,95% within 20 years, and %% within 30 years. At any given stmss, high-strength concretes show less creep than low-strength concretes. ACI 209R-82 , provides guidance for predicting creep in concrete structures. 2.0 EVALUATION 2.1 Conditions There is no condition in CCNPP that could aggravate the effect of concrete creep initiated right after concrete construction. Most of the concrete creep p will have occurred well before the time of a license renewal application. Therefore, creep of concrete structural components should not be regarded Q1 as an aging mechanism for license renewal. 2.1 Potential Aging Mechanism Determination Creep is not a potential aging mechanism for any turbine building concrete structural components because creep proceeds at a decreasing rate with age and is not expected to continue after 40 years. 2.3 Impact on Intended Functions l l Since creep is not a potential aging mechanism, it will not affect the ! intended functions of any turbine building structural component. 2.4 Design and Construction Considerations At CCNPP, all turbine building reinforced concrete components were designed based on the working stress design method. The induced stresses are much lower than the ultimate strength of the concrete, which is specified as f', = 3,000 psi for all turbine building concrete structural components. Therefore, creep in all concrete components is minimal because of the low compressive stresses in concrete and the use of high-p strength concrete. Besides, creep proceeds at a decreasing rate with age; 5/7/96 E F-2 Revision 2
l i 1 l i I O Creep b normally,96 % of creep has occurred within 30 years.2 Therefore, creep is , not expected to continue during the license renewal period. 2.5 Plausibility Determination i Not applicable. l 2.6 Existing Programs Not applicable. i
3.0 CONCLUSION
Most of the concrete creep occurred well before the time of license renewal application. Therefore, creep of concrete structural components should not be regarded as an aging mechanism for license renewal.
,m 4.0 RECOMMENDATION Not applicable.
1
5.0 REFERENCES
- 1. " Class 1 Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991.
l l
- 2. " Prediction of Creep, Shrinkage, and Temperature Effects in l Concrete Structures," American Concrete Institute, ACI 209R-82.
- 3. " Specification for Furnishing and Delivery of Concrete - Calvert
! Cliffs Nuclear Power Plant Unit No.1 and 2," CCNPP's Design Specification No. 6750-C-9, Revision 8, April 1970. 1 i i 5/7/96 E F-3 Revision 2 l
I i O APPENDIX G - SHRINKAGE i V 1.0 MECIIANISM DESCRIPTION 2 A workable concrete mix typically contains more water than is needed to offset the effects of hydration. When concrete is exposed to air, large portions of the free water evaporate. As water evaporates, capillary tension develops in the water remaining in the concrete while the concrete dries and shrinks in volume. Should these stresses exceed the tensile l strength of the concrete, a crack forms. Initial shrinkage occurs during l l curing and continues months after placement. Subsequent drying and l shrinkage occurs in concrete that is not continuously wet or submerged. According to ACI 209R-822,91% of the shrinkage occurs during the first year,98% in 5 years, and 100% in 20 years. l Excessive shrinkage causes cracking of the concrete surfaces, which i provides a means for aggressive elements to make contact with the l embedded steel /rebar, thus promoting the possibility of corrosion. The l l aging mechanism due to corrosion of embedded steel /rebar is discussed l in Appendix E.
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I 2.0 EVALUATION 1 ! i 2.1 Conditions There is no condition in CCNPP that could aggravate the effect of concrete i l shrinkage initiated right after concrete construction. Most of the concrete ! shrinkage will have occurred well before the time of a license renewal application. Therefore, shrinkage of concrete structural components should not be regarded as an aging mechanism within the scope of license - renewal. 2.2 Potential Aging Mechanism Determination ! Shrinkage is not a potential aging mechanism for any turbine building concrete structural component because shrinkage in concrete proceeds at a decreasing rate with age and is not expected to continue after 40 years. 2.3 Impact on Intended Functions l Since shrinkage is not a potential aging mechanism, it will not affect the intended functions of any turbine building structural component. I 5/7/96 E G-1 Revision 2
Shrinkage i 2.4 Design and Construction Considerations I l Since shrinkage can be minimized by keeping the water content of the l paste as low as possible, the use of low slump concrete is a major factor in l controlling shrinkage.8 As stated in paragraph 12.1.2.1 of CCNPP design specification No. 6750-C-9,4 a low slump of 3 inches was specified for all concrete used in CCNPP's turbine building. The development of concrete cracking due to shrinkage can also be minimized by providing adequate reinforcing steel. For this purpose, l CCNPP has adopted the minimum reinforcing steel requirements specified in ACI 318-635
- Since low slump concrete is used at Calvert Cliffs to minimize concrete l cracks from shrinkage and LJnimum reinforcing steel requirements are used to mitigate crack propagation, shrinkage of any concrete component of the turbine building is minimal.
2.5 Plausibility Determination i - 1 Not applicable. 2.6 Existing Programs I Not applicable. ! l
3.0 CONCLUSION
i l Shrinkage in concrete is not a long-term aging mechanism and is not expected to continue after 40 years during the license renewal period. 4.0 RECOMMENDATION i Not applicable. l O 5/7/96 E G-2 Revision 2
i Shrinkage 1
5.0 REFERENCES
- 1. " Class I Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991.
- 2. " Prediction of Creep, Shrinkage, and Temperature Effects in Concrete Structures," American Concrete Institute, ACI 209R-82
- 3. Design and Control of Concrete Mixtures,13th Edition, Portland l Cement Association.
- 4. " Specification for Fumishing and Delivery of Concrete - Calvert f Cliffs Nuclear Power Plant Unit No.1 and 2," CCNPP's Design Specification No. 6750-C-9, Revision 8, April 1970.
I
- 5. " Building Code Requirements for Reinforced Concrete," American Concrete Institute, ACI 318-63.
