ML20112C011
| ML20112C011 | |
| 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 9605240121 | |
| Download: ML20112C011 (100) | |
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} Calvert CliffsNuclearPowerPlant i
l License RenewalProject 4 ,
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Aging Management Review Report l
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} for the i
i Intake Structure i
i Revision 2
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4 May, f996 .
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Prepared by: 8 d Dater v I R.L. Tucker i
Reviewed by: . Date: />'/7tf
- B.M. Tilden Approved by
- - Date: I!20 %
. W. Doroshuk i
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i lO 96052401p1 96052P DR ADOCK 05000517 PDR l .
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l LIFE CYCLE MANAGEMENT UNIT l FINAL REPORT l
INTAKE STRUCTURE AGING MANAGEMENT REVIEW RESULTS f
l l TABLE OF CONTENTS i l LIST OF ATTACHMENTS iii l LIST OF APPENDICES iv l
! LIST OF TABLES v l LIST OF EFFECTIVE PAGES vi l
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1.0 INTRODUCTION
1-1 l 1.1 Intake Structure Description 1-1 i
1.1.1 Intake Structure LCM Description 1-1 1.1.2 Intake Structure LCM Boundary 1-1 1.1.3 Intake Structure Intended Functions 1-2 1.2 Evaluation Methods 1-3 t
1.3 Intake Structure Specific Definitions 1-3 1.4 Intake Structure Specific References 1-3 2.0 STRUCTURAL COMPONENTS WITHIN THE SCOPE OF 2-1 l LICENSE RENEWAL l
3.0 STRUCTURAL COMPONENTS PRE-EVALUATION 3-1 l
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l LIFE CYCLE MANAGEMENT UNIT l FINAL REPORT INTAKE STRUCTURE AGING MANAGEMENT REVIEW RESULTS l l
l 4.0 STRUCTURAL COMPONENTS AGING EFFECTS EVALUATION 4-1 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 l 4.2.3 Plausible Aging Mechanisms 4-2 l
4.2.4 Aging Management Program Identification 4-3 l
l 4.2.5 Aging Management Recommendations 4-3 i
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 l 5.2.3 New Programs 5-2 l
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U FINAL REPORT INTAKE STRUCTURE AGING MANAGEMENT REVIEW RESULTS l
l LIST OF ATTACHMENTS Attachment 1 Potential Aging Mechanisms Applicable to Structural Components Attachment 2 Plausible Aging Mechanisms Applicable to Structural Components Attachment 3 Structural Components - Aging Mechanism Matrix Codes Anachment 4 Sununary of Aging Management Review Results l
l' Attachment 5 A6 equate Program Evaluation Attachment 6 NOT USED Attachment 7 Walkdawn Report - Examination ofintake Structure - Calvert Cliffs Nuclear Power Plani Attachment 8 Attributes in New Program l
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U FINAL REPORT INTAKE STRUCTURE AGING MANAGEMENT REVIEW RESULTS LIST OF APPENDICES l
Appendix A Freeze-Thaw Appendix B Leaching ofCalcium Hydroxide Appendix C Aggressive Chemicals Appendix D Reaction with Aggregates Appendix E Corrosion in Embedded Steel /Rebar Appendix F Creep Appendix G Shrinkage l Appendix H Abrasion and Cavitation AppendixI Cracking of Masonry Block Walls Appendix J Settlement Appendix K Corrosion in Steel l
Appendix L Corrosion in Liner l
Appendix M Corrosion in Tendons AppendixN Prestressing Losses Appendix 0 Weathering Appendix R Elevated Temperature i
Appendix S Irradiation Appendix T Fatigue f
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LIFE CYCLE MANAGEMENT UNIT O FINAL REPORT INTAKE STRUCTURE AGING MANAGEMENT REVIEW RESULTS LIST OF TABLES Inhlt lille Page Number l l-1 Intake Structure Specific References 1-4 2-1 Intake Structure Structural Components Within the Scope of License Renewal 2-2 4-1 List of Potential Aging Mechanisms for -
Intake Structure Structural Components 4-5 4-2 Intake Structure Aging Effects Evaluation Summary 4-6 l
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i AGING MANAGEMENT REVIEW RESULTS FINAL REPORT INTAKE STRUCTURE y REVISION 2
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INTAKE STRUCTUREAGING MANAGEMENT REVIEW RESULTS LIST OF EFFECTIVE PAGES l Revision Pages Summary of Change i l
0 All Initial revision prepared using LCM-10S, Revision 1. ,
1 All Changes made to reflect disposition of Technical Problem Reports written l against Revision 0 and to correct transcription errors between the results and j 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. !
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O FINAL REPORT AGING MANAGEMENT REVIEW RESULTS INTAKE STRUCTURE vi REVISION 2
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1.0 INTRODUCTION
1.1 INTAKE STRUCTURE DESCRIPTION This section describes the scope and boundaries of the intake Structure as it was evaluated. l Section 1.1.1 provides a brief synopsis of the structure as described in existing plant l documentation. The Intake Structure's system boundary is defined in Section 1.1.2 to l l
clarify the portions of the Intake Structure considered in this evaluation. Section 1.1.3 is a i detailed breakdown of the unique system functions and is provided as a basis for I component scoping and the identification of component-specific functions.
1.1.1 Intake Structure LCM Descriotion l
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ne Intake Structure is a Class I structure situated to the east of the main plant and )
is primarily a reinforced concrete structure, founded on a slab varying in elevation from -26'0" to -14'3". It houses twelve circulating water pumps supplying water ,
from the Chesapeake Bay to the condensers and to six safety related saltwater l
pumps providing cooling water to various plant equipment. Trash racks and .
l traveling water screens are provided to protect the condensers from foreign bodies )
l present in the bay water. Vertical guides are provided down the sides of each l intake channel to receive stop-logs. Running the full length of the structure is a p gantry crane having a lifting capacity of thirty-five tons. Fish collection and U holding facilities were added to allow environmental aquatic studies. The screen well enclosure is part of the Intake Structure.
I 1.1.2 Intake Structure LCM Boundary The Intake Structure and'its structural components provide support and shelter to safety related and non-safety related equipment. The system boundary addressed by this scoping and evaluation included all Intake Structure structural components serving such functions but did not include commodity items such as pipe supports and snubbers. Structural components within this system boundary include l supports for the following major device types:
l l Motors (MOTOR) and pumps (PUMP).
Also included in the system boundary are structural supports for non-safety related access platforms. During an abnormal event such as a seismic event, failure of 7
I these non-safety-related components must not adversely affect the operability of other safety related components.
Per the BGE Integrated Plant Assessment Methodology, Intake Structure (System 009) components which have unique identifiers in the NUCLEIS Equipment Technical database (such as penetrations) were evaluated using the Aging Management Review procedure for systems. The results of this task are AGING MANAGEMENT REVIEW RESULTS FINAL REPORT INTAKE STRUCTURE l-1 REVISION 2 l
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l documented and a separate AMR Report entitled " Aging Management Review l Report for the Intake Structure System."
1.13 Intake Structure Intended Functions I
A detailed review of the Intake Structure intended functions was completed during l the system scoping process described in the BGE Integrated Plant Assessment Methodology. "Ihe following system functions for the Intake Structure were identified as structural intended functions on Table IS of " Component Level Scoping of Four Site Structures; Intake Structure, Turbine Building, FOST Enclosure, CST Enclosure."
1.13.1 Function LR-S-1 Provides 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'.
l 1.133 Function LR-S-4 O Serves as a missile barrier (internal or external).
1.13.4 Function LR-S-5 Provides structural and/or functional support to non-safety-related equipment whose failure could directly prevent satisfactory accomplishment of any of the required safety-related functions. 1 1.13.5 Function LR-S-6 Provides a flood protection barrier (internal flooding event).
1.13.6 Function LR-S-7 Provides rated fire barriers to confine or retard a fire from spreading to or from adjacent areas of the plant.
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l l ' CST NO.12 Enclosure does not perform Radiation Shielding, equipment qualification, and HELB protection aspects of this function.
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V 1.2 EVALUATION METHODS Intake structure structural components within the scope of license renewal were evaluated in accordance with BGE procedure EN-1-305*, Revision 0, " Component Aging Management Review Procedure for Structures." The results of these evaluations are summarized in Sections 3.0 through i 5.0.
1.3 INTAKE STRUCTURE SPECIFIC DEFINITIONS This section provides the definitions for any specific terms unique to the Intake Structure structural component level evaluation.
Ican Definition None N/A 1.4 INTAKE STRUCTURE SPECIFIC REFERENCES References utilized in the completion of the Intake Structure structural component level evaluation are listed in Table 1-1. Drawings and procedures used as source documents in the evaluation were taken at the revision level of record at the start of this task which was October 1994. He updates performed in Revisions I and 2 of this report incorporated several TPRs. He update performed is Revision 2 was performed to address a new strategy in the aging management of corrosion affects on structural steel. Only references affected by the Revisions I and 2 have been revised.
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- Revision 0 and Revision I were done to LCM-10S. EN-1-305 is new version of L,CM-10S which updated procedure format and terminology only.
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V Table 1-1 Intake Structure Specific References Darument ID D~ new ' title Revision No. Dgg 1%DC UFSAR Calvert Cliffs Nuclear Power Plant Units I and 14 1992 Report
[ 2, Updated Final Safety Analysis Report Technical Calvert Cliffs Nuclear Power Plant. Units I and I82 9/27/93 Report Specification 2, Technical Specification 159 9/27/93
- Componentlevel Scoping ofFour Site i 1996 Report Structures; intake Structure, Turbine Building, FOST Enclosure, CST Enclosure EPRI RP-2643-27 Class I Structures License Renewal Industry - 12/91 Report Report NUMARC 90-01 Pressurized Water Reactor Containment i 9/91 Report Structures License Renewal Industry Report
- Mather, B.,'How to Make Concrete that will be -
11/89 Paper immune to the effects of freezing and thawing,'
ACI FallConvention, San Diego ASTM C33-82 " Standard Specification for Concrete -
1982 Spec Aggregates," American Society of Testing and Materials Civil and Structural Dedgn Criteria for Calvert 0 8/2/91 Guide l O Cliffs Nuclear Power Plant Unit No. I and 2, by Bechtel Power Corp.
6750-C-9 Specification for Furnishing and Delivery of 8 4/70 Spec i Concrete - Calvert Cliffs Nuclear Power Plant l Unit No, I and 2 I ACI31843 ' Building Code Requirements for Reinforced - 1%3 Code l
Concrete " American Concrete Institute
- ACI 201.2R47
- Guide to Durable Concrete," American - 1%7 Standard Concrete Institute
" Concrete Manual," U.S. Department of the 8* Edition 1975 Code Interior l 6750 C 23E Specification for Fumishing and Installation of 0 11/73 Spec Piezometer - Calvert Cliffs Nuclear Power Plant Unit No. I and 2 l AS'IM C-28946 ' Potential Reactivity of Aggregates (Chemical - 1966 Code Method)," American Society of Testing and Materials ASTM C-29545 " Petrographic Examination of Aggregates for - 1%5 Code Concrete,' American Society of Testing and Materials
- letter from Charles County Sand & Gravel Co. - 6/30/72 letter to Bechtel Corp.
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O Table 1-1 Intake Structure Specific References Document ID Document Title Revician No_ ggg h Skoulikidas,T.,Tsakopoulos, A., and - - Paper Moropoulos, T., " Accelerated Rebar Corrosion When Connected to Ughtning Conductors and Protectxm of Rebars with Needies Diodes Using Atmospheric Electricity,'in Publicmion ASTM l STP 906, " Corrosion Effects of Stray Cunents and the Techniques for Evaluming Conosion of Rebarsin Concrete" l
ACI-209R-82 ' Prediction of Creep, Shrinkage, and -
1982 Standard Temperature Effects in Concrete Structures,"
l American Concrete institute l
- " Design and Control of Concrete Mixtures," 1.'* Edition 1988 Guide Portland Cement Association l
IAEA-TECDOC-670 - " Pilot Studies on Management of Aging of -
10/92 Report Nuclear Power Plant Components,' intemmional Atomic Energy Agency MN-3100 Painting and Other Protective Coatmas -
9/94 Proc TRD A-1000 Coating Application Performance Standard 8 8/91 Spec m 6750 A-24 Specification for Painting and Special Coatings 12 10/82 Spec 6750-C-19 Specification for Fumishing. Detailing, 3 9/70 Spec Fabricating, Delivering, and Erecting Structural Steel ACI215R-74 "Considerauon for Design of Concrete - 1986 Standard Structures Subjected to Fatigue Loading,"
American Concrete Institute
! - " Specification for the Design, Fabrication, and - 1%3 Spec
( Erection of Structural Steel for Buildings,"
American Institute of Steel Construction ,
- Brockengrough, R.L. and Johnson, B.G., ' Steel - 5/74 Text Design Manual," United States Steel Corporaim l NUREG 0797 Safety Evaluation Report Related to the - 7/81 SER l Operation of Comanche Peak Steam Electric Station, Units 1 and 2 ANSI /AND-6.4 " Guidelines on the Nuclear Analysis and Design - 1985 Code l of Ccsvete Radiation Shielding for Nuclear Fower Plants," American Nuclear Standard
- Hilsdorf, H.R., Kropp, J., and Koch, IU., "The - 1978 Paper Effects ofNuclear Radiation on the Mechanical i Properties of Concretc," Douglas McHenry i international Symposium on Concrete and
- Concrete Structures, American Concrete Institute Publication SP-55 AGING MANAGEMENT REVIEW RESULTS FINAL REPORT
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Intake Structure Specific References l Document ID Document Title Revicinn No Dgg g f NUREGCR4652,ORNIM% Naus, D.L. " Concrete Component Aging and its - 9/86 Paper 10059 Significance Relative to Life Extension of Nuclear Power Plants," Oak Ridge National Laboratory, Oak Ridge,1N ACl349-85 " Code Requirements for Nuclear Safety Related -
1985 Code Concretc Structures," American Concrete Institute
- EQ Design Manual, Calvert Cliffs Nuclear 17 1992 Guide Power Plant SW-06 Technical Procedure . intake Structure Cavities 0 5/92 Proc Sub-Surface Cleaning l ASME Section III Division 2 " Code for Concrete Reactor Vessels and - 1986 Code j Containments," American Society of Mechanical l
Engineers Boiler and Pressure Vessel Code i
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INTAKE STRUCTURE l-6 REVISION 2
LIFE CYCLE MANAGEMENT 2.0 STRUCTURAL COMPONENTS WITHIN THE SCOPE OF LICENSE RENEWAL l
The intake Structure components were scoped in accordance with the process described in the BGE Integrated Plant Assessment Methodology. The intake Structure was scoped using procedure LCM-llS. The purpose of component scoping is to identify all structural components whose functions are identified in Section 1.1.3. These structural components are designated as components within the scope oflicense renewal. j i l l As a result of the scoping,26 structural component types were identified as providing one I
- of the structure's intended functions listed in Section 1.1.3. A summary of the scoping result is provided in Table 2-1.
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LIFE CYCLE MANAGEMENT Table 2-1 Intake Structure Structural Comnonents Within the Scone of Licenne Renewal COMPONENT TYPE INTENDED FUNCTION (S) l Foundations LR-S-2 i Concrete Columns LR-S-2,4, and 7 Concrete Walls LR-S-1,2,4, and 7 l
Concrete Beams LR-S-2 and 4 Ground Floor Slabs and Equipment Pads LR-S-1 and 2 Elevated Floor Slabs LR-S-1 and 2
- RoofSlabs LR-S-2 l
Cast-in-Place Anchors /Embedments LR-S-1,2,6, and 7 l
j Grout LR-S-1 and 2
! Fluid Retaining Walls and Slabs LR-S-1,2, and 6 l PostInstalled Anchors LR-S-2 and 5 j Fire Doors, Jambs, and Hardware LR-S-2 and 7
- Access Doors, Jambs, and Hardware LR-S-2 Caulking and Sealants LR-S-2,6, and 7 Watertight Doors LR-S-6 Steel Beams LR-S-1 and 2 Baseplates LR-S-1 and 5 Floor Framing LR-S-1 and 5 l RoofFraming LR-S-2 Steel Bracing LR-S-2 and 5 Platform Hangers LR-S-5 Steel Decking LR-S-2
! Floor Grating LR-S-5 Checkered Plate LR-S-2 Stairs and Ladders LR-S-5 l
Sluice Gates LR-S-1 4
AGING MANAGEMENT REVIEW RESULTS FINAL REPORT INTAKE STRUCTURE 2-2 REVISION 2
l LIFE CYCLE MANAGEMENT O 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.
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LIFE CYCLE MANAGEMENT 4.0 STRUCTURAL COMPONENTS AGING EFFECTS EVALUATION 4.1 EVALUATION The evaluation of Intake Structure's structural components within the scope of license
- renewal. was completed in accordance with BGE procedure, " Component Aging i Management Review Procedure for Structures," EN-1-305, Revision 0. This procedure l evaluated all twenty-six component types identified in Section 2.1. The evaluation accomplished the following
(1) Identified POTENTIAL aging mechanisms for each structural component type. !
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- environmental conditions l l
- material of constmetion l
- impact on intended functions l
l (3) Developed attributes for programs to manage the effects of aging from those
- agmg mechanisms identified as PLAUSIBLE. l l \
1 l (4) Evaluated program adequacy to demonstrate that the effects of aging will be j
! managed so that the intended function (s) will be maintained for the period of ,
I extended operation.
These steps are discussed in greater detail in the sections that follow.
