Text

Rev 2 to Aging Mgt Review Rept for Fuel Oil Storage Tank 21 Enclosure, Final Rept
	ML20112B995
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: ML20112B954; ML20112B964; ML20112B970; ML20112B974; ML20112B979; ML20112B995; ML20112C003; ML20112C011; ML20112C020; ML20112C024; ML20112C036; ML20112C042;
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{{#Wiki_filter:_ a i i i O l Calvert Cliffs Nuclear Power Plant } LicenseRenewalProject i l 4 i ( Aging Management Review Report i for the i, 1 Fuel Oil Storage Tank No. 21 Enclosure O 4 1 Revision 2 i May, 1996 i Prepared by: d[ Date: 1 R.L. Tucker E Reviewed by: Date: B.M. Tilden 7!24hf4 Approved by: Date p...Dere.bek 4 !o 9605240115 960522 PDR ADOCK 05000317 P PDR

I LIFE CYCLE MANAGEMENT l FINAL REPORT {' FUEL OIL STORAGE TANK No. 21 ENCLOSURE AGING MANAGEMENT REVIEW RESULTS TABLE OF CONTENTS Section Page Number TABLE OF CONTENTS i l l LIST OF A'ITACHMENTS iii LIST OF APPENDICES iv LIST OF TABLES v l l LISTOFEFFECTIVE PAGES vi i l j I.0 INTRODUCTION 1-1 1.1 Fuel Oil Storage Tank No. 21 Enclosure Description 1-1 1.1.1 Fuel Oil Storage Tank No. 21 Enclosure LCM Description 1-1 l 1.1.2 Fuel Oil Storage Tank No. 21 Enclosure LCM Boundary 1-1 1.1.3 Fuel Oil Storage Tank No. 21 Enclosure Intended Functions 1-1 1.2 Evaluation Methods 1-2 l l 1.3 Fuel Oil Storage Tank No. 21 Enclosure Specific Definitions 1-2 1.4 Fuel Oil Storage Tank No. 21 Enclosure Specific References 1-2 2.0 STRUCTURAL COMPONENTS WITHIN THE SCOPE OF LICENSE RENEWAL 2-1 3.0 STRUCTURAL COMPONENTS PRE-EVALUATION 3-1 i i J AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE i REVISION 2

LIFE CYCLE MANAGEMENT FINAL REPORT !q V FUEL OIL STORAGE TANK No. 21 ENCLOSURE AGING MANAGEMENT REVIEW RESULTS TABLE OF CONTENTS Section Pane Number 4.0 STRUCTURAL COMPONENTS AGING EFFECTS EVALUATION 4-1 4.1 Evaluation 41 4.2 Aging Mechanisms 41 4.2.1 Potential AgingMechanisms 4-1 4.2.2 Component Grouping 4-2 l 4.23 Plausible Aging Mechanisms 4-2 4.2.4 Aging Management Program Identification 4-3 4.2.5 Aging Management Recommendations 4-3 5.0 PROGRAM EVALUATION 5-1 f3 (J 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 5-1 5.2.3 New Programs 5-2 O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE ii REVISION 2

i LIFE CYCLE MANAGEMENT FINAL REPORT FUEL OIL STORAGE TANK No. 21 ENCLOSURE AGING MANAGEMENT REVIEW RESULTS LIST OF ATTACHMENTS Potential Aging Mechanisms Applicable to Stmetural Components Plausible Aging Mechanisms Applicable to Structural Components Structural Components - Aging Mechanism Matrix Codes Summary of Aging Management Review Results Adequate Program Evaluation NOT USED i Walkdown Report " Examination of Fuel Oil Storage Tank #21 Enclosure - Calvert Cliffs Nuclear Power Plant" Attributes in New Program O l l l O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE iii REVISION 2

LIFE CYCLE MANAGEMENT FINAL REPORT ) FUEL OIL STORAGE TANK No. 21 ENCLOSURE AGING MANAGEMENTREVIEW RESULTS LIST OF APPENDICES 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 Shnnkage Appendix H Abrasion and Cavitation AppendixI Cracking ofMasonry Block Walls O Appendix J Settlement Appendix K Corrosion in Steel Appendix L Corrosion in Liner Appendix M Corrosion in Tendons Appendix N Prestressing Losses Appendix 0 Weathering Appendix R Elevated Temperature Appendix S Irradiation Appendix T Fatigue O/ AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE iv REVISION 2

i LIFE CYCLE MANAGEMENT l O FINAL REPORT FUEL OIL STORAGE TANK No. 21 ENCLOSURE AGING MANAGEMENT REVIEW RESULTS LIST OFTABLES i Iltle Inhlt Page Number 1-1 Fuel Oil Storage Tank No. 21 Enclosure Specific References 13 2-1 FOST #21 Enclosure Structural Components Within the Scope of License Renewal 2-2 4-1 List of Potential Aging Mechanisms for FOST #21 4-5 Enclosure Structural Components 4-2 FOST #21 Enclosure Aging Effects Evaluation Summary 4-6 0 l O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE y REVISION 2

LIFE CYCLE MANAGEMENT f3 V FINAL REPORT FUEL OIL STORAGE TANK No. 21 ENCLOSURE AGING MANAGEMENT REVIEW RESULTS LIST OF EFFECTIVE PAGES Revision Pages Summary of Change 0 All Initial revision prepared using LCM-10S, Revision 1. 1 All Changes made to reflect disposition of Technical Problem Reports written against Revision 0 and to correct transcription errors between the results and the final report sections. 2 All Wording changes to make the language in the final report sections more consistent with the language used in the Integrated Plant Assessment Methodology. Also, technical changes regarding the aging management strategy used to address degradation effects associated with corrosion in' structural steel,. O O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE vi REVISION 2

LIFE CYCLE MANAGEMENT

1.0 INTRODUCTION

1.1 FUEL OIL STORAGE TANK No. 21 ENCLOSURE DESCRIPTION This section describes the scope and boundaries of the Fuel Oil Storage Tank (FOST) #21 Enclosuir as it was evaluated. Section 1.1.1 provides a brief synopsis of the system as described in existing plant documentation. The FOST #21 Enclosure boundary is defined in Section 1.1.2 to clarify the portions of the stmeture considered in this evaluation. Section 1.13 is a detailed breakdown of the unique system functions and is p.ovided as a basis for component scoping and the identification of component-specific functions. 1.1.1 Fuel Oil Stormee T==b No. 21 Fae6-e IfM DescQ=*Ia= The FOST #21 Enclosure is a Seismic Category I concrete structure located in the " yard" west of the Unit No. 2 Containment Building. The enclosure houses and protects the Fuel Oil Storage Tank #21 from tomado generated missiles, and tornado winds. The enclosure will also withstand a transmission tower falling on it without damage to the FOST. Additionally, the enclosure acts as a dike for the FOST #21. In the event of a FOST failure, fuel can be supplied to the Emergency Diesel Generators from the enclosure by way of a non-safety-related line. 1.1.2 Fuel Oil Storage Tank No. 21 Enclosure LCM Boundarv The FOST #21 Enclosure and its structural components provide shelter to safety O related and non-safety related equipment inside the enclosure. The system boundary addressed by this scoping and evaluation included all the enclosure structural components, such as concrete foundations, walls, and slabs, serving this function. Also included in the system boundary are structural or functional supports for non-safety related stairs and platforms. During an abnormal event such as a seismic event, failure of these non-safety-related equipment supports must not adversely affect the operability of other safety related components. 1.1.3 Fuel Oil Stormee T==h No. 21 Fachare Inem=Aad Functions A detailed review of the FOST #21 Enclosure intended functions was completed during the system scoping process described in the BGE Integrated Plant Assessment Methodology. The following system functions for the FOST #21 Enclosure were identified as structural intended functions on Table IS of " Component 1.evel Scoping For Four Site Structures; Intake Structure, Turbine Building. FOST Enclosure, CST Enclosure": l 1.1.3.1 Function LR-S-1 i Provides structural or functional support, or both, to safety-related i equipment. O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE l-1 REVISION 2

LIFE CYCLE MANAGEMENT 1.13.2 Function LR-S-2 Provides shelter or protection to safety-related equipment' 1.133 Function LR-S-4 Serves as a missile (intemal or external) barrier i 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 oithe required safety related functions. 1.2 EVALUATION METHODS The FOST #21 Enclosure structural components within the scope ofliccuse renewal were evaluated 2 in accordance with BGE procedure EN-1-305, Revision 0, " Component Aging Management Review Procedure for Structures." The results of these evaluations are summvized in Sections 3.0 through 5.0. 13 FUEL OIL STORAGE TANK No. 21 ENCLOSURE SPECIFIC DEFLNITIONS p This section provides the definitions for any specific terms unique to the FOST #21 Enclosure V component level evaluation. D Definition None N/A 1.4 FUEL OIL STORAGE TANK No. 21 ENCLOSURE SPECIFIC REFERENCES References utilized in the completion of the FOST #21 Enclosure 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. The updates performed in Revisions 1 and 2 of this report incorporated several TPRs. The update performed in Revision 2 was perfomed to address a new strategy in the aging management of corrosion effects or structural steel. Only references affected by Revisions I and 2 have been revised. 8 FOST No. 21 Enclosure does not perform radiation sheilding, equipment qualification, or HELB protection aspects of this function. 2 Revision 0 and Revision I were done to LCM-10S. EN-1-305 is the new version of LCM-10S l which updated procedure format and terminology only. O l AGING MANAGEMENT REVIEW RESULTS FINAL REPORT l FOST #21 ENCLOSURE l-2 REVISION 2 l

i LIFE CYCLE MANAGEMENT Table 1-1 Fuel Oil Storage Tank No. 21 Enclosure Specific References Document ID. Document Title Revitian No Dgg Igg UFSAR Calvert Cliffs Nuclear Power Plant Units 1 and 14 1992 Report 2 UpdatedFinalSafety AnalysisReport Technical Calvert Cliffs Nuclear Power Plant, Units I and 182 9/27/93 Report Specification 2, Technical Specification 159 9/27/93 Componerd sevel Scoping of Four Site 1 1996 Report Structures; Intake Structme, Turbine Building, FOST Enclosure, CST Enclosure EPRI RP-2643-27 Class I Structures Licerue Renewal Industry 12/91 Report l Report NUMARC 9001 Pressurized Water Reactor Contamment i 9/91 Report Structures IJcense Renewal Industry Report Exanunanon of Fuel Oil Storage Tank #21 9/94 Report Enclosure Calvert Cliffs Nuclear Power Plant, September 21,1994 d Troxc!!, G.E., Davis, H.E., and Kelly, J.W., 2 Edition 1%8 Text " Composition and Properties of Concretc," McGraw Hill Mather, B., "How to Make Concrete that will be 11/89 Paper l immune to the effects of freenng and thawing,* l ACIFallConvention SanDiego ASW C33-82 " Standard Specification for Concrete 1982 Spec l Aggregates," Amencan Society ofTesting and Materials 1 l Civil and Structural Design Criteria for Calvert 0 8/2/91 Guide j l Cliffs Nuclear Power Plant Unit No. I and 2, by i l Bechtel Power Corp. { l 6750 & 9 Specification for Fumishing and Delivery of 8 4no Spec l Concrete Calvert Cliffs Nuclear Power Plan' i Unit No. I and 2 1963 Code ACI31843 " Building Code Requirements for Reinforced Cen _ - - - 1%7 Standard ACI 201.2R-67 " Guide to Durable Concrete," American l Concrete Institute l CRC Handbook of Tables for Applied Engineer 2 Edition Text d Science " Concrete Manual,' U.S. Department of the 8* Edition 1975 Code intenor ASW C-289-66

Potential Reactivity of Aggregates (Chemical 1966 Code Method)," American Society of Testing and Materials i

AGING MANAGEMENT REVIEW RESULTS FINAL REPORT 1 FOST #21 ENCLOSURE 1-3 REVISION 2

l l l LIFE CYCLE MANAGEMENT Table 1-1 Fuel Oil Storage Tank No. 21 Enclosure Specific References Document ID Document Title Revtsian No. Dalg Ing ASTM C-295 65 ' Petrographic Examination of Aggregates for 1%$ Code Concrete," American Society of Testing and i l Malenals j-letter from Charles County Sand & Gravel Co. 6/30n2 letter l to Bechtel Corp. l Skoulikidas,T.,Tsakopoulos, A.,and Paper Moropoulos, T., " Accelerated Rebar Corrosion When Connected to Lightning Conductors and Protection of Rebars with Needles Diodes Using Atmospheric Electricity,"in Publication ASTM S1? 906, " Corrosion Effects of Stray Currents and the Techniques for Evaluating Corrosion of Rebars in Concrete" ACI-209R 82 " Prediction of Creep, Shrinkage, and 1982 Standard Temperature Effects in Concrete Structures," American Concrete Institute " Design and Control of Concrete Mixtures," 13* Edition 19g8 Guide l Portland Cement Association j IAEA TECDOC-670

Pilot Studies on.F

^ f Aging of 10/92 Report o i Q-Nuclear Power Plant Components," Intemational Q Atomic Energy Agency MN-3-100 Painting and Other Protective Coatings 9/94 Proc l TRD A 1000 Coating Application Performance Standard 8 8/91 Spec 6750-A-24 Specification for Painting and Special Coatings 12 10/82 Spec 6750-C-19 Spccification for Furnishing. Detailing, 3 900 Spec Fabricating, Delivering, and Erecting Structural Steel l ACI 215R 74

Consideration for Design of Concrete 1986 Standard Structures Subjected to Fatigue loading?