<v _
l I i 1 2 S/7/96 E G-3 Revision 2
l l l ! l (JN APPENDIX H - ABRASION AND CAVITATION 1.0 MECIIANISM DESCRIPTION! l As water moves over concrete surfaces, it can carry abrasive materials or it ! can create a negative pressure (vacuum) that can cause abrasion and l cavitation, if significant amounts of concrete are removed by either of these processes, pitting or aggregate exposure occurs due to loss of cement I paste. These degradations are readily detected by visual examination in ) accessible locations. l Abrasion and cavitation occur only in concrete structures that are continuously exposed to flowing water. Cavitation damage is not common if velocities are less than 40 fps. In closed conduits, however, ; degradation due to cavitation can occur at velocity as low as 25 fps when abrupt changes in slope or curvature exist. 2.0 EVALUATION 2.1 Conditions Neither the turbine building nor its structural components are exposed to continuously flowing water. 2.2 Potential Aging Mechanism Determination Attack by abrasion and cavitation is not a potential aging mechanism for the structural components of the turbine building because the structure is not exposed to continuously flowing water.
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l 2.3 Impact on Intended Functions Not applicable. 2.4 Design and Construction Considerations Not applicable, j 2.5 Plausibility Determination t Not applicable. l 5/7/96 E H-1 Revision 2
Abrasion and Cavitation O 2.6 Existing Programs Not applicable. I
3.0 CONCLUSION
l The CCNPP turbine building is not exposed to centinuously flowing water. Therefore, abrasion and cavitation are not a potential aging , l mechanism for any structural components of the turbine building. 4.0 RECOMMENDATION Not applicable. l
5.0 REFERENCES
- 1. " Class I Structures License Renewal Industry Report," EPRI's Project RP:2643-27, December 1991.
I 1 i I O 5/7/96 E H-2 Revision 2
l O V APPENDIX i - CRACKING OF MASONRY BLOCK WALLS 1.0 MECIIANISM DESCRIPTION' Masonry blocks walls can be designed as structural or shield walls. Masonry block wall cells may or may not contain reinforcing steel to provide structural strength to the wall. The extent of grouted cells varies with the specific design requirements for a bearing wall. Some age-related degradation mechanisms that affect masonry block walls are the same as those that affect seinforced concrete walls. The potential for embedded steel and reinforced steel corrosion in block walls is similar to that of reinforced concrete. Masonry block walls are vulnerable to unique age-related degradation mechanisms. , Any restraint imposed on a masonry block wall that will prevent the wall from free expansion or contraction will induce stresses within the wall. Restraint against expansion results in small stresses depending on the strength of the block wall I materials and thus rarely causes degradation of the concrete block wall. Moreover, l expansion of the wall is offset by shrinkage from carbonation and drying. Restraint l against free contraction causes tensile stresses within the wall. If these stresses J n exceed the tensile strength of the unit, the bond strength between the mortar and the j unit, or the shearing strength of the horizontal mortarjoint, cracks occur to relieve ()
'~
the stresses. Expansion or' contraction of masonry block walls may be caused by-changes in temperature, changes in moisture content of the constituent materials, carbonation, and movement of adjacent structural components (e.g., supporting floor or foundations). I Shrinkage due to moisture loss is among the principal causes of volume changes in masonry block walls. Factors affecting the drying shrinkage are the type of aggregate used, the method of curing, and the method of storage. Units made with sand and gravel aggregate will normally exhibit the least shrinkage; those with pumice, the highest. The difference between the moisture content of the masonry units during construction and the building in use will determine the amount of shrinkage that occurs. High-pressure steam curing and proper drying of concrete masonry units reduce the potential shrinkage of the walls. If proper isolation is not provided at the joint between the masonry block wall and the supporting structural components (e.g., floor slabs or beams), long-term creep and variation in stiffness of the supporting components can also cause cracking. Durability of the masonry mortar used at the block joints may affect the long-term stmetural integrity of the trasonry block wall. Although aggressive environments and the use of unsound materials may contribute to the deterioration of mortarjoints, most degradation results from water entering the concrete masonry and freezing. ( 5/7/96 a11 Revision 2
J i l Cracking of Masonry Block Walls The mechanisms cited above which cause cracking of concrete block walls are age-related. Although they are ongoing processes throughout a plant's life, most cracking occurs in the early stages of plant operation. 2.0 EVALUATION 2.1 Potential Aging Mechanism Determination There is no masonry block wall in the Class I portion of the turbine building. Therefore, this aging mechanism does not apply to the turbine building. 2.2 Conditions Not applicable. 2.3 Design Considerations Not applicable. 2.4 Impact on Intended Functions _ Not applicable. 2.5 Plausibility Determination Not applicable. 2.6 Existing Programs Not applicable. l l O I l S/7/96 a 1-2 Revision 2
i Cracking of Masonry Block Walls
3.0 CONCLUSION
Cracking of masonry block walls is not a plausible aging mechanism for CCNPP's turbine building. 4.0 RECOMMENDATION l Not applicable.
5.0 REFERENCES
- 1. " Class i Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991.