4.2 AGING MECHANISMS ,
j 4.2.1 Patentini Aoine Machanierne l
l This step of the aging evaluation identifies aging mechanisms that are considered l 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 l and conducive environmental service conditions.
i A comprehensive list of eighteen 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 I
references used to prepare this list include the fm. wing:
AGING MANAGEMENT REVIEW RESULTS FINAL REPORT INTAKE STRUCTURE 4-1 REVISION 2 l i
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- NRC NPAR Repons
- IAEA Reports
- DOE Reports l
The list of aging mechamsms and materials they affect are shown in Table 4-1.
l The 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 aging management review results.
Each aging mechanism wu evaluated for applicability (i.e., POTENTIAL) to the ,
structural component type based on its material of construction and the i
environmental conditions where the component type could be located. This 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 Fcoping of the component list of aging mechanisms are presented in the second column of Table 4-1.
4.2.2 Component Grouping i
O r* sre P i8 er tr=ct r i ce-Pe t> *ica r -ithi ta ceP er iice se renewal is primarily based on their materials and their special functions, if any, that contribute to safety, or in the opinion of the evaluator, warrant special attention. The components are grouped into four categories:
l (1) Concrete (including reinforcing steel) i ,
I I (2) Structural steel (3) Architectural items such as doors, roofing materials, and protective coating (4) Additional components that may have a unique function in the structure 4.2.3 Plausible Aging Mechanisms ,
I The identification of PLAUSIBLE aging mechanisms is accomplished through a l careful review of the POTENTIAL aging mechanism list, the development of l 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 Intake Structure structural component not being able to perform its intended function. An aging O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT INTAKE STRUCTURE 4-2 REVISION 2 I
LIFE CYCLE MANAGEMENT s O i mechanism is also considered plausible if there is insufficient evidence to '
conclude that future degradation will have no impact on the intended functions of l the Intake Stmeture structural component. The plausibility determinanon is made i through a careful consideration of all the factors required to allow the aging i mechanism to occur. In particular, the aging mechanism is scoped for plausibility ,
on the basis of: !
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- Material of construction
- Environmetaal service conditions
- Design and construcuon considerations
- Impact on intended functions
- Physical conditions of the component The results of the aging mechamsm plausibility scoping is an aging mechanism- !
component matrix listing the aging mechanism and its disposition. The aging. i mechamsm matrix developed for each structural component type is included in !
Attachment 3 in the evaluation results. ;
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Aging mechamsms determmed to be PLAUSIBLE are provided specific aging i management recommendations to mitigate the effects of the aging mechamsm. j l Table 4-2 summarizes the results of the plausibility determmation and recommendations for the Intake Structure.
Lo 4.2.4 Aging Management Program Identincation Once plausible aging muhanisms have been identified, the evaluation is L continued to determine whether existing plant programs adequately address the effects of aging for the renewal term. If existing programs would not manage the effects of aging during a renewal term, a one-time inspection could be conducted, modifications could be made to the programs, or new programs could be initiated to adequately manage the effects of aging. This evaluation did no'. include a determmation of whether recommended changes to existing programs or new program recommendations would actually be implemented or which programs would be included in the FSAR Supplement.
4.2.5 Aging Management Recommendations The evaluation of all structural component types in the Intake Structure identified a total of ten aging mechamsms that have the POTENTIAL to degrade these components. A detailed review of the specific component intended functions, ,
material of construction and its basis of design and construction 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 ,
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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 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 coating structural steel of components in the intake Structure.
(2) Develop an age related degradation inspection program for coated surface of structural steel that are not readily accessible.
(3) Sample the water quality of groundwater using the existing groundwater monitoring wells.
(4) Perform a conditional assessment of the concrete used to construct the fluid retaining walls and slabs. This can be accomplished during the cleanmg of the Intake Structure cavities.
O (5) Develop a new program to address the inspection and maintenance of fluid retaining walls and slabs in the Intake Structure.
(6) Develop a new program to address the inspection and maintenance of caulking and seahnts in the Intake Structure.
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l LIFE CYCLE MANAGEMENT Table 4-1 l
I let of Patantial Aoine Mecha=i- for Intaba Sineture Sinetural Camnar=#c i
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Potential to Affect i Aoine Mechanlem Descrintian Intake Structure? Materials Affected Freeze-Thaw Yes Concrete Leaching of Calcium flydroxide Yes Concrete Aggressive Chemicals Yes Concrete Reaction with Aggregates Yes Concrete ;
i Corrosion in Embedded Steel /Rebar Yes Steel, Concrete I Creep No Concrete l Shrinkage No Concrete I Abrasion and Cavitation Yes Concrete i l g Cracking of Masonry Block Walls No* Block Walls U Settlement Yes Structure Corrosion in Steel Yes Steel Corrosion in Liner No* Steel Liners (Carbon and
- Stainless)
Corrosion in Tendons No* Post-tensioning System Prestressing Losses No* Post-tensioning System Weathering Yes Caulking and Sealants Elevated Temperature No Concrete Irradiation No Steel, Concrete Fatigue Yes Steel, Concrete l
l Affected components do not exist in the Intake Structure.
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~ m LIFE CYCLE MANAGEMENT Table 4-2 Ine=b St :---e A E- *--g EKects Er*---h E -y SIRUCTURAL COMPONENTS PLAUSIBLE AGING MECHANISM RECOMMENDA110N REMARKS !
I'oundations Aggressive clenucats The observation wells, installed during constructum, can te ressored to See; -
4-- in Appendres B C, D, E, J ami T.
sample the groundwater for water quality testmg. This data can be Corros on in embedded steel /reter used to evalunee the impact of chenucal anack on the exterior surfaces of exposed components.
Concrete Columns None None See jusuficanon in f .,- h D and T.
Concrete Walls None None See jusaficanon in Agyeruhces A, B, C, D, E. O, and T.
Concrete Beams None None See jusaficanon in Agyendees D and T.
Ground Floor Stabs and Aggressive chenucats The observation wells, mstaHed durirg construction, can be ressored to See jusencanon in Appenhees B, C D. E, J and T.
Equipment Pads sample the .~.'_... for water giality testing. This data can be Cornmon in embedded steet/reter used to evaluate the impact of chemmal anack on the exterior surfa:es I of exposed -.im.;..
Elevated Floor Stabs None None See jusuficanon in Appendices D and T.
Roof Stats None None See jusoficanon in Appendices A, B, C, D, E, O, am! ,
T.
Cast-in-Place Corrosen in steel See recommendation for *Seeel Beams
- See jusaficanon in A;ipendix K.
Anchors /Embedrnents thid Retaining Walls and Slabs Aggressive chemicals The fluid retainirig walls and slabs are isinccessible for visual SeejlLa,,in Agyemlices B, C, D E, and H.
impecton. An inspection procedure to assess the condinon of the Corrosion in embedded sseet/reber concrete should be developed and incorporated into CCNPP procedure SWE.
PostInstalled Anchors Corrosion in steel See recommendanon for *Seeel Beams
- Sec jusuficanon in Appendix K.
Fire Doors, Jambs, ami Corrosion in seeel See m - ' - for "Sarel Beams
- See justification in Appenhx K. '
Hardware Access Doors, Jambs, and Corrosion in steel See en - ---tion for
- Steel Beams
- See jusoficanon in Agyemlix K.
Hantware AGING MANAGEMENT REVIEW RESULTS FINAL REPORT INTAKE STRUCTURE 4-6 REVISION 2
Q kJ N J LIFE CYCLE MANAGEMENT TaNe 4-2 Intake Structure Apxq Effects Eysmiion E -=v SIRUCIURAL COMPONENTS PLAUSIBLE AGING MECIIANISM RECOMMENDATION REMARKS Caulkmg aM Sealants Weathering Caulking and scalams which perform a fire terrier function will te See justifration in Appendix O.
addressed try the Appendix R Program. For caulking and scalants which perform an inieMed function other than fire barrier, an mspecton armi maimenance program which will idemify degradanon and ensure correcove action is taken before the component losses its ability to perform its iniended funcnon will be developed. The resoluten so Issue Report IR199541698 will form the basis for this prognm.
Watertight Doors Corrosion in steel See recommendation for
- Steel Beams
- See justifration in Appendix K.
Steel Beams Corrosion in steel
^U 'N " "8 d "" " " " " D* See justifration in Appendix K.
protectrve coar g. For accessible areas, signifrant coating degradation arri/or the presence of corrosion wdl be identified, an issue report written, and corrective action taken through the following existing site programs:
PEG-7, System Walkdowns
, Ql 2-100, Issue Reportmg MN-3-100, Prutecove Coating Program.
For those structural steel- - - - - not readily accessible, sigmficara coating degradation aru!!or the presence of corrosen will be determined utilizing an age related degradation irr:pection.
Baseplanes Corrosion in sacel Seei=. :- ,. for
- Steel Beams" See justifration in Appendix K.
Floor Framing Corrosion in steel See recommendation for " Steel Beams
- See justifration in Appendix K.
Roof Framing Corrosion in sacel See im.... .h for
- Steel Beams
- See justifration in Appendix K.
Steel Bracing Corrosion in steel See -.. M . for *Seeel Beams
- See justifration in Appenhx K.
Platformllangers Corrosion in steel See c_-- !-tion for " Steel Beams" See justifration in Amendix K.
Steel Decking Cormsion in steel Seei m . : r-- for " Steel Beams
- Seejustifration in Appeniix K.
AGING MANAGEMENT REVIEW RESULTS FINAL REPORT INTAKE STRUCTURE 4-7 REVISION 2
O O O LIFE CYCLE MANAGEMENT Table 4-2 toe ira Structure Aoine EKects Ev 8 ==*ian Sg-STRUCTURAL COMPONENTS PLAUSIBLE AGING MECHANISM RECOMMENDA110N REMARKS Floor Gratmg Corrosion in steel See recommendation for "Seect Beams
- SeeM.b. in Appendix K.
Checkered Plate Corrosion in steel Seeis. '
- ------ for " Steel Beams
- See justification in Appendix K.
Stairs and Ladders Corrosum in secel See % for
- Steel Beams" See juss'ficanon in Appendix K.
Sluice Gates Corro= ion in steel See recommendation for "Seeel Beams" Seejustificationin A R endit K.
AGING MANAGEMENT REVIEW RESULTS FINAL REPORT INTAKE STRUCTURE 4-8 REVISION 2
e
! LIFE CYCLE MANAGEMENT 7'N, 5.0 PROGRAM EVALUATION I 5.1 PROGRAM ADEQUACY EVALUATION l Program adequacy evaluations were completed in accordance with EN-1-305, Revision 0, l for those programs or aging degradation management alternatives developed to address l PLAUSIBLE component aging mechanisms. The evaluation ofprograms or aging degradation management attematives considered the following criteria as a means of establishing the adequacy of specific CCNPP programs:
1 l.
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.
3, Adequate programs must be implemented by the facility operating procedures and reviewed by the onsite review committee.
The results of the program adequacy evaluations are provided in Section 5.2.
5.2 STRUCTURAL COMPONENTS SUBJECT TO ADEQUATE PROGRAMS O 5.2.1 Frintino Proernma The program evaluation task reviewed all existing CCNPP programs that were established to tronitor, inspect, and repair Intake Structure structural components that are degraded by identified plausible aging mechanisms.
The Appendix R Program, implemented through procedure STP-F-592-1/2 for 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 combination 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.
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AGING MANAGEMENT REVIEW RESULTS FINAL REPORT INTAKE STRUCTURE 5-1 REVISION 2
LIFE CYCLE MANAGEMENT O 5.2.2 Modified Existino Program =
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 efTects 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 license renewal period.
5.2.3 New Proernme 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 includes the following.
Foundations: 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 intake Structure foundation.
p Ground floor slabs: An investigative program to test the water quality of the i
groundwater should be developed to determine if there is any possibility of aggressive chemical attack on the Intake Structure ground floor slab.
Fluid retaining walls and slabs: A periodic inspection program for the fluid retaining walls and slabs should be developed. The inspection program can be combined with CCNPP technical procedure SW-06, " Intake Structure Cavities Sub-Surface Cleaning." During the cleaning operation, video of the concrete surfaces could be reviewed for any signs ofdeterioration.
Caulking 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 sealants not covered by the Appendix R Program.
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AGING MANAGEMENT REVIEW RESULTS FINAL REPORT INTAKE STRUCTURE 5-2 REVISION 2
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l LIFE CYCLE MANAGEMENT O
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.
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O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT INTAKE STRUCTURE 5-3 REVISION 2 i
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l I LIFE CYCLE MANAGEMENT lh List of Attachments and Appendices i For the Intake Structure Aging Management Review Total Pares 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, Aging Management Review Results 3 Attachment 5, Adequate Program Evaluation 9 Attachment 6, Not Used 0 Attachment 7, Walkdown Repon - Examination of the intake Structure 5 Attachment 8, Attributes in New Program 10 1 l
Appendices 1 Appendix A - Freeze-Haw 5 Appendix B - Leaching of Calcium Hydroxide 6 Appendix C- Aggressive Chemicals 5 Appendix D - Reactions with Aggregates 6 Appendix E - Corrosion of Embedded Steel /Rebar 5 (s Appendix F - Creep Appendix G - Shrinkage 3
3 Appendix H - Abrasion and Cavitation 3 ,
i Appendix I - Cracking of Masonry Block Walls 3 l Appendix J - Settlement 4 I Appendix K - Corrosion of Steel 5 Appendix L - Corrosion of Liner 3 .,
Appendix M - Corrosion of Tendons 2 Appendix N - Prestress Losses 2 j Appendix O - Weathering 3 l
Appendix P - Not Used 0 Appendix P - Not Used 0 Appendix R - Elevated Temperature 3 Appendix S -Irradiation 4 Appendix T - Fatigue 8 O
V AGING MANAGEMENT REVIEW RESULTS HNAL REPORT INTAKE STRUCTURE REVISION 2 1
O Attachment 1 l
4 Potential Aging Mechanisms Applicable to Structural Components l
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1 Sheet 1 of l O
O O O ATTACHMENT 1: POTENTIAL AGING MECHANISMS APPLICABLE TO STRUCTURAL COMPONENTS REVISION: 2 DATE: 5 0/96 STRUCTURE NAME: Intake Structure SYSTEM NUMBER: _9_ Sheet 2_ of 3 ;
f 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 Foundations - V V V V - - -
NA 4 - - - - 4 Furiction LR-S-2 Concrete Columns - - - 4 - - - - NA - - - - - 4 Functions LR-S-2, 4, and 7 Concrete WaHs V V V V V - - - NA - - - - - 4 Functions LR-S-1, 2,4, and 7 Concrete Beams - - - 4 - - - -
NA - - - - - V Functions LR-S-2 and 4 Ground Floor Slabs & Equip. Pads - V V V V - - - NA V - - - - 4 Functions LR-S-1 and 2 Elevated Floor Slabs - - - 4 - - - -
NA - - - - - 4 Functions LR-S-1 and 2 Roof Stabs 4 4 V V V - - - NA - - - - - V Function LR-S-2 CasthPlace Anchors / Embed. - - - - - - - -
NA - V - - - V Functions LR-S-1,2,6 and 7 Grout - - - - - - - - NA - - - - - -
Functions LR-S-1 and 2 Fluid Retaining Walls and Slabs - V V V V - - 4 NA - - - - - - Functions LR-S-1,2, and 6 Post Installed Anchors - - - - - - - - NA - 4 - - - -
Functions LR-S-2 and 5 Fire Doors, Jambs. Hardware - - - - - - - - NA - V - - - -
Functions LR-S-2 and 7 Access Doors. Jambs, Hardware - - - - - - - -
NA -
4 - - - -
Function LR-S-2 Caulking and Sealants - - - - - - - -
NA - - 4 - - - Function LR-S-2,6 and 7 Watertight Doors - - - - - - - -
NA - 4 - - - -
Function LR-S-6 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 1 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 Elevated temperature - Not potential
O O O ATTACHMENT 1: POTENTIAL AGING MECHANISMS APPLICABLE TO STRUCTURAL COMPONENTS REVISION: 2 DATE: 5/7/96 STRUCTURE NAME: Intake Structure SYSTEM NUMBER: _9_ Sheet 3_ of 3 REMARKS STRUCTURAL POTENTIAL AGING MECHANISMS APPLICABLE TO STEEL COMPONENTS COMPONENTS ,
K L M N R S T Steel Beams i NA NA NA - - 4 Functions LR-S-1 and 2 4 NA NA NA - - 4 Functions LR-S-1 and 5 Basemates Floor Framing i NA NA NA - - 4 Functions LR-S-1 and 5 Roof Frarning 4 NA NA NA - - 4 Function LR-S-2 Steel Bracing 4 NA NA NA - - 4 Functions LR-S-2 and 5 Platform Hangers 4 NA NA NA - - 4 Function LR-S-5 Steel Decking 4 NA NA NA - - 4 Function LR-S-2 Floor Grating 4 NA NA NA - - - Function LR-S-5 Checkered Plate 4 NA NA NA - - - Function LR-S-2 Stairs and Ladders 4 NA NA NA - - - Function LR-S-5 Sluice Gates 4 NA NA NA - - - Function (R-S-1 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 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 O (Not Used) NA Not applicable F Creep L Corrosion in Liner R Elevated temperature - Not potential
______.._._______________________________m - _ - - - . . _ _ _ _ . - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ___ _ _ _ _ _ _ _ _ ____.__.-___-___
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1 Attachment 2 l
i l Plausible Aging Mechanisms Applicable to Structural Components
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ATTACHMENT 2: PLAUSIBLE AGING MECHANISMS APPLICABLE TO STRUCTURAL COMPONENTS REVISION: 2 DATE: 5/7/96
- STRUCTURE NAME: Intake Structure SYSTEM NUMBER: 3_ Sheet 2_ of 3, ,
REMARKS STRUCTURAL PLAUSIBLE AGING MECHANISMS APPLICABLE TO CONCRETE / ARCH. COMPONENTS COMPONENTS A B C D E F G H I J K O R S T Foundatens - 102 PA 104 PB - - -
NA 107 - - - -
109 Function LR-S-2 Concrete Columns - - - 104 - - - -
NA - - - - -
109 Functions LR-S-2,4. and 7 Concrete Walls 101 102 103 104 105 - - -
NA - - - - -
109 Functions LR-S-1,2,4, and 7 Concrete Beams - - - 104 - - - - NA - - - - - 109 Functions LR-S-2 and 4 0- mnd Floor Stabs & Equip. Pads - 102 PA 104 PB - - -
NA 107 - - - - 109 Functions LR-S-1 and 2 Elevated Floor Slabs - - -
104 - - - - NA - - - - -
109 Functions LR-S-1 and 2 Roof Slabs 101 102 103 104 105 - - -
NA - - - - -
109 Function LR-S-2 Cast 4n-Place Anchors / Embed. - - - - - - - -
NA -
PC - - - 109 Functions LR-S-1,2,6, and 7 Grout - - - - - - - -
NA - - - - - -
Functions LR-S-1 and 2 Fluid Retaining Walls and Slabs -
102 PA 104 PB - - 106 NA - - - - - - Functions LR-S-1,2, and 6 Post Installed Anchors - - - - - - - -
NA - PC - - - -
Functions LR-S-2 and 5 Fire Doors, Jambs, Hardware - - - - - - - -
NA -
PC - - - - Functions LR-S-2 and 7 Access Doors, Jambs, Hardware - - - - - - - -
NA -
PC - - - - Function LR-S-2 Caulking and Sealants - - - - - - - -
NA - - PD - - - Function LR-S-2,6, and 7 Watertight Doors - - - - - - - - NA -
PC - - - - Function LR-S-6 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 Elevated temperature - Not potential i
O O O f
ATTACHMENT 2: PLAUSIBLE AGING MECHANISMS APPLICABLE TO STRUCTURAL COMPONENTS REVISION: 2 DATE: 5/7/96 '
STRUCTURE NAME: Intake Structure SYSTEM NUMBER: J_ Sheet 3_ of 3 ;
RETAARKS STRUCTURAL PLAUSIBLE AGING MECHANISMS APPLICABLE TO STEEL COMPONENTS COMPONENTS K L M N R S T Steel Beams PC NA NA NA - - 109 Functions LR-S-1 and 2 r Bzseplates PC NA NA NA - - 109 Nat;uns LR-S-1 and 5 i i
Floor Framing PC NA NA NA - -
109 Functions LR-S-1 and 5 t Roof Frammg PC NA NA NA - - 109 Function LR-S-2 ,
, s Steel Bracing PC NA NA NA - - 109 Functions LR-S-2 and 5 i Fttform Hangers PC NA NA NA - -
109 Function LR-S-5 Steel Decking PC NA NA NA - - 109 Function LR-S-2 i Floor Grating PC NA NA NA - - -
Function LR-S-5 Checkered Plate PC NA NA NA - - -
Cunction LR-S-2 Stairs and Ladders PC NA NA NA - - -
Function LR-S-5 Sluice Gates PC NA NA NA - - -
Function LR-S-1 i
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l Legend: A Freeze-thaw G Stwinkage 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 Settleme it P (Not Used) V (Not Used) l E Corrosion in embedded steet/rebar K Corrosion in steel Q (Not Used) NA Not applicable i F Creep L Corrosion in Liner R Elevated temperature - Not potential s
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i Attachment 3 l I
- Structural Components f
i Aging Mechanism Matrix Codes 4
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.O. ATTACHMENT 3 i I
STRUCTURAL COMPONENTS - AGING MECHANISM MATRIX CODES l
REVISION:__2_. DATE: 5/7/96
\
l STRUCTURE NAME: Intaka structure SYSTEM NUMBER: 9 Sheet 2 of 3 CODE JUSTlFICATION REMARKS 101 See Appendix A l l l 102 See Appendix B !