American Concrete Institute f

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 504 Text Design Manual,* United States Steel Corporation 61-813-E ' Yard Tank Foundations, Sheet No.1 - Calvert 5 Dws Cliffs Nuclear Power Piant Unit No. I and No. 2

Design and Control of Concrete Admixtures",

13* Edition 1988 Guide Portland Cement Association l i y AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE l-4 REVISION 2 l

~.. _. _. _ _ _ _. ___ J d 1 LIFE CYCLE MANAGEMENT 1 Table 1-1 ' O Fuel Oil Storage Tank No. 21 Enclosure Specific References Document ID. Document Title Revismn No. Dgg Igg 1985 Code ANSI /ANS-6.4 " Guidelines on the Nuclear Analysis and Design of Concrete Radiation Shielding for Nuclear Power Plants,' Anurican Nuclear Standard Hilsdort H.R., Kropp, L and Koch, HJ.,"The 1978 Paper ElTects of Nuclear Radiation on the Mechanical Propertws of Concretc," Douglas McHenry intemahonal Symposium on Concrete and Concrete Structures, American Concrete Institute Publication SP-55 NUREGCR4652,ORNLAM. Naus, DJ.,' Concrete P-Aging and its 9/86 Paper 10059 Significance Relative to Ufe Extension of Nuclear Power Plants," Oak Ridge National 1Accatory, Oak Ridge,1N 1985 Code ACl349-85 " Code Requirements for Nuclear Safety Related Concrete Structures," Amencan Concrete institute EQ Design Manual Calvert Cliffs Nuclear 17 1992 Guide Power Pimt ASME Section Ill, Division 2

Code for Concrete Reactor Vessels and 1986 Code l

Contamments," Amencan Soc'wty of Mechanical 3 Engmeets Boiler and Pressure Vessel Code AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE l-5 REVISION 2

1 LIFE CYCLE MANAGEMENT o 2.0 STRUCTURAL COMPONENTS WTTHIN THE SCOPE OF LICENSE RENEWAL The FOST #21 Enclosure components were scoped in accordance with the process described in the BGE Integrated Plant Assessment Methodology. The FOST #21 Enclosure was scoped using procedure LCM-1IS. The purpose ofcomponent scoping is to identify all structural components whose functions are identified in Section 1.13. Thesc structural components are designated as within the scope oflicense renewal. j 1 l As a result of the scoping,16 structural component types were identified as providing one of the structure's intended functions listed in Section 1.13. A summary of the scoping result is in Table 2-1. l O l i O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE 2-1 REVISION 2 1

LIFE CYCLE MANAGEMENT Table 2-1 FOST #21 F=ehare Structural Comnam mts Wiekin the han. ofI1 :r Rr=reval STRUCTURAL COMPONENT TYPE INTENDED FUNCTION (S) l l Foundations LR-S-1 and 2 Concrete Walls LR-S-2 and 4 l Concrete Roof Slabs LR-S-2 and 4 l Cast-in-Place Anchors LR-S-1,2,4, and 5 Grout LR-S-1,2,4, and 5 l Post-Installed Anchors LR-S-5 l Steel Beams LR-S-2 and 4 l Baseplates LR-S-2 and 4 RoofFraming LR-S-2 and 4 Bracing LR-S-5 Platform Hangers LR-S-5 Decking LR-S-2 and 4 Floor Grating LR-S-5 O Stairs and Ladders LR-S-5 Anchor Brackets LR-S-1 Caulking and Scalants LR-S-1 and 2 l \\ l l l / NG MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE 2-2 REVISION 2 1

i 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. i l l O l l l l t l l r l i O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE 3-1 REVISION 2

LIFE CYCLE MANAGEMENT O 4.0 STRUCTURAL COMPONENTS AGING EFFECTS EVALUATION 4.1 EVALUATION The aging evaluation for FOST #21 Enclosure structural components within the scope of l license renewal was completed in accordance with BGE procedure, " Component Aging Management Review Procedure for Structures," EN-1-305, Revision 0. This procedure evaluated all 16 component types identified in Section 2.1. The evaluation accomplished the following: (1) Identified POTENTIAL aging mechanisms for each structural component type. (2) Identified PLAUSIBLE component aging mechanisms for each structural component type or specific components within the component type based on the following: i envi;onmental conditions I material of construction impact on intended functions (3) Developed attributes for programs to manage the effects of aging from those aging mechanisms identified as PLAUSIBLE. (4) Evaluated program adequacy to demonstrate that the effects of aging will be managed so that the intended function (s) will be maintained for the period of extended operation. These steps are discussed in greater detail in the sections that follow. 4.2 AGING MECHANISMS ,4 4.2.1 Potential Aging Mechanisms This step of the aging evaluation identifies aging mechanisms that are considered to be POTENTIAL for a given component type. An aging mechanism is considered POTENTIAL for a structural component if the evaluation concludes that the aging mechanism could occur in generic applications of the struciural component type throughout the plant due to susceptible materials of construction and conducive environmental service conditions. A comprehensive list of 18 aging medianisms was developed that may be applicable to structural component types. This was based on the EPRI industry i 4

O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE 4-1 REVISION 2 l

4

LIFE CYCLE MANAGEMENT O reports prepared for the PWR containment structure and Class I structures. Other references used to prepare this list include the following: NRC NPAR Reports IAEA Reports l DOE Reports = The list of aging mechanisms and materials they affect are in the first colunm of Table 4-1. The specific description of each is provided in Attachment 1 of l procedure EN-1-305 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 was evaluated for applicability (i.e., POTENTIAL) to the structural component type based on its material of construction and the j environmental conditions where the component type could be located. This approach ensures all the components within a component type will be evaluated l if the potential of degradation exists. The results of the structural component type POTENTIAL scoping of the component list of aging mechanisms are presented in Table 4-1. ) 4.2.2 Cearanent Gramping The grouping of structural components which are within the scope oflicense 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: (1) Concrete (including reinforcing steel) (2) Structural steel (3) Architectural items such as doors, roofing materials, and protective coating (4) Additional components that may have an unique function in the structure 4.2.3 Plausible AginF Mechanisms 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 l. plausible if when it is allowed to continue without any additional preventative or i O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE 4-2 REVISION 2 ~ -er

- - ~ -_ ~. -. l s LIFE CYCLE MANAGEMENT O mitigative measures, the aging mechanism would result in the FOST #21 Enclosure structural component not being able to perform its intended function. An aging mechanism is also considered plausible if there is insufficient evidence i to conclude that future degradation will have no impact on the intended functions of the enclosure's structural component. The plausibility determination is made through a careful consideration of all the factors required to allow the aging mechanism to occur. In particular, the aging mechanism is scoped for plausibility on the basis of: I f Material of construction i Environmental service conditions Design and construction considerations Impact on intended functions Physical conditions of the component The results of the aging mechanism plausibility scoping is an aging mechanism i component matrix listing the aging mechanism and its disposition. The aging [ mechanism matrix developed for each structural component type is included in in the evaluation results. l Aging mechanisms determined to be PLAUSIBLE are provided specific aging O - t r ce - 4 tie te -iti. t 16 <r et erts i - ca i. Table 4-2 summarizes the results of the plausibility determination and recommendations for the FOST #21 Enclosure. 4.2.4 Aging Management Program Identification i Once plausible aging mechanisms have been identified, the evaluation is 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 l be initiated to adequately manage the effects of aging. This evaluation did not include a determination of whether recommended changes to existing programs i 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 FOST #21 Enclosure identified a total of eight (8) aging mechanisms that have the POTENTIAL to degrade these components. A detailed review of the specific component intended functions, material of construction and its basis of design and ,!O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE 4-3 REVISION 2

i LIFE CYCLE MANAGEMENT O construction identified PLAUSIBLE component aging mechanisms as shown in the second column of Table 4 2. In some cases, the conclusion that the aging 1 mechanism is PLAUSIBLE was made becaux 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 i assessment, to verify conditions conducive to degradation do not exist, and to l 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 components in accessible areas. (2) Develop an age related degradation inspection program for coated i surfaces of structural steel components that are not readily accessible. i (3) Develop a new program to address the inspection and maintenance of caulking and scalants. i 1 l lO 1 l. i l l l l l l i !O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT i t FOST #21 ENCLOSURE 4-4 REVISION 2

LIFE CYCLE MANAGEMENT O Table 4-1 List of Potential Aelne Mechanisma for FOST #21 Enclosure Structural Comnonents Potential to Affect AeIne Mechanism Descrintion FOST#11 Endosurm? Materials Affected Freeze-Thaw Yes Concrete Leaching of Calcium 11ydroxide Yes Concrete Aggressive Chemicals Yes Concrete Reaction with Aggregates Yes Concrete Corrosion in Embedded Steel /Rebar Yes Steel, Concrete Creep No Concrete Shrinkage No Concrete Abrasion and Cavitation No Concrete Cracking of Masonry Block Walls No* Block Walls j Settlement Yes Concrete Corrosion in Steel Yes Steel Corrosion in Liner No* Steel Liners Corrosion in Tendons No* Steel Prestressing Losses No* Steel Weathering Yes Caulking and Sealants Elevated Temperature No Concrete Irradiation No Concrete, Steel Fatigue No Concrete Affected Components do not exist in the FOST #21 Enclosure O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE 4-5 REVISION 2

P 3 OV d LIFE CYCLE MANAGEMENT Table 4-2 F' ST #21 Fnclosure Agine Effects Evaluation Summary O STRUCTURAL PLAUSIBLE AGING COMPONENTS MECilANISM RECOMMENDATION REMARKS Foundsions None None Seejustifwation in Appendices B, C, D. E and J. Concrete Wans None None Seejustification in Appendices A, B, C, D, E, and J. Concrete Roof Stab None None Secjustification in Appendices A, B, C, D, E, and J. Cast-in-place Anchors Conosion in steel See.%..,. Aion for " Steel Beams

Seejustification in Appendix K.

gg g All exposed surfaces of structund steel m.v ,6 are covered by a gg id m protective coating. For accessible areas, s,gnifcant coating degradation i and/or the presence of corrosion will be identified, an issue report written, and corrective action taken through the following existing site programs. PEG-7 SystemWalkdowns QIr2-100 Issue Reporting MN-3-100, Protective Coating Program. For those structural steel m.v-~..a not readily accessible, significant coating degradation and/or the presence of corrosion will be determined utilizing an age related degradation inspection. Baseplates Cormsion in steel See. ...-.Aion for

Steel Beams
See)=rh-in Appendix K.

RoofFraming Corrosion in steel See.%.. Aion for

Steel Beams
Seejustification in Appendix K.

Fbst-Installed Anchors CorTosion in steel See. ..a.Jation for

Steel Beams
Seejustification in Appendix K.

Bracing Cormsion in steel See "ation for " Steel Beams

Secjustification in Appendix K.

Platform Ilangers Corrosion in steel See.._..Jr.aion for" Steel Beams" Seejustification in Appendix K. floor Grating Corrosion in stecI See..._.2.-J.iion for

Steel Beams
Seejustifmation in Appendix K.

AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE 4-6 REVISION 2

) O O LIFE CYCLE MANAGEMENT Table 4-2 FOST #21 Enclosure Aging Effects Evaluation Summary STRUCT1]RAL PLAl%Illt.E AGING COMPONENTS MI. ' 't SNISM RECOMMENDA110N REMARKS Stairs and I. adders Cormsionin sed See.m-. - Leion for

Steel Beams
Seejustification in Appendix K.

Anchor Brackets Corrosion in steel Sec km..m..i.; ion for

Steel Beams
Seejustification in Append.x K.

Decking Corrosion in steel See.sm..-.,i.: ion for " Steel Beams" Secjustification in Appendix K. Caulking and Scalants Weathenng Develop an inspection and....i.. a pmgram which will identify Seejustification in Appendix 0 degradation and ensure corrective action is taken before the component loses its ability to perform its intended function. The resolution to issue Report IRl995-01698 will form the basis for this program. i AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE 4-7 REVISION 2

) i LIFE CYCLE MANAGEMENT UNIT l 0 5.0 PROGRAM EVALUATION 5.1 PROGRAM ADEQUACY EVALUATION l l Program adequacy evaluations were completed in accordance with EN-1-305, Revision 0, l for those programs or aging management alternatives developed to address PLAUSIBLE component aging mechanisms. The evaluation of programs or aging management l alternatives considered the following criteria as a means of establishing the adequacy of specific CCNPP programs: 1. Adequate programs must ensure management of the affects of aging for those structural components subject to PLAUSIBLE aging mechanisms. 2. Adegaate 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. (U] The results of the program adequacy evaluations are provided in Section 5.2. l 5.2 STRUCTURAL COMPONENTS SUBJECT TO ADEQUATE PROGRAMS 5.2.1 Fristing Proernma The program evaluation task reviewed all existing CCNPP programs that were established to monitor, inspect, and repair structural components that are degraded by identified plausible aging mechanisms. 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. 5.2.2 Modified Frinting Proernma This section provides the summary results for those structural components that were determined to have an existing CCNPP Program / Activity that with modification would become an adequate program to manage the effects of aging during the renewal period. The evaluation started from evaluating structural component types and applicable aging mechanisms and has focused to specific l components or locations. No modified existing programs were identified to j manage the effects of aging into the license renewal period. llO AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE 5-1 REVISION 2

s LIFE CYCLE MANAGEMENT UNIT D 5.2.3 New Programs Caulkina and Scalant'; A program should be developed in conjunction with the resolution to Issue Re port IR1995-01698 to address the requirements for the -- inspection and maintenance ofcaulking and scalants. Non-acceccible Struchiral 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. O l O AGING MANAGEMENT REVIEW RESULTS FINAL REPORT FOST #21 ENCLOSURE 5-2 REVISION 2

LIFE CYCLE MANAGEMENT List of Attachments and Appendices g For the Fuel Oil Storage Tank No. 21 Enclosure d Aging Management Review Total Panes, Potential Aging Mechanisms Applicable to Structural Components 3, Plausible Aging Mechanisms Applicable to Structural Components 3, Structural Components Aging Mechanism Matrix Codes 3, Aging Management Review Results 3, Adequate Program Evaluation 9, Not Used 0, Walkdown Report - Examination of Fuel Oil Storage Tank No. 21 Enclosure 5, Attributes in New Program 10 Appendices Appendix A-Freeze-Thaw 5 Appendix B - Leaching of Calcium Hydroxide 6 Appendix C - Aggressive Chemicals 5 Appendix D - Reactions with Aggregates 6 Appendix E - Not Used 0 Appendix F - Creep 3 Appendix G - Shrinkage 3 Appendix H - Abrasion and Cavitation 3 Appendix I - Cracking of Masonry Block Walls 3 Appendix J - Settlement 4 l Appendix K - Corrosion of Steel 5 Appendix L - Corrosion of Liner 3 Appendix M - Corrosion of Tendons 2 Appendix N - Prestress Losses 2 Appendix 0 - Weathering 3 Appendix P - Not Used 0 Appendix R-Elevated Temperature 3 Appendix S -Irradiation 4 Appendix T - Fatigue 8 i AGING MANAGEMENT REVIEW RESULTS FINAL REPORT s FOST #21 ENCLOSURE REVISION 2 l l

4-

O i

d a i 1 Potential Aging Mechanisms Applicable to Structural Components i i i

i. O

) i 1 4, i i I k i Sheet 1 of_3_ O

O O O ATTACHMENT 1: POTENTIAL AGING MECHANISMS APPLICABLE TO STRUCTURAL COMPONENTS REVISION: _2 DATE: 5/7/96 STRUCTURE NAME: Evel Oil Storaae Tank No. 21 Enclosure SYSTEM NUMBER: - Sheet 2_ of _.3 STRUCTURAL POTENTIAL AGING MECHANISMS APPLICABLE TO CONCRETE / ARCH. COMPONENTS REMARKS COMPONENTS A B C D E F G H I J K O R S T Foundations 4 4 4 4 NA 4 Functions LR-S-1,2 Concrete Walls 4 4 4 4 4 NA 4 Function LR-S-2,4 Concrete Roof Stabs 4 4 4 4 4 NA 4 Function LR-S-2,4 Cast-in-Place Anchors NA 4 Functions LR-S-1,2. 4, 5 Grout NA Functions LR-S-1,2,4,5 Post-Installed Anchors NA 4 Functions LR-S-5 Caulking and Sealants NA 4 Functions LR-S-1,2 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) i E Corrosion in embedded steet/rebar K Corrosion in steel O (Not Used) NA Aging Mech not app!. F Creep L Corrosion in Liner R Elevated temperature Aging Mech not poten.