i O V _ l i iO i j 5/7/96 m I-3 Revision 2
i (] APPENDIX K - CORROSION OF STEEL v 1.0 MECIIANISM DESCRIPTION' l Steel corrodes in the presence of moisture and oxygen as a result of electrochemical reactions. Initially, the exposed steel surface reacts with oxygen and moisture to 1 form an oxide film as rust. Once the protective oxide film has been formed and ifit is not disturbed by erosion, alternating wetting and drying, or other surface actions,
)
the oxidation rate will diminish rapidly with time. Chlorides, either from seawater, the atmosphere, or groundwater, increase the rate of corrosion by increasing the electrochemical activity. If steel is in contact with another metal that is more noble in the galvanic series, corrosion may accelerate. In some . cases, corrosion of structural steel in contact with water may be microbiologically induced due to the presence of certain organisms, which is l sometimes referred to as microbiologically influenced corrosion (MIC). These organisms, which include microscopic forms such as bacteria and macroscopic types such as algae and barnacles, may influence corrosion on steel under broad ranges of pressure, temperature, humidity, and pH. MIC effects on carbon steel may result in random pitting and general corrosion. (% (") The rate of steel corrosion depends on site-specific environmental conditions and measures taken to prevent corrosion; A steel-structure surface subjected -to- - alternately wet and dry conditions corrodes faster than one exposed to continuously wet conditions. Atmospheric corrosion proceeds much more rapidly in areas where the atmosphere is chemically polluted by vapors of sulfur oxides and similar substances. Steel will corrode much faster in the vicinity of seawater because of sodium chloride in the atmosphere. The corrosion rate of steel usually increases . with rising temperatures. ) Corrosion products such as hydrated oxides of iron (rust) form on exposed, unprotected surfaces of the steel and are easily visible. The affected surface may degrade such that visible perforation may occur. In the case of exposed surfaces of structural steel with protective coatings, corrosion may cause the protective coatings to lose their ability to adhere to the corroding surface. In this case, damage to the coatings can be visually detected well in advance of significant degradation. O b E K-1
l l l Corrosion of Steel u/ l 2.0 EVALUATION l 2.1 Conditions i Steel can corrode in the presence of moisture and oxygen as a result of ' electrochemical reactions, especially in areas where there is an inadequate drainage system. In the turbine building, structural steel components vulnerable to corrosion are the steel members such as base plates and brackets that are not readily accessible for visual inspection and that can form pockets to harbor liquids. 2.2 Potential Aging Mechanism Determination Corrosion is a potential aging mechanism for the following turbine building steel components because conditions conducive to steel corrosion discussed in Sections 1.0 and 2.1 exist: Steel beams Functions LR-S-1,2, and 7 Baseplates Functions LR-S-1,2,4,5, and 7 , l C - Floor framing Functions LR-S-1,2, and 7 l Steel bracing Function LR-S-4 Platform hangers Function LR-S-5 Steel decking Functions LR-S-1,2, and 7 Jet impingement Function LR-S-4 barriers ) i 1 Floor grating Function LR-S-5 l Stairs and ladders Function LR-S-5 Cast-in-place anchors Functions LR-S-1,2,6, and 7 Post-installed anchors Functions LR-4 and 5 Building siding clips Functions LR-S-2 Fire doors, jambs, Functions LR-S-2,6, and 7 and hardware (J n K-2
i p Corrosion of Steel O Access doors, jambs, Functions LR-S-2,6, and 7 and hardware Watertight doors Functions LR-S-2,6, and 7 l where: LR-S-1: Provides structural and/or functional support (s) for safety-related equipment. LR-S-2: Provides shelter / protection for safety-related equipment. LR-S-4: Serves as a missile barrier (internal or external). LR-S-5: Provides structural and/or functional support (s) for non-safety-related equipment whose failure could directly prevent satisfactory accomplishment of any of the required safety-related functions. t LR-S-6: Provides flood protection barrier (intemal flooding event). j _ LR-S-7: Provides rated fire barriers to confine or retard a fire from spreading to or from adjacent areas of the plant. j l 2.3 Impact on Intended Functions If corrosion of steel is allowed to degrade the above structural steel components unmitigated for an extended period of time, this aging mechanism could affect all intended functions of components listed in Section 2.2. 2.4 Design and Construction Considerations Since corrosion was considered a potential degradation mechanism for all structural steel components of the turbine building, its effects were considered in the original design. As a result, all exposed structural steel surfaces in the turbine building except grating and metal decking, which are galvanized steel, were shop-painted or field-painted during the constmetion phase in accordance with CCNPP's design specifications No. 6750-C-192 and No. 6750-A-24'. b v n K-3
I n Corrosion of Steel l Q l Maintenance of protective coatings on CCNPP's equipment and stmetures inside containment follows the requirements specified in Calvert Cliffs Instruction Procedure MN-3-100'. This program sets forth procedural controls that comply with 10 CFR Part 50, Appendix B and satisfy the protective coating requirements in Regulatory Guide 1.54 which endorses ANSI N101.4-1972. The post-installed anchors used for the platforms in the auxiliary feednter pump enclosure are liitti Kwik Bolt concrete anchors. Hilti anchor bolts are made of cold-rolled, high strength steel having a rust-resistant zine coating. Anchors used for the jet impingement barriers are A354 Gr BD. 2.5 Plausibility Determination Based on the discussion in Sections 2.1, 2.3 and 2.4, corrosion could affect the intended functions of all stmetural steel members and is, therefore, a plausible aging mechanism for all steel components listed in Section 2.2. 2.6 Existing Programs a 5 System engineer walkdowns under PEG-7 will provide the discovery mechanism for degraded coating conditions. Conditions adverse to quality (such as degraded paint or corrosion) is reported in an issue Report under QL-2-100'. The coatings program under MN-3-100* provides the administrative control over how corrective actions are performed. The combination of these existing plant programs will ensure that corrosion effects on accessible structural steel is adequately managed. These programs do not provide for the evaluation of the coating condition on structural steel components that are not normally accessible. An age related degradation inspection program as defined in the BGE Integrated Plant Assessment Methodology is necessary to address the aging effects of the non-accessible structural steel components.
3.0 CONCLUSION
All structural steel components of CCNPP's turbine building are vulnerable to corrosion attack if a corrosive environment prevails. All exposed structural steel surfaces in the turbine building are covered by a protective coating. In areas accessible for coating inspection, damage to coating can be detected visually well in advance of degradation due to corrosion of the structural steel. Aging management of degraded coating conditions on accessible structural steel in the Turbine Building is accomplished through the combination of existing plant n K-4
I 1 I Corrosion of Steel O) J programs. Ilowever, structural steel components not readily accessible require additional aging management. 4.0 RECOMMENDATION i Coatings on structural steel in accessible areas of the Class 1 portion of the Turbine j Building is adequately managed by existing plant programs A new program utilizing an age related degradation inspection should be developed to address degradation of coatings on structural steel components that are not nonnally accessible
5.0 REFERENCES
- 1. " Class 1 Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991.
- 2. " Specification for Fumishing, Detailing, Fabricating, Delivering, and Erecting Stmetural Steel," CCNPP's Design Specification No. 6750-C-19, Revision 3, September 1970.
/
V 3. " Specification for Painting and Special Coat,ings,." CCNPP's Design , Specification No. 6750-A-24, Revision 12, October 1982.
- 4. " Painting and Protective Coatings," Calvert Clifts Nuclear Power Plant I
Administrative Procedure MN-3-100, Revision 2, Date 4/2/96
- 5. " Plant Engineering Section System Walkdowns", Plant Engineering Section Guideline PEG-7, Baltimore Gas and Electric Company, Revision l 4,11/30/95.