103 See Appendix C l
104 See Appendix D i
l See Appendix E 105 106 See Appendix H ,
107 See Appendix J 108 Not Used 109 See Appendix T l
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.. , _ . _ _ = . _ _ - _ _ _ . _ _ - _ _ _ . . . _ _ . . _ .
1 ATTACHMENT 3 STRUCTURAL COMPONENTS - AGING MECHANISM MATRIX CODES '
REVISION: ,_2__ DATE: 5/7/96 STRUCTURE NAME: Intake Structure SYSTEM NUMBER: 9 - Sheet 3 of 3 CODE JUSTIFICATION REMARKS PA See Appendix C l PB See Appendix E PC See Appendix K PD See Appendix O O
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l Attachment 4 Aging Management Review Results O
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O O O Attachment 4
SUMMARY
OF AGING MANAGEMENT REVIEW RESULTS REVISION: 2 DATE: Sn/96 STRUCTURE / SYSTEM NUMBER: 9 STRUCTURE NAME: Intake Stiucture COMPONENTS AFFECTED AGING MECHANISM CONCRETE STEEL ARCH. PROGRAM / COMMENT Freeze-%aw None None None Not Needed Leaching ofCa(OH)2 None None None Not Needed Aggressive Chemicals Foundations None None None existing. Need to investigate the Ground Floor Slab water quality ofgroundwater.
Fluid Retaining Walls and None existing. Need to investigate Slabs inaccessible areas of the intake ,
structure.
Reaction with Aggregates None None None Not Needed Corrosion of Embedded Foundations None None None existing. Need to investigate Steel /Rebar Ground Floor Slab water quality of groundwater.
Fluid Retaining Walls and None existing. Need to investigate Slabs inaccessible areas of the intake structure.
Creep None None None Not Needed Shrinkage None Neae None Not Needed Abrasion / Cavitation None None None Not Needed Cracking of Masonry Block None None None Masonry block walls do not exist in the Walls intake structure. ,
Sheet 2.of.1
O O O Attachement 4
SUMMARY
OF AGING MANAGEMENT REVIEW RESULTS REVISION:__2_ ,
DATE: Sn/96 STRUCTURE / SYSTEM NUMBER: 9 STRUCTURE NAME: Intake Structure ;
COMPONENTS AFFECTED AGING MECHANISM CONCRETE STEEL ARCH. PROGRAM / COMMENT Settlement None None None Not Needed None All carbon steel None PEG-7,QL-2-100,MN-3-100,ARDI Corrosion in Steel components Corrosion in Liner None None None Steel liners do not exist in the intake ;
structure.
Corrosion in Tendons None None None Prestressed tendons do not exist in the ,
intake structure.
Prestressing Losses None None None Prestressed tendons do not exist in the intake structure. ,
Weathering None None Caulking and Appendix R Program for components :
sealants with fire protection function. For non-Appendix R corr.ponents, develop an ,
inspection and maintenance program to identify degradation and ensure corrective action is taken. The resolution toissue Report IRl995-01698 to form the basis of this program.
Elevated Temperature None None None Not Needed Irradiation None None None Not Needed Fatigue None None None Not Needed Sheet 3_ ofl
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i Attachment 5 l 1
(
4 Adequate Program Evaluation l
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Attachment 5 0m ADEQUATE PROGRAM EVALUATION REVISION:._2_ DATE: 5/7/96 STRUCTURE / SYSTEM NUMBER: 9 STRUCTURE NAME: Intake Structure STRUCTURAL COMPONENT DESCRIPTION: All accessible steel surfaces AGING MECHANISM DESCRIPTION: Corrosion of steel CCNPP PA or Task ID: MN-3-100. PEG-7. OL-2-100 Criteria 1: Adequate programs must ensure mitigation of the effects of age related degradation for the SSCs within the scope oflicense renewal.
DISCOVERY DESCRIPTION / BASIS:
- 1. Is there a frequency interval in the PA or Task?
YES_X_ NO _
Basis: System Engineer Walkdowns as directed by PEG-7 are conducted neriodically as mandated by system nerformance. nlant oneratina conditions. or as reauired bv niant
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management. Walkdowns can be iob snecific or outage related but otl5erwise tvolcally occur on a monthlv basis.
- 2. Is the frequency interval consistent with industry standards, industry experience, experience unique to Calvert Cliffs, or vendors' recommendations?
YES .X_ NO __
Basis: The PEG-7 walkdown freauency is consistent with industrv standards and can be -
modified as neceuarv to reflect uniaue olant onersting conditions snecific 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 Sheet .2_ of _2 l
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, Attachment 5 - Adequate Program Evaluation (continued) p%J REVISION:_2__ DATE: 5/7/?6 AGING MECHANISM DESCRIPTION: Corrosion of steel CCNPP PA or TASK ID: MN-3-100 PEG-7. OL-2-100 i l
Critsria 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. j j ASSESSMENT / ANALYSIS / CORRECTIVE ACTION DESCRIPTION / BASIS
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- 1. Does the PA or Task have an action or alert value or condition parameter to determine the need I 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 anproorinte technical orocedures for corrective action based on the contings service level.
- 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?
YES_X_ NO _
Basis: Conditions adverse to anality and functionalitv. indications of eauinment stress or abuse.
safety or fire hn7ards. and general housekeening deficiencies are noted during PEG-7 system walkdowns conducted monthlv. Structural degradation occurs at a sufficiently slow rate such that monthly insoections would detect degradation before loss of function could occur.
- 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 nre based on insoection of the surface condition of the painted comoonent. This anoroach does not need to be revised during the renewal oeriod.
Sheet .3_ of _2
F l Attachment 5 - Adequate Program Evaluation (continued)
REVISION: 2_._ DATE: 5/7/96 AGING MECHANISM DESCRIPTION: Corrosion of steel )
i CCNPP PA or TASK ID: MN-3-100 PEG-7. OL-2-100 .
l 4. Does the PA or Task ensure that corrective action is taken?
YES .X_ NO _
Basis: PEG-7 reouires deficiencies to be documented on 3 system walkdown renort. Conditions adverse to anality will result in the initiation of an Issue Reoort ner OL-2-100 reauirements. MN-3-100 invokes the nonrooriate technical nrocedure to ensure oroner I aonlication and that a analified orotective conting is used.
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- 5. Does the PA or Task ensure that the corrective action is appropriately scheduled?
YES X_ NO __
Basis: OL-2-100 assigns a due date for corrective action to occur. The completion date is driven by engineering iudgment based on the condition of the degraded coating and its contribution to the comoonent's intended function.
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i Attachment 5 - Adequate Program Evaluation (continued) lO REVISION: 2_ DATE: Sn/96 AGING MECHANISM DESCRIPTION: Corrosion of steel CCNPP PA or TASKID: MN-3-100 PEG-7. O1 2-100 Criteria 3: Adequate programs must be implemented by the facility operating procedures and j reviewed by the onsite review committee.
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i l CONFIRMATIO14/ DOCUMENTATION DESCRIPTION / BASIS: l 1
- 1. Does the PA or Task have a review / approval process?
YES_X. NO _ i Basis: The orocedure reauires sinnatures from annronriate levels of sunervision (i c.. 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?
l YES_X. NO _
Basis: The " Record of Revisions and Changes" of the orocedure documents the changes to the urocedure.
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At%chment 5 l l ADEQUATE PROGRAM EVALUATION REVISION:_2_ DATE: 5/7/96 STRUCTURE / SYSTEM NUMBER: None STRUCTURE NAME: Intake Structure STRUCTURAL COMPONENT DESCRIPTION: Caulkine and Sealants ~
l AGING MECHANISM DESCRIPTION: Weatherina i
CCNPP PA or Task ID: STP-F-592-1/2 i
i Criteria 1: Adequate programs must ensure mitigation of the effects of age-related j degradation for the SSCs identified as within the scope oflicense renewal.
l l DISCOVERY DESCRIPTION / BASIS:
- 1. Is there a frequency interval in the PA or Task?
YES.X_ NO __
l
,. Basis: Both the Unit I and Unit 2 procedures are imnlemented in accordance with the frecuenev j
( intervals snecified in olant Technical Snecification Section 4.7.12. j i
- 2. Is the frequency interval consistent with industry standards, industry experience, experience 1 unique to Calvert Cliffs, or vendors' recommendations? I l
YES .X_ NO __
Basis: The freauency interval is consistent with that commonly used in the industry for surveillance of fire barrier penetration seals. The freauency interval has been annroved ;
in association with the imnlementation of the CCNPP Annendix R Program.
- 3. Will the PA or Task be applicable to all structural components under the same component type?
YES .X_ NO_
Basis: The orocedure is annlicable to fire barrier nenetration seals includina electrical conduit and cable trav penetration seals. HVAC duct nenetration cealc and mechanical n_ ine g*netration seals. The crocedure also covers insnection of the fire resistivity of rated
- walls. ceilinoc and floors. Data sheets are nrovided with the procedure to identify the fire areas reauiring insnection.
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Attachment 5 - Adequate Program Evaluation (continued)
I REVISION:_2_ DATE: 5/7/96 AGING MECHANISM DESCRIPTION: Weatherine CCNPP PA or TASK ID: STP-F-592-1/2 Criteria 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.
j 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 l for corrective action?
l YES X_. NO _ ,
Basis: Acceptance criteria is nrovided for each tvoc of nenetratic,n in Attachment A to the Unit I and Unit 2 nrocedures. The accentance criteria nrovides the basis for determining the need for corrective action.
! 2. Does the action value or condition provide sufficient indication of degradation to ensure that i there will not be a functional failure prior to the next PA or Task?
l O YES X_. NO _
I Basis: The procedures in both units mandate visual insnection of the nenetration fire barriers for indications of degradation or damage. The criteria imnlemented in the Calvert Cliffs nenetration fire .rier surveillance nrocedures will ensure the fire barriers perform their intended functicns at all times. This reauirement is imnlemented 5 accordance with the reauirements of Annendix R and CCNPP Technical Snecifications.
- 3. Will the action value or condition parameter remain the same during the renewal period ?
YES _X. NO __
Basis: Since the surveillance nrocedures and the acceptance criteria in the nrocedures are to ensure the availability and the reliability of the fire barrier nenetration semic. this ard;sptance criteria should not be changed during the renewal neriod.
l l
lOI Sheet w
Attachment 5 - Adequate Program Evaluation (continued)
REVISION:_2_ DATE: Sn/96 AGING MECHANISM DESCRIPTION: Weatherine CCNPP PA or TASKID: STP-F-592-1/2
- 4. Does the PA or Task ensure that corrective action is taken?
YES.X_ NO _
Basis: In accordance with Sections 5.4. 7.1. and Attachment B of the crocedures for both units.
any insoection results determined to be unsatisfactory will be renorted to the Shift Suoervisor for nossible Tech Soce 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 reoorting reauirements soecified in Technical Soecification 4.7.12 of both Units I and 2.
f%
V O Sheet.t er.2
n...- u _. , n.. . _ . . . ..n a .- - . - ,xc. a - - , - u e .. . . . . . --
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 Criteria 3: Adequate programs must be implemented by the facility operating procedures and reviewed by the onsite review committee.
, CONFIRMATION / DOCUMENTATION DESCRIPTION / BASIS:
l
- 1. Does the PA or Task have a review / approval process?
YES_X_ NO _
l Basis: This orocedure has a review /anoroval nrocess ner EN-4-104.
- 2. Does the PA or Task have a change / revision process? ;
1 1
YES .X._ NO _ l I
Basis: This nrocedure has a change / revision orocess ner EN-4-104.
O l
1 Sheet _9_ of _2
> l
. .O Attachment 7 Walkdown Report I
Examination ofIntake Structure Calvert Cliffs Nuclear Power Plant 1 O
4 1
1 Sheet 1 of l
- . :. . =
4 Attachment 7 g%J Examination ofIntake Structure Calvert Cliffs Nuclear Power Plant October 27,1994 Date of Insnection: October 27,1994 Particinantc: Lloyd Philpot G/C i David Knepper G/C Patrick McCarraher G/C l
summarv: An inspection of the intake Structure was performed to support the Component Evaluation and Program Evaluation of the Intake Structure. Prior to the l inspection a checklist was developed to establish those characteristics indicative of specific aging mechanisms. The interior and exterior of the structure was
)
inspected, with the exception of the fluid retaining walls and slabs which were
) inaccessible for a visual exammation.
Results: The inspection checklist and corresponding findings are included on the following pages. l This information will be used as input to the intake structure evaluation as needed. j I
Sheet _2._ of _1
O O O Attachment 7 LCM INSPECriON CHECKLIST INTAKE STRUCTURE Ap5mndix Aging Mechanism Characteristic Comments A Freeze-thaw Scaling, cracking, spalling No scaling, cracking, or spalling was observed B Iraching of calcium hydroxide Irachate Only minor leachate was observed.
The quantity and location indicates the CaOH is insignificant and is not a concern C Aggressive chemicals Spills, discoloration No aggressive chemicah were observed inside the intake structure.
Fluid retaining walls and slabs located below the intake structure's pump room were inaccessible for visual inspection D Reaction with aggregates Map cracking No map cracking was observed E Corrosion in embedded steel /rebar Cracking, rust staining, spalling No cracking, staining, or spalling was observed inside the intake structure.