O O O ATTACHMENT 1: POTENTIAL AGING MECHANISMS APPLICABLE TO STRUCTURAL COMPONENTS REVISION: _2__ DATE: 5/7/96 STRUCTURE NAME: Fuel Oil Storace Tank No. 21 Enclosure SYSTEM NUMBER: - Sheet _3 of _3 i I STRUCTURAL POTENTIAL AGING MECHANISMS APPLICABLE TO STEEL COMPONENTS REMARKS COMPONENTS j. K L M N R S T Steel Beams 4 NA NA NA Functions LR-S-2,4 Baseplates 4 NA NA NA Functions LR-S-2,4 Roof Framing i NA NA NA Functions LR-S-2,4 Bracing 4 NA NA NA Function LR-S-5 Platform Hangers 4 NA NA NA Function LR-S-5 Decking 4 NA NA NA Functions LR-S-2,4 Floor Grating 4 NA NA NA Function LR-S-5 Stairs & Ladders 4 NA NA NA Function LR-S-5 t Anchor Brackets 4 NA NA NA Function LR-S-1 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 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 steel /rebar K Corrosion in steel Q (Not Used) NA Aging Mech not appl. F Creep L Corrosion in Liner R Elevated temperature Aging Mech not poten. - ~ ~ - -

O - Plausible Aging Mechanisms Applicable to Structural Components O Page 1 of 3 O

O O O ATTACHMENT 2: PLAUStBLE AGING MECHANISMS FOR STRUCTURAL COMPONENTS REVISION: 2 DATE: 5/7/96 STRUCTURE NAME: Fuel Oil Storaoe Tank No. 21 Encinauta SYSTEM NUMBER: - Sheet _2. of _3 STRUCTURAL PLAUSIBLE AGING MECHANISMS APPLICABLE TO CONCRETE / ARCH. COMPONENTS REMARKS COMPONENTS A B C D E F G H I J K O R S T Foundations 102 103 104 105 NA 106 Functions LR-S-1,2 Concrete Walls 101 102 103 104 105 NA 106 Function LR-S-2,4 Concrete Roof Slabs 101 102 103 104 105 NA 106 Function LR-S-2,4 Cast-in-Pface Anchors NA PA Functions LR-S-1,2,4,5 Grout NA Functions LR-S-1, 2, 4, 5 Post-InstsNed Anchors NA PA Function LR-S-5 Caulking and Sealants NA PB Functions LR-S-1,2 1 Legend: A Freeze-thaw G Shrinkage M Corrosion in tendons S Irradiation 8 Leaching of calcium hydroxide H Abrasion and cavitation N Prestressing losses T Fatigue C Aggressive chemicals I Cracking of masonry block wans O Weathering U (Not Used) i 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 Aging Mech not appl F Creep L Corrosion in Liner R Elevated tamperature Aging Mech not poten.

O O O ATTACHMENT 2: PLAUSIBLE AGING MECHANISMS FOR STRUCTURAL COMPONENTS REVISION: 2 DATE: 5/7/96 STRUCTURE NAME: Fuel Oil Storaae Tank No. 21 Enclosure SYSTEM NUMBER: - Sheet.3. of 3 STRUCTURAL PLAUSIBLE AGING MECHANISMS APPLICABLE TO STEEL COMPONENTS REMARKS COMPONENTS K L M N R S T Steel Beams PA NA NA NA Functions LR-S-2,4 Baseplates PA NA NA NA Functions LR-S-2,4 Roof Framing PA NA NA NA Functions LR-S-2,4 Bracing PA NA NA NA Function LR-S-5 Platform Hangers PA NA NA NA Function LR-S-5 Decking PA NA NA NA Functions LR-S-2,4 Floor Grating PA NA NA NA Function LR-S-5 Stairs & Ladders PA NA NA NA Function LR-S-5 Anchor Brackets PA NA NA NA Function LR-S-1 b I r 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 steel /rebar K Corrosion in steel Q (Not Uced) NA Aging Mech not appl. F Creep L Corrosion in Liner R Elevated temperature Aging Mech not poten.

l lO 1 l l r Structural Components Aging Mechanism Matrix Codes 1 O i l Sheet 1 of_3_ lo

ATTACHMENT 3 STRUCTURAL COMPONENTS - AGING MECHANISM MATRIX CODES REVISION: 2 DATE: 5/7/96 STRUCTURE NAME: FOST #21 Enclosure 1 SYSTEM NUMBER: Sheet 2 of 3 CODE JUSTIFICATION REMARKS 101 See Appendix A 102 See Appendix B 103 See Appendix C 104 See Appendix D 105 See Appendix E 106 See Appendix J O O

i l l l i /~h V ATTACHMENT 3 I l STRUCTURAL COMPONENTS - AGING MECHANISM MATRIX CODES l REVISION: 2 DATE: 5/7/96 l STRUCTURE NAME: FOST #21 Enclosure SYSTEM NUMBER: Sheet 3 of 3 CODE JUSTlFICATION REMARKS PA See Appendix K PB See Appendix 0 I l l l llO i 1 4 O 4

l O Summary of Aging Management Review Results O Sheet 1 of_.1_ O

O O O

SUMMARY

OF AGING MANAGEMENT REVIEW RESULTS Revision: 2 Date: 5/7/96 STRUCTURE / SYSTEM NUMBER: STRUCTURE NAME: FOST #21 Enclosure COMPONENTS AFFECTED AGING MECHANISM CONCRETF/ ARCH. STEEL PROGkAM/ COMMENT Freeze-Thaw None None Not Needed Leaching of Ca(Oll)2 None None Not Needed Aggressive Chemicals None None Not Needed Reaction with Aggregates None None Not Nee'ded Corrosion of Embedded None None Not Needed Steel /Rebar Creep None None Not Needed Shrinkage None None Not Needed Abrasion / Cavitation None None Not Needed Cracking of Masonry Block None None Not Needed because there are no Walls masonry block walls in the FOST #21 Enclosure. Settlement None None Not Needed 1.All structural steel members Corrosion in Steel None PEG-7,QIe2-100,MN-3-100,ARDI Corrosion in Liner None None Not Needed because there is no liner plate in the FOST #21 Enclosure. Sheet 2_ofl

O O O

SUMMARY

OF AGING MANAGEMENT REVIEW RESULTS Revidon:_2_ Date: 5/7/96 STRUCTURE / SYSTEM NUMBER: STRUCTURE NAME: FOST #21 Enclosure COMPONENTS AFFECTED AGING MECHANISM CONCRETE / ARCH. STEEL PROGRAM / COMMENT Corrosion in Tendons None None Not Needed because there are no tendons in the FOST #21 Enclosure. Prestressing Losses None None Not Needed because there are no tendons in the FOST #21 Enclosure. Weathering Caulking and Scalants l None Develop an inspection and maintenance program to identify degradation and ensure corrective action is taken. The resolution ofissue Report IRl995-01698 to form the basis of this program. Elevated Temperature None None Not Needed Irradiation None None Not Needed Fatigue None None Not Needed sheet 3_orl

1 s 1 i. i i 4 4 1 i Adequate Program Evaluation i I j i l 4 I 1 i 4 i i 1 d 4 i l Sheet _1_ of _fi

ATTACHEMENT 5 - ADEQUATE PROGRAM EVALUATION REVISION 2 DATE: 5/7/96 STRUCTURE / SYSTEM NUMBER: STRUCTURE NAME: FOST # 21 Enclosure STRUCTURAL COMPONENT DESCRIPTION: Accessible Structural Steel AGING MECHANISM DESCRIPTION: Corrosion of steel CCNPP PA or Task ID: MN-3-100/ PEG-7/OL-2100 Criteria 1: Adequate programs must ensure mitigation of the effects of age related degradation for the SSCs within the scope oflicense renewal. DISCOVERY DESCRIPTION /BA. SIS: 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 oeriodically as mandated by system nerformance. plant ooerating conditions. or as reauired by olant management. Walkdowns can be iob soecific or outage related but otherwise tvolcally occur on a monthly basis. O 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 frecuency is consistent with industrv standards and can be modified as necessary to reflect uniaue olant ooerating conditions soecific to CCNPP. O V Sheet _2_ of _6

l .. ~ ATTACHMENT 5 - ADEQUATE PROGRAM EVALUATION (continned) REVISION 2 DATE: 5/7/96 AGING MECHANISM DESCRIPTION: Corrosion of steel CCNPP PA or Task ID: MN-3-100/ PEG-7/OL-2-100 l 3. Will the PA or Task be applicable to all structural components under the same component type? YES _X _ NO.__ l Basis: All coated surfaces in areas that are " reasonably accessible" are visually insnected during the PEG-7 activity O l i I f Sheet.3_ of _fi 4 I

~ _ -...- t ATTACHMENT 5 - ADEQUATE PROGRAM EVALUATION (continued) -O x8visio" o^rs: s'>'ee AGING MECHANISM DESCRIPTION Corrosion of steel l l CCNPP PA or Task ID: MN-3-100/ PEG-7/OL-2-100 l Criteria 2: Adequate programs must contain acceptance criteria against which the need for i corrective action will be evaluated, and ensure that timely corrective action will be taken when these acceptance criteria are not met. l ASSESSMENT / ANALYSIS / CORRECTIVE ACTION DESCRIPTION / BASIS: l 1. Does the PA or Task have an action or alert value or condition parameter to determine the need for corrective action? YES.X_ NO.__. l Basis: There is no cuantitative alen value to determine the need for corrective action. PEG-7 l allows for denradad continos to be documented on a checklist which is then used to l prioriti7e corrective actionsi MN-3-100 snecifies annronrinte technical nrocedures for corrective action based on the continge service level. l DV 2. Does the action value or condition provide sufficient indication of degradation to ensure that l there will not be a functional failure prior to the next PA or Task? YES X_ NO __. Basis: Conditions adverse to aunlity and functionalitv. indications of couinment stress or abuse. safety or fire hn7mrds. and general houcakaaning deficiencies are noted during PEG-7 system walkdowns conducted monthlv. Structural degradation occurs at a sufficiently slow rate such that monthly incnectioc3 would detect denradation before loss of function could occur 3. Will the action'value or condition parameter remain the same during the senewal period ? YES _X_ NO __ Basis: The corrective actions and condition parameters prescribed in MN-3-100 are baced on intnection of the surface condition of the painted comnonent This annroach does not need to be revised during the renewal neriod. l i O Sheet _4_ of_fi

l ATTACHMENT 5 - ADEQUATE PROGRAM EVALUATION (continued) REVISION 2 DATE: 5/7/96 AGING MECHANISM DESCRIPTION: Corrosion of steel CCNPP PA or Task ID: MN-3-100/ PEG-7/OL-2-100 4. Does the PA or Task ensure that corrective action is taken? YES_X_ NO __ Basis: PEG-7 reauires deficiencies to be documented on a svctem walkdown renort. Cnnditions adverse to aunlitv will result in the initiation of an Iccue Renort ner OL-2-100 reauirements. MN-3-100 invnkes the annronriate technical nrocedure to ensure nroner annlication and that a aunlified nrotective enatina is used. 5. Does the PA or Task ensure that the corrective action is appropriately scheduled? YES _.X_ NO._ l Basis: OL-2-100 assions a due date for corrective action to occur. The comnletion date is driven by enaineerine indoment haced on the condition of the dearaded enatina and its I contribution to the comnonent's intended function l t l l t i Sheet 5_of_6 i

ATTACHMENT 5 - ADEQUATE PROGRAM EVALUATION (continued) REVISION 2 DATE: S/7/96 AGING MECHANISM DESCRIPTION: Corrosion of steel CCNPP PA or Task ID: MN-3-100/ PEG-7/OL-2-100 Criteria 3: Adequate programs must be implemented by the facility operating procedures and reviewed by the onsite review committee. .) CONFIRMATION / DOCUMENTATION DESCRIPTION / BASIS: 1. Does the PA or Task have a review / approval process? i YES_2. NO Basis: Tsese procedures reonires signatures from approoriate levels of suoervision (i.e.. POSRC. Manager of Calvert Cliffs Nuclear Power Plant. and GSOA) mRer tsey are 4 submitted by tse resoonsible engineer. I 4 2. Does the PA or Task have a change / revision process? YES X. NO _ jO eesis: 1se ecord of aevisionsano Csanses oftse n,occa.re ooe.me 1s1se esanee 101se i procedure. l a Sheet.6._ of _6

4 e i 1!O i 1 i i i i i 1 1 i a N i l l Walkdown Report i Examination of Fuel Oil Storage Tank #21 Enclosure - 4 Calvert Cliffs Nuclear Power Plant \\ A O 4 I i e i i i l Sheet 1 of _.fi. l l i

r l Examination of Fuel Oil Storage Tank #21 Enclosure l Calvert Cliffs Nuclear Power Plant t l September 21,1994 1 l Date of Walkdown: September 21,1994 Partic".mte Lloyd Philpot G/C David Knepper G/C l summarv: A walkdown of the Fuel Oil Storage Tank #21 Enclosure was performed to support the Component Evaluation and Program Evaluation of the Fuel Oil Storage Tank

21 Enclosure. Prior to the walkdown a checklist was developed to establish those characteristics indicative of specific aging mechanisms. The interior and exterior of the enclosure was inspected, with the exception of the enclosure roof.

Results. The walkdown checklist and corresponding findings are included on the following j pages. This information will be used as input to the enclosed evaluation as needed. l l i O sheet 2 ef 1 l i I

O O O LCM WAIXDOWN CHECKLIST FUEL OIL STORAGE TANK #21 ENCLOSURE Date 9/21/94 Appendix Aoine Mech =8an theristic Comments A Freezenhaw Scaling, cracking, spalling No scaling, cracking, spalling observed. i B CaOH Leaching Leachate Only minor leachate was observed, the quantity and location indicates the CaOH leaching is insignificant and is not a concern. C Aggressive Chemical No. 2 fuel oil Fuel oil contained in tank, only very small amounts on concrete. This is not a concern since concrete is not adversely affected by fuel oil. Other chem. present No other chemical stored in enclosure. D Aggregate Reaction Map cracking No map cracking observed. E Embed Steel /Rebar Corr. Hairline cracks No hairline cracks observed.. Rust staining No rust staining observed. Spalling No spalling observed. Sheet _3_of _5_

O O O i l I l LCM WALKDOWN CHECKLIST FUEL OIL STORAGE TANK #21 ENCLOSURE Date 9/21/94 I Appendix Ah Mech-b Characteristic Comments Severe cracks No severe cracks observed I l I Masonry Block walls Confirm no block walls No block walls in the enclosure. K Steel Corrosion Steel beams Roof beams in tank room are coated with sprayed-on fire proofmg material. All other beams painted, minor surface corrosion observed, the corrosion is not a concern at this time based on the magnitude and severity. Steel deck Steel deck galvanized, no corrosion observed. Anchor bolts Anchor bolts were painted, no corrosion observed. Inaccessible areas Physical access to roof beams is difficult, also visual access of the roof beams is not possible since beams are fire proofed. Sheet A_of_1 2 a... .m . w + -m

O O O LCM WALKDOWN CHECKLIST FUEL OIL STORAGE TANK #21 ENCLOSURE Date 9/21/94 Appendix Aoine Meh-8== Characteristic Comments O Weathering Scaling, cracking, spalling No scaling. cracking, or spalling of concrete chm. rved. R Elevated Temperature Heat sources Only minor heat generating sources (local heat tracing and room heater) were observed in the enclosure. S Irradiation Radiation levels No monitored radiation sources inside or outside the enclosure. Radiation levels are below level requiring radiation posting. T Fatigue Mechanical components No operating mechanical equipment inside the enclosure. Vibrating equipment No vibrating equipment inside the enclosure. Sheet _5__of _5_

O Attributes in New Program O Sheet.L of 1 ATTRIBUTES IN NEW PROGRAM REVISION: 2 DATE: S/7/96 STRUCTURE / SYSTEM NUMBER: None STRUCTURE NAME: Fuel Oil Stornoe Tank No. 21 Enclosure STRUCTURAL COMFONENT DESCRIPTION: Caulkino and Sealanta AGING MECHANISM: Wantherine APPLICABLE APPENDIX: Annendix O BACKGROUND: The intended functions of emulkino and canlants are to nrovide shelter and nrotection to safety relatad caninment inside the Fuel Oil Stornoe Tank No. 21 ~ ~ Fnclosure. Caulkino and semiants nced in the Fuel Oil Stornoe Tank No. 21 Enclosure contribute to the overall wantheriratinn of the structure. The canikino and cenlante are comnonente which are tvnically replacaA on condition. ~ However incnections in the nInnt revealed that an inanection nrogram was - 1 reouired to adannatalv manaoe the meine of these comnnnents. RECOMMENDED O ATTRIBUTES: The nanneement program for the canikino and =malants is recommended to be develoned in association with the resolution to Issue Report IR1995-01698. The program must manane the aging of the caniking and cenlants in the Fuel Oil Storage Tank No. 21 Enclosure which sunnort intended functions of the structure. The recommended annrnaches are:

1. Identify all emulking and centants Incations that suonort the structure's intended fimetions.

2. Develon an incnection and maintenance nronram which will identify

) degradation and ensure corrective action is taken before the comnonent loses the ability to nerform its intended function. The nrogram should concentrate on caulking and cenlants located in exterior walls and in interior walls and floors where shelter and nrotection functions are nerformed. Sheet.2_ of _1

ATTRIBUTES IN NEW PROGRAM (continued) l REVISION: 2 DATE: 5/7/96 STRUCTURAL COMPONENT DESCIUPTION: Caulking and Sealants AGING MECHANISM: Weatherina APPLICABLE APPENDIX: Annendix O BASIS: The manmoement nronram for the enutking and eenlantc is recommended to be develoned in association with the resolution to Icene Renort IR1995-01698. The issue renort identified iointe in the Auxiliary Buildina which showed signs of ) degradation. This concern is also annlicable to the Fuel Oil Stornae Tank No. 21 Enclosure. Resolution of this issue renort will ensure develonment of an noina mannoement nrogram for caulkino and centants in the Fuel Oil Stornoe Tank No. 21 Enclosure such that these comnonents will be able to nerform their intended functions both during the current license neriod and the neriod of extended operations. O l I s i 4

O sa 12 erai

i. --

1 1 l ATTRIBUTES IN NEW PROGRAM (cominued) l REVISION: 2 DATE: S/7/96 STRUCTURE / SYSTEM NUMBER: None STRUCTURE NAME: Fuel Oil StorageTank No. 21 Enclosure STRUCTURAL COMPONENT DESCRIPTION: Non-accessible structural steel ARDM DESCRIPTION: Corrosion of Steel APPLICABLE APPENDIX: Appendix K BACKGROUND: The intended functions of structural steel are to provide structural suonort to safety related cauinment and to support the overall enclosure's functions of sheltering and orotecting safety related eauinment and serving as a missile barrier. Safety related structural steel is covered with an anorooriate protective l contina Corrosion of structural steel can only occur if these orotective continos have been degraded. Aging management of degraded conting conditions on ' accessible structural steel in the FOST #21 Enclosure is accomplished through the combination of existing plant programs. However. structural steel comoonents not readily accessible reauire additional aging management. RECOMMENDED ATTRIBUTES: An age related degrarlation insoection (ARDI) program as described in the BGE Integrated Plant Assessment Methodology should be imolemented to address corrosion of non-accessible structural steel components which suonort the l intended functions of the FOST #21 Enclosure. The ARDI Program must consist of the following-1. Identification of non-accessible locations. l l 1. Selection of reoresentative structural steel comoonents for insoection. 2. Develonment of an insnection samnie size. l 3. Use of Anorooriate insoection techniaues. 4. Reauirements for reoorting of results and corrective actions if aging concerns are identified. l .O sa et 4 er 5

ATTRIBUTES IN NEW PROGRAM REVISION: 2 DATE: S/7/96 STRUCTURAL COMPONENT DESCRIPTION: Non-accessible structural steel ARDM DESCRIPTION: Corrosion of Steel APPLICABLE APPENDIX: Appendix K 1 l BASIS: The ARDI Procram will ensure that degraded conditions due to corrosion of steel are identified and corrected such that non-accessible structural steel comoonents of the FOST #21 Enclosure will be canable of nerforming their intended functions under all l design conditions reauired by the current licensing le. sis. l 1 1 1 ) l O l l l i i l l Sheet _1_ of _1 m-

l APPENDIX A - FREEZE-THAW 1.0 MECHANISM DESCRIPTION' Repeated cycles of freezing and thawing can alter both the mechanical properties and physical form of the concrete, thus affecting the structural integrity of the component. De freeze-thaw l phenomenon occurs when water freezes within the concrete's pores, creating hydraulic I pressure. This pressure either increases the size of the cavity or forces water out of the cavity mto surrounding voids. 1 i Freeze-thaw damage is characterized by scaling, cracking, and spalling. Scaling or surface i flaking occurs in the presence of moisture and is aggravated by the use of deicing salts. Cracks or spalling occun when voids are already filled with water, and freezing causes pressure to increase in extreme cases of freeze-thaw damage, the cover over reinforcing steel l l 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 aggressive environments. l To minimize the adverse effects of freeze-thaw, three factors must be considered in the design and placement ofconcrete.2 The cement paste must have an entrained air system with an appropriate void spacing factor. l l The aggregate must be of a sufficiently high quality to resist scaling. l [l i C/ He in-place concrete must be allowed to mature sufficiently before exposure to cyclic freezing and thawing. As shown in Figure A-1, the optimal air content range extends from 3 to 6 percent based on i the nominal maximum size of coarse aggregate.8 2.0 EVALUATION I l 2.1 Conditions According to Specification ASTM C33-82, " Standard Specification for Concrete l Aggregates,"' the CCNPP site is located in the geographic region subject to severe weathering l conditions. As stated in CCNPP's " Civil and Stmetural Design Criteria,"5the frost penetration depth is 20 to 22 inches. l 2.2 Potential Aging Determination Freeze-thaw is a potential aging mechanism for the following concrete structural components of Fuel Oil Storage Tank #21 Enclosure because they are exposed to outside cold weather: Concrete Walls Functions LR-S-2 and 4 i Concrete roof slab Functions LR-S-2 and 4 O V 5/7/96 m A-1 Revision 2

l l Freeze-Thaw [ l where: l LR-S-2: Provides shelter / protection for safety-related equipmerit. l LR-S-4: Serves as a missile barrier (internal or extemal). 2.3 Impact on Intended 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 peried of time, this aging mechanism could affect all the intended functions of components listed in Section 2.2. j 2.4 Design and Construction Considerations CCNPP concrete design specification No. 6750-C-9' specifies: 9.3.1 The Portland cement concrete furnished unless otherwise l spectfled herein, shall conform to ASTM C-94 Specificationfor Ready l Mix Concrete, ACI 318-63 Building Code Requirementsfor Reinfcrced Concrete, ACI 301-66 Standard Specificatiomfor Structural Concrete for Building, and A CI Manual ofConcrete Inspection. I 10.1.2.2 Allaggregateshallconform to ASTMDesignation C33.. U Section 10.1.16 of ASTM Designation C33-67 specifies that: Procedures for making freering and thawing tests of concrete are described in ASTM Method C290, " Test for Resistance of Concrete Specimens to Rapid Free:ing and Thawing in Water," and in ASTM Method C291, " Resistance ofConcrete Specimem to Rapid Freezmg m Air and Thawingin Water." Both ASTM Methods C290 and C291 cover the method for determining the resistance of concrete specimens to rapidly repeated cycles of freezing and thawing in the laboratory. I Design specification No. 6750-C-9 for CCNPP also specifies: i 10.4.2.1 The Subcontractor shall specify the air entraining agent he proposes to use. It shall be in accordance with ASTM C-260, capable of entraining 3-5% air, be completely water soluble, and be completely l dissolved when it enters the batch. The Subcontractor shallgive 30 days advance notice ofthe type ofAEA heproposes to use. ACI 318' and its relevant ACI standards and ASTM specifications provide the physical property requirements of aggregate and air-entraining admixtures, chemical and physical ) requirements of air-entraining cements, and proportioning of concrete including containing ] entramed air to maximize the concrete resistance to freeze-thaw action. 2 4

O 5/7/96 E A-2 Revision 2

- - ~ . - ~ ~. l l Freeze-Thew LO l l 2.5 Plausibility Determination Based on the discussion on Section 2.4, concrete used for the Fuel Oil Storage Tank #21 Enclosure was designed and constructed in ecco.d-w with the requirements specified in ACI-318 and its relevant ACI standards and ASTM specificatums. Those requirements satisfy I the attributes discussed in Section 1.0 that maximize concrete's resistance to freeze-thaw I action. In addition, a walkdown of the enclosure documented no evidence of damage from l freeze-thaw'. Therefore, freeze-thaw is not a plausible aging mechanism for the enclosure l walls and roof slab. t 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 FOST #21 stmetural components, no management program is necessary.

3.0 CONCLUSION

l 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 l temperatures and in constant contact with moisture, these v- ; =e were constructed with concrete designed to maximize its resistance to freeze-thaw cycles. A walkdown inspection of the Fuel Oil Storage Tank #21 Enclosure found no indication of freeze-thaw effect on the concrete structure. This fmding further substantiates the conclusion that freeze-thaw is not a j plausible aging mechanism for the structural components ofthe FOST #21 Enclosure. 4.0 RECOMMENDATION L l Freeze-thaw is not a plausible aging mechanism for any concrete structural components of the enclosure. No funher evaluation or recommendation is required. I

5.0 REFERENCES

i 1. " Class 1 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. 3. Troxell, G. E., Davis, H. E., and Kelly, J. W., Comparition and Properties of Concrete, Second Edition, McGraw-Hill,1%8. 4. " Standard Specification for Concrete Aggregates," American Society of Testing and Materials, ASTM C33-82. l 5. Civil and Stmetural Design Criteria for Calvert Cliffs Nuclear Power Plan! Unit No. I and 2, by Bechtel Power Corporation, Revision 0, August 2,1991. O 5/7/96 e A-3 Revision 2

l Freeze-Thaw 1 (% l 0 1 6. " Specification for Furnishing and Delivery of Concrete - Calvert Cliffs Nuclear l Power Plant Unit No. I and 2," CCNPP's Design Specification No. 6750-C-9, I Revision 8, April 1970. 7. " Building Code Requirements for Reinforced Concrete," American Concrete Institute, ACI 318-63. 8. " Examination of Fuel Oil Storage Tank #21 Enclosure - Calvert Cliffs Nuclear Power Plant," September 21,1994. 9. " Design and Control of Concrete Mixtures", Portland Cement Association,13* l Edition. l l l l I i -s l l i 1 l l l l 4 2 ( l \\ 577/96 m A-4 Revision 2 l

1 i j e i j Freeze-Thaw

O 6

Expansion, percent 0.20 Freeze.thow cycles: 300 0.18 { specimens: 3 x 3 :lik in. concrete prisms Cement: Type I,517 lb per cu yd } Slump: 2 3in. O.14 I k O.12 ,-{-in.monimum size aggregote ) 1 1 - )in. 0.10 ' I '" 0.06 k O.06 i p \\ O.04 V OD2 t t 3 't g e O 2 4 6 8 10 12 14 Air content, percent Figure A-1 Relationship between Air Content Aggregate Size and Concrete Expansion (Reference 3) O 5/7/96 E A-5 Revision 2

APPENDIX B - LEACHING OF CALCIUM HYDROXIDE O 1.0 MECHANISM DESCRIPTION' Water, either from rain or melting snow, that contains small amounts of calcium ions can readily dissolve calcium compounds in concrete when it passes through cracks, inadequately prepared construction joints, or areas inadequately consolidated during placing. The most readily soluble calcium compound is calcium hydroxide (lime). 'Ihe aggressiveness or affmity 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 i flowing liquid, ponding, or hydraulic pressure are more susceptible to degradation by leaching J than those structures that water merely passes over. Leaching of calcium hydroxide is visible on concrete surfaces that have dried. The teachate is almcst colorless until carbon dioxide is absorbed and the material dries as a white deposit. The white deposit is a product of water, free time from the concrete, and carbon dioxide that has been absorbed from the air. When calcium hydroxide is leached away, other cementitious constituents become exposed to chemical decomposition, eventually leaving behind silica and alumina gels with little or no strength.2 Leaching over a long period of time increases the porosity and pemicability of concrete, making it more susceptible to other forms of aggressive attack and reducing the strength of concrete. Leaching also lowers the Ph of concrete and threatens the integrity of the exterior protective oxide film ofrebar. l Resistance to leaching and efflorescence can be enhanced by using concrete with low p permeability. A dense concrete with a suitable cement content that has been well cured is less 9 gj susceptible to calcium hydroxide loss from percolating water because ofits low permeability and low absorption rate. The design attributes to enhance water-tightness include low water-to-cement ratio, smaller corse aggregate, long curing periods, entrained air, and thorough consolidation.8 Figure B-1 shows the impact on permeability due to water-to-cement ratio and curing time. 2.0 EVALUATION i 'l 2.1 Conditions j l The Fuel Oil Storage Tank #21 Enclosure walls and roof are exposed to the outside environment and are expected to have rainwater passing over the exterior surface. The enclosure roof is provided with a drainage system to prevent ponding. The enclosure foundation is four feet four inches below grade (elevation 42'-8"), and as such does not contact the ground water table. 1 O 5/7/96 m B-1 Revision 2

l Leaching of Calcium Hydroxide 2.2 Potential Aging Determination l Leaching of calcium hydroxide is a potential aging mechamsm for the following structural components of Fuel Oil Storage Tank #21 Enclosure because they could be exposed to i I flowing liquid, ponding, or hydraulic pressure: ) + Concrete foundation Functions LR S-1 and 2 + Concrete walls Functions LR-S-2 and 4 i + Concrete roof Functions LR-S-2 and 4 l i i where: l LR S-1: Provides structural and/or functional support (s) for safety-related l equipment. l LR-S-2: Provides shelter / protection for safety-related equipment. LR-S-4: Serves as a missile barrier (intemal or external). l 2.3 Impact on Intended Functions If the effects of leaching of calcium hydroxide 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 hpts listed m Section 2.2. 2.4 Design and Construction Considerations Leaching attack can be minimized by providing a low-permeability concrete mix design l during construction. CCNPP concrete design specification No. 6750-C-9* specifies: 9.3.1 1he Portland cement concrete furnished unless otherwise speciped herein, shall conform to ASTM C-94 Specifcationfor Ready Mix Concrete, ACI 318-63 Building Code Requirementsfor Reinforced Concrete, ACI 301-66 Standard Specipcationsfor Structural Concrete for Building, and ACI Manual ofConcrete Inspection. I2.1 Concrete Quality 12.1.1.1 Portlandcementshallconform to ASTM Designation C-94-67, Alternate No. I andACI301-66. t 4 'Q i i S/7/96 E B-2 Revision 2 1 L

l l Leaching of Calcium Hydroxide OO 12.1.2.1 Concreteshallmeetthefollowingrequiremenn: l Nonainet i 28 Day .bnp at Stung Madnaum Gau .nrength (psi) Point of Tolerance Aggregene Use anntLocanon Placennent (in) She (in) l B-l 3.000 3 3M in StructuralConcrete Walls & Slabs (B-2 alt) less than 12"shick & Congested Rebar. B-2 3.000 3 s% l-% in Turbine PedestalandOther StructuralConcrete 12.1.5 Mix Design l 12.1.5.1 The Constructor shall retain an approved Testing Laboratory, l at his own cost, to design and test initial concrete mixes. The initial l l mixes shall be designedin accordance with AC1 Standards 613 and 301 l to produce a required strength of15 percent over specified strengthfor reinforced concrete at 28 days and 25 percent over specified strength for post-tensioned concrete at 28 dmsfor each class ofconcrete with slump andmaximum si:es ofoggregate as specifiedin the Classification t Table (Section 12.1.2). l 12.1.5.2 The Constructor shallfurnish the Subcontractor with mit designs one month prior to the manufacture of concrete. Furnishing l mix designs shall not relieve the Subcontractor ofhis responsibilityfor l compliance with the provisions of the Specification. Where necessary, the Constructor shallincrease or decrease cementfactors as deemed j necessaryfor design mixes using statistical methods described in the ACI 214-65 for the particular class of concrete. An increase in the water-cement ratio ofa mit design or a decrease in its cement quantity shall constitute a new mir design and the provisions ofSection 12.1.5.1 ofthis Specification shallapply. Calcium chloride shallnot be used 2.5 Plausibility Determination Based on the discussion in Section 2.1, the Fuel Oil Storage Tank #21 Enclosure walls and l roof wall are exposed to water passing over the surface. The enclosure foundation is located above the designed underground water table and thus is not subjected to hydraulic pressure. However, as discussed in Section 2.4, concrete used for the FOST #21 Enclosure was 5 designed in accordance with ACI 318 and its relevant ACI standards and ASTM l specifications to maximize resistance to leaching of calcium hydroxide. A walkdown' observed only slight traces of leachate on the enclosure walls. This was judged to have no adverse impact on the integrity of the concrete. Therefore, leaching of calcium hydroxide is not a plausible aging mechanism for the enclosure foundation, w311s, roof slab. u) S/7/96 E B-3 Revision 2

l-i Leaching of Calcium Hydroxide O I 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 leaching of calcium hydroxide. Since leaching of calcium j hydroxide is not a plausible aging mechamsm that could degrade the enclosure's structural components, no management program is necessai.