- 6. " Issue Reporting and Assessment", Calvert Clifts Nuclear Power Plant Admir.istrative Procedure QL-2-100, Revision 4. Date 1/2/96 l
4 G n K-5 l l
{} APPENDIX L - CORROSION OF LINER 1.0 MECHANISM DESCRIPTION'# 1.1 Carbon Steel Liner Carbon steel liner corrosion can be either galvanic or electrochemical. Electrochemical corrosion of carbon steel is caused by exposure to aggressive aqueous solutions, which is described in Appendix K, " Corrosion of Steel." Galvanic corrosion occurs only in the presence of electrolyte when the electrical potential difference between dissimilar metals placed in contact with each other results in the flow of electrons between them. The less resistant metal becomes the anode in this couple and is subject to corrosion, while the more resistant metal becomes the cathode and corrodes very little, if at all. The rate of galvanic corrosion is a function of the potential difference between the metals and the geometric relationship of the metals. Galvanic corrosion reduces the thickness of the anode metal. Liner corrosion reduces liner plate thickness. Excessive reduction in thickness compromises the pressure retention capability of the liner. Corroded surfaces of the Q,fy liner could result in separation of the protective coatings from the steel surface, and
~
coating degradation becomes apparent. _ l.2 Stainless Steel Liner The stainless steel liner is prone to stress corrosion cracking (SCC), which is defined as cracking under the combined actions of corrosion and tensile stresses. The phenomenon of SCC can result in fracture of the metal. The stresses may be either applied (external) or residual (intemal). The stress corrosion cracks themselves may be either transgranular or intergranular, depending on the metal and the corrosive agent. As is normal in all cracking, the cracks are perpendicular to the tensile stress. Usually there is little or no obvious visual evidence of corrosion. The three principal factors necessary to initiate stress corrosion cracking are tensile stresses, corrosive environment, and susceptible material. The tensile stresses necessary to cause SCC must be at or near the material's yield point. This is facilitated when the material is substantially cold worked, contains residual stress from welding, or is subjected to significant applied loads. Different corrosive environments induce different levels of SCC on various materials. With respect to material susceptibility, austenitic stainless steels, such as SA-240 Type 304, are prone to SCC, particularly when sensitization is present as in heat-affected zones and at creviced geometries. In a sensitized condition, Type 304 stainless steel may develop intergranular stress corrosion cracking (IGSCC). The heat-affected zones of welds in Type 304 stainless IGSCC occurs when changes in the O steel are potential sites for IGSCC. h microstructure take place due to the welding heat, rendering the heat-affected zones i 5/7/96 n L-1 Revision 2 l
l i . Corrosion of Liner
" sensitized", and when high residual stresses occur in and around the welds. The degree of sensitization depends on the metal's composition. For example, sensitization usually occurs when Cr combines with carbon. A low carbon content stainless steel, such as Type 304L, is relatively immune to IGSCC in the fuel pool environments. This is because the low carbon content (0.03 percent maximum) of Type 304L results in sensitization levels during welding so low that its heat-affected zones are resistant to IGSCC in the fuel pool environments.
2.0 EVALUATION 2.1 Potential Aging Mechanism Determination There are no steel liners in the Class I portion of the turbine building. Therefore, this aging mechanism does not apply to the turbine building. 2.2 Conditions Not applicable. ( _s 2.3 Impact on Intended Functiops Not applicable. 2.4 Design and Construction Considerations Not applicable. 2.5 Plausibility Determination Not applicable. 2.6 Existing Programs Not applicable.
3.0 CONCLUSION
Corrosion of steel liners is not a plausible aging mechanism for CCNPP's turbine building. O 5/7/96 a L-2 Revision 2
Corrosion of liner 4.0 RECOMMENDATION Not applicable.
5.0 REFERENCES
- 1. " Pressurized Water Reactor Containment Structures License Renewal Industry Report," NUMARC Report 90-01, Revision 1, September 1991.
- 2. " Class I Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991.
O . l O 5/7/96 E L-3 Revision 2
O APPENDIX M - CORROSION OF TENDONS 1.0 MECHANISM DESCRIPTION' When corrosion of prestressing tendons occurs, it is generally in the form of localized corrosion. Most corrosion-related failures of prestressing tendons have been attributed to pitting, stress corrosion, hydrogen embrittlement, or some combination of these. Pitting is a highly localized form of corrosion. The primary parameter affecting its occurrence and rate is the environment surrounding the metal. The presence of halide ions, particularly chloride ions, is associated with pitting corrosion. Stress corrosion results from the simultaneous presence of a conducive environment, a susceptible material, and tensile stress. The environmental factors known to contribute to stress corrosion cracking (SCC) in carbon steels are hydrogen sulfide, ammonia, nitrate solutions, and seawater. Prestressing tendon anchor heads, which are constructed of a high strength, low alloy steel bolting material, are vulnerable to SCC. Hydrogen embrittlement (technically, not a form of corrosion) occurs when (p) hydrogen atoms, produced by corrosion or excessive cathodic protection potential, enter the metal lattice. Hydrogen produced. by corrosion is not usually sufficient to- - - -- result in hydrogen embrittlement of carbon steel. Cathodic polarization is the usual method by which this hydrogen is produced. The interaction between the dissolved hydrogen atoms and the metal atoms results in a loss of ductility manifested as brittle fracture. Corrosion of prestressing wires causes cracking or a reduction in the wires' cross-sectional area. In either case, the prestressing forces applied to the concrete are reduced. If the prestressing forces are reduced below the design level, a reduction in design margin results. 2.0 EVALUATION 2.1 Potential Aging Mechanism Determination There are no prestressed tendons in the Class 1 portion of the turbine building. l Therefore, this aging mechanism does not apply to the turbine building. 2.2 Conditions Not applicable. O 5/7/96 9**1 Revision 2
. . - ~ . - . - _ . . .. .. . . .-. - -_- . . - - .- . .
l Corrosion of Tendons 2.3 Impact on Intended Functions Not applicable. l 2.4 Design and Construction Considerations Not appi: cable. l 2.5 Plausibility Determination Not applicable. 2.6 Existing Programs Not applicable. l r
3.0 CONCLUSION
I Corrosion of tendons is not a plausible aging mechanism for CCNPP's turbine l Q building. i 4.0 RECOMMENDATION Not applicable.