Fluid retaining walls and slabs located below the intake structure's pump room were inaccessible for visual inspection F Creep NA Creep is not a potential aging mechanism for this structure G Shrinkage NA Shrinkage is not a potential aging mechanism for this structure Sheet _1_ of _5_
O O O ;
j Attachment 7 l
LCM INSPECTION CHECKLIST l-INTAKE STRUCTURE l~
W Aging Mechanian Characteristic Casements H Abrasion and cavitation Cracking, spalling Fluid retaining walls and slabs located below the intake structure's pump room were inaccessible for visual !
inspection I Cracking of masonry block walls NA This aging mechanism is not applicable to the intake structure 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 program could be used to control this ,
aging mechanism L Corrosion in liner NA This aging mechanism is not applicable j to the intake structure M Cerrosion in tendons NA 'Ihis aging mechamsm is not applicable to the intake structure N Prestressing losses NA This aging mechanism is not applicable ,
to the intake structure j O Weathering Scaling, cracking, spalling No scaling, cracking, on galling was observed on the exterior concrete zurfaces of the intake structure.
Sheet 4 of _5_
O O O l
l Attachment 7 l
l l LCM INSPECTION CHECKLIST INTAKE STRUCTURE Appemhr Aging Mechanism Characteristic Comments R Elevated temperatures Heat sources Only minor heat generating sources (room heaters) were observed in the enclosure. Fans were being used to cool salt water pump motors S Irradiation Radiation No monitored radiation sources were observed inside the intake structure T Fatigue Vibrating equipment The intake structure contains vibrating equipment. Fatigue caused by this I
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 _5_ of._5_
O Attachment 8 Attributes in New Program O
Sheet 1 of_ID_
J
- . ~ - - - . . - . . . - . - . - . - - - . - - - . . .-. .- . . . . - -_
Attachment 8 ATTRIBUTES IN NEW PROGRAM REVISION:_.2.__ DATE: 5/7/96 STRUCTURE / SYSTEM NUMBER: 9 STRUCTURE NAME: Intake Structure STRUCTURAL COMPONENT DESCRIPTION: Foundations ,
I l
AGING MECHANISM DESCRIPTION:Anoreceive chemicalc l
APPLICABLE APPENDIX: Annendix C 1
1 BACKGROUND: The intended function of the intake structure's foimdation is to provide protection and shelter to safetv-related and non-safety related eauinment inside 1 the intake structure. Chemical attack is olausible if the chemistry of the j groundwater has become sionificantiv more nooressive than was originally anticinated.
RECOMMENDED ATTRIBUTES: Since dearadation of the below erade nortion of the intake structure foundation m would be plausible if the water chemistrv has become more nooressive. the nronosed nrogram will begin with investientive tacke followed bv corrective action if nececcarv. The secommend A annroach is:
- 1. Restore the groundwater observation wells installed during initial nlant gggstruction for samnlino purnose.
- 2. Secure camnles of the aroundwater for water chemistry testing. If the water chemistry meets the original design reauirements (Cl ions < 500 nom. SQ, ions
< 1500 nomi no further action is nececcarv. -
- 3. If the water chemistrv tests conclude that the concrete comnonents are being degraded by chemical agents the levels of chemical concentration will need to be accessed to determine the annronriate corrective action. !
BASIS: Becance of the desion and construction of the intake structure foundation. and the knowledge of the water chemistrv during the desion of the olant it is unlikely that chemical attack to concrete is a maior concern.
Sheet .2_ of _1D
l l Attachment 8 ATTRIBUTES IN NEW PROGRAM (continued)
! REVISION:__2_ DATE: S/7/96 STRUCTURE / SYSTEM NUMBER: 9 STRUCTURE NAME: Intake Structure STRUCTURAL COMPONENT DESCRIPTION: Foundations AGING MECHANISM DESCRIPTION: Corrosion of FmhaAAad Steel /Rebar APPLICABLE APPENDIX: Annendix E l
l BACKGROUND: The intended function of the intaka structure's foundation is to nrovide nrotection and shelter to safetv-relatad and non. safety relatad eoninment inside f
the intake structure. Corrosion of embadded steel /rebar in the foundation is I nlancible if the chemistry of the aroundwater has become sinnificantly more nooressive than was orioinally anticinated.
l RECOMMENDED ATTRIBUTES: Since degradation of the below grade nortion of the intake structure foundation t
would be olmucible if the water chemistry has become more nooressive. the ,
l nronosed nrocram will benin with investientive tacks followefby corrective
' ' ~
l action if nececcarv. The recommended annroach is:
- 1. Restore the groundwater observation wells installed during initial nlant l construction for samoling nurnose.
- 2. Secure namnles of the groundwater for water chemistry testino. If the water chemistry meets the original design reauirements ( nH > 4.0. Cl ions < S00 nom. SO3 ions < 1500 nom ). no further action is nececenrv. .
- 3. If the water chemistry tests concInda that the concrete comnonents are being degraded by chemical noents. the levels of chemical concentration will need to l be assessed to determine the anoronrinte corrective action.
l BASIS: Beranca of the design and construction of the intake structure foundation and the knowledee of the water chemistrv during the desion of the olant it is unlikely that corrosion of embaddad steel /rebar in the foundation is a maior concern.
\ Sheet .3._ of _l0
i, i
4 4 Attachment 8 O ATTRIBUTES IN NEW PROGRAM (continued)
REVISION:._2__ DATE: 5/7/96 l
STRUCTURE / SYSTEM NUMBER: 9 4 l
STRUCTURE NAME: Intake Structure l i
4 STRUCTURAL COMPONENT DESCRIPTION: Ground floor slab AGING MECHANISM DESCRIPTION:Agaressive chemicalc l
i APPLICABLE APPENDIX: Annendir C l
J_ BACKGROUND: The intended function of the intake structure's around floor slah is to provide j suonort. protection and shelter to safetv-related and non-safety related i caninment inside the intake structure. Chemical attack is nlantible if the clkemistry of the groundwater has become sionificantiv more nearessive than was j orioinally anticinated.
1
- RECOMMENDED ATTRIBUTES: Since degradation of the below grada nortion of the intake structure ground floor slab would be olancible if the water chemistrv has become more negressive. the j t pronosed nronram will begin with investigative tackc followed bv corrective action if necessarv. The recommended anornach is:
l . Restore the eroimdwater observation wells inctalled during initial nlant construction for namnlina nurnose.
J i
j 2. Secure namnles of the aroundwater for water chemistry testina. If the water
~
[I chemistry meets the original design renuirements (Cl ions < 500 nnm. SO, iQas .
- < 1500 nomt no further action is nececcarv. -
a f
- 3. If the water chemistry tests conclude that the concrete comnonents are being ,
, denraded by chemical anents. the levels of chemical concentration will need to
~
be assessed to determine the anoronriate corrective action.
BASIS: Because of the design and con =truction of the intake structure around floor slab.
and the knowledoe of the water chemistrv durinn the desian of the olant it is unlikely that chemical attack to concrete is a maior concern.
I V) Sheet .d._ of _10 l
1 3
[ l I l l
l Attachment 8 O
V ATTRIBUTES IN NEW PROGRAM (continued)
REVISION:._2__ DATE: 5/7/96 j STRUCTURE / SYSTEM NUMBER: 9 STRUCTURE NAME: Intake Structure STRUCTURAL COMPONENT DESCRIPTION: Ground floor slah AGING MECHANISM DESCRIPTION: Corrosion of Fmbaddad Steel /Rebar l
l- APPLICABLE APPENDIX: Apnendix E l
l BACKGROUND: The intended function of the intake structure's around floor clah is to provide l suonort. nrotection. and shelter to safety-relatad and non-safety related l eauipment inside the intake structure. Corrosion of embaAAad steel /rebar in the
, around floor slah is nlausible if the chemistrv of the aroundwater has become sionificantly more nooressive than was originally anticinated.
RECOMMENDED
! ATTRIBUTES: Since denradation of the below ar=Aa nortion of the intake structure around floor
! slab would be olancible only if the water chemistry has become more nooressive.
~~
the nronosed nrogram will begin with inventioative tack < followed by corrective l action if nececcarv. The recommended annroach is- l l
- 1. Restore the aroundwater observation wells installed during initial niant construction for samnling nurnose.
- 2. Secure namnles of the groundwater for water chemistry testing. If the water chemistrv meets the orioinal design reauirements ( nH > 4.0. Cl ions < S00 nom. SOf ions < 1500 nom i no further action is nececurv. .
- 3. If the water chemistry tests conclude that the concrete comnonents are being degraded by chemical agents. the levels of chemical concentration will need to be assessed to determine the anpronriate corrective action.
l BASIS: Because of the design and construction of the intake structure around floor slah.
and the knowledge of the water chemistrv during the design of the olant. it is unlikely that corrosion of embaddaA steel /rebar in the ground floor slah is a major concern.
l I
Sheet _i_ of_ID I
i
i
(
l Attachment 8 1
i i ATTRIBUTES IN NEW PROGRAM (continued)
! REVISION:._2_. DATE: 5/7/96 i
STRUCTURE / SYSTEM NUMBER: 9 STRUCTURE NAME: Intake Structure STRUCTURAL COMPONENT DESCRIPTION: Fluid retaining walls and slahs
]
j AGING MECHANISM DESCRIPTION:Avoressive chemicals 1
- APPLICABLE APPENDIX
- Annendix C 1
'4 BACKGROUND: The intended functions of the intake structure's fluid retainine walls and slahs
~
are to provide structural supnort to safetv-related eauinment to provide shelter / protection to safetv-related cauinment. and to nrovide a flood barrier
{ (internal flooding eventt l RECOMMENDED ATTRIBUTES: Since the concrete surfaces of the fluid retainino walls and slabs of the intake j structure are exnosed to saltwater from the Chesaneake Bay and since these areas are inaccessible for visual insnection. nuoressive chemicals is considered a I nlancible aging mechanism. It is recommended that a neriodic insnection 3 program be imnlemented nrior to anolication for license renewal.
- 1. This neriodic insnection orogram could be combined with an existing sub-
, surface cleaning procedure. SW-06. During sub-surface cleaning onerations. a
- video camera could be used to record the condition of the concrete surfaces.
i.
d j 2. A condition survey of the concrete should be nerformed in accordance with j: , . snecification ACI 201.1. Any nitting. scaling. or signs of aggregnte exnosure .
i should be renaired in accordance with ACI recommended nrocedures.
BASIS: Since it is nossible for saltwater or dissolved chemicale in the saltwater to
' ~
denrade the concrete surfaces of the intake structure's fluid retainine walls and I
slabs. aggressive chemicals is considered a plancible aging mechanism until such time that a visual insnection of the walls and slabs can be nerformed.
i b
Sheet .fi_ of_10 t
1
Attachment 8 O ATTRIBUTES IN NEW PROGRAM (continued)
REVISION:_2_. DATE: 5/7/96 l
STRUCTURE / SYSTEM NUMBER: 9 STRUCTURE NAME: Intake Structure STRUCTURAL COMPONENT DESCRIPTION: Fluid retaining walls and slabs
! AGING MECHANISM DESCRIPTION: Corrosion in embedded steel /rebar l
j= APPLICABLE APPENDIX: Annendix E l BACKGROUND: The intended functions of the intake structure's fluid retainine walls and slabs ge to nrovide structural suonort to safetv-related couinment[to provide shelter / protection to safetv-related eauinment and to provide a flood barrier (internal flooding eventi RECOMMENDED ATTRIBUTES: Since embadded steel /rebar of the fluid retnining walls and slabs of the intake 11DLeture could be exnosed to saltwater from the Chacan>=Le Bay and since these areas are inaccessible for visual insnection. corrosion in embedded steel /rebar is considered a clausible aging mechanism. It is recommended that a neriodic insnection nrocram be imnlemented nrior to annlication for license renewal.
P
- 1. This periodic insnection program could be combined with an existing sub-surface cleaning procedure. SW-06. During sub-surface clenning onerations. a video camera could be used to record the condition of the concrete surfaces.
- 2. A condition survey of the concrete should be nerformed in accordance with snecification ACI 201.1. Any cracks or signs of staining on the concrete ,
surfaces should be investigated.
BASIS: Since it is nossible for saltwater to degrade the embedded steel /rebar of the intake structure's fluid retainine walls and slabs. corrosion in embedded steel /rebar is considered a pinuiible aging mechanism until such time that a visual insnection of the walls and slabs can be nerformed.
Sheetl of 10
l Attachment 8 ATTRIBUTES IN NEW PROGRAM REVISION:_2__ DATE: 5/7/96 I
STRUCTURE / SYSTEM NUMBER: None i
l STRUCTURE NAME: Intake Structure l
STRUCTURAL COMPONENT DESCRIPTION: Caulking and Sealants AGING MECHANISM: Wentherine
- l. APPLICABLE APPENDIX: Annendix 0 i BACKGROUND: The intended functions of ennikina and cenlants are to nrovide shelter and nrotection to safety related cauipment (including HFI R and radiation nrotection)
- inside the Intake Structure. The enulkine and cenlants have an additional
! intended function to nrovide a flood nrotective barrier for internal flooding events. The caulking and cenlants are components which are tynically renlaced on condition. However insnections in the olant revealed that an insnection oronram was reautred to adeauntely manage the aging of these comnonents.
l
, Note: The caulking and scalants which reauire a new program to manage their ;
nging do not nerform the intended function of a fire barrier. Caulking and senlants which nerform a fire barrier function are managed under an existing orogram.
RECOMMENDED l ATTRIBUTES: The management nrogram for the caulking and sentants is recommended to be develoned in association with the resolution to Issue Report IR1995-01698. The pronram must manage the agina of the caulking and sentants in the intake Structure which suonort intended functions of the structure. The recommended approaches are:
- 1. Identify all non-Annendix R caulkino and cenlants locations that suonort the structure's intended functions.
- 2. Develon an inu cction and maintenance program which will identify denr=dation and ertsure corrective action is taken before the comnonent loses the l
ability to nerform its intended function. The oronram should concentrate on caulkina and sentante located in exterior walls and in int.erior walls and floors where NFI R and floodina functions are nerforang, i
I O Sheet _lL. of_lD m__- _ _ _ _ ________*_______-__vs - -
_ _ _ . . _ r-- T- ' - .- =P *"'-
l I
i Attachment 8 O ATTRIBUTES IN NEW PROGRAM (continued) l REVISION:._2_ DATE: S/7/96 l
STRUCTURE / SYSTEM NUMBER: 9
! STRUCTURE NAME: Intake Structure STRUCTURAL COMPONENT DESCRIPTION: Foundations AGING MECHANISM DESCRIPTION: Corrosion of Embedded Steel /Rebar l APPLICABLE APPENDIX: Annendix E l
BASIS: The management nronram for the caulking and senlants is recomi tended to be develooed in association with the resolution to Issue Renort IR1995-01698. The l issue reoort identified icints in the Auxiliary Building which showed simis of degradation. This concern is also anplicable to the Intake Structure. Resolution of this issue renort will ensure develonment of an aging management nrogram ;
for caulking and sentants in the Intake Structure such that these components will 1 l be able to nerform their intended functions both during the current license neriod and the neriod of extended onerations.
O
[
i 3
Sheet .9__ of _19
t i l
! Attachment 8 l ATTRIBUTES IN NEW PROGRAM (continued)
REVISION:._2_. DATE:. 5/7/96 i STRUCTURE / SYSTEM NUMBER: None STRUCTURE NAME: Intake Structure STRUCTURAL COMPONENT DESCRIPTION: Non-accessible structural steel l l
ARDM DESCRIPTION: Corrosion of Steel l 1
1 APPLICABLE APPENDIX: Annendix K BACKGROUND: Safety related structural steel in the Intake Structure is covered with an appronriate protective contino. Corrosion of structural steel can only occur if these orotective continas have been denraded. Aoino manacement of denraded
~ ~
coating conditions on n'ecessible structural steel in th'e Intnis Structure is~
accomnlished through the combination of existino olant orograms. However. l l structural steel comnonents not readily accessible reouire additional aging !
- management.
RECOMMENDED ATTRIBUTES: An age related degradation insnection (ARDD program as described in the BGE '
Integrated Plant Assessment Methodolony should be imnlemented to address ,
corrosion of non-accessible structural stee! comnonents which suonort the intended functions of the Intake Structure. The ARDI Program must consist of l 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 Anoronriate insnection techniaues.
- 4. Reauirements for renorting of results and corrective actions if noino concerns are identified.
BASIS: The ARDI Program will ensure that degraded conditions due to corrosion of steel are identified and corrected such that non-accessible structural steel l comnonents of the Intake Structure will be capable of nerforming their intended functions under all design conditions reauired by the current licensing basis.
l p
, Q Sheet 10_of 10
l 1
l l
APPENDIX A - FREEZE-THAW _
1.0 MECHANISM DESCRIPTION 1
- Repeated cycles of freezing and thawing can alter both the mechanical properties l and physical form of the concate, thus affecting the structuralintegrity of the l component. The freeze-thaw phenomenon occurs when water freezes within the l concrete's pores, creating hydraulic pressure. This pmssure either increases the j size of the cavity or forces water out of the cavity into surrounding voids.
Freeze-thaw damage is characterized by scalmg, cracking, and spalhng. Scalmg i or surface flaking occun in the presence of moisture and is aggravated by the use of deicing salts. Cracks or spallmg occurs when voids are already filled with ,
water, and freezing causes pressure to increase. In extame cases of freeze-thaw i damage, the cover over reinforcing steel is reduced, and the reinforcing steel is eventually exposed to accelerated corrosion. Concrete is vulnerable to the ,
expansive effects of the resulting corrosion products, thereby weakening the '
concrete's resistance to further attack by aggmssive environments.