3.0 CONCLUSION

i De Fuel Oil Storage Tank #21 Enclosure walls, and roof slab are exposed to water. No ponding or hydraulic pressure will form to leach the calcium hydroxide. The enclosure,s foundation is above the ground water table and therefore will not be subjected to flowing j water or hydraulic pressure. Additionally, the concrete mix was designed for low permeability i and high coupwive strength which provide the best protection against leaching. This conclusion is supported by a walkdown inspection' during which only minor traces of leaching marks were detected in various areas of the enclosure. nese indications werejudged to have no impact on FOST #21 Enclosure integrity. Therefore, leaching of calcium hydroxide is not a plausible aging mechamsm for any concrete stmetural components of the FOST #21 Enclosure. i -O-4.0 RECOMMENDATION i Leaching of calcium hydroxide is not a plausible aging mechanism for any concrete structural components of the Fuel Oil Storage Tank #21 Enclosure. No further evaluation or recommendation is required.

5.0 REFERENCES

1. " Class I Structures License Renewal Industry Report," EPRI's Project RP-2643 27, December 1991, 2. Troxell, G. E., Davis, H. E., and Kelly, J. W., Composition and Properties of Concrete, Second Edition, McGraw Hill,1968. 3. " Guide to Durable Concrete," American Concrete Institute, ACI-201.2R-67. 4. " Specification for Furmshmg 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. 5. " Building Code Requirements for Reinforced Concrete," American Concrete j institute, ACI 318-63. f i 6. "Exammation of the Fuel Oil Stor.uge Tank #21 Enclosure - Calvert Cliffs Nuclear /~'N Power Plant," September 21,1994. . V 4 i ( S/7/96 E B-4 Revision 2 l

Leaching of Calcium Hydroxide O 7. Concrete Manual, Eighth Edition, U.S. Department of the Interior,1975. 8. " Design and Control of Concrete Mixtures", Portland Cement Association, 11urteenth Edition. t I l O i l 1 4!O i l 5/7/96 E B-5 Revision 2

Leaching of Calcium Hydroxide 14 6 est per er 2.5 I 2.o m.ir.eees reer Speamous! 9e4 Adiuke eve

ace.1 f.S ws.o.co s.o os4 O

c= o.so \\ s i a r n e.ri.s et i.e % w e.e.re Effects of WateKement Ratio and Curing Duration on Permeability (Reference 8) 1 O i 5/7/96 Figure B-1E B-6 Revision 2

l I l APPENDIX C - AGGRESSIVE CHEMICALS O 3 1.0 MECHANISM DESCRIPTION i Concrete, being highly alkaline (pH > 12.5), is vulnerable to degradation by strong i acids. Acid attack can increase porosity and permeability of concrete, reduce its l alkaline nature at the surface of the attack, reduce strength, and render the concrete subject to further deterioration. Portland cement concrete is not acid-resistant, i although varying degrees of resistance can be achieved depending on the materials used and the attention to placing, consolidating, and curing. No Portland cement concrete, regardless of its composition, will withstand exposure to highly acidic fluids forlong periods. Below grade, sulfate solutions of sodium, potassium, and magnesium sometimes found in groundwater may attack concrete, often in combination with chlorides. The exposed surfaces of structures located 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 funher exposure to aggressive chemicals. Groundwater chemicals can also damage foundation concrete. A dense concrete with low permeability may provide an i acceptable degree of protection against mild acid attack. Any factors that tend to I v improve the compressive strength of the concrete will have a beneficial effect on low permeability. Therefore, the better the quality of the constituent material, the less permeable the concrete. Low water-to-cement ratio, smaller aggregate, long curing l period, entrained air, and thorough consolidation all contribute to watenightness. Concrete thus constmeted has a low permeability and :fTective protection against sulfate and chloride attack. Minimum degradation threshold limits for concrete have l 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. 2.0 EVALUATION l 2.1 Conditions The Fuel Oil Storage Tank #21 supplies fuel oil for the operation of the Emergency Diesel Generators, the Auxiliary Heating Boiler, and the Diesel-Driven Fire Pump. A walkdown confumed the only significant inventory ofliquid stored inside the Fuel Oil Storage Tank #21 Enclosure is No.2 fuel oil'. Petroleum oils; heavy, light, and d volatile have no effect on unprotected concrete. Therefore, the enclosure interior surface and all internal structural components are not exposed to the risk of aggressive chemicals. O S/7/96 E C-1 Revision 2

f l i Aggressive Chemicals llO There is no heavy industry near the CCNPP site that could release aggressive chemicals to the atmosphere. However, the enclosure concrete is exposed to an environment containing chloride ions due to the enclosure's proximity to the Chesapeake Bay. l The outside, below-grade surface of the enclosure is above the groundwater table. The potential for degradation by aggressive chemicals in the groundwater is not possible. 2.2 Potential Aging Determination Attack by aggressive chemicals is a potential aging mechanism for the following l concrete structural components of the enclosure because they are exposed to outside environment: + Concrete foundation Functions LR-S-1 and 2 + Concrete walls Functions LR-S-2 and 4 Concrete roof slab Functions LR-S-2 and 4 + /~'T where: g ] l l LR-S-1: Provides structural and/or functional support (s) for safety-l related equipment. l LR-S-2: Provides shelter / protection for safety-related equipment. I l LR-S-4: Serves as a missile barrier (internal or extemal). 2.3 Impact on Intended Functions t 1 i If the effects of attack by aggressive chemicals were not considered in the original i 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 l The FOST #21 Enclorure was constructed with concrete that complies with 2 CCNPP's design specification No. 6750-C-9 to assure low permeability. These properties provide the best protection against chemical attacks. 1 s% 5/7/96 E C-2 Revision 2

l Aggressive Chemicale O 2.5 Plausibility Determination l i Based on the discussion in Sections 2.1 and 2.4, attack by aggressive chemicals is i not a plausible aging mechanism for the Fuel Oil Storage Tank #21 Enclosure concrete. l 2.6 Existing Pingrams There are no existing programs at CCNPP that are designed specifically to identify or to repair damage to concrete due to aggressive chemicals. Since attack by aggressive chemicals is not a plausible aging mechanism for the Fuel Oil Storage Tank #21 Enclosure concrete, no management program is needed for these components.

3.0 CONCLUSION

Attack by aggressive chemicals is not plausible for the Fuel Oil Storage Tank #21 Enclosure concrete because: concrete with low permeability was used in construction of the enclosure; there is no heavy industry near the CCNPP site to release aggressive chemicals; the below-grade portion of the enclosure is above the groundwater table; and there are no source of aggressive chemicals stored inside the enclosure. j 4.0 RECOMMENDATION i Not Applicable.

5.0 REFERENCES

l. " 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. " Examination of Fuel Oil Storage Tank #21 Enclosure - Calvert Cliffs Nuclear Power Plant", September 21,1994. 4. " CRC Handbook of Tables for Applied Engineering Science", second edition; Table 6-57. l0 S/7/96 ll C-3 Revision 2

. ~, APPENDIX D - REACTIONS WITH AGGREGATES O 1.0 MECHANISM DESCRIPTION' 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 l solutions of deicing salt. However, it is only when the expansive reaction products l 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 l identified as alkali-aggregate, cement-aggregate, and expansive alkali-carbonate l reactions. Alkali-aggregate reaction, more properly designated as alkali-silica reaction, involves aggregates that contain silica and alkaline solutions. All silica minerals have the potential to react with alkaline solution, but the degree of reaction and ultimate damage incurred can vary significantly. Alkali-silica reaction can cause expansion and severe cracking of concrete structures. Reactive materials in the l presence of potassium, sodium, and calcium oxides derived from the cement react to form solids, which can expand upon exposure to water. Cement-aggregate reaction occurs when the alkalis in cement and some siliceous constituents of the aggregates react. This reaction is complicated by environmental conditions that produce high concrete shrinkage and alkali concentrations on the surface due to drying. Sand-gravel aggregates from some river systems in the Midwestern United States have been involved in deteriorated concrete attributable to j this reaction. Expansive alkali-carbonate reaction occurs between certain carbonate aggregates and l alkalis, and produces expansion and cracking. Certain limestone aggregates, usually l 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. Moisture must be available for chemical reactions between aggregates and alkalis to occur. Consequently, areas that are either consistently wet or alternately wet and dry are susceptible to deterioration given the presence of potentially reactive aggregates. t l O i 5/7/96 E D-1 Revision 2

} Reactions with Aggregates O The deleterious effects of reactive aggregates are best avoided by using aggregates from sources that have a proven record of service. If such records are unavailable, aggregates should be examined petrographically to identify potentially reactive constituents. Chemical reactions of aggregates for both fast and slow reaction rates were recognized as early as 1940. The method to identify the reactive constituents in concrete 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"' in 1952 and 1954, respectively. Both standards provide guidance for selecting aggregates and cements to avoid alkali-aggregate reactions. 2.0 EVALUATION 2.1 Conditions The aggregates used in the concrete of the CCNPP Fuel Oil Storage Tank #21 Enclosure 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. A walkdown of the FOST #21 Enclosure revealed no evidence of map cracking i which is a key indicator of aggregate reaction'. 2.2 Potential Aging Determination Reaction with aggregates is a potential Aging for the following concrete structural components if reactive aggregates were used in the concrete structure construction: + Concrete foundation Functions LR-S-1 and 2 Concrete walls Functions LR-S-2 and 4 Concrete roof slab Functions LR-S-2 and 4 where: LR-S-1: Provides structural and/or functional support (s) for safety-retated equipment. LR-S-2: Provides shelter / protection for safety-related equipment. LR-S-4: Serves as a missile barrier (internal or external). f( 5/7/96 E O-2 Revision 2

l l l Reactions with Aggregates qb 2.3 Impact on Intended Functions if the effects of reaction with aggregates were not considered in the original design l or are allowed to degrade the above structural components unmitigated for an j extended period of time, this aging mechanism could affect all the intended functions of components listed in Section 2.2. l i I 2.4 Design and Construction Considerations l l All aggregates used in construction of the CCNPP Fuel Oil Storage Tank #21 Enclosure were investigated, tested, and examined based on the following specifications: ) l i CCNPP's design specification No. 6750-C-9' specifies: 10.1.1.1 Cement shall be Portland cement, Type 11 conforming to ASTMDesignation C-150,... The cement shall not contain more than 0.60 percent by weight of alkalies calculated as Na Oplus 0.658 K 0. Only one brand ofcement shall be used l z 2 i for all uork... 0 15.2.3.1 The E!dder, at his expense, shall retain an l approved independent testing laboratory to sample and test i aggregates and the aggregate source in accordance with l methods as specified in ASTM Designation C-33. l Acceptability of aggregate and source shall be based on l thefollowingASTMtests: i I l MethodofTest ASTMDesignation i 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 if alluvial, 2-1/2 pounds each ofsand and coarse material which has been certified as sampled at the proposed aggregate source by an approvedtestinglaboratory. O S/7/96 m D-3 Revision 2

r l 1 l I r 1 h Reactions with Aggregates O 3 15.2.3.6.. Aggregates will be tested dseing theprogress - l of the work....Thefollowing user tests will be performed on every 4,000 tons ofaggregates delivered to theJobsite: i MethodofTest ASTMDes& nation l t l 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 i CCNPPs concrete specification. The aggregates used in the enclosure concrete were specifically investigated, tested, and examined in accordance with the ASTM l specifications to determine potential for reactivity with alkalis. i 2.5 Plausibility Determiention l Based on the discussion in Section 2.4, the aggreptes used in CCNPPs Fuel Oil Storage Tank #21 Enclosure concrete were specifically investipted, tested, and examined in ecce.A.ce with the pertinent ASTM specifications to minimize the potential for reactivity with alkalis. This conclusion is supported by a walkdown O inspection report' that documented no indications of concrete damage due to this mechanism. For these reasons, reactions with aggreptes will not degrade any concrete components of the enclosure and will have no adverse impact on the intended functions of these concrete structural components. Therefore, reaction with aggregates is not a plausible aging mechanism for any concrete structural components of the CCNPP Fuel Oil Storage Tank #21 Enclosure. 2.6 Existing Programis There are no existing programs at CCNPP that are designed specifically to identify or to repair damage incurred by reaction with aggregates. Since reaction with aggregates is not a plausible aging mechanism that could degrade the enclosure's structural components, no management program is necessary. )

3.0 CONCLUSION

1 l l Since the potential effects of aggrepte reactions on all concrete components were i j well known and understood, measures to avoid using reactive aggreptes were implemented for CCNPP in design specification No. 6750-C-9. The aggregates used i in the Fuel Oil Storage Tank #21 Enclosure concrete were specifically investigated, } tested, and examined in accordance with applicable ASTM specifications to minimize any reactivity of aggregates with alkalis. O. 4 5/7/96 E D-4 Revision 2 4 i i +

i I Reactions with Aggregates O 1 l 4.0 RECOMMENDATION Reaction with aggregates is not a plausible aging mechanism for any concrete l component of the CCNPP FOST #21 Enclosure and requires no further evaluation or recommendation. l

5.0 REFERENCES

i 1. " Class I Structures License Renewal Industry Report," EPRI's Project RP-1 2643-27, December 1991. 2. " Potential Reactivity of Aggregates (Chemical Method), American Society of Testing and Materials, ASTM C-289-66. l 3. " Petrographic Examination of Aggregates for Concrete," American Society i of Testing and Materials, ASTM C-295-65. 4. Letter from Charles County Sand & Gravel Co., Inc. to Bechtel Corporation, l June 30,1972. 5. " Specification for Furnishing and Delivery of Concrete - Calvert Cliffs Nuclear Power Plant Unit No. I and No. 2," Design Specification No. 6750-C-9, Revision 8, April 1970. 6. " Examination of the Fuel Oil Storage Tank #21 Enclosure - Calvert Cliffs Nuclear Power Plant," September 21,1994. i i 5/7/96 E D-5 Revision 2

t l APPENDIX E - CORROSION OF EMBEDDED STEEL /REBAR oU 1.0 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 i 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), conosion 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, aggregates, admixtures, and water), or they may be introduced environmentally. The ] seerity 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 pivanizing material is not considered a dissimilar metal, its application will not eggravate corrosion of the structure. m

d Studies have also been conducted to determine the effects of stray electrical currents on reinfc,rcing 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 i l under a given exposure and, hence, is more likely to have lower electrical conductivity and better resistance to corrosion. Such concrete also resists absorption of salts and their penetration into the embedded steel and provides a barrier to oxygen, an essential element of the corrosion process. Low water-txement ratios [ 5/7/96 a E-1 Revision 2