5.0 REFERENCES
- 1. " Pressurized Water Reactor Containment Structures License l Renewal Industry Report," NUMARC Report 90-1, Revision 1, i September 1991.
l i l i %, i t S/7/96 m M-2 Revision 2
l Q APPENDlX N - PRESTRESS LCSSES
, 1.0 MECIIANISM DESCRIPTION' As the plant ages, tendons that were prestressed during construction tend to lose tension. Termed prestress losses, these reductions in stress are not readily l observable. Several factors contribute to prestress losses:
+
Stress relaxation of prestressing wires Shrinkage, creep, and elastic deformation of concrete Anchorage seating losses l Tendon friction Reduction in wire cross section due to corrosion l 2.0 EVALUATION (A) 2.1 Potential Aging Mechanism Determination l l There are no prestressed tendons in the Class I portion of the turbine building. Therefore, this aging mechanism does not apply to the turbine building. 2.2 Conditions Not applicable. 2.3 Impact on Intended Functions l l Not applicable. 2.4 Design and Construction Considerations Not applicable. 2.5 Plausibility Determination Not applicable. O i V 5/7/96 m N-1 Revision 2
.. . =. . - - . . . -- - _ - . _ . . . - -- - ..
( Prestress Losses l l 2.6 Existing Programs Not applicable. l l
3.0 CONCLUSION
Prestress loss in tendons is not a plausible aging mechanism for CCNPP's turbine l building. 1 l 4.0 RECOMMENDATION ) l Not applicable. l
5.0 REFERENCES
- 1. " Pressurized Water Reactor Containment Structures License Renewal g
Industry Report," NUMARC Report 90-1, Revision 1, September 1991. I i i i i lO 4 a 5/7/96 E N-2 Revision 2 b
)
1 APPENDIX O - WEATHERING (v7 1.0 MECHANISM DESCRIPTION ' Components and structures that are located in an environment that is exposed to ambient conditions are susceptible to degradation due to weathering (indoor and outdoor). Aging mechanisms associated with weathering include exposure to sunlight (ultraviolet exposure), changes in humidity, ozone cycles, temperature and pressure fluctuations, and snow, rain, or ice. The effects of weathering on most materials are evidenced by a decrease in elasticity (drying out), an increase ir; ,, and shrmkage. 2.0 EVALUATION 2.1 Conditions According to Specification ASTM C33-82, " Standard Specification for Concrete Aggregates," 2 the CCNPP site is located in the geographic region subject to severe weathering conditions. All outdoor components will experience the extreme temperature ranges, rain, snow, and changes in humidity expected at the CCNPP site. Additionally, inside the Turbine Building, components will experience similar temperature and humidity changes, throughout the life of the plant. h L ./ 2.2 Potential Aging Mechanism Determination Weathering is a potential aging mechanism for the following architectural components of the Turbine Building because they are exposed to the outside environment or similar in-building conditions: e Caulking and sealants Functions LR-S-2,6, and 7 where: j LR-S-2: Provides shelter / protection for safety-related equipment. LR-S-6: Provides a flood protection barrier (intemal flooding event). LR-S-7: Provides rated fire baniers to confine or retard a fire from spreading to or from adjacent areas of the plant. 2.3 Impact on Intended Functions l If the effects of weathering were not considered in the original design or are allowed to , degrade the above components unmitigated for an extended period of time, this aging l mechanism could affect all the intended functions of the components listed in Section 2.2. 13 V 5/7/96 a 0-1 Revision 2
n Weathering V 2.4 Design and Construction Considerations < The caulking and scalants are components which are typically replaced on condition. Ilowever, inspections have indicated that a program ofinspection and maintenance should be developed. Issue Report IR1995-01698 ' was written to address this issue. 2.5 Plausibility Determination Based on the discussion in Sections 23 and 2.4, weathering has been determined to be plausible for caulking and scalants in the CCNPP Turbine Building 2.6 Existing Programs The caulking and scalants which perform a fire barrier function are addressed under the Appendix R Program as implemented by procedure STP-F-592-1/2
- for penetration fire barrier inspection. This procedure was determined to be adequate for managing the effects of weathering for the caulking and scalants.
3.0 CONCLUSION
[S Weathering is a plausible aging mechanism for the caulking and scalants in the Class I portion ( of CCNPP's Turbine Building. Management of the aging mechanism for caulking and sealants which perfonn functions other than those of a fire barrier will be establishedin conjunction ' with the resolution to Issue Report IR1995-01698. The Appendix R Program addresses the aging management for caulking and scalants which perform a fire barrier function. 4.0 RECOMMENDATION Caulking and sealants which act as fire barriers are currently maintained through implementation of the Appendix R inspection program (STP-F-592-1/2). However, caulking and sealants which perform intended functions other than fire barrier do not have a program to manage their aging. An inspection program should be established in conjunction with the resolution to Issue Report IR1995-01698 to manage the effects of weathering for the caulking and sealants not included under the Appendix R Program. i a 5/7/96 m 0-2 Revision 2
l Weathering
5.0 REFERENCES
- 1. " Class 1 Structures License Renewal Industry Report," EPRI's Project RP-2643 27, December 1991.
- 2. " Standard Specification for Concrete Aggregates," American Society of Testing and Materials, ASTM C33-62.
- 3. BGE Issue Report IR1995-01698, Building Joints (Aux. Bldg. Exterior), dated 07/13/95.