To mmmuze the adverse effects of freeze-thaw, three factors must be considered in the design and placement of concrete:2 i
[
The cement paste must have an entrained air system with an appropriate void spacing factor. l The aggregate must be of a sufficiently high quality to msist scaling.
The in-place concrete must be allowed to mature sufficiently before l exposure to cyclic freezing and thawing.
As shown in Figure A-1, the optimal air content range extends from 3 to 7 percent l based on the nommal maximum size of coarse aggregate.S I
l 2.0 EVALUATION *l l
2.1 Conditions According to Specification ASTM C33-82, " Standard Specification for Concrete Aggregates,"4 the CCNPP site is located in the geographic region subject to severe l weathering conditions. As stated in CCNPP's " Civil and Structural Design Criteria,"5 the frost penetration depth is 20 to 22 inches.
2.2 Potential Aging Mechanism Determination Freeze-thaw is a potential aging mecharusm for the following concrete structural component of the intake structure because it is exposed to outside cold weather:
Concrete walls Functions LR-S-1,2,4, and 7
- Roof slab Functions LR-S-2 5/7/96 E A-1 lievision 2 1
Freeze-Thaw where:
i 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.
LR-S-4: Serves as a missile barrier (internal or external).
i LR-S-7: Provides rated fire barriers to confme or retard a fire from l spreading to or from adjacent areas of the plant.
l Other concrete structural components are either below the frost line or are located l' inside the intake structure. Therefore, freeze-thaw is not a potential aging mechamsm for all other structural components.
2.3 Impact onIntended Functions If the effects of freeze-thaw were not considered in the original design or are allowed to degrade the above structural components unmitigated for an extended period of time, this aging mechamsm could affect all the intended functions of the l A components listed in Section 2.2.
V 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 Specifcationfor 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 that:
Procedures for making freezing and thawing tests of concrete are described in ASTM Method C290,
- Test for Resistance of Concrete Specimens to Rapid Freezing and Thawing in Water," and in ASTM Method C291,
- Resistance of Concrete Specimens to Rapid Freezing
, in Air and Thawing in Water."
l 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.
5/7/96 E A-2 Revision 2
, Freeze-Thaw O
1 Design specification No. 6750-C-9 for CCNPP also specifies.
10.4.2.1 The Subcontractor shall specify the air entraining agent he ;
- proposes to use. It shall be in acccrdance with ASTM C-260, capable {
of entraining 3-5% air, be completely water soluble, and be
- completely dissolved when it enters the batch. The Subcontractor l shall give 30 days advance notice of the type of AEA he proposes to l use. i
, ACI 3187 and its relevant ACI standards and ASTM specifications provide the
, physical p-operty requirements of aggregate and air-entraining admixtures, 5
chemical and physical requirements of air-entraining cements, and proportioning of concrete containmg entrained air to maxmuze the concrete resistance to freeze-1 thaw action.
d 2.5 Plausibility Determination Based on the discussion on Section 2.4, concrete used for the intake structure walls and roof slab was designed and constructed in accordance with the requirements specified in ACI-318 and its relevant ACI standards and ASTM
- specifications. Those requirements satisfy the attributes discussed in Section 1.0 that maximize concrete's resistance to freeze-thaw action. In addition, a 4 (s walkdown of the intake structure conducted October 27, 1994 documented no evidence of damage from freeze-thaw. Therefore, freeze-thaw is not a plausible aging mechanism for the intake structure walls or roof slab.
2.6 Existing Programs There are no existing programs at CCNPP that are designed specifically to identify or to repair freeze-thaw damage. Since freeze-thaw is not a plausible aging mechanism that could degrade the intake structure's structural components, no management program is necessary.
3.0 CONCLUSION
The CCNPP site is located in the geographic region subject to severe weathering conditions. Although freeze-thaw cycles can degrade concrete components that are exposed to cold temperatures and in constant contact with moisture, these components were constructed with concrete designed to maxmuze its resistance to freeze-thaw cycles. A walkdown inspection of the intake structure performed on October 27, 1994 found no indication of freeze-thaw effect on the concrete structure. Freeze-thaw is not a plausible aging mechanism for the structural components of the intake structure.
S/7/96 N A-3 Revision 2
. - . ~ _ . _ - . . . - _ - . _ . _ . . - _ - .-. .
i Freeze-Thaw 4.0 RECOMMENDATION Freeze-thaw is not a plausible aging mechanism for any concrete structural l components of the intake structure. No further evaluation or recommendation is required.
[
5.0 REFERENCES
l l 1. " Class I Structures License Renewal Industry Report," EPRI's Project RP-
! 2643-27, December 1991.
- 2. Mather, B., "How to Make Concrete that Will Be Immune to the Effects of Freezing and Thawing," ACI Fall Convention, San Diego, November 1989.
l l
( 3. " Design and Control of Concrete Mixtures," Portland Cement l Association, Thirteenth Edition.
- 4. " Standard Specification for Concrete Aggregates," American Society of Testing and Materials, ASTM C33-82.
l \ 5. Civil and Structural Design Criteria for Calvert Cliffs Nuclear Power ;
l Plant Unit No.1 and 2, by Bechtel Power Corporation, Revision 0, ;
i- August 2,1991.
( 6. " Specification for Furnishing and Delivery of Concrete - Calvert Cliffs i
Nuclear Power Plant Unit No.1 and 2," CCNPP's Design Specification l No. 6750-C-9, Revision 8, April 1970.
l
- 7. " Building Code Requirements for Reinforced Concrete," American Concrete Institute, ACI 318-63. ,
l 1
1 l
1 i
I i
O 5/7/96 E A-4 . Revision 2
,. __..m___ . . _ _ _ . _ . . _ .m _ ._......_.,.-__m...__ _ . ~ . . _ . . _ . . _ . . . . . _ . . _ _ , _ . . _ . . - . . _ _ _ _ - .
l l
O rr -Ta -
+
i I
Expansion, percent 0.20 Freeze thow cycles: 300 0.18 -
Specimens: 3 x 3 :11) in.
{ concrete prisms O.16 - **" #" ' ' # ** i l Slump: 2 3 in.
O.14 -
1 0.12 -
!l r{ in.monimum site oggregote l
0.10 -
- ) in.
O.08 - ! "Ik I"-
- f i
A O.06 - ,k l U (\\\
0.04 -
! OD2 - b-~
t t g .g g g O
O 2 4 6 8 10 12 14 l Air content, percent ,
Figure A-1 l
Relationship between Air Content Aggregate Size and Concrete Expansion (Reference 3) i l
l 5/7/96 E A-S Revision 2
.._ - ~ -.-..- . - - -.- - - -.- ._
APPENDIX B - LEACHING OF CALClUM HYDROXIDE 1.0 MECHANISM DESCRIPTION 1 Water, either from rain or melting snow, that contains small amounts of calcium ions can readily dissolve calcium compounds in concrete when it passes thmugh cracks, inadequately prepared construction joints, or areas inadequately consolidated during placing. h most readily soluble calcium compound is calcium hydroxide (lime), h aggressiveness or affinity of water to leach calcium hydroxide depends on its dissolved salt content and its temperature.
Since leaching occurs when water passes through the concrete, structures that are subject to flowing liquid, ponding, or hydraulic pressure are more susceptible to
- i. degradation by leaching than those structums 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. h white deposit is a product of water, free lime from the concrete, and carbon dioxide that has been absorbed from the air.
l When calcium hydroxide is leached away, other cementitious constituents become exposed to chemical decomposition, eventually leaving behind silica and alumma 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 other forms cf aggressive attack and reducing the strength of concrete. leaching also lowers the pH of concate and thmatens 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 of its low permeability and low absorption rate. & 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-txement ratio and curing time. .
- 2.0 EVALUATION l
2.1 Conditions
& intake structure walls and roof slab are exposed to the outside environment and are expected to have rainwater passing over the exterior surface. The roof slab is provided with a roof drainage system to prevent ponding. The underside of the intake structure ground floor slab could be in contact with underground water. h fluid retainmg slabs and walls will be in contact with the intake water.
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Leaching of Calcium Hydroxide 2.2 Potential Aging Mechanism Detennination Leaching of calcium hydroxide is a potential aging mechamsm for the following structural component of the intake structure because it could be exposed to
, flowing liquid, ponding, or hydraulic pressure:
Foundations Functions LR-S-2 l
Concete walls Functions LR-S-1,2,4, and 7 l l
l Ground floor slab Functions LR-S-1 and 2 )
Roof slab Function LR-S-2 Fluid retaining Functions LR-S-1,2, and 6 slabs and walls where:
LR-S-1: Provides structural and/or functional support (s) for safety-related equipment.
- /3 LR-S-2
- Provides shelter / protection for safety-related equipment.
l U 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 spreading to or from adjacent areas of the plant. ,
i Leaching of calcium hydroxide is not a potential aging mechamsm for other
- l structural components of the intake structure because they are located inside the l building.
I 2.3 Impact on Intended Functions l
If the effects ofleaching of calcium hydroxide were not considered in the original design or are allowed to degrade the above otructural 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.
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Leaching of Calcium Hydroxide 2.4 Design and Construction Considerations Leaching attack can be nunmuzed by providing a low-permeability concrete mix design during construction. CCNPP umcrete design specification No. 6750-C-94 specifies:
9.3.1 1e n Portland cement concrete furnishcJ, unless otheruise speciped herein, shall conform to ASTM C-94 Specifcation for Ready Mix Concrete, ACI 318-63 Building Cok Requirements for Reinforced Concrete, ACI 301-66 Standard Specifcations fe Structural Concrete for Building, and ACI Manual of Concrete inspection.
12.1 Concrete Quc.lity 12.1.1.1 Portland cement shall conform to ASTM Designation C-94-67, Alternate No.1 and ACI301-66.
12.1.2.1 Concrete shall meet thefo!!owing requirements:
Nombent l 28-Day Slanny nt Slanny ~ ~v tc.s t .
Class Strength Poort of T&t~r Agwestte Use andloistion
\ (ps0 Placement (in i Size (inJ ,
A-1 2,000 4 11 W4 in. Electrical Duct Encasement & Lean Conctete Backfnli A-2 2,000 4 t1 1-H in. Electreal Duct Encasement & Lean Concrete Backfnli B-1 3,000 3 1% W4 in Struc ura! Concrete Walls & Slabs less t uan 12' thick & Congested Rebe ' .
B-2 3,000 3 t% 1-% in. Turbt e Pedestal & other Structural Concrete !
1 B Grout 3,000 - - h4 Cors rucnon loints C-1 4,000 3 e% W4 in. Walls & Slabs Isss than 1~~ %k &
Congested Rebar C-2 4,000 2 1% 1-H rn. Contatnment Base Slab and OthN Structural Concrete C-3 4,000 3 1% NB in. Starr Treads High Density 4,000 Hugh Densnty Concretefor Nuclear Concrete Shseldsng. Use Where Directed.
C Grout 4,000 - - h4 Containment Jotnts !
D-1 5,000 3 1% W4 un. Walls and Slabsless than 12' thsch
, and Congested Rebar
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Leaching of Calcium Hydroxide O,
a Ncusinal 1 28-Day 56sup at Shssp Mazhuss i Clas. Sinngtle Pokt of Tolerana Aggregate use andlacetion
+ (ps0 Plaunnent (in.) Size
^
< (in.)
2 D-2 5,000 2 t% 1-% in. Contatnment Walls and Lome and
. Other Structural Concrete D Grout 5,000 - - N4 Construction lotnts Dry Pack 4,000 0 - N4 As Dxrected Tremie 4,000 6 .y4 in. As Directed Concrete 1 AA 1,000 5 t2 1-M sn. Earth Alternate
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j AAA 1,000 5 12 .y4 in. Earth Alternate i 12.1.5 Mix Design 12.1.5.1 The Constructor sha!! retain an approved Testing Laboratory, at his own cost, to design and test initial concrete mixes.
The initial mixes shall be designed in accordance uith ACI Standards 613 and 301 to proc'uce a required strength of15 percent
% over speciped strength for reinforced concrete at 28 days and 25 percent over speciped strengthfor post-tensioned concrete at 28 days ;
- for each class of concrete with slump and maximum sizes of
- aggregate as specifed in the Classifcation Table (Section 12.1.2).
i' 12.1.5.2 The Constructor shallfurnish the Subcontractor with mix ,
designs one month prior to the manufacture of concrete. Furnishing l mix designs shall not relieve the Subcontractor of his responstbility '
l for compliance with the provisions of the Specifcation. 5%ere necessary, the Constructor shall increase or decrease cementfactors as deemed necessaryfor design mixes using statistical methods descrnbed
- in the ACI 214-65 for the particular class ofconcrete. An increase in the water-cement ratio of a mix design or a decreme in its cement quantity shall constitute a new mix design and the provisions of Section 12.1.5.1 of this Specipcation shall apply. Calcium chloride shall not be used.
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LeachFng of Calcium Hydroxide O
2.5 Plausibility Determination Based on the discussion in Section 2.1, the intake structure walls, roof slab, ground floor slab, and fluid retammg sla'ss and walls may be subjected to some contact with flowing water. However, as discussed in Section 2.4, concrete used for these structural components was designed in accordance with ACI 3185 and its relevant ACI standards and ASTM specifications to maxunize resistance to l leaching of calcium hydroxide. A walkdown of the intake structure 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 mecharusm for the intake structure.
2.6 Existing Pmgmms 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 agmg mechanism that could degrade the safety related structural components of the intake structure, no management program is necessary.
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3.0 CONCLUSION
O Although some of the intake structure's structural components could be subjected to flowing liquids due to underground water, rainwater, or intake water, the concrete mix was designed for low permeability and high compressive strength which provide the best protection against leaching. Therefore, leaching of calcium hydroxide is not a plausible aging mecharusm for any concrete structural ,
components of the intake structure. This conclusion is supported by an October l 27,1994 walkdown inspection during which only minor traces of leaching were '
detected.
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4.0 RECOMMENDATION leaching of calcium hydroxide is not a plausible aging mechanism for any concrete structural components of the intake structure. No further evaluation or recommendation is required.
5.0 REFERENCES
- 1. " Class I Structures License Renew.d Industry Report, ' EPRI's Project RP-2643-27, December 1991.
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Leaching of Calcium Hydroxide
- 2. " Design acd Control of Concrete Mixtures," Portland Cement Association, Thirteenth Edition.
- 3. " Guide to Durable Concate," American Concrete Institute, ACI-201.2R-67.
- 4. " Specification for Furnishing and Delivery of Concrete Calvert Cliffs Nuclear Power Plant Unit No. I and 2," CCNPP's Design Specification No. 6750-C-9, Revision 8, April 1970. l l
- 5. " Building Code Requirements for Remforced Concrete," American ConcreteInstitute, ACI318-63.
Leonege, est per er 2.5 2.0 fesi.eir-entresnee merwe 1 Spesunene:Ia4-in.dieks l Preenwo: 20pei C 1.5
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i w/C = 0.80 1.0 CA4 l l
0.-
0.50 s
0 to as 1 3 7 Period of easiet euring and ege et toot.seye Figure B-1 l
l Effect of Water. Cement Ratio j and Curing Duration on Permeability I
( Reference 2)
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i APPENDIX C - AGGRESSIVE CHEMICALS bs i
1.0 MECHANISM DESCRIPTION 1 l Concrete, being highly alkaline (pH > 12.5), is vulnerable to degradation by strong acids. ~ Acid attack can increase porosity and permeability of concrete, reduce in, alkaline nature at the surface of the attack, reduce strength, and render the concrete subject to further deterioration. Portland l cement concrete is not acid-resistant, although varying degrees of l
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 l sometimes found in groundwater may attack concrete, often in l 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
[ allow further exposure to aggressive chemicals. Groundwater chemicals can also damage foundation concrete. A dense concrete with low l permeability may provide an acceptable degree of protection against mild l acid attack. Any factors that tend to improve the compressive strength of the concrete will have a beneficial effect on low permeability. Therefore, l
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 thur constructed has a low permeability and effective protection against sulfate and chloride attack. Muumum degradation threshold limits for concrete have been established at 500 ppm chloride or 1,500 ppm sulfates. The use of an appropriate cement type (e.g., ASTM C150, Type
! II) and pozzolan (e.g., fly ash) also increases sulfate resistance.
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Aggressive Chemicals 2.0 EVALUATION 2.1 Conditions l
l There are no aggressive chemicals stored inside the intake structure.
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 atrnasphere. However, the intake structure l walls, roof slab, and fluid retaining slabs and walls are exposed to an l environment containing chloride ions due to the plant's proximity to the l Chesapeake Bay.
l The exterior, below-grade surface of the intake structure is exposed to soil and groundwater. The potential for degradation by aggressive chemicals depends on the quality of concrete, the chemical composition of soil and groundwater, and the level of groundwater in relation to below-grade portions of the structure. The below-grade portion of the intake structure wallis protected by a waterproof membrane.
O 2.2 Potential Aging Mechanism Determination Attack by aggressive chemicals is a potential aging mechanism for the ;
following concrete structural components of the intake structure because l they are exposed to the outside environment:
Foundations Functions LR-S-2 1
. Concrete walls Functions LR-S '1,2,4, and 7
. Ground floor slabs Functions LR-S-1 and 2 Roof slabs Function LR-S-2 l . Fluid retaining slabs Functions LR-S-1,2, and 6 i and walls where:
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- LR-S-1: Provides structural and/or functional support (s) for l j safety-related equipment.
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Aggressive Chemicals LR-S-2: Provides shelter / protection for safety-related equipment.
LR-S-4: Serves as a missile barrier (intemal or extemal).
LR-S-6: Provides flood protection barrier (intemal 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.
Other concrete structural components are located inside the intake structure; therefore, attack by aggressive chemicals is not a potential aging mechanism.