Corrosion of Embedded Steel /Robar Ov 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) is treated as embedded steel in the evaluation of corrosion effects, because of me environment and the technical basis for its corrosion induction. The base plates under the roof beams or those used as part of attachments to the concrete surface, and cast-in-place anchors are treated as structural steel, and the evaluation of their corrosion effects is addressed in Appendix K. 2.1 Conditions The only substance with a significant inventory stored inside the Fuel Oil Storage Tank #21 Enclosure is No.2 fuel oil. Based on the discussion in Appendix C, fuel oil has no effect on concrete. Thus the ability of the enclosure's concrete to protect the embeded steel /rebar is not diminished by the fuel oil. The primary area of concern for the enclosure is the chlorides in the atmosphere from the Chesapeake Bay could gain access to the embedded steel. This concern applies to both the interior and exterior turfaces of the enclosure since the enclosure is not a " weather-tight" structure and thus is exposed to this environment. The below-grade surfaces are above the groundwater table and will not be exposed to groundwater on a continuous basis. 2.2 Potential Aging Determination Corrosion of embedded steel /rebar is a potential aging mechanism for the following stmetural components of FOST #21 Enclosure because they are exposed to the outside environment and could be subjected to corrosive environments: + Concrete foundation Functions LR-S-1 and 2 + Concrete walls Functions LR-S-2 and 4 + Concrete roof slab Functions LR-S-2 and 4 O 5/7/96 a E-2 Revision 2

Corrosion of Embedded Steel /Rebar O i where: 4 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). l l 4.3 Impact on Intended Functions j 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 intended functions of components listed in Section 2.2. 2.4 Design and Construction Considerations i gs The Fuel Oil Storage Tank #21 Enclosure was constructed with concrete that l complies with CCNDP'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. During initial plant construction, a cathodic protection system was installed at the CCNPP site to mitigate steel corrosion,' including the rebars in the FOST #21 Enclosure wall and concrete basemat. 2.5 Plausibility Determination Based on the discussion in Sections 2.1 and 2.4, corrosion is not a plausible aging mechanism for embedded steel /rebar in the Fuel Oil Storage Tank #21 Enclosure's foundation, walls, and roof slab. This conclusion is supported by a 1994 walkdown inspection report' that documented no indications of damage to concrete due to corrosion of embedded steel /rebar. 2.6 Existing Programs There are no existing programs at CCNPP that are designed specifically to identify } or to repair damage of the concrete structure due to corrosion of embedded steel /rebar. O I S/7/96 E E-3 Revision 2 1

l l l Corrosion of Embedded Steel /Rebar

3.0 CONCLUSION

j Based on the discussion in Sections 2.1 and 2.4, corrosion of embedded steel /rebar is i not a plausible aging mechanism for concrete components of the Fuel Oil Storage Tank #21 Enclosure. No further evaluation required. 4.0 RECOMMENDATION 1 In addition, the existing cathodic protection system was designed for a service life of 40 years" and should be evaluated to ensure that the system will continue to perform l its design function during the license renewal period.

5.0 REFERENCES

1. " Class I Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991. /~'N 2. Skoulikidas, T., Tsakopoulos, A., and Moropoulos, T., " Accelerated Rebar V 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 Repor QFSAR)," Baltimore Gas and Electric Co. 5. " Examination of the Fuel Oil Storage Tank #21 Enclosure - Calvert Cliffs Nuclear Power Plant," September 21,1994. l I i O l 5/7/96 a E-4 Revision 2 l

APPENDIX F - CREEP C\\ V 1.0 MECHANISM DESCRIPTION' Creep is defined as the time-dependent increase of strain in hardened concrete that has been subjected to sustained stress. The sustained stress results from the dead load and live load of the stmeture and from temperature effects. Creep deformation is a function ofloading history, environment, and material properties of the concrete. The time-dependent deformation of concrete under compressive load consists of strain resulting from progressive cracking at the aggregate-cement paste interface, from moisture exchange with the atmosphere, and from moisture movement within the concrete. The effects of temperatures on creep are not linear. At 122 *F, creep strain is about two to three times as great as at room temperature (68 - 75 *F.) But from 122 'F to 212 F, creep strain continues to increase four to six times that experienced at room temperatures. While little is known about creep rate beyond 212 'F, the maximum creep rate may have occurred between 122 F and 176 'F.2 Creep is not visible because 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 f characterized as follows: Increased water-txement ratio results in increased creep magnitude. + Increased aggregate-to-cement ratio results in increased creep magnitude for a given volume of concrete. Creep deformation is approximately proportional to the applied load for a + level not exceeding about 40% to 60% of the ultimate strength of concrete. Concrete age at application of load affects creep (i.e., the older the + concrete, the less the creep). Creep increases with increased temperature. + Aggregate with a high modulus of elasticity and low porosity will + minimize creep. O Sf7/96 E F-1 Revision 2

l I Creep lO Creep-induced concrete cracks are typically not large enough to result in concrete deterioration or in exposure of the reinforcing steel to environmental stressors. Cracks of this magnitude do not reduce the concrete's compressive strength. Creep is significant when new concrete is subjected to load and decreases exponentially with time. Any degradation is noticeable in the first few years of plant life. According to ACI 209R-82,2 78% of creep occurs within the first year,93% within 10 years,95% within 20 years, and 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. Prestressed concrete structures may be subject to more pronounced creep and relaxation effects, particularly in combination with elevated temperatures. Its effect 1 is reflected in terms of prestressing loss in tendons, which is discussed in Appendix N. l 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 Detemination Creep is not a potential aging mechanism for any Fuel Oil Storage Tank #21 Enclosure's 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 enclosure's structural components. 2.4 Design and Construction Considerations The Fuel Oil Storage Tank #21 Enclosure was constructed of concrete with f.= 3,000 psi'. The primary function of the concrete enclosure is to provide tomado and tomado-missile protection for the fuel oil tank. Thus the concrete is seldom loaded to its design condition, and is subjected to low forces during normal plant operation condition. Therefore, creep in all concrete components is minimal because of the 5/7/96 m F-2 Revision 2

Creep low compressive stresses in concrete and the use of high-strength concrete. Besides, creep proceeds at a decreasing rate with age; normally,96 % of creep has occurred within 30 years.2 Therefore, creep is not expected to continue during the license renewal period. 2.5 Plausibility Determination Not applicable. j 2.6 Existing Programs Not applicable.

3.0 CONCLUSION

Most of the concrete creep occurred well before the time of license renewal application. Therefore, creep of concrete structural components should not be regarded as an aging mechanism for license renewal. 4.0 RECOMMENDATION Not applicable.

5.0 REFERENCES

1. " Class I Structures License Renewal Industry Report," EPRI's Project RP-2643-2'i, December 1991. 2. " Prediction of Creep, Shrinkage, and Temperature Effects in Concrete Structures," American Concrete Institute, ACI 209R-82. 3. BG&E Drawing 61-813-E, Rev 5; " Yard Tank Foundations, Sheet No.1 - Calvert Cliffs Nuclear Power Plant Unit No. I and 2, O 5/7/96 m F-3 Revision 2

APPENDIX G - SHRINKAGE oU I.0 MECHANISM DESCRIPTION' A workable concrete mix typically contains more water than is needed to offset the effects of hydration. When concrete is exposed to air, large portions of the free water evaporate. As water evaporates, capillary tension develops in the water remaining in the concrete while the concrete dries and shrinks in volume. Should these stresses exceed the tensile strength of the concrete, a crack forms. Initial shrinkage occurs during curing and continues months after placement. Subsequent drying and shrinkage occurs in concrete that is not continuously wet or submerged. 2 According to ACI 209R-82,91% of the shrinkage occurs during the first year,98% in 5 years, and 100% in 20 years. Excessive shriakage causes cracking of the concrete surfaces, which provides a means fe:' 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 ccnstruction. Most of the concrete shrinkage l 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 Determination Shrinkage is not a potential aging mechanism for any of the Fuel Oil Storage Tank

21 Enclosure concrete structural components 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 FOST #21 Enclosure structural components. 2.4 Design and Construction Considerations Since shrinkage can be minimized 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.' 4 Specification 6750-C-9 and Drawing 61-813-E specify a low slump of 3 ( 1/2) inches. p%) l 5/7/96 E G-1 Revision 2

Shrinkage i Since low slump concrete is used at Calvert Cliffs to minimize concrete cracks shrinkage of any concrete component of the enclosure is minimal. l 2.5 Plausibility Determination 1 Not applicable. l 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 J Not applicable.

5.0 REFERENCES

1. " Class 1 Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991. 2. " Prediction of Creep, Shrinkage, and Temperature Effects in i Concrete Structures," American Concrete Institute, ACI 209R-82 3. Design and Control of Concrete Mixtures, Ilth Edition, Portland l Cement Association, July 1968. 1 4. " Specification for Furnishing and Delivery of Concrete - Calven Cliffs Nuclear Power Plant Unit No. I and 2," CCNPP's Design Specification No. 6750-C-9, Revision 8, April 1970. l l S. BG&E Drawing 61-813-E, Revision 5; " Yard Tank Foundations, l Sheet No.1 - Calvert Cliffs Nuclear Power Plant, Units 1 and 2".

O W7/9C E G-2 Revision 2

1 i APPENDIX H - ABRASION AND CAVITATION O i 1.0 MECHANISM DESCRIPTION' 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 l significant amounts of concrete are removed by either of these processes, pitting or aggregate exposure occurs due to loss of cement paste. These degradations are readily detected by visual examination in accessible locations. Abrasion and cavitation occur only in concrete structures that are continuously exposed to flowing water. Cavitation damage is not common if velocities are less than 40 fps. In closed conduits, however, degradation due to cavitation can occur at l velocity as low as 25 fps when abrupt changes in slope or curvature exist. l 2.0 EVALUATION l i i 2.1 Conditions l The Fuel Oil Storage Tank (FOST) #21 Enclosure is not exposed to continuously flowing water. 2.2 Potential Aging Determination i Attack by abrasion and cavitation is not a potential aging mechanism for the structural components of FOST #12 Enclosure because it is not exposed to l continuously flowing water. 2.3 Impact on Intended Functions Not applicable. l 2.4 Design and Construction Considerations Not applicable. 2.5 Plausibility Determination Not applicable. I 2.6 Existing Programs Not applicable. 0 1 5/7/96 m H-1 Revision 2 l r

l l Abrasion and Cavitation !O

3.0 CONCLUSION

l 1 1 The CCNPP Fuel Oil Storage Tank #21 Enclosure is not exposed to continuously flowing water. Therefore, abrasion and cavitation are not a potential aging mechanism for any structural component of the enclosure. 4.0 RECOMMENDATION Not applicable.

5.0 REFERENCES

l 1. " Class I Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991. l O l l I i l l l l l l .I i i i O 5/7/96 E H-2 Revision 2 l

APPENDIX 1 - CRACKING OF MASONRY BLOCK WALLS O v i 1.0 MECHANISM DESCRIFTION2 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 for 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 concrete. Masonry block walls are vulnerable to unique age-related degradation l 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 l depending on the strength of the block wall materials and thus rarely j causes degradation of the concrete block wall. Moreover, expansion of the D wall is offset by shrinkage from carbonation and drying. Restraint against l V . free contraction causes tensile stresses within the wall. If these stresses l exceed the tensile strength of the unit, the bond strength between the l 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 curing, and the method of storage. Units made with sand and gravel aggregate will normally exhibit l the least shrinkage; those with pumice, the highest. The difference between the moisture content of the masonry units during construction and the building in use will determine the amount of shrinkage that High-pressure steam curing and proper drying of concrete occurs. 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. o l 5/7/96 ml.1 Revision 2 l

l I Cracking of Masonry Block Walls O l Durability of the masonry mortar used at the block joints may affect the l long-term structural integrity of the masonry block wall. Although aggressive environments and the use of unsound materials may contribute l to the deterioration of mortar joints, most degradation results from water entering the concrete masonry and freezing. l The mechanisms cited above which cause cracking of concrete block walls are age-related. Although they are ongoing processes throughout a plant's life, most cracking occurs in the early stages of plant operation. 2.0 EVALUATION l 2.1 Potential Aging Determination There are no masonry block walls in the Fuel Oil Storage Tank #21 l Enclosure. Therefore, this aging mechanism does not apply to the l enclosure. 2.2 Conditions Not applicable. 2.3 Design Considerations Not applicable. l 2.4 Impact on Intended Functions Not applicable. l l 2.5 Plausibility Determination Not applicable. 2.6 Existing Programs Not applicable. !lO 5/7/96 E l-2 Revision 2 l i

l l l l_ Cracking of Masonry Block Walls llO

3.0 CONCLUSION

l l Cracking of masonry block walls is not a plausible degradation mechanism for CCNPP's Fuel Oil Storage Tank #21 Enclosure. i l 4.0 RECOMMENDATION l Not applicable. l l

5.0 REFERENCES

1. " Class 1 Structures License Renewal Industry Report", EPRI's Project RP-2643-27, December 1991. i O l i !O S/7/96 E l-3 Revision 2

APPENDIX J - SETTLEMENT P \\ 1.0 MECHANISM DESCRIPTION 2 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 confined soil occurs due to excavation 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 has no effect on the structure and is not considered an aging i 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 settlement rate will decline after completion of construction. Settlement of structures is usually small and is typically determined by hm 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). When buildings experience significant settlement, cracks in structural members, differential elevations of supporting members bridging between buildings, or both may be visibly detected. 1 1 2.0 EVALUATION 2.1 Conditions 2 The bottom of the FOST #21 Enclosure spread footing is elevation 39.5 feet, which is approximately 20 feet below the average ground elevation as defined in the UFSAR section 2.7.6.2. The basemat is situated primarily on the Pleistocene deposit. This soil has a firm to dense consistency and is able support loads on the order of 2000 to 3000 psf without adverse settlement. This value increased by the weight of the removed overburden increases the soils bearing capacity to 3500 to 4500 psf. Thus the bearing capacity of the foundation strata is capable of supporting the FOST #21 Enclosure without excessive settlement. v 5/7/96 E J-1 Revision 2

-~ - Settlement O i 2.2 Potential Aging Determination Settlement is a potential aging mechanism for all structural components in the FOST #21 Enclosure. The concrete foundation is the only structural I component directly supported by the soil media, if excessive settlement j occurs in the foundation the effects will impact the concrete walls and roof slab. Thus the following structural components are subject to the l settlement aging mechanism. l Concrete foundation LR-S-1 and 2 + Concrete walls LR-S-2 and 4 + Concrete roof slab LR-S-2 and 4 j where: LR-S-1: Provides structural and/or functional support (s) for safety-related equipment. O V LR-S-2: Provides shelter / protection for safety-related equipment. LR-S-4: Serves as a missile barrier (internal or external). 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 components unmitigated for an extended period of time, this aging mechanism could affect ITLR functions LR-S-1,2, and 4 of the enclosure. 2.4 Design and Construction Considerations The FOST #21 Enclosure concrete spread footing is situated on firm to dense soil such that the enclosure structure tends to uniformly settle as a rigid body. Most of the predicted settlement is expected in terms of l uniform settlement, which has no adverse effect on the structural components of the enclosure. Any differential settlement is expected to be small and have negligible effect on the structural components. O lv S/7/96 m J-2 Revision 2

L Settlement O I The excavation for the FOST #21 Enclosure was above the groundwater table. A dewatering system was installed during plant construction to maintain the groundwater table at El.10'-0".2 This groundwater table level was considered in the original design of all underground structures.4 2.5 Plausibility Determination - Based on the discussion in Sections 2.1 and 2.4, the soil type at the CCNPP FOST #21 Enclosure is firm to dense. As discussed in Section 2.4, the expected settlement is small and the differential settlement is negligible. A dewatering system was installed to mininuze the fluctuation of groundwater table, thus providing stable geological conditions of the plant site. Therefore, settlement is not a plausible aging mechanism for any structural components of the FOST #21 Enclosure. 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 Fuel Oil Storage l Tank #21 Enclosure's structural components, no management program is s necessary.