- 4. " Penetration Fire Barrier Inspection," CCNPP's Surveillance Test Procedure, STP-F-592-1.7 OV .
l l l l 5/7/96 m 0-3 Revision 2
l (] APPENDIX R - ELEVATED TEMPERATURE 1.0 MECHANISM DESCRIPTION' During normal plant operation, solar heat load and equipment heat loads contribute to an increase in temperature of the internal environment of a structure. Of all structural components in a structure, only components made of concrete material are potentially affected within the temperature range in which the stmeture will experience during normal plant operating conditions. As a result of elevated temperature, compressive strength, tensile strength, and the modulus of elasticity of concrete could be reduced by greater than 10 percent in the temperature range of 180 to 200 F. Long-term exposure to high temperatures (> 300 F) may cause surface scaling and cracking. Othenvise, there is no visible physical manifestation of concrete degradation due to exposure to elevated temperature. 2 ASME Code , Section III, Division 2 indicates that as long as concrete temperatures do not exceed 150 F, aging due to elevated temperature exposure is not significant. Localized hot spots are limited in area and do not exceed 200 F by design. ACI-349' allows local area temperatures to reach 200 *F before special provisions are required.
/~N
~
2.0 EVALUATION - 2.1 Conditions Table B-3 of Baltimore Gas and Electric Company's EQ Manual
- lists the maximum anticipated temperature during normal and accident conditions in the Auxilia.7 Feedwater Pump Room to be 140 *F.
2.2 Potential Aging Mechanism Determination Elevated temperature is not a potential aging mechanism for concrete structural components of the turbine building because they are not exposed to temperatures higher than the degradation threshold of elevated temperature for concrete (150 *F). Therefore, elevated temperature is not a potential aging mechanism for these components. 2.3 Impact on Intended Functions i Since elevated temperature is not a potential aging mechanism it will not affect the l intended functions of any safety related component located inside the turbine building. O Sfygg n R-1 Revision 2
1 l l Elevated Temperature l l 2.4 Design and Construction Considerations Since elevated temperature has no impact on the intended functions of components located inside the turbine building, no further discussion of CCNP's design and construction considerations is necessary. 2.5 Piausibility Determination Based on the discussion in Sections 2,1, no structural components are exposed to temperatures higher than the degradation threshold of elevated temperature for concrete. Therefore, elevated temperature is not a plausible aging mechanism for any structural components of the CCNPP turbine building. 2.6 Existing Programs Since elevated temperature is not a plausible aging mechanism, a program to control ; this degradation mechanism is not needed to maintain the intended functions of the Class I ponion of the turbine building. e (
3.0 CONCLUSION
Based on this evaluation, elevated temperature is not a plausible aging mechanism because none of the intended functions of the turbine building are affected by thb aging mechanism. 4.0 RECOMMENDATION Elevated temperature is not a plausible aging mechanism for any structural components of the turbine building. Therefore, no further evaluation or recommendation is necessary.
5.0 REFERENCES
- 1. " Class i Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991.
- 2. " Code for Concrete Reactor Vessels and Containments," ASME Boiler and Pressure Vessel Code, Section III, Division 2,1986.
O S/7/96 m R-2 Revision 2
1 l 1 i l l Elevated Temperature
\
- 3. " Code Requirements for Nuclear Safety Related Concrete Structures,"
American Concrete Institute, ACI 349-85.
- 4. "EQ Design Manual - Calvert Cliffs Nuclear Power Plant, Unit No. I and 2," Baltimore Gas and Electric Co.
l l l s i i ( l l l i I i f lO J S/7/96 m R-3 Revision 2
_ = . O V APPENDIX S -IRRADIATION 1.0 MECHANISM DESCRIPTION i2 1.1 Concrete Concrete components in a nuclear power plant exposed to excessive neutron or 2 gamma radiation (incident flux > 10" MeV/cm -sec)' could be impaired due to aggregate growth, decomposition of water or thermal warming of concrete. As the temperature of concrete increases and free water within the concrete evaporates, the structural characteristics of concrete are degraded. With the water loss, concrete can experience a decrease in its compressive, tensile, and bonding strengths, and in its modulus of elasticity. However, this loss of free water which results in a small decrease in concrete density will have little effect on concrete's gamma attenuation properties unless water loss is significant, depleting the presence of hydrogen atoms which contribute to concrete's shielding characteristics of fast neutrons. Typically, gamma radiation affects the cement paste portion of the concrete, producing heat and causing water migration. Existing experimental data provide some general information on the impact of direct p radiation on the mechanical properties of concrete' The average concrete sample does not begin to experience a compressive or tensile strength loss until exposure exceds a neutron fluence of 10" neutrons /cm2 . The experimental datai -indicate- - 2 minimal compressive loss for exposure up to 5x10" neutrons /cm , 1.2 Reinforcing Steel Steel degradation due to neutron irradiation is caused by the displacement of atoms l from their normal lattice positions to form both interstices and vacancies. The effect of this mechanism is to increase the yield strength, decrease the ultimate tensile ductility, and increase the ductile-to-brittle transition temperature. These defects on a macroscopic level produce what is referred to as radiation-induced embrittlement, - which is encountered in the design and operation of reactor pressure vessels. By comparing the currently available stress-strain curves for unirradiated and irradiated mild steel, a reduction in ductility of rebar subjected to high radiation exposure (> 2 5 10" neutrons /cm ) is indicated . 1.3 Structural Steel The efTects of irradiation on structural steel are the same as those described for reinforcing steel with regard to the effects on yield strength and the modulus of elasticity. Structural steel will exhibit an increase in yield strength and a decrease in 2 ductility after it is subjected to fluence in excess of 10" neutrons /cm . O 5/7/96 E S-1 Revision 2
I l I Irradiation I 2.0 EVALUATION 2.1 Conditions Table B-3 of Baltimore Gas and Electric Company's EQ Manual' lists the total integrated dose (rads) in the auxiliary feedwater pump room as negligible. l 2.2 Potential Aging Mechanism Determination l l Irradiation is not a potential aging mechanism for structural components of the i
- turbine building because of the negligible levels of radiation present in the
! environment. Therefore, irradiation is not a potential aging mechanism for these i components. { 2.3 Impact on Intended Functions Since irradiction is not a potential aging mechanism, it will not affect the intended functions of any safety related component located inside the turbine building. l l _ 2.4 Design and Construction Consideration Since irradiation has no impact on the intended functions of components located inside the turbine building, no further discussion of CCNPP's design and construction considerations is necessary. l l 2.5 Plausibility Determination i l Based on the discussion m Section 2.1, no structural component is exposed to radiation higher than the degradation threshold set forth in Sections 1.1,1.2, and 1.3
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for concrete and steel. Therefore, irrat'iation is not a plausible aging mechanism for any structural component of the CCNPP turbine building. 2.6 Existing Programs l , There are no existing programs at CCNPP designed to identify damages to structural components of the turbine building due to radiation. However, since this is not a plausible aging mechanism that could degrade these components, no future program is necessary. I b < v i S/7/96 m S-2 Revision 2
Irradiation
3.0 CONCLUSION
Based on this evaluation, irradiation is not a plausible aging mechanism because none of the intended functions of the turbine building are affected by this aging mechanism. l 1 4.0 RECOMMENDATIONS Irradiation is not a plausible aging mechanism for the structural components in the turbine building. No further evaluation or recommendation is required.