2.3 Impact on Intended Functions lf the effects of attack by aggressive chemicals were not considered in the original design or are allowed to degrade the above structural components unmitigated for an extended period of time, this aging mechanism could affect all the intended functions of the components listed in Section 2.2.
%)
2.4 Design and Construction Censiderations The intake structure 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 below-grade portion of the intake structure walls. These properties provide the best protection against chemical attacks.
2.5 Plausibility Determination The concrete walls and roof slabs were designed and constructed to cope with the saltwater environment at the intake structure. Also, since there is no heavy industry near the CCNPP site wliich could add aggressive chemicals to the atmosphere, attack by aggressive chemicals is not a plausible aging mechanism for these components.
Based on the discussion in Sections 2.1 and 2.4, attack by aggressive l
chemicals is not a plausible aging mechanism for the structural l components located inside the intake structure.
Fluid retaining walls and slabs located below the intake structure's pump room were inaccessible for visual inspection. Since the intake water could l
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Aggressive Chemicals contain chemicals that might attack the concrete, aggressive chemicals is a plausible aging mechanism for the fluid retaining walls and slabs. I Because the chemical content of the groundwater is unknown, attack by aggressive chemicals to the foundation and ground floor slab 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.
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3.0 CONCLUSION
Attack by aggressive chemicals is not plausible for concrete components inside the intake structure, however, the foundation and the underside of the ground floor slab may be exposed to groundwater, Because the quality of the groundwater is not known, degradation due to aggressive p chemicals is plausible. Also, based on this evaluation, aggressive l V chemicals is a plausible aging mechanism for fluid retaining walls and slabs in the intake structure. l l
4.0 RECOMidENDATION During initial plant construction, groundwater observation wells were j installed to monitor the fluctuation of the groundwater table, and samples ,
I were taken for groundwater quality testing.' Although the wells are still in place, the monitoring activities have been discontinued. It is recommended that the groundwater water quality be tested using these wells. This data can be used to evaluate the effects of chemical attacks on the foundation and the underside of the intake structure's ground floor slab.
The concrete surfaces of the fluid retaining walls and slabs in the intake structure should be exammed and evaluated for signs of aggressive chemical attack. Damaged areas should be repaired using an appropriate concrete repair procedure. A periodic inspection program could ba implemented as part of CCNPP technical procedure SW-063 O
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Aggressive Chemicals O
5.0 REFERENCES
- 1. " Class I Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991.
- 2. " Specification for Furnishing and Delivery of Concrete - Calvert Cliffs Nuclear Power Plant Unit No. I and 2," CCNPP's Design Specification No. 6750-C-9, Revision 8, April 1970.
- 3. " Intake Structure Cavities - Sub-Surface Cleaning," Technical Procedure SW-06, Revision 0, May 1992.
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- 4. " 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.
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!O S/7/96 E C-5 Revision 2 1
APPENDIX D - REACTIONS WITH AGGREGATES 1.0 MECHANISM DESCRIPTION 2 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 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.
Three principal deleterious reactions between aggregates and alkalis have been identified as alkali-aggregate, cement-aggregate, and expansive alkali-carbonate reactions.
Alkali-aggregate reaction, more properly designated as alkali-silica l reaction, involves aggregates that contain silica and alkaline solutions. All 1 silica minerals have the potential to react with alkaline solution, but the degree of reaction and ultimate damage incurred can vary significantly.
Alkali-silica reaction can cause expansion and severe cracking of concrete O structures. Reactive materials in the presence of potassium, sodium, and calcium oxides derived from the cement react to form solids, which can expand upem 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.
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.
Aggregates that react with alkalis can cause expansion of varying severity, 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.
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Moisture must be available for chemical reactions between aggregates and alkalis to occur. Consequently, areas that are either consistently wet or
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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 constitrants in concrete aggregates was first published in ASTM C-289, " Potential Reactivity of 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.
1 2.0 EVALUATION '
2.1 Conditions The aggregates used in the concrete of the CCNPP intake structure came from sites in Charles County, Maryland *, which is not in the geographic 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:
Foundations Function LR-S-2
. Concrete columns Functions LR-S-2,4, and 7
. Concrete walls Functions LR-S-1,2,4, and 7 Concrete beams Functions LR-S-2 and 4 Ground floor slab Functions LR-S-1 and 2 l
j and equipment pads Elevated floor slabs Functions LR-S-1 and 2 O
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Reactions with Aggregates U) '
Roof Slabs Function LR-S-2 Fluid retaining slabs Functions LR-S-1,2, and 6 and walls 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 extemal).
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.
A t
V) 2.3 Impact on Intended Functions If the effects of reaction with aggregates were not considered in the original design or are allowed to degrade the above structural components ;
unmitigated for an extended period of time, this aging mechanism could !
affect all the intended functions of components listed in Section 2.2.
2.4 Design and Construction Considerations All aggregates used in construction of the CCNPP intake structure 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 i cement shall be usedfor allwork.
15.2.3.1 The Bidder, at his expense, shall retain an approved independent testing laboratory to sample and
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a Reactions with Aggregates O
test aggregates and the aggregate source in accordance with methods as specified in ASTM Designation C-33.
Acceptability of aggregate and source shall be based on thefollowing ASTM tests:
Method of Test ASTM Designation PotentialReactivity C-289 15.2.3.4 Upon award of the subcontract, the Subcontractor shall submit for petrographic analysis, in accordance with ASTM Designation C-295, a 5-pound sample of quarried material, or sf alluvial, 2-1/2 pounds each of sand and coarse material which has been certtfied 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 tons of aggregates delivered to ;
thejobsite: l Method of Test ASTM Designation PotentialReactivity C-289 Both ASTM C289 and C295 provide guidance for selecting aggregates and cements to avoid alkali-aggregate reactions, and both standards were specified for use in CCNPP's concrete specification. The aggregates used in the intake structure concrete were specifically investigated, tested, and ;
examined in accordance with the ASTM specifications to deterrnine potential for reactivity with alkalis.
2.5 Plausibility Determination Based on the discussion in Section 2.4, the aggregates used in CCNPP's l intalce structure concrete were specifically investigated, tested, and I l examined in accordance with the pertinent ASTM specifications to i mininuze the potential for reactivity with alkalis. For this reason, reactions with aggregates will not degrade any concrete components of the intake
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,O Reactions with Aggregates structure and will have no adverse impact on the intended functions of these concrete structural components. Therefore, reaction with aggregates l l is not a plausible aging mechanism for any concrete structural components l of the CCNPP intake structure. This conclusion is supported by an
]
, October 27, 1994 walkdown inspection mport that documented no l indication of concrete damage due to this mechanism.
2.6 Existing Programs There am no existing programs at CCNPP that are designed specifically to identify or to repair damage incurred by reaction with aggregates. Since l reaction with aggregates is not a plausible aging mechanism that could degrade the intake structure 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 reactive aggregates were implemented for CCNPP in design specification No. 6750-C-9. The aggregates used in the intake structure concrete were :
specifically investigated, tested, and examined in accordance with i applicable ASTM specifications to mininuze any reactivity of aggregates 1 with alkalis. This conclusion is supported by an October 27,1994 )
walkdown inspection during which no trace of reactions with aggregates was detected.
4.0 RECOMMENDATION Reaction with aggregates is not a plausible aging mechanism for any
! concrete component of the CCNPP intake structure and requires no further evaluation or recommendation.
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5.0 REFERENCES
- 1. "Clars I Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991.
j 2. " Potential Reactivity of Aggregates (Chemical Method)," American i Society of Testing and Materials, ASTM C-289-66.
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Reactions with Aggregates 1
- 3. " Petrographic Examination of Aggregates for Concrete," American Society of Testing and Materials, ASTM C-295-65.
- 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.1 and No. 2," Design Specification No.
6750-C-9, Revision 8, April 1970.
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APPENDIX E - CORROSION OF EMBEDDED STEEUREBAR I.0 MECHANISM DESCRIPTION' 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 still insignificant until a pH of 4.0 is reached. A reduction in pH can be caused by the leaching of alkaline products through cracks, the entry of acidic materials, or carbonation. Chlorides can be present in constituent materials of the original concrete mix (i.e., cement, j aggregates , admixtures, and water), or they may be introduced environmentally. The ;
severity of 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 structures. Since galvanizing material is not considered a dissimilar metal, its application will not aggravate corrosion of the structure.
Studies have also been conducted to determine the effects of stray 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 2
age-related ,
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 concrete from a series of hairline cracking, rust staining, spalling, and more severe cracking. These conditions can ultimately impair structural integrity.
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 of the concrete is also a major factor affecting corrosion resistance. Concrete of low permeability contains less water under a given exposure and, hence, is more likely to have lower electrical conductivity and better resistance to corrosion. Such concrete also resins absorption of salts and their penetration into the embedded steel and provides a barrier to
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I Corrosion of Embedded Steel /Rebar O
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.
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 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 There is no significant inventory of aggressive chemicals stored inside the intake structure. Therefore, the intake structure's interior surface and internal structural components are not exposed to the risk of aggressive chemicals which could lead to ;
the deterioration of the concrete surface and corrosion of embedded steel or I d reinforcing steel.
There is no heavy industry near the CCNPP site that could release aggressive 1 chemicals to the atmosphere. However, the intake structure walls and roof slab are exposed to an environment containing chloride ions due to the plant's proximity to i the Chesapeake Bay.
The primary area of concem is the below-grade exterior surface which could be ,
exposed to groundwater on a more or less continuous basis and the fluid retaining walls and slabs which are continuously exposed to saltwater. A waterproof membrane protects the below grade portion of the intake structure's walls, however, the foundation and the underside of the ground floor slabs are exposed to groundwater.
2.2 Potential Aging Mechanism Determination I Corrosion of embedded steel /rebar is a potential aging mechanism for the following structural component of the intake structure because they are exposed to the outside ,
environment and could be subjected to corrosive attack: )
i i Foundation Functions LR-S-2 l
! - Concrete walls Functions LR-S-1,2,4, and 7 5/7/9C a E-2 Revision 2
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l Corrosion of Embedded Steel /Rebar
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Ground ficor slab Functions LR-S-1 and 2 Roofsir.bs Functions LR-S-2 l
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Fluid retaining Functions LR-S-1,2, and 6 walls and slabs where:
LR-S-1: Provides structural and/or functional support (s) for safety-related l equipment.
LR-S-2: Provides shelter / protection for safety-related equipment.
LR-S-4: Serves as a missile barrier (intemal or external).
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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 or from adjacent areas of the plant.
1 O Other concrete structural components are located inside the intake structure; therefore, corrosion of embedded steel /rebar is not a potential aging mechanism.
2.3 Impact on Intended Functions If the effects of corrosion of embedded steel /rebar were not considered in the original design or are allowed to degrade the above structural components unmitigated for an extended period of time, this aging mechanism could affect all the l
intended functions of the components listed in Section 2.2.
! 2.4 Design and Construction Considerations The intake structure was constructed with concrete that complies with CCNPP's design specification No. 6750-C-9', which adheres to the relevant ACI Codes and ASTM specifications for a concrete structure of low permeability. Also proper concrete covers were 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 below
- grade portion of the intake structure's walls.
2.5 Plausibility Determination The concrete walls and roof slabs were designed and constructed to cope with the saltwater environment at the intake structure. Also, since there is no heavy industry 5/7/96 E E-3 Revision 2 i
i
Corrosion of Embedded Steel /Rebar near the CCNPP site which could add aggressive chemicals to the atmosphere, corrosion of embedded steel /rebar is not a plausible aging mechanism for these components.
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 intake structure.
As discussed in Section 2.1, the below-grade portion of the foundations and the ground 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 groundwater is not known, corrosion of embedded steel /rebar is a plausible aging mechanism for the foundation and the ground floor slab.
Fluid retaining walls and slabs located below the intake structure's pump room were inaccessible for visual inspection. Since the intake water could contain chemiests that might attack the concrete and since the chloride content of the saltwater is highly corrosive to embedded steel or rebar, corrosion of embedded steel /rebar is a plausible aging mechanism for the fluid retaining walls end slabs.
2.6 Existing Programs There are no existing programs at CCNPP that are designed specifically to identify or to repair damage caused by corrosion of embedded steel /rebar.
3.0 CONCLUSION
l Based on the discussion in Sections 2.1 and 2.4, corrosion of embedded steel /rebar is not a plausible aging mechanism for concrete components inside the intake structure.
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 foundation and the ground floor slab.
Based on this evaluation, corrosion of embedded steel /rebar is a plausible aging mechanism for fluid retaining walls and slabs in the intake structure.
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.' Although the wells are still in place, the monitoring b
v activities have been discontinued. It is recommended that the groundwater water 5/7/96 a E-4 Revision 2
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! Corrosion of Embedded Steel /Rebar quality be tested using these wells. This data can be used to evaluate the effects of I
chemical attacks on the foundation and the underside of the intake structure's ground floor slab.
The concrete surfaces of the fluid retaining walls and slabs in the intake structure should be examined and evaluated for signs of cracking, spalling, or rust staining prior to application for license renewal. Damaged areas should be repaired using an appropriate concrete repair procedure. A periodic inspection program could be implemented as past of CCNPP technical procedure SW-065 .
5.0 REFERENCES
- 1. " Class 1 Structures License Renewal Industry Report," EPRI's Projec: RP-2643-27, December 1991.
- 2. Skoulikidas, T., Tsakopoulos, A., and Moropoulos, T., " Accelerated Rebar Corrosion When Connected to Lightning 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 Furnishing and Delivery of Concrete - Calvert Cliffs Nuclear Power Plant Unit No. I 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. " Intake Structure Cavities - Sub-Surface Cleaning," Technical Procadure SW-06, Revision 0, May 1992.
- 6. " Specification for Furnishing and Installation of Piezometers - Calvert Cliffs Nuclear Power Plant Unit No. I and 2," CCNPP's Design Specification No. 6750-C-23E, Revision. O, November 1973.
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C APPENDIX F - CREEP j
l 1.0 MECHANISM DESCRIPTION 1 Creep is defmed 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 loadi.ig 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
'A V Creep is not visible because micro-cracking 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 charactenzed as follows:
Increased water-to-cement ratio results in increased creep magnitude.
Increased aggregate-txement ratio results in increased creep i magnitude for a given volume of concrete.
l Creep deformation is approximately proportional to the applied load for a level not exceeding about 40% to 60% of the ultimate strength of concrete.
Concrete age at application of load affects creep (i.e., the older the concrete, the less the creep).
l Creep increases with increased temperature. l 4
Aggregate with a high modulus of elasticity and low porosity will mmmuze creep.
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!O Creep Creep-induced concrete cracks are typically not large enough to result in concrete deterioration or in exposure of the minforcing 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 96% within 30 years. At any given stress, 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 will have occurred well before the time of a license renewal application.
Therefore, creep of concrete structural components should not be regarded
\. as an aging mechanism for license renewal.
2.1 Potential Aging Mechanism Determination Creep is not a potential aging mechanism for any intake structure 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 Since creep is not a potential aging mechanism, it will not affect the intended functions of any intake structure structural component.
2.4 Design and Construction Considerations
- At CCNPP, all intake structure minforced 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 intake structure concrete structural
, components. Therefore, creep in all concrete components is minimal l because of the low compressive stresses in concrete and the use of high-
! strength conentie. Desides, creep proceeds at a decreasing rate with age; 5/7/96 m F.2 Revision 2
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u Creep i
i normally, % % of creep has occurred within 30 years.2 Therefore, creep is )
not expected to continue during the license renewal period. j i
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2.5 Plausibility Determination i Not applicable.
l 2.6 Existing Programs Not applicable.
3.0 CONCLUSION
Most of the concrete creep occurred well before the time of license renewal j application. Therefore, creep of concrete structural components should l not be regarded as an aging mechanism for license renewal.
l N 4.0 RECOMMENDATION (d
Not applicable.
5.0 REFERENCES
l l 1. " Class I Structures License Renewal Industry Report," EPRI's l Project RP-2643-27, December 1991. ,
- 2. " Prediction of Creep, Shrinkage, and Temperature Fffects in Concrete Structures," American Concrete Institute, ACI 209R-82.
- 3. " Specification for Furnishing and Delivery of Concrete - Calvert l Cliffs Nuclear Power Plant Unit No. I and 2," CCNPP's Design Specification No. 6750-C-9, Revision 8, April 1970.
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i g APPENDIX G - SHRINKAGE !
U 1.0 MECHANISM DESCRIPTION 1 A workable concrete mix typically contains more water than is needed to offset the effects of hydration. When concrete is exposed to air, large l 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 ,
strength of the concrete, a crack forrre. Initial shrinkage occurs during l curing and continues months after placement. Subsequent drying and I 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.
Excessive shrinkage causes cracking of the concrete surfaces, which provides a means for aggressive elements to make contact with the embedded steel /rebar, thus promoting the possibility of corrosion. The aging mechanism due to corrosion of embedded steel /rebar is discussed in Appendix E.
2.0 EVALUATION 2.1 Conditions There is no condition in CCNPP that could aggravate the effect of concrete 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 for license renewal.
2.2 Potential Aging Mechanism Determination Shrinkage is not a potential aging mechanism for any intake structure 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 Since shrinkage is not a potential aging mechanism, it will not affect the intended functions of any intake structure structural component.
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Shrinkage 2.4 Design and Construction Considerations Since shrinkage can be mininuzed by keeping the water content of the paste as low as possible, the use of low slump concrete is a major factor in controlling shrinkage.S 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 intake structure.