3.0 CONCLUSION

CCNPP's FOST #21 Enclosure is situated on primarily Pleistocene deposit, j which is a firm to dense soil and will support light foundation loads without adverse settlement. Additionally, the bearing capacity of the soil .{ is nearly doubled when the weight of the removed overburden is considered. In addition, the groundwater table is maintained below the enclosure's foundation elevation. Long-term settlement is not expected to l continue after 40 years. Therefore, settlement is not a plausible aging mechanism for the structural components of the FOST #21 Enclosure. 4.0 RECOMMENDATION Settlement is not a plausible aging mechanism for the concrete components of the Fuel Oil Storage Tank #21 Enclosure and requires no further evaluation or recommendation. i!O l 5/7/96 m J-3 Revision 2

l l Settlement O i

5.0 REFERENCES

l 1. " Class I Structures License Renewal Industry Report," EPRI's l 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 l Components," International Atonde Energy

Agency, l

IAEA-TECDOC-670, October 1992. i 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. l lO I l l l l l l l O l S/7/96 m J-4 Revision 2

l l APPENDIX K - CORROSION OF STEEL O i 1 1.0 MECHANISM DESCRIPTION' Steel corrodes in the presence of moisture and oxygen as a result of electrochemical reactions. Initially, the exposed steel surface reects with oxygen and moisture to fonn an oxide film as rust. Once the protective oxide film has been formed and ifit is not disturbed by erosion, alternating wening and drying, or other surface actions, the oxidation rate will diminish rapidly with time. Chlorides, either from seawater, the atmosphere, or groundwater, incaase the rate of corrosion by increasing the clectrochemical activity. If steel is in contact with another metal that is more noble in the galvanic series, codoson may accelerate. In some cases, corrosion of structural steel in contact with water may be microbiologically induced due to the presence of cenain organisms, which is sometimes referred to as microbiologically influenced corrosion (MIC). These organisms, which include microscopic forms such as bacteria and macroscopic types i such as algae and bamacles, may influence corrosion on steel under broad ranges of pressure, temperature, humidity, and pH. MIC effects on carbon steel may result in random pitting and general corrosion. The rate of steel corrosion depends on site-specific environmental conditions and i s measures taken to prevent corrosion. A steel structure surface subjected to l alternately wet and dry conditions corrodes faster than one exposed to continuously J l 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 cormde much faster in the vicinity of seawater because of l 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 su faces 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 l 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 l coatings can be visually detected well in advance of significant degradation. l J S/7/96 mK1 Revision 2 I

i Corrosion of Steel r l i lO l 2.0 EVALUATION 2.1 Conditions Steel can cerrode in the presence of moisture and oxygen as a result of electrochemical reactions, especially in areas where there is exposure to the changing coastal atmospheric conditions. In the Fuel Oil Storage Tank #21 l Enclosure structural steel components such as steel beams, baseplates, metal decking, and cast-in-place anchors are vulnerable to corrosion from atmospheric l conditions since the enclosure is not a " weather-tight" facility. 2.2 Potential Aging Mechanism Determination ) Corrosion is a potential aging mechanism for the following enclosure structural steel ] components because conditions conducive to steel corrosion discussed in Sections ] l 1.0 and 2.1 exist: 1 + Steel beams Functions LR-S-2 and 4 Roofframing Functions LR-S-2 and 4 O Steei oeckinS r ctie ta-S-2 a 8 4 Base plates Functions LR-S-2 and 4 Cast-in-place anchois Functions LR-S-12 and 4 + + Post-Installed Anchors Functions LR-S-5 Bracing Functions LR-S-5 + Platform Hangers Functions LR-S-5 + Floor Grating Functions LR-S-5 + Stairs and Ladders Functions LR-S-5 i + Anchor Brackets Functions LR-S-1 l where: LR-S-1: Provides structural and/or functional support (s) for safety-related equipment. (O l S/7/96 m K-2 Revision 2

i l' Corrosion of Steel LR-S-2: Provides shelter / protection for safety-related equipment. LR-S-4: Serves as a missile barrier (intemal or external). j LR-S-5: Provides structural and/or functional suppon to non-safety related equipment whose failure could directly prevent satisfactory accomplishment of any of the required safety related functions. 2.3 Impact on Intended Functions If corrosion of steel is allowed to degrade the above structural steel components unmitigated for an extended period of time, this aging mechanism could affect all intended functions of components listed in Section 2.2. 2.4 Design and Construction Considerations Since corrosion was considered a potential degradation mechanism for structural steel components of the Fuel Oil Storage Tank #21 Enclosure, its effects were l 2 considered in the original design. Per BGE Drawing 61-813-E, eli exposed stmetural steel surfaces in the enclosure except the roof beams are hot dipped galvanized in accordance with ASTM A123, and the roof beams are coated in rdance with CCNPP's design specifications No. 6750-C-19' and No. 6750-A-ac l Maintenance of protective coatings on CCNPP's equipment and structures inside containment follows the requirements specified in Calven Cliffs Administrative 5 l Procedure MN-3-100. This program sets fonh procedural controls that comply with 10 CFR Pan 50, Appendix B and satisfy the protective coating requirements in Regulatory Guide 1.54 which endorses ANSI N101.4-1972. A walkdown' identified that the cast in place anchors and post-installation anchors used for stairway and platform suppon were painted after installation. 2.5 Plausibility Determination Based on the discussion in Sections 2.1,2.3 and 2.4, corrosion could affect the intended functions of all structural steel members and is, therefore, a plausible aging l mechanism for all steel components listed in Section 2.2. l 4 v 5/7/96 m K-3 Revision 2

l Corrosion of Steel i 2.6 Existing Programs System engineer walkdowns under PEG-7' will provide the discovery mechanism for degraded coating conditions. Conditions adverse to quality (such as degraded l paint or corrosion) is reported in an Issue Report under QI 2-100'. The coatings 8 l program under MN-3-100 provides the administrative control over how corrective ections are performed. The combination of these existing plant programs will ensure 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 l steel components that are not normally accessible. An age related degradation inspection program as defined in the BGE Integrated Plant Assessment Methodology l is necessary to address the aging effects of the non-accessible structural steel l components,

3.0 CONCLUSION

The Fuel Oil Storage Tank #21 Enclosure structural steel components, such as steel beams, baseplates, metal decking, and cast-in-place anchors are vulnerable to i corrosion attack if a corrosive environment prevails. All exposed structural steel surfaces in the FOST #21 Enclosure except for decking and grating, which are galvanized are covered with 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. 3.1 Aging management of degraded coating conditions on accessible structural steel in j the FOST #21 Enclosure is accomplished through the combination of existing plant programs. However, structural steel components not readily accessible require l additional aging management. I l 4.0 RECOMMENDATION i All coated structural steel components in the FOST #21 Enclosure should be inspected to evaluate the condition of the coating, and repaired as required. 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 i components that are not normally accessible. l t !O 5/7/96 E K-4 Revision 2

l Corrosion of Steel ) I i l

5.0 REFERENCES

l 1. " Class 1 Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991. ] 2. BGE Drawing 61-813-E, Rev 5; " Yard Tank Foundations, Sheet No.1, Calvert Cliffs Nuclear Power Plant Unit No. I and No. 2". 3. " Specification for Furnishing, Detailing, Fabricating, Delivering, and Erecting Structural Steel," CCNPP's Design Specification No. 6750-C-19, i Revision 3, September 1970. ] l 4. " Specification for Painting and Special Coatings," CCNPP's Design l Specification No. 6750-A-24, Revision 12, October 1982. l 5. " Painting and Protective Coatings," Calvert Cliffs Nuclear Power Plant Administrative Procedure MN-3-100, Revision 2, Date 4/2/96 6. " Examination of Fuel Oil Storage Tank #21 Enclosure - Calvert Cliffs Nuclear Power Plant", September 21,1994. O l 7. " Plant Engineering Section System Walkdowns", Plant Engineering Section Guideline PEG-7, Baltimore Gas and Electric Company, Revision 4,11/30/95. j j 8. " Issue Reponing and Assessment", Calvert Cliffs Nuclear Power Plant l Administrative Procedure QL-2-100, Revision 4. Date 1/2/96 ( l l l 1 O S/7/96 m K-5 Revision 2

APPENDIX L - CORROSION OF LINER od 1.0 MECHANISM DESCRIPTIONL2 1.1 Carbon Steel Liner Carbon steel liner corrosion can be either galvanic or electrochemical. Electrochemical corrosion of carbon steel is caused by exposure to aggressive aqueous solutions, which is described in Appendix K, " Corrosion of Steel." Galvanic corrosion occurs only in the presence of electrolyte when the electrical potential difference between dissimilar metals placed in contact with each other results in the flow of electrons between them. The less resistant metal becomes the anode in this couple and is subject to corrosion, while the more resistant metal becomes the cathode and corrodes very little, if at all. The rate of galvanic corrosion is a function of the potential difference between the metals and the geometric relationship of the metals. Galvanic corrosion reduces the thickness of the anode metal. Liner corrosion reduces liner plate thickness. Excessive reduction in thickness compromises the pressure retention capability of the liner. ("j 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 The stainless steel liner is prone to stress corrosion cracking (SCC), which is defined as cracking under the combined actions of corrosion and tensile stresses. The phenomenon of SCC can result in fracture of the metal. The stresses may be either applied (extemal) or residual (internal). 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 i little or no obvious visual evidence of corrosion. The three principal factors necessary to initiate stress corrosion cracking are tensile stresses, corrosive environment, and susceptible material. The tensile stresses necessary to cause SCC must be at or near the material's yield point. This is facilitated when the material is substantially cold worked, contains residual stress from welding, or is subjected to significant applied loads. l Different corrosive environments induce different levels of SCC on various materials. With respect to material susceptibility, austenitic stainless steels, such as SA-240 Type 304, are prone to SCC, particularly when g. 5/7/96 E L-1 Revision 2 l

Corrosion of Liner sensitization is' present as in heat-affected zones and at creviced geometries. In a sensitized condition, Type 304 stainless steel may develop intergranular stress corrosion cracking (IGSCC). The heat-affected zones of welds in Type 304 stainless 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 in boundaries combines with carbon. A low carbon content stainless steel, such as. Type 304L, is relatively immune to IGSCC in the fuel pool environments. This is because the low carbon content (0.03 percent maximum) of Type 304L results in sensitization levels during welding so low that its heat-affected zones are resistant to IGSCC in the fuel pool environments. 2.0 EVALUATION 2.1 Conditions The Fuel Oil Storage Tank #21 Enclosure does not contain any carbon steel or stainless steelliner plates. 2.2 Potential Aging Determination Corrosion of liners is not a potential aging mechanism for the Fuel Oil Storage Tank #21 Enclosure because no liners exist in the enclosure. 2.3 Impact on Intended Functions Not Applicable. 2.4 Design and Construction Considerations Not Applicable. 2.5 Plausibility Determination Not Applicable. O 5/7/96 E L-2 Revision 2

Corrosion of Liner O 2.6 Existing Programs Not Applicable.

3.0 CONCLUSION

Corrosion of liners is not a plaush degradation mechanism for CCNPP's Fuel Oil Storage Tank #21 Enclosure. 4.0 RECOMMENDATION Not Applicable.

5.0 REFERENCES

1. " Pressurized Water Reactor Containment Structures License Renewal Industry Report," NUMARC Report 90-01, O Revision 1, September 1991. V 2. " Class 1 Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991. O 5/7/96 E L-3 Revision 2

APPENDIX M - CORROSION OF TENDONS qb 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 tendons have been attributed to pitting, stress corrosion, hydrogen embrittlement, or some combination of these. Pitting is a highly localized form of corrosion. The primary parameter affecting its occurrence and rate is the environment surrounding the metal. The presence of halide ions, particularly chloride ions, is associated with pitting corrosion. Stress corrosion results from the simultaneous presence of a conducive environment, a susceptible material, and tensile stress. The environmental factors known to contribute to stress corrosion cracking (SCC) in carbon steels are hydrogen sulfide, ammonia, nitrate solutions, and seawater. Prestressing tendon anchor heads, which are constructed of a high strength, low alloy steel bolting maw al, are vulnerable to SCC. I Hydrogen embrittlement (technically, not a form of corrosion) occurs when hydrogen atoms, produced by corrosion or excessive cathodic protection potential, enter the metal lattice. Hydrogen produced by corrosion is not usually sufficient to result in hydrogen embrittlement of carbon steel. Cathodic polarization is the usual method by which this hydrogen is produced. The interaction between the dissolved hydrogen atoms and the metal atoms results in a loss of ductility manifested as brittle fracture. Corrosion of prestressing wires causes cracking or a reduction in the wires' I cross-sectional area. In either case, the prestressing forces applied to the concrete are reduced. If the prestressing forces are reduced below the design level, a reduction in design margin results. 2.0 EVALUATION l 2.1 Conditions Tendons are not used in the Fuel Oil Storage Tank #21 Enclosure. i l S/7/96 E M-1 Revision 2 l t

i l Corrosion of Tendons O l 2.2 Potential Aging Determination-i l l Not Applicable. 2.3 Impact on Intended Functions Not Applicable. l 2.4 Design and Construction Considerations Not Applicable. 2.5 Plausibility Determination Not Applicable. 2.6 Existing Programs Not Applicable. nU

3.0 CONCLUSION

Corrosion of tendons is not a plausible degradation mechanism for l CCNPP's Fuel Oil Storage Tank #21 Enclosure. 4.0 RECOMMENDATION Not Applicable. i 1

5.0 REFERENCES

1 1. " Pressurized Water Reactor Containment Structures License Renewal Industry Report," NUMARC Report 90-1, Revision 1, September 1991. i i O I S/7/96 E M-2 Revision 2

APPENDIX N - PRESTRESS LOSSES O l 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 + l + Reduction in wire cross section due to corrosion 2.0 EVALUATION 2.1 Conditions The Fuel Oil Storage Tank #21 Enclosure does not contain nor utilize any prestressed or post-tensioned elements. 2.2 Potential Aging Determination Prestress losses is not a potential aging mechanism for Fuel Oil Storage Tank #21 Enclosure since the structure contains no prestress or post-tensioned elements. 1 2.3 Impact on Intended Functions Not Applicable. 2.4 Design and Construction Considerations Not Applicable. l iO w- . n., nea.a

Prestress Losses O 2.5 Plausibility Determination Not Applicable. 2.6 Existing Programs Not Applicable.

3.0 CONCLUSION

Prestress losses is not a plausible degradation mechanism for CCNPP's Fuel Oil Storage Tank #21 Enclosure. 4.0 RECOMMENDATION Not Applicable.