5.0 REFERENCES
l
- 1. " Class I Structures License Renewal Industry Report," EPRrs '
Project RP-2643-27, December 1991. '
- 2. " Pressurized Water Reactor Containment Structures License
] / Renewal Industry Report," NUMARC Report 90-1, Revision 1, September,1991. -
l
- 3. " Guidelines on the Nuclear Analysis and Design of Concrete l Radiation Shielding for Nuclear Power Plants", American Nuclear Standard ANSI /ANS-6.4
- 4. Hilsdorf, H.R., Kropp, J., and Koch, H.J., "The Effects of Nuclear !
Radiation on the Mechanical Properties of Concrete," Douglas McHenry International Symposium on Concrete and Concrete Structures, American Concrete Institute Publication SP-55,1978
- 5. Naus, D.J., " Concrete Component Aging and its Significance Relative to Life Extension of Nuclear Power Plants,"
NUREG/CR-4652, ORNUTM-10059, Oak Ridge National Laboratory, Oak Ridge, Tenn., September 1986
- 6. " Code Requirements for Nuclear Safety Related Concrete Structures," ACI 349-85, American Concrete Institute, Detroit, Michigan l
- 7. "EQ Design Manual - Calvert Cliffs Nuclear Power Plant, Unit No.
I and 2," Baltimore Gas and Electric Co. I t ! ( S/7/96 m S-3 Revision 2
l l t l l O APPENDIX T - FATIGUE V 1 l 1.0 MECHANISM DESCRII' TION 1 1 Fatigue is a common degradation of structural members pmduced by periodic or cyclic loadings that are less than the maximum allowable static loading. Fatigue results in progressive, localized damages to structural materials. Two types of fatigue exist for structural components. The first mechamsm, sometimes referred to as low-cycle fatigue, is low frequency (<100 cycles for concrete structures and <1 x 105 for steel structures) of high-level repeated loads due to abnormal events such as SSE or strong winds. Structures exposed to such ! events must be thoroughly evaluated by analysis or by inspection or both after occurrence. The fatigue degradation caused by such loading may not occur or may occur only a few times during the service life of a structure. Therefore, low-cycle fatigue is not age-related and is not a license renewal issue. The other fatigue mechamsm is high frequency of low-level, repeated loads such as equipment vibration. Referred to as high-cycle fatigue, it is an age-related l degradation mechanism. l 1.1 Concate n The fatigue strength of concrete structures has become a concern due to the i widespread adoption of ultimate strength design procedures and the use of high- _ strength materials that require concrste structural members to perform satisfactorily under high-stress levels. Repeated loading causes cracking in component materials of a member and alters its static load-carrymg characteristics. Fatigue strength of plain concrete is essentially the same whether the mode of loading is tension, compression, or flexure. The stress-to-fatigue life relationship can be represented by an S-N curve as shown in Figure T-1, where S represents the maximum stress in the cycle and N represents the number of cycles required to produce failure. A series of specimen testing determines fatigue behavior, and . the results are plotted on a log-scale. At a given number of service cycles (N) the material has a defined allowable fatigue strength. Review of S-N curves of plain concrete beams in ACI report 215R-742 indicates the following: l Fatigue strength of concrete decreases with the increasing number of cycles. The S-N curves for concrete are approximately linear between 102 and 107 cycles. *iMs indicates that there is no limiting value ofstress below which the fatigue life willbe infnite. A decrease of the range between maximum and minimum load results in l increased fatigue strength for a given number of cycles. When the minimum ' and maximum loads are equal, the strength of the specimen corresponds to the static strength of concrete determined under normal test conditions. O 5/7/96 m T-1 Revision 2 l
l l , O V Fatigue Thefatigue strength ofplain concretefor a life of10 million cyclesfor tension, compression, orflexure is roughly about 55 percent ofits static strength. Fatigue fracture of concrete is characterized by considerably larger strains and cracking as compared with fracture of concrete under static loading. Fatigue failure of reinforcing steel has not been a significant factor in its application as reinforcement in concrete structures. There have been few documented cases of reinforcing fatigue failures in the concrete industry. ACI report 215R-742 notes that the lowest stress range known to have caused a fatigue failure of a straight hot-rolled deformed bar embedded in a concrete beam is 21 ksi. This failure occurred after 1.25x106 cydes of loading on a concrete beam contammg a No.11, Grade 60 rebar, when the mmimum stress level was 17.5 ksi. 1.2 Steel Fatigue of steel structures may cause progressive degradation and is initiated by plastic deformation within a locahzed region of the structure. A nonuniform distribution of stresses through a cross-section may cause a stress level to exceed the yield point within a small area and cause plastic movement after the number of stress reversal cydes reaches the material's endurance limit. This is the maximum stress to which the steel can be subjected for a given service life. Such []/. L conditions will eventually produce a minute crack. The localized plastic movement further aggravates the nonuniform stress distribution, and further plastic movement causes the crack to grow' . , The fatigue behavior of steel structures strongly depends on their surface l conditions (e.g., whether they are polished or in an as-received condition). The fatigue strength of structural steel components is generally represented by a modified Goodman diagram as shown in Figures T-2, which is generated from the S-N curves. The fatigue strength of structural steel decreases as the number of cydes increases until the fatigue limit is reached. If the maximum stress does not exceed the fatigue limit, an unlimited number of stress cycles can be applied at that stress ratio without causing failure. l 2.0 EVALUATION 2.1 Conditions Some of the internal structural components of the turbine building are subject to high cyde, low-level repeated load, such as equipment vibration load, during normal plant operation. The building siding dips were designed for abnormal events such as seismic and hurricane loads that are regarded as low cyclic load condition. Such loads may not occur or may occur for a very short duration only a few times during the service life of the turbine building. Therefore, the fatigue damage of these structural components is not age-related. Sf7/96 m T-2 Revision 2