The development of concrete cracking due to shrinkage can also be mininuzed by providing adequate reinforcing steel. For this purpose, CCNPP has adopted the minimum reinforcing steel requirements specifiedin ACI318-635 Since low slump concrete is used at Calvert Cliffs to mininuze concrete cracks from shrinkage and minimum reinforcing steel requirements are used to mitigate crack propagation, shrinkage of any concrete component of the intake structure is minimal.
2.5 Plausibility Determination Not applicable.
2.6 Existing Programs Not applicable.
^
3.0 CONCLUSION
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 Not applicable.
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4 l
l Shrinkage
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 Cement Association.
- 4. " 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.
- 5. " Building Code Requirements for Reinforced Concrete," American Concrete Institute, ACI 318-63.
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l APPENDIX H - ABRASION AND CAVITATION 1.0 MECHANISM DESCRIPTION 2 As water moves over concrete surfaces, it can carry abrasive materials or it can create a negative pressure (vacuum) that can cause abrasion and 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 i 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, I degradation due to cavitation can occur at velocity as low as 25 fps when ;
abrupt changes in slope or curvature exist. l l
2.0 EVALUATION .
2.1 Conditions i O The concrete surfaces of fluid retaining walls and slabs inside the intake structure are exposed to flowing water. The walls and slabs serve to l channel water from the Chesapeake Bay to the circulating water pumps j and the salt water pumps. The intake water flows through a trash rake ]
and a system of traveling screens before entering the area below the intake i structure pump room.
2.2 Potential Aging Mechanism Determination .
Attack by abrasion and cavitation is a potential aging mechanism for fluid retaining walls and slabs inside the intake structure because they are exposed to rapidly flowing water in an area not readdy accessible for visualinspection.
. Fluid retaining slabs Functions LR-S-1,2, and 6 and walls where:
l LR-S-1: Provides structural and/or functional support (s) for safety-related equipment.
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Abrasion and Cavitation
. LR-S-2: Provides shelter / protection for safety-related )
equipment.
l LR-S-6: Provides flood protection barrier (internal flooding ;
event). l 2.3 Impact on Intended Functions l If the effects of abrasion and cavitation were not considered in the original design or are allowed to degrade the above structural components unmitigated for an extended period of time, this aging mechanism could affect all the intended functions of the components listed in Section 2.2.
2.4 Design and Construction Considerations The intake structure was constructed with concrete that complies with I CCNPP's design specification No. 6750-C.92, which adheres to the relevant ACI codes and ASTM specifications for a concrete structure of low permeability. Adherence to these codes and specifications provides the ;
best protection against abrasion and cavitation.
Also, a series of trash rakes and traveling screens removes much of the floating debris which could cause structural damage to the fluid retaining ,
walls and slabs.
2.5 Plausibility Determination :
1 The condition of the fluid retaining walls and slabs in the intake structure ,
could not be determined during the walkdown of the structure. These areas were inaccessible for visual inspection, however, the intake structure was designed for a 0.5 fps bay water approach velocity at the intake baffle wall for fish impbgcmmt considerations. Additionally, the velocities in the discharge camduits have been estimated to only approach 8.9 fps (based on information contained in BCE's Supplement to the Environmental Report dated November 8,1971). Based on this information, it does not seem practical that the velocity of the bay water in the intake wells (suction of Saltwater and Cin ulating Water pumps) will exceed 40 fps. This has been verified by plant documentation and design information by calculating the flow velocity at the intake of a single circulating water pump. This velocity was calculated to be approximately 12 fps. Since this velocity is much less than 40 fps, abrasion and cavitation is not a plausible aging mechanism for the fluid retaining walls and slabs of the intake structure. l 5/7/96 E H-2 Revision 2 J
c Abrasion and Cavhation 2.6 Existing Programs There are no existing programs at CCNPP that are designed specifically to identify or to repair damage of the cor.cate structure due to abrasion and cavitation. Since abrasion and cavitathn is not a plausible aging mechanism that could degrade structural components of the intake structure, no management program is necessary.
3.0 CONCLUSION
The concrete components of the intake structure are constructed of high quality, low permeability concrete. The maximum flow velocity of intake water through the fluid retaining walls and slabs is well below 40 fps.
Floating debris is removed from the intake water by a series of trash rakes and traveling screens. Based on this evaluation, abrasion and cavitation is not a plausible aging mechanism for fluid retaining walls and slabs in the intake structure.
4.0 RECOMMENDATION Abrasion and cavitation is not a plausible aging mechanism for any structural components of the intake structure. 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. " 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.
- 3. Technical Procedurc SW-06, ' Intake Structure Cavities Sub-Surface Cleaning," Revision 1.
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1 O
V APPENDIX l - CRACKING OF MASONRY BLOCK WALLS 1.0 MECHANISM DESCRIPTIONI 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 reinforced concrete walls. The potential for embedded steel and reinforced steel corrosion in block walls is similar to that of reinforced concete.
Masonry block walls are vulnerable to unique age-related degradation I 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 materials and thus rarely causes degradation of the concrete block wall. Moreover, expansion of the wall is offset by shrinkage from carbonation and drying. Restraint against O' free contraction causes tensJe stresses within the wall. If these stresses exceed the tensile strength of the unit, the bond strength between the mortar and the unit, or the shearing strength of the horizontal mortar joint, 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).
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 cunng, 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 moisbre content of the masonry units during construction and the building in e 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.
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_. - . .-. . = ~ . _ _ _ _ - _ _ . _ _ . - .. -
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l p Cracking of Masonry Block Walls l O
Durability of the masonry mortar used at the block joints may affect the long-term structural integrity of the masonry block wall. Although aggressive environments and the use of unsound materials may contribute to the deterioration of mortar joints, most degradation results from water entering the concrete masonry and freezing.
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.
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2.0 EVALUATION l 2.1 Potential Aging Mechanism Determination ,
l There is no masonry block wall in the safety related portion of the intake structure. Therefore, this aging mechanism does not apply to the intake ,
structure.
]
I 2.2 Conditions Not applicable.
2.3 Design Considerations Not applicable.
I 2.4 Impact on Intended Functions ,
Not applicable.
2.5 Plausibility Determination l Not applicable.
l l 2.6 Existing Programs Not applicable.
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Cracking of Masonry Block Walls
3.0 CONCLUSION
Cracking of masonry block walls is not a plausible degradation l mechanism for CCNPP's intake structure.
l l
j 4.0 RECOMMENDATION Not applicable.
1 i
5.0 REFERENCES
l 1. " Class 1 Structures License Renewal Industry Report,"
] EPRI's Project RP-2643-27, December 1991.
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q APPENDlX J __ SETTLEMENT 1.0 MECHANISM DESCRIPTION 1 ,
All structures settle during construction and for months after construction.
The amount of settlement depends on the physical properties of foundation material. These properties range from rock (with little or no settlement likely) to compacted soil (with some settlement expected).
Settlement may occur during' the design life from changes in environmental conditions, such as lowering of the groundwater table.
Settlement can occur in two stages: elastic expansion and time-dependent ,
settlement. Elastic expansion of the confmed soil occurs due to excavation l unloading and results in a slightly upward movement. During )
construction, the soil moves downward as load is applied. This elastic movement should be small and is complete when construction is completed. It haa no effect on the structure and is not ransidered an aging ;
mechanism 2 The excavation unloading and structural loading cause a '
small change in the void ratio of the soil. This change results in a very small amount of time-dependent settlement. The set +1ement rate will decline after completion of construction.
Settlement of structums is usually small and is typically deternuned by survey. Concrete and steel structural members can be affected by differential settlement between supporting foundations, within a building, or between buildings. Severe settlement can cause misalignment of equipment and lead to overstress conditions within the structure 3 When buildings experience significant settlement, cracks in structural members, differential elevations of supporting members bridging between buildings, or both may be visibly detected.
2.0 EVALUATION 2.1 Conditions 2 The basemat elevation of the intake structure at CCNPP is approximately 110 feet below the original ground elevation. The basemat is situated on Miocene soil, which is exceptionally dense and will support heavy ,
foundation loads. The major soil types are sandy silts, silty sands, and i slightly clayed sands. The ultimate bearing capacity of the foundation strata is in excess of 80,000 psf, and the allowable bearing upacity is 15,000 psf. The design contact pressure of the intake structure foundation '
is only 2,500 psf. This contact pressure is only 23 percent of the overburden pressure removed due to excavation.
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I Settlement 2.2 Potential Aging Mechanism Determination Settlement is a potential aging mechanism for all structural components in the intake structure. Since the foundation and the ground floor slab are ;
the only structur.il component directly supported by the soil media, and l also for convenience of discussion, only the foundation and the ground j floor slab are identified as the structural components subject to the aging ,
mechanism due to settlement. l I
Foundation Functions LR-S-2 Ground floor slab and Functions LR-S-1 and 2 l equipment pads where:
LR-S-1: grovides structural and/or functional support (s) for safety-related equipment.
O ta-s-2: ereviaes sheitereerotect1 n rer saretv-reiatea eeuiement.
2.3 Impact on Intended Functions If the effects of settlement 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 intended functions LR-S-1 and 2 of the foundation and the ground floor slab.
2.4 Design and Construction Considerations I
In addition to soil bearing capacity, settlement was also investigated in the ;
design of the intake structure. A maximum post-construction settlement l of 1/2 inch was predicted in the original intake structure design 2 Since 1 the intake structure foundation is situated on an exceptionally dense soil, the structure tends to uniformly settle as a rigid body. Most of the predicted 1/2 inch settlement is in terms of uniform settlement, which has no adverse effect on the structural components of the intake structure. A small fraction of the 1/2 inch settlement will be in terms of differential settlement. It is so small that the effect on the structural component is negligible.
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Settlement p) 2.5 Plausibility Determination Based on the discussion in Sections 2.1 and 2.4, the soil type at the CCNPP intake structure is exceptionally dense, and the design contact pressure is lower than the removed overburden and is also lower than the allowable bearing capacity. As discussed in Section 2.4, the predicted settlement is small and the differential settlement is negligible. Therefore, settlement is not a plausible aging mechanism for any structural components of the intake structure. This conclusion is supported by an October 27, 1994 walkdown inspection report that documented no indication of structural damage due to settlement.
2.6 Existing Programs There are no existing programs at CCNPP that are designed specifically to identify or to repair damage to concrete incurred by settlement. Since this is not a plausible aging mechanism that could degrade the intake structure's structural components, no management program is necessary.
3.0 CONCLUSION
CCNPP's intake structure is situated on Miocene soil, which is exceptionally dense and will support heavy foundaSon loads.
Additionally, the structural load on the intake structure foundation is lower than the removed overburden weight. Therefore, the soil bearing stress is well below its ultimate bearing capacity, and the long-term settlement is predicted to be only 1/2 inch.2 In addition, the settlement rate declined after completion of construction. Long-term settlement is not expected to continue after 40 years. Therefore, settlement is not a plausible aging mechanism for the structural components of the intake structure. This conclusion is supported by an October 27,1994 walkdown inspection during which no trace of structural damage due to settlement was detected.
4.0 RECOMMENDATION Settlement is not a plausible aging mechanism for the foundation or the ground floor slabs of the intake structure and requires no further evaluation or recommendation.
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f Settlement
5.0 REFERENCES
- 1. " Class I Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991.
- 2. "Calvert Cliffs Nuclear Power Plant, Units 1 and 2, Updated Final Safety Analysis Report (UFSAR)," Baltimore Gas and Electric Co.
- 3. " Pilot Studies on Management of Aging of Nuclear Power Plant Components," International Atomic Energy Agency, IAEA-TECDOC-670, October 1992.
- 4. Civil and Structural Design Criteria for Calvert Cliffs Nuclear Power Plant, Units 1 and 2, by Bechtel Power Corporation, Revision 0, August 2,1991.
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l g APPENDIX K - CORROSION OF STEEL u
( 1.0 MECHANISM DESCRIPTION' 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 form an oxide fihn as rust. Once the protective oxide film has been formed and ifit l
is not disturbed by erosion, alternating wetting r.nd drying, or other surface actions, the oxidation rate will diminish rapidly with time. Chlorides, either from seawater, l 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 l
l in the galvame series, corrosion may accelerate.
l In some cases, corrosion of structural steel in contact with water may be microbiologically induced due to the presence of certain organisms, which is .
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 I 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 j measures taken to prevent corrosion. A steel structure surface subjected to 4 alternately wet and dry conditions corrades 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.
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Corrosion of Steel 2.0 EVALUATION 2.1 Conditions Steel can corrode in the presence of rpoisture and oxygen as a result of electrochemical reactions, especially in areas where there is an inadequate drainage system. In the intake structure, structural steel con.ponents 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 intake stmeture steel components because conditions conducive to steel corrosion discussed in Sections 1.0 and 2.1 exist:
Steel beams Functions LR-S-1 and 2 Baseplates Functions LR-S-1 and 5 Floor framing _ Functions LR-S-1 and 5 Roofframing Function LR-S-2 Steel bracing Functions LR-S-2 and 5 Platform hangers Function LR-S-5 Steel '-xking Function LR-S-2 Floor grat.7 Function LR-S-5 Checkered plate Function LR-S-2 Stairs and ladders Function LR-S-5 Sluice gates Function LR-S-1 Cast-in-place anchors Functions LR-S-1,2,6, and 7 Post-installed anchors Functions LR-2 and 5 l
Functions LR-S-2 and 7 !
Fire doors, jambs,
. and hardware 5/7/96 m K-2 Revision 2
(
Corrosion of Steel (O
v Access doors, jambs, Function LR-S-2 and hardware Watertight doors Function LR-S-6 and hardware 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-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.
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.
2.3 Impact on Intended Functions ,
If corrosion of steel is al. lowed 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 intake structure, its effects were considered in the original design. As a result, all exposed structural steel surfaces in the intake structure except grating, checkered plate, and metal decking, which are galvanized steel, were shop-painted or field-painted during the construction phase in accordance with 2 3 CCNPP's design specifications No. 6750-C-19 and No. 6750-A-24 .
Maintenance of protective coatings on CCNPP's equipment and structures follows 4
the requirements specified in Calvert Cliffs Administrative 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.
O The post-installed anchors used for the platforms in the intake structure are Hilti Kwik Bolt concrete anchors made of cold-rolled, high strength steel. A walkdown' 5/7/96 m K-3 Revision 2
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l Corrosion of Steel O
V identified that these anchors were painted after installation with a rust-resistant zinc coating.
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l 2.5 Plausibility Determination ,
l Based on the discussion in Sections 2.1,23 and 2.4, corrosion could affect the ,
intended functions of all structural steel members and is, therefore, a plausible aging i mechanism for all steel components listed in Section 2.2.
2.6 Existing Programs 6
l System engineer walkdowns under PEG-7 will provide the discovery mechanism for degraded coating conditions. Conditions adverse to quality (such as degraded 7
paint or corrosion) is reported in an Issue Report under QL-2-100. The coatings 4
program under MN-3-100 provides the administrative control over how corrective l actions are performed. The combination of these existing plant programs will ensure l that corrosion effects on accessible structural steel is adequately managed. These l programs do not provide for the evaluation of the coating condition on structural steel components that are not normally accessible. An age related degradation j inspection program as defined in the BGE Integrated Plant Assessment l Methodology is necessary to address the aging, effects of the non-accessible structural steel components -
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3.0 CONCLUSION
All structural steel components of CCNPP's intake stmeture are vulnerable to corrosion attack if a corrosive environment prevails. All exposed structural steel
! surfaces in the intake structure 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 intake Structure is accomplished through the combination of existing plant l
programs. However, structural steel components not readily accessible require
! additional aging management ;
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Corrosion of Steel f3 V
4.0 RECOMMENDATION Coatings on structural steel in accessible areas 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 am not normally accessible 5.0 REFEREhCES
- 1. " Class I Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991.
- 2. " Specification for Furnishing, Detailing, Fabricating, Delivering, and Erecting Structural Steel," CCNPP's Design Specification No. 6750-C-19, Revision 3, September 1970.
- 3. " Specification for Painting and Special Coatings," CCNPP's Design Specification No. 6750-A-24, Revision 12, October 1982.
/7 4. " Painting and Protective Coatings," Calvert Cliffs Nuclear Power Plant V Administrative Procedure MN-3-100, Revision 2, Date 4/2/96
- 5. " Examination of Intake Structure - Calvert Cliffs Nuclear Power Plant",
October 27,1994.
- 6. " Plant Engineering Section System Walkdowns", Plant Engineering Section Guideline PEG-7, Baltimore Gas and Electric Company, Revision 4,11/30/95.
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- 7. " Issue Reporting and Assessment", Calvert Cliffs Nuclear Power Plant Administrative Procedure QL-2-100, Revision 4. Date 1/2/96 O
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e APPENDIX L- CORROSION OF LINER l
1.0 MECHANISM DESCRII'TIONL2 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 I 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 1 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 liner could result in separation of the protective coatings from the steel surface, and coating degradation becomes apparent.
1.2 Stainless Steel Liner A 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 (extemal) 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 l residual stress from welding, or is subjected to significant applied loads.
l Different corrosive environments induce different levels of SCC on various materials. With respect to material susceptibility, austenitic stainless l
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Corrosion of Liner 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. l 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 steel are potential sites for IGSCC. IGSCC occurs when changes in the microstructure take place due to the welding heat, rendering the heat-affected zones " 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 l 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.
O 2.o evituirion 2.1 Potential Aging Mechanism Determination There are no steel liners in the intake structure. Therefore, this aging mechanism does not apply to the intake structure.
2.2 Conditions Not applicable.
2.3 Impact on Intended Functions Not applicable.
2.4 Design and Construction Considerations Not applicable.
2.5 Plausibility Determination Not applicable.
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Corrosion of Liner l
l 2.6 Existing Programs Not applicable.