5.0 REFERENCES

1. "Pressunzed Water Reactor Containment Structures License Renewal Industry Report," NUMARC Report 90-1, Revision 1, September 1991. 0 5/7/96 E N-2 Revision 2

r APPENDIX 0 -WEATHERING nU 1 l l l 1.0 MECHANISM DESCRIPTION 2 l Components and structures that are located in an environment that is exposed to ambient conditions are susceptible to degradation due to weathering (indoor and i outdoor). Aging mecharusms associded 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 shrmkage, l 2.0 EVALUATION 2.1 Conditions According to Specification ASTM C33-82, " Standard Specification for Concrete Aggregates," 2 the CCNPP site is located in the geographic region subject to severe weathering conditions. All outdoor components will experience the extreme temperature ranges, rain, snow, and changes in humidity expected at the l CCNPP site. Additionally, inside the Fuel Oil Storage Tank No. 21 Enclosure, components will experience simdar temperature and humidity changes, l throughout the life of the plant. 2.2 Potential Aging Detennination Weathering is a potential aging mechamsm for the following architectural components of the Fuel Oil Storage Tank No. 21 Enclosure because they are exposed to the outside environment or simdar in-building conditions: Caulking and scalants Functions LR-S-1 and 2 where: LR-S-1: Provides structural and/or functional support (s) for safety-related equipment. l LR-S-2: Provides shelter / protection for safety-related equipment. 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 mechamsm could affect all the intended functions of the components listed in Section 2.2. l l lO 5/7/96 E O-1 Revision 2

~.. Weathering O 2.4 Design and Construction Considentions Caulking and sealants used in the Fuel Oil Storage Tank No. 21 Enclosure contribute to the overall weatherization of the structure. The caulking and sealants are components which are typically replaced on condition. However, l inspections have indicated that that a program of inspection and maintenance should be developed. Issue Report IR1995-01698 3 was written to address this issue. 2.5 Plausibility Determination l Based on the discussion in Sections 2.3 and 2.4, weathering has been determmed to be plausible for caulking and sealants in the CCNPP Fuel Oil Storage Tank No. l 21 Enclosure. L 2.6 Existing Programs l The caulking and sealants do not have an established prograin to manage this aging mechanism. l

3.0 CONCLUSION

j Weathering is a plausible aging mechars;= for the caulking and sealants in the Fuel Oil Storage Tank No. 21 Enclosure. Management of the aging mechanism for j caulking and sealants will be established in conjunction with the resolution to 1 Issue Report IR1995-01698. 4.0 RECOMMENDATION A program should be established in conjunction with the resolution to Issue Report IR1995-01698 which will adequately manage this aging mechanism for the caulking and sealants in the Fuel Oil Storage Tank No. 21 Enclosure.

5.0 REFERENCES

1. " Class 1 Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991. 2. " Standard Specification for Concrete Aggregates," American Society of Testing and Materials, ASTM C33-82. l l 3. BCE Issue Report IR1995-01698, Building Joints (Aux. Bldg. Exterior), i dated 07/13/95. i lO 5/7/96 E O-2 Revision 2

APPENDIX R - ELEVATED TEMPERATURE O('M 1 l I.0 MECHANISM DESCRIPTION' During normal plant operation, solar heat load and equipment heat loads contribute to an increase in temperature of the internal environment of a stmeture. Of all stmetural components in a structure, only components made of concrete material are potentially affected within the temperature range in which the stmeture will experience during normal plant operating conditions. As a result of elevated temperature, compressive strength, tensile strength, and the modulus of elasticity of concrete could be reduced by greater than 10 percent in the temperature range of I 80 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. 2 ASME Code, Section III, Division 2 indicates that as long as concrete temperatures do not exceed 150 *F, aging due to elevated temperature exposure is not significant. Localized hot spots are limited in area and do not exceed 200 F by design. ACI-349' allows local area temperatures to reach 200 'F before special provisions are required. l 2.0 EVALUATION 2.1 Conditions The Fuel Oil Storage Tank #21 Enclosure is a concrete structure located in the " yard" west of the Unit No.2 Containment Building. The enclosure has several large openings to relieve tomadic pressure differentials. Thus the interior and exterior of the enclosure is subjected to outdoor ambient temperatures. The CCNPP was 8 designed for a temperature range of 20 *F to 90 'F. A walkdown confirmed the l enclosure contains no significant heat generators which could increase the enclosure temperature 2150 F'. 2.2 Potential Aging Determination Elevated temperature is not a potential aging mechanism for Fuel Oil Storage Tank j i

21 Enclosure since no source exists which could produce temperatures 2150 F.

l 2.3 Impact on Intended Functions Not Applicable. O S/7/96 m R-1 Revision 2 l l

l l l l Elevated Temperature O l 2.4 Design and Construction Considerations Not Applicable. l 2.5 Plausibility Determination Not Applicable. l 2.6 Existing Programs l Not Applicable. 1

3.0 CONCLUSION

Elevated Temperatures is not a plausible degradation mechanism for CCNPP's Fuel Oil Storage Tank #21 Enclosure. 4.0 RECOMMENDATION O l Not Applicable. i

5.0 REFERENCES

1. " Class I Structures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991. 2. " Code for Concrete Reactor Vessels and Containments," ASME Boiler and Pressure Vessel Code, Section III, Division 2,1986. 3. " Code Requirements for Nuclear Safety Related Concrete Structures," American Concrete Institute, ACI 349-85. 4. " Examination of Fuel Oil Storage Tank #21 - Calvert Cliffs Nuclear power Plant", September 21,1994 5. "Calven Cliffs Nuclear Power Plant, Units 1 and 2, Updated Final Safety Analysis Report (UFSAR)," Baltimore Gas and Electric Co. O 5/7/96 m R-2 Revision 2 l

APPENDIX S -IRRADIATION l 1.0 MECHANISM DESCRIPTIONn.21 1.1 Concrete t Concrete components in a nuclear power plant exposed to excessive neutron or i l gamma radiation (incident flux > 10 MeV/cm'-sec)D3 could be impaired due to l 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 l properties unless water loss is significant, depleting the presence of hydrogen atoms which contribute to concrete's shielding characteristics of fast neutrons. Typically, gamma radiation affects the cement paste portion of the concrete, producing heat and causing water migration. Existing experimental data provide some general information on the impact of direct Hl radiation on the mechanical properties of concrete. The average concrete sample does not begin to experience a compressive or tensile strength loss until exposure 2 exceeds a neutron fluence of 10" neutrons /cm. The experimental dataH1 indicate he minimal compressive loss for exposure up to 5x10" neutrons /cm. Figures S-1, S-2, 2 and S-3 address the impact of exposure on the compressive strength, modulus of elasticity, and tensile strength, respectively. Figure S-4 graphically presents the effects of gamma exposure on the compressive and tensile strengths of concrete. 1.2 Reinforcing Steel, Structural Steel, and Liner Steel degradation due to neutron irradiation is caused by the displacement of atoms from their normal lattice positions to form both interstices and vacancies. The effect of this mechanism is to increase the yield strength, decrease the ultimate tensile ductility, and increase the ductile-to-brittle transition temperature. These defects on a macroscopic level produce what is referred to as radiation-induced embrittlement, which is encountered in the design and operation of reactor pressure vessels. By comparing the currently available stress-strain curves for unirradiated and irradiated mild steel, a reduction in ductility of rebar subjected to high radiation exposure (> 10" neutrons /cm )is indicated.[5] 2 1.3 Tendon The effects of irradiation on prestressing wires in tendons are the same as those described for reinforcing steel with regard to the effects on yield strength and the modulus of elasticity. For prestressing wires, radiation exposure will cause a l O 5/7/96 m S-1 Revision 2

i irradiation O l decrease in the expected relaxation. The grease used in the tendon sheaths loses I viscosity due to gamma radiation.W 2.0 EVALUATION 2.1 Conditions The Fuel Oil Storage Tank #21 Enclosure is located in the " yard" west of the unit No. 2 Containment Building. The background radiation levels at the enclosure are very low (<2.5 mr/hr). A walkdown confmned the enclosure contained no high radiation sources'. Thus the total radiation exposure to the enclosure is very small and much less than the limits defined above. 2.2 Potential AgingDetermination Irradiation is not a potential aging mechanism for the Fuel Oil Storage Tank #21 Enclosure based on the low background radiation level, and the lack of a radiation source sufficient to produce the damaging radiation levels. G 2.3 Impact on Intended Functions i l Not Applicabic. 2.4 Design and Construction Consideration l l Not Applicable. l 2.5 Plausibility Determination I Not Applicable. 2.6 Existing Programs Not Applicable.

3.0 CONCLUSION

l Irradiation is not a plausible degradation mechanism for CCNPP's Fuel Oil Storage Tank #21 Enclosure. l /~'d 5/7/96 m S-2 Revision 2

t 1 j lrradiation O i I 4.0 RECOMMENDATIONS Not Applicable.

5.0 REFERENCES

1. " Class I Stmetures License Renewal Industry Report," EPRI's Project RP-2643-27, December 1991. 2. " Pressurized Water Reactor Containment Structures License l Renewal Industry Report," NUMARC Report 90-1, Revision 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, HJ., "The Effects of Nuclear Radiation on the Mechanical Properties of Concrete," Douglas McHenry International Symposium on Concrete and Concrete Structures, American Concrete Institute Publication SP-55,1978 5. Naus, DJ., " Concrete Component Aging and its Significance Relative to Life Extension of Nuclear Power Plants," NUREG/CR-4652, ORNLfrM-10059, Oak Ridge National Laboratory, Oak Ridge, Tenn., September 1986 l l 6. " Examination of Fuel Oil Storage Tank #21 - Calvert Cliffs Nuclear Power Plant", September 21,1994 l l l l l l eO 5/7/96 m S-3 Revision 2 l

i l APPENDIX T-FATIGUE iOv 1 1.0 MECHANISM DESCRIPTION' 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, localized damages to structural materials. Two types of fatigue exist for stmetural components. He first mechanism, sometimes I referred to as low-cycle fatigue, is low frequency (<100 cycles for concrete structures and <1 x 5 10 for steel structures) of high-level repeated loads due to abncrmal events such as SSE or strong winds. Structures exposed to such events must be thoroughly evaluated by analysis or by inspection or both after occurrence. The fatigue degradation caused by such loading may not occur or may occur only a few times during the service life of a structure. Therefore, low-cycle fatigue is not age-related and is not a license renewal issue. 1 The other fatigue mechanism is high frequency oflow-level, repeated loads such as equipment vibration. Referred to as high-cycle fatigue, it is an age-related degradation mechanism. 1.1 Concrete' 4 ) ne fatigue strength of concrete structures has become a concern due to the widespread adoption of ultimate strength design procedures and the use of high-strength materials that j l g require concrete structural members to perform satisfactorily under high-stress levels. j ( Repeated loading causes cracking in component materials of a member and alters its static i 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 cycle and N represents the number of cycles required to produce failure. A series of specimen testing determines fatigue behavior, and the results are plotted on a log-scale. At a given number of service cycles (N) the material has a defined allowable fatigue strength. Review of S-N curves 2 of plain concrete beams in ACI report 215R 74 indicates the following: Fatigue strength ofconcrete decreases with the increasing number ofcycles. The S-N curves for concrete are approximately linear between 10' and 10' cycles. i This indicates that there is no limiting value ofstress below which thefatigue hfe willbe infinite. j i 1 l A decrease ofthe range between maximum andminimum loadresults in increased fatigue strengthfor a given number ofcycles. When the minimum and maximum loads are equal, the strength ofthe specimen corresponds to the static strength of concrete determined under normal test conditions. Thefatigue strength ofplain concretefor a hfe of10 million cyclesfor tension, compression, orflexure is roughly about SS percent ofits static strength. Fatigue fracture of concrete is characterized by considerably larger strains and cracking as compared with fracture of concrete under static loading. l F7/96 E T-1 Revision 2

. - ~ - -. -~ - - 4 Fatigue O l Fatigue failure of reinforcing steel has not been as significant a factor in its application as for reinforcement in concrete stmeture. There have been few documented cases of reinforcing 2 fatigue failures in the concrete industry. ACI report 215R 74 notes that the lowest simss range known to have caused a fangue failure of a straight hot-rolled deformed bar embedded in a concrete beam is 21 ksi His failure occurred aAer 1.25x10' cycles of loading on a concrete beam containing a No.11, Grade 60 rebar, when the minimum stress level was 17.5 ksi. 1.2 Steel' i Fatigue of steel structures may cause progressive degradation and is mitiated by plastic l deformation within a localized region of the structure A nonunifonn 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 aAer the number of stress reversal cycles reaches the matenal's endurance limit. His is the maximum stress to which the steel can be subjected for a given service life. Such conditions will eventually produce a minute crack. The localized plastic movement further aggravates the nonuniform stress distribution, and further plastic movement causes the crack to grow, i The fatigue behavior of steel structures strongly depends on their surface conditions (e.g., whether they are polished or in an as-received condition). De fatigue strength of structural steel components is generally renresented by a modified Goodman diagram as shown in O. Figures T-2 and T-3, which is generated from the S-N curves. The fatigue strength of structural steel decreases as the number of cycles increases until the fatigue limit is reached. If the maximum stress does not exceed the fatigue limit, an unlimited number of stress cycles can be applied at that stress ratio without causing failure. 2.0 EVALUATION 2.1 Conditions ' ne Fuel Oil Storage Tank #21 Enclosure is designed for abnormal events such as seismic and i tomadic 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 enclosure. A walkdown confirmed the enclosure does not house any rotating or vibrating equipment'. Thus the enclosure is not subjected to high cycle, low-level repeated loads during normal operation. Derefore, the fatigue damage of the enclosure is not age-related. I i l' i l i O i 5/7/96. 5 T-2 Revision 2

l l Fatigue 2.2 Potential Aging Determination Fatigue is not a potential aging mechanism for the Fuel Oil Storage Tank #21 Enclosure l because it is not subjected to the high frequency oflow level, repeated loads. 2.3 Impact on Intended Functions Not Applicable. 2.4 Design and Construction Considerations Not Applicable. 2.5 Plausibility Determination Not Applicable. 2.6 Existing Programs Not Applicable. )

3.0 CONCLUSION

Fatigue is not a plausible degradation mechanism for CCNPPs Fuel Oil Storage Tank #21 Enclosure. 4.0 RECOMMENDATION Not Applicable.

5.0 REFERENCES

1. " Class I Structures License Renewal Industry Report," EPRI's Project RP-2643-

27. December 1991.

2. ' Consideration for Design of Concrete Structures Subjected to Fatigue Loading," American Concrete Institute, ACI 215R 74,1986. l i l O 5/7/96 E T-3 Revision 2 I

= l l Fatigue O 3. 'Exammation of Fuel Oil Storage Tank #21 Enclosure - Calvert Cliffs Nuclear Power Plant", September 21,1994 l l 4. Brockengrough, R.L., and Johnson, B.G., Steel Design Manual, United States Steel Corporation. l I l.O , Smin ~ E [Sman =0.75 1 c% d%'N %~ P=80% L 0.8 s s l s ' ~~. P=50%(avg.)/ N ~~~ ~ g* N 0.6 Smin L =5% % s - = 0.15 P 3 Smax moX d i Ir. Probability l .O.4 of Failure l O.2 i 1 L O-l 0 1.0 102 103 104 105 10' 107 Cycles to Failure, N Fatigue Strength of Plain Concrete Beams (Source: Reference 2) i .O 5/7/96 Figure T 15 T-4 Revision 2 ~

4 Fatigue O

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Y* ~ D. // ar AwUWE YEA.D POWT*yes, qm / f /' As s a s / \\ 20 Ng 'g ScumCE-US STEL APPtKD atm#0i f s M A IOOD00 CICLES s becauC18-SM m Putrts ( 5 400JDOCCitLES s e sancut Laar s CVC \\ [ Y < =. ~ =20 -40 0 e0. 20 30 ao 30 60 STIESEE G3, tai I i i Fatigue Strength of As-Received A36 1 Structural Carbon Steel (Source: Reference 4) l O 5/7/96 Figure T-2m T-5 Revision 2 \\}}

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