i Fatigue 2.2 Potential Aging Mechanism Detennination Fatigue is a potential aging mechamsm for the following structural components of i the turbine building because they could experience high frequency of low-level, repeated loads such as equipment vibration load: Concrete walls Functions LR-S-1,2,4,6,7 Ground slab and Functions LR-S-1,2,4,6,7 equipment pads i Elevated floor slab Functions LR-S-1,2,6,7 ; Steel beams Functions LR-S-1,2,7 l l Base plates Functions LR-S-1,2,4,5,7 l Floor framing Functions LR-S-1,2,7 Steel bracingFunction LR-S-4 h G Platform hangers Function LR-S-5 Decking Functions LR-S-1,2,7 l where: LR-S-1: Provides structural and/or functional support (s) for safety-related equipment. l LR-S-2: Provides shelter / protection for safety-related equipment. LR-S-4: Serves as a missile barrier (internal or external). LR-S-5: Provides structural and/or functional supports for non-safety-related equipment whose failure could directly prevent satisfactory accomplishment of any of the required safety-related functions. LR-S-6: Provides flood protection barrier (internal flooding event). LR-S-7: Provides rated fire barriers to confine or retard a fire from spreading to or from adjacent areas of the plant. Fatigue is not a potential degradation mechanism for other turbine building structural components because they are not subject to the high frequency of low l level, repeated loads. o 5/7N 6 m T-3 Revision 2 l r
l Fatigue l 2.3 Impact on Intended Functions If the effects of fatigue were not considered in the original design or are allowed l to degrade the above structural components unmitigated for an extended period of time, this aging mechanism could affect allintended functions of components listed in Section 2.2. 2.4 Design and Construction Considerations All internal concrete components of the CCNPP turbine building were designed in accordance with ACI-318-63? The design code limited the maximum permissible design stress level to less than 50 percent of static strength, which is less than the fatigue strength of concrete (55 percent of static strength). In l addition, actual concrete stresses induced by cyclic loads during normal plant l operation, such as those from machine vibration, are a small portion of the combined stresses resulting from static and dynamic loads. This means that the stress range (magnitude of stress fluctuation) is also small and within the limit l that yields extremely long fatigue life (> 107 cycles, which is equivalent to infinite l life), as shown in Figure T-1. t All structural steel components in the turbine building were designed in accordance with American Institute of Steel Construction (AISC-1%3) (]V specification.5 For the design _of steel members and connections subject to l repeated variation oflive load stress, this specification requires that consideration l be given to the number of stress cycles, the expected range of stress, and the type
- and location of a member or detail. For life cycles of more than 2x106 loading, the i maximum stress may not exceed two-thirds of the basic allowable stress provided l in Sections 1.5 and 1.6 of the AISC specification, which is equivalent to 40 percent i of the materialyield strength. l l
ASTM A-36 carbon steelis typically used for all structural steel components in the turbine building. As shown in the fatigue strength curves in Figures T-2 and T-3, the fatigue limit for as-received A-36 steel is about 20 ksi at a life cycle of approximately 2x106, which is about 55 percent of the material yield strength. The maximum design stresses of all steel components were limited to 40 percent of material yield strength and are less than the material fatigue limit. Again, the . actual steel stresses induced by cyclic loads are a small portion of the combined l l stresses resulting from static and dynamic loads. j 2.5 Plausibility Determination Based on the discussion in Section 2.4, fatigue will not degrade the structural components listed in Section 2.2. Therefore, fatigue is not a plausible aging l mechanism for any structural components of the turbine building. O v Sf7/96 a T-4 Revision 2
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\j 2.6 Existing Pmgrams l
There are no existing programs at CCNPP that are designed specifically to identify or to repair the damage to structural components due to fatigue. Since fatigue is not a plausible aging mechanism that could degrade the turbine building structural components, no management program is necessary.
3.0 CONCLUSION
Some concrete components in the turbine building of CCNPP are subject to high cydes of low- level repeated load. These components were designed in accordance with ACI-318-633, which limits the maximum design stress to less than 50 percent of the static stress of the concrete. The concrete fatigue strength is about 55 percent of its static strength at the extremely high cydes (>107 cydes) of loading. Therefore, fatigue will not degrade any concrete component in the turbine building and requires no further evaluation. Steel components in the turbine building subject to high-cyde (>105 cycles) loading conditions were designed in accordance with the AISC-63 specification.5 The maximum stress in steel components and connections is smaller than the 1 (
- fatigue limit of steel. Fatigue degradation will have no adverse effects on the
, ( continued safety function performance during the license renewal term and l requires no further evaluation for all' structural steel componients in th6 ttirbine buildmg. j l l 4.0 RECOMMENDATION Fatigue is not a plausible aging mechanism for the structural components in the turbine building. Therefore, no further evaluation or recommendation is l necessary.
5.0 REFERENCES
! 1. ." Class i Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991.
l
- 2. " Consideration for Design of Concrete Structures Subjected to Fatigue 1.oading," American Concrete Institute, ACI 215R-74,1986.
j 3. " Building Code Requirements for Reinforced Concrete, American Concrete Institute, ACI 31843. l
- 4. Civil and Structural Design Criteria for Calvert Cliffs Nudear Power Plant, Unit No.1 and 2, by Bechtel Power Corporation, Revision 0, August 2,1991.
S/7/96 n T-5 Revision 2
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- 5. " Specification for the Design, Fabrication and Erection of Structural Steel for Buildings," American Institute of Steel Construction,1%3.
- 6. Brockengrough, R.L., and Johnson, B.G., Steel Design Manual, United States Steel Corporation.
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