3.0 CONCLUSION
Corrosion of steel liners is not a plausible aging mechanism for CCNP's l
intake structure.
4.0 RECOMMENDATION I
Not applicable.
I
5.0 REFERENCES
l
- 1. "Pressunzed Water Reactor Containment Structures License
[ Renewal Industry Report," NUMARC Report 90-01, l Revision 1, September 1991.
l 2. ' Class 1 Structures License Renewal Industry Report,"
EPRI's Project RP-2643-27, December 1991.
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i q APPENDIX M - CORROSION OF TENDONS V
l 1.0 MECHANISM DESCRIPTION 2 When corrosion of prestressing tendons occurs, it is generally in the form
- of localized corrosion. Most corrosion-related failures of prestressing l tendons have been attributed to pitting, stress corrosion, hydrogen l 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.
I The preser.:e 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.
O "vdrese e-dr111>eme=* <teca icalir. =e* a rer- er corresie-) e<< rs when hydrogen atoms, produced by corrosion or excessive cathodic 1
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 j hydrogen is produced. The interaction between the dissolved hydrogen i atoms and the metal atoms results in a loss of ductility manifested as l 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 I 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 intake structure. Therefore, this aging mechanism does not apply to the intake structure.
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Corrosion of Tendons t
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2.2 Conditions Not applicable.
2.3 Impact on Intended Functions l
l Not applicable. .
2.4 Design and Construction Considerations
- Not applicable. l l
2.5 Plausibility Determination ;
l Not applicable. l l 2.6 Existing Programs i
Not applicable.
i O
3.0 CONCLUSION
1 i
I l Corrosion of tendons is not a plausible aging mechanism for CCNP's l
intake structure.
l
, i l 4.0 RECOMMENDATION i l
Not applicable.
5.0 REFERENCES
I 1. " Pressurized Water Reactor Containment Structures License i Renewal Industry Report," NUMARC Report 90-1, Revision 1, September 1991.
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APPENDIX N - PRESTRESS LOSSES O I I 1.0 MECHANISM DESCRIPTION 1 As the plant ages, tendons that were prestressed during construction tend to lose tension. Termed prestress losses, these reductions in stress are not readily observable. Several factors contribute to prestress losses:
Stress relaxation of prestressing wires Shrinkage, creep, and elastic deformation of concrete Anchorage seating losses Tendon friction 1 Reduction in wire cross section due to corrosion i
1 2.0 EVALUATION 2.1 Potential Aging Mechanism Determination There are no prestressed tendons in the intake structure. Therefore, this aging mechanism does not apply to the intake structure.
2.2 Conditions Not applicable.
2.3 Impact on Intended Functions Not applicable.
2.4 Design and Construction Considerations Not applicable.
2.5 Plausibility Determination Not applicable.
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Prestress Losses 2.6 Existing Programs Not applicable. !
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3.0 CONCLUSION
l Prestress loss in tendons is not a plausible aging mechanism for CCNP's intake structure.
I 4.0 RECOMMENDATION Not applicable.
1 i
5.0 REFERENCES
l
- 1. " Pressurized Water Reactor Containment Structures License Renewal Industry Report," NUMARC Report 90-1, Revision 1, September 1991.
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APPENDlX O -WEATHERING 1.0 MECHANISM DESCRIPTION 2 Components and structures that are located in an environment that is exposed to ambient conditions are susceptible to degradation due to weathering (indoor or 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 in hardness, and shrinkage.
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 i humidity expected at the CCNPP site. Additionally, inside the Intake l Structure, components will experience similar temperature and humidity changes, throughout the life of the plant.
2.2 Potential Aging Mechanism Determination I
Weathering is a potential aging mechanism for the following architectural components of the intake Structure because they are exposed to the .
outside environment or similar in-building conditions:
. Caulking and sealants Functions LR-S-2,6, and 7 where:
LR-S-2: Provides shelter / protection for safety-related equipment.
LR-S-6: Provides a flood protection barrier (internal flooding l
event).
i LR-S-7: Provides rated fire barriers to confine or retard a fire from spreading to or from adjacent areas of the plant.
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i Weathering l
2.3 Impact on Intended Functions 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 mechanism could affect all the intended functions of the components listed in Section 2.2.
2.4 Design and Construction Considerations The caulking and sealants are components which are typically replaced on condition. However, inspections have indicated that that a program of inspection and maintenance is required to be developed. Issue Report IR1995-01698 8 was written to address this issue. .
i 2.5 Plausibility Determination Based on the discussion in Sections 2.3 and 2.4, weathering has been determined to be plausible for caulkmg and sealants in the CCNPP Intake Structure.
(
\ 2.6 Existing Programs The caulking and sealants and expansion joints which perform a fire barrier function are addressed under the Appendix R Program as implemented by procedure STP-F-592-1/2 4 for penetration fire barrier inspection. This procedure was determined to be adequate for managing the effects of weathering for the caulking and sealants and expansion joints.- ,
3.0 CONCLUSION
Weathering is a plausible aging mechanism for the caulking and sealants in the intake Structure. Management of the aging mechanism for caulking and sealants which periorm functions other than fire barrier will be established in conjunction with the resolution to Issue Report IR1995-01698. The Appendix R Program addresses the aging management for caulking and sealants which perform a fire barrier function.
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l q Weathering O
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l 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 IR199541698 to manage the effects of weathering for the caulking and sealants not included under the Appendix R Program.
5.0 REFERENCES
- 1. " Class I 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 C33-82.
- 3. BGE Issue Report IR1995-01698, Building Joints (Aux. Bldg.
Exterior), dated 07/13/95.
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APPENDIX R - ELEVATED TEMPERATURE 1.0 MECHANISM DESCRIPTION 1 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 structure 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. Otherwise, there is no visible physical manifestation of concrete degradation due to exposure to elevated temperature.
ASME Code 2,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-3493 allows local area temperatures to O reach 200 *F before special provisions are required.
2.0 EVALUATION 2.1 Conditions Table B-3 of Baltimore Gas and Electric Company's EQ Manual 4 lists the maximum anticipated temperature during normal and accident conditions .
in the intake Structure Pump Room to be 141 *F.
2.2 Potential Aging Mechanism Determination Elevated temperature is not a potential aging mechanism for concrete structural components of the intake structure 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.
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i l l Elevated Temperature 2.3 Impact on Intended Functions Since elevated temperature is not a potential aging mechanism, it will not I affect the intended functions of any safety related component located l inside the intake structure.
2.4 Design and Construction Considerations Since elevated temperature has no impact on the intended functions of components located inside the intake structure, no further discussion of CCNP's design and constructien considerations is necessary.
2.5 Plausibility Determination Based on the discussion in Sections 2.1, no structural components are exposed % 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 intake structure.
2.6 Existing Programs Since elevated temperature is not a plausible aging mechanism, a program to control this aging mechanism is not needed to maintain the intended functions of the intake structure.
3.0 CONCLUSION
Based on this evaluation, elevated temperature is not a plausible aging mechanism because none of the intended functions of the intake structure are affected by this aging mechanism.
4.0 RECOMMENDATION Elevated temperature is not a plausible aging mechanism for any structural components of the intake structure. Therefore, no further evaluation or recommendation is necessary, 1
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Elevated Temperature
5.0 REFERENCES
i
- 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 111, Division 2,1986. :
I l
- 3. " Code Requirements for Nuclear Safety Related Concrete l Structures," American Concrete Institute, ACI 349-85. !
- 4. "EQ Design Manual - Calvert Cliffs Nuclear Power Plant, Unit l No.1 and 2," Baltimore Gas and Electric Co.
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APPENDIX S -IRRADIATION l
1 l
1.0 MECHANISM DESCRIPTIONL2 l
1.1 Concrete j Concrete components in a nuclear power plant exposed to excessive neutron or gamma radiation (incident flux > 1010 MeV/cm2-sec)3 could be i 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 i i
characteristics of fast neutrons. Typically, gamma radiation affects the cement paste portion of the concrete, producing heat and causing water migration.
A)
( Existing expe-imental data provide some general information on the impact of direct radiation on the mechanical properties of concrete 4 The average concrete sample does not begin to experience a compressive or tensile strength loss until exposure exceeds a neutron fluence of 101' neutrons /cm2 The experimental data' indicate minimal compressive loss for exposure up to 5x101' neutrons /cm2 1.2 Reinforcing Steel Steel degradation due to neutron irradiation is caused by the displacement of atoms from their normal lattice positions to form both interstices and vocsncies. 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 I encountered in the design and operation of reactor pressure vessels. By i comparing the currently available stress-strain curves for ururradiated and irradiated mild steel, a reduction in ductility of rebar subjected to high radiation exposure (> 1018 neutrons /cm2) is indicated 5 O
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1.3 Structural Steel The effects 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 l strength and a decrease in ductility after it is subjected to fluence in excess of 101: neutrons /cm2 2.0 EVALUATION 2.1 Conditions Table B-3 of Baltimore Gas and Electric Company's EQ Manual 7 lists the total integrated dose (rads) in the intake structure pump room as negligible.
2.2 Potential Aging Mechanism Determination i
Irradiation is not a potential aging mechanism for structural components j O er *8e 1 1 se str ci re seca se er tse estis18ie ieveis er raaiatie Prese
- in the environment. Therefore, irradiation is not a potential aging 1
mechanism for these components.
2.3 Impact on Intended Functions Since irradiation is not a potential aging mechanism, it will not affect the intended functions of any safety related component located inside the intake structure. -
2.4 Design and Construction Consideration Since irradiation has no impact on the intended functions of components located inside the intake structure, no further discussion of CCNPP's design and construction considerations is necessary.
2.5 Plausibility Determination Based on the discussion in Section 2.1, no structural component is exposed l to radiation higher than the degradation threshold set forth in Sections 1.1, 1
1.2, and 1.3 for concrete and steel. Therefore, irradiation is not a plausible aging mechanism for any structural component of the CCNPP intake structure.
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trradiation 2.6 Existing Programs There are no existing programs at CCNPP designed to identify damages to structural components of the intake structure due to radiation. However, since this is not a plausible aging mechanism that could degrade these components, no future program is necessary.
3.0 CONCLUSION
Based on this evaluation, irradiation is not a plausible aging mechanism because none of the intended functions of the intake structure are affected by this aging mechanism.
4.0 RECOMMENDATIONS Irradiation is not a plausible aging mechanism for the structural h, components in the intake structure.
recommendation is required.
No further evaluation or
5.0 REFERENCES
- 1. " Class I Structures License Renewal Industry Report," ,
EPRI's Project RP-2643-27, December 1991. l
- 2. "Pressunzed Water Reactor Containment Structures License i RenewalIndustry Report," NUMARC Report 90-1, Revision l 1, September,1991.
- 3. " Guidelines on the Nuclear Analysis and Design of Concrete 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 5/7/96 E S-3 Revision 2
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- 5. Naus, D.J., " Concrete Component Aging and its Significance Relative to Life Extension of Nuclear Power Plants,"
NUREG/CR-4652, ORNL/TM-10059, Oak Ridge National Laboratory, Oak Ridge, Tenn., September 1986 l
- 6. " Code Requirements for Nuclear Safety Related Concrete ;
Structures," ACI 349-85, American Concrete Institute, l Detroit, Michigan l 1
- 7. "EQ Design Manual - Calvert Cliffs Nuclear Power Plant, Unit No.1 and 2," Baltimore Gas and Electric Co.
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l o APPENDlX T- FATIGUE O
1.0 MECHANISM DESCRIPTION 1 Fatigue is a common degradation of structural members produced by periodic or !
cyclic loadings that are less than the maximum allowable static loading. Fatigue results in progressive, locahzed damages to structural materials.
Two types of fatigue exist for structural components. The first mechanism, sometimes referred to as low-cyde fatigue, is low frequency (<100 cydes 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-cyde fatigue is not age-related and is not a license renewalissue.
The other fatigue mecharusm is high frequency of low-level, repeated loads such as equipment vibration. Referred to as high<yde fatigue, it is an aging.
l 1.1 Concrete The fatigue strength of concrete structures has become a concern due to the widespread adoption of ultimate strength design procedures and the use of high-O O
strength materials that require concrete structural members to perform satisfactorily under high-stress levels. Repeated loading causes cracking in component materials of a member and alters its static load-carrying 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 cyde 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 cydes (N) the material has a defmed 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. This indicates that there is no limiting value ofstress below which the fatiguelife willbeinfnite.
A decrease of the range between maximum and minimum load results in increasedfatigue strengthfor a given number of cycles. When the minimum and maximum loads are equal, the strength of the specimen corresponds to the static strength ofconcrete determined under normal test conditions. \
l Thefatigue strength ofplain concretefor a life of10 million cycles for tenswn, 1 compression, orflexure is roughly about 55 percent ofits static strength.
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l- !
gg Fatigue i Fatigue fracture of concrete is characterized by considerably larger strains and -
cracking as compared with fracture of concrete under static loading. t t
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 failums 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 contaming a No.11, Grade 60 rebar, when the minimum 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 localiwd 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 l of stress reversal cycles reaches the material's endurance limit. This is the i maximum stress to which the steel can be subjected for a given service life. Such '
l conditions will eventually produce a minute crack. & locahzed plastic movement further aggravates the nonuniform stress distribution, and further j plastic movement causes the crack to grow. ;
The fatigue behavior of steel structures strongly depends on their surface conditions (e.g., whether they are polished or in an as-received condition), h l
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 l of cydes increases until the fatigue limit is reached. If the maximum stress does not exceed the fatigue limit, an unhmited number of stress cydes can be applied at that stress ratio without causing failure. .
2.0 EVALUATION 2.1 Conditions ,
l Some of the internal structural components of the intake structure are subject to high cyde, low-level repeated load, such as equipment vibration load, during ;
normal plant operation. The intake structure's walls and roof slabs 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 intake
! structure. Therefore, the fatigue damage of these structural components is not
[
age-related.
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2.2 Potential Aging Mechanism Detennination l
Fatigue is a potential aging mechamsm for the following structural components of the intake structure because they could experience high frequency of low-level, repeated loads such as equipment vibration load:
l Foundations Function LR-S-2 Concrete columns Functions LR-S-2,4, and 7 Concrete walls Functions LR-S-1,2,4, and 7 l
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Concrete beams Functions LR-S-2 and 4 l .
Ground slab and Functions LR-S-1 and 2 l equipment pads l .
Elevated floor slab Functions LR-S-1 and 2 l i
i Roof slabs Function LR-S-2 l -
Steelbeams Functions LR-S-1 and 2 O -
Baseplates Functions LR-S-1 and 5 i
)
Floor framing Functions LR-S-1 and 5 Roof framing Function LR-S-2
. SteelbracingFunctions LR-S-2 and 5 1
Platform hangers Function LR-S-5 - l l
Steel decking Function LR-S-2 l
where:
LR-S-1: Provides sinactural 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 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).
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Fatigue 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 aging mecharusm for other intake structure structural components because they are not subject to the high frequency of low level, repeated loads.
2.3 Impact onIntended Functions If the effects of fatigue were not considend in the original design or are allowed to degrade the above structural components unmitigated for an extended period of time, this aging mecharusm could affect allintended functions of components listed in Section 2.2.
2.4 Design and Construction Consideraticas Allinternal concrete components of the CCNPP intake structure were designed in accordance with ACI-318-63.3 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 addition, actual concrete stresses induced by cyclic loads during normal plant operation, such as p
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 that yields extremely long fatigue life (> 107 cydes, which is equivalent to infinite life), as shown in Figure T-1.
All structural steel components in the intake structure were designed in accordance with American Institute of Steel Construction (AISC-1%3) specification.5 For the design of steel members and connections subject to repeated variation oflive load stress, this specification requires that consideration '
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 maximum stress may not exceed two-thirds of the basic allowable stress provided in Sections 1.5 and 1.6 of the AISC specification, which is equivalent to 40 percent of the material yield strength.
ASTM A-36 carbon steelis typically used for all st-uctural steel components in the intake structure. 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 stresses resulting from static and dynamic loads.
O 5/7/96 ' E T-4 Revision 2 J
F 1
I Fatigue l
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 mechanism for any structural component of the intake structure.
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 intake structure's structural components, no management program is necessary.
3.0 CONCLUSION
Some concrete components in the intake structure 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 l about 55 percent of its static strength at the extremely high cydes (>107 cydes) of l
loading. Therefore, fatigue will not degrade any concrete component in the l intake structure and requires no further evaluation.
Steel components in the intake structure subject to high-cyde (>105 cydes) loading conditions were designed in accordance with the AISC-63 specification.5 The maximum stress in steel components and connections is smaller than the fatigue limit of steel. Fatigue degradation will have no adverse effects on the continued safety function performance during the license renewal term and requires no further evaluation for all structural steel components in the intake structure. ;
4.0 RECOMMENDATION Fatigue is not a plausible aging mechanism for the structural components in the intake structure. Therefore, no further evaluation or recommendation is necessary.
t l
l
5.0 REFERENCES
- 1.
- Class I Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991.
- 2. "Co.isideration for Design of Concrete Structures Subjected to Fatigue I.oading," American Concrete Institute, ACI 215R-74,1986.
- 3. " Building Code Requirements for Reinforced Concrete," American Concrete Institute, ACI 318-63.
l S/7/96 E T-5 Revision 2
Fathue O
- 4. 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.
S. " 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.
o O
O 5/7/96 E T-6 Revision 2
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i O S/7/96 m T-7 Revision 2
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O i 5/7/96 E T-B Revision 2
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