Assessment and management of ageing of major nuclear power plant components important to safety: concrete containment buildings

162 Pages·1998·10.562 MB·English

by  International Atomic Energy Agency

IAEA-TECDOC-1025
Assessment and
management of ageing of major
nuclear power plant components
important to safety:
Concrete containment buildings
m
INTERNATIONAL ATOMIC ENERGY AGENCY
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ASSESSMED MNNAAT NAGEMENF AOTG EINF MGO AJOR
NUCLEAR POWER PLANT COMPONENTS IMPORTANT OT SAFETY:
CONCRETE CONTAINMENT BUILDINGS
IAEA, VIENNA, 1998
IAEA-TECDOC-1025
ISSN 1011-4289
©IAEA, 1998
Printed by the IAEA in Austria
June 1998
FOREWORD
At present, there are over four hundred operational nuclear power plants (NPPs) in
IAEA Member States. Operating experience has shown that ineffective control of the ageing
degradation of the major NPP components (e.g. caused by unanticipated phenomena and by
operating, maintenance, designr o manufacturing errors),n ac jeopardize plant safetyd na also
plant life. Ageing in NPPs must be, therefore, effectively managed to ensure the availability of
design functions throughout the plant service life. From the safety perspective, this means
controlling within acceptable limits the ageing degradation and wearout of plant components
important to safety so that adequate safety margins remain, i.e. integrity and functional
capability in excess of normal operating requirements.
This TECDOa nCi esno sie riesf o reporte hst no assessmen dtna managementfo
ageing of the major NPP components important to safety. The current practices for the
assessment of safety margins (fitness-for-service) and the inspection, monitoring and
mitigatf iooang eing degradatf ioosne lected componef noCts anada deuterium-uranium
(CANDU) reactor, boiling water reactor (BWR), pressurized water reactor (PWR), and water
moderated, water cooled energy reactor (WWER) pl eadrnoatsc ume rheeptn onteridt s. These
practice irenas tendeo hdt e llliapn volved direcd itnnlayd irectn leyi nsure isnhagt fe operation
of NPPs; and also to provide a common technical basis for dialogue between plant operators
and regulators when dealing with age-related licensing issues. Since hert epore trasw ritten
from a safety perspective, they do not address life or life-cycle management of the plant
components, which involves the integration of ageing management and economic planning.
The target audience of the reports consists of technical experts from NPPs and from
regulatory, plant design, manufacturing and technical support organizations dealing with
specific plant components addressed in the reports.
The component addressed in the present report is concrete containment buildings of
nuclear power plants. The report presents results of a Co-ordinated Research Programme
(CRn PoM) anagemenf ot Ageinf go Concrete Containment Buildings is tbI. asae ndo
combination of a worldwide survey of NPP owners/operators, knowledge of practice in
Member States of the CRP participants, and literature reviews. The report was finalized using
a feedback fry ao1Mm 9a 97 Technical Committee meeting, whis caawht tende ydbt echnical
experts from nine Member States.
e hcTontrib eudhttor aortfs td irnneagv ie fwoth is TECDOe riCaddn een etihfti tead
of this publication. Their wors kig reatly appreciaten dIp. articule ahcrto, ntributiof onD .J.
Naus of the USA is acknowledged. The IAEA officer who directed the preparation of the
report was J. Pachner of the Division of Nuclear Installation Safety.
EDITORIAL NOTE
In preparing this publication for press, staff of the IAEA have made up the pages from the
original manuscrlpt(s). The views expressed do not necessarily reflect those of the IAEA, the
governments of the nominating Member States or the nominating organizations.
Throughout the text names of Member States are retained as they were when the text was
compiled.
e Tosufh ep articular designations of countrr ieotes rritories dt ooiy mnejnus padlyg emyebnt
the publisher, the IAEA, as to the legal status of such countries or territories, of their authorities and
institutions or of the delimitation of their boundaries.
The mention of names of specific companies or products (whether or not indicated as
registered) does not imply any intention to infringe proprietary rights, nor should it be construed as
an endorsement or recommendation on the part of the IAEA.
CONTENTS
1. INTRODUCTION .............................................................................................................1
1.1. Objective........................................................................................................................!
1.2. Background....................................................................................................................!
1.2.1. Safety aspects of concrete containment building (CCB) ...................................1
1.2.2. Need for systematic ageing management of CCB.............................................1
1.2.3. IAEA programme on safety aspects of NPP ageing..........................................3
1.2.4. Implementation of CRP on management of ageing of CCBs............................4
1.3. Scope..............................................................................................................................5
1.4. Structure of report..........................................................................................................5
References to Chapter 1 ...................................................................................................................6
2. CONCRETE CONTAINMENT BUILDINGS.......................................................................7
2.1. Description.....................................................................................................................?
2.1.1. Pressurized water reactors..................................................................................7
2.1.2. Boiling water reactors........................................................................................?
2.1.3. Pressurized heavy water reactors.....................................................................10
s cooaled rGeactors......2....1.. ..4............................................................0.........1...... ....
2.1.5. Water-water power reactors.............................................................................10
2.2. Materials fo construction.............................................................................................14
2.3. Applicable codes and standards ...................................................................................23
References to Chapter 2.................................................................................................................23
3. UNDERSTANDING AGEING............................................................................................24
3.1. Ageing..........................................................................................................................24
3.2. Ageing mechanisd menfasf ects...................................................................................24
3.2.1. Concrete...........................................................................................................24
3.2.2. Mild steel reinforcing.......................................................................................35
3.2.3. Prestressing systems.........................................................................................37
3.2.4. Liners ...............................................................................................................39
3.2.5. Structural steel piles.........................................................................................40
3.2.6. Anchorages.......................................................................................................40
References to Chapter 3.................................................................................................................41
4. DETECTING AGEING........................................................................................................44
4.1. Current practice............................................................................................................44
4.1.1. Concrete...........................................................................................................44
4.1.2. Reinforcing steel..............................................................................................60
4.1.3. Prestressing systems.........................................................................................62
4.1.4. Penetrations......................................................................................................64
4.1.5. Liners ...............................................................................................................64
4.1.6. Waterstops, sd egnaaalss kets ..........................................................................66
4.1.7. Protective coatings...........................................................................................66
References to Chapter 4 .................................................................................................................67
5. ASSESSMENT AND REPAIR OF AGEING EFFECTS ....................................................68
5.1. Initial considerations....................................................................................................68
5.2. Mitigatiod rnnae pair methods.....................................................................................71
5.2.1. Techniques and materials for repair of damaged concrete...............................71
5.2.2. Remedial measure technir qcouoefrrs osion-damaged concrete......................84
5.2.3. Remedial measures for liners and coatings......................................................90
5.3. Existing guidelines.......................................................................................................91
Refereo nCcthea spter 5.................................................................................................................92
6. OPERATING EXPERIENCE...............................................................................................95
6.1. Degradation experience................................................................................................95
6.2. Inspection experience...................................................................................................95
6.2.1. Methods utilized by owners/operators.............................................................95
6.2.2. Observation nmos ethods used.......................................................................107
6.3. Repair experience....................................................................................................... 111
Referenceso t Chapter 6...............................................................................................................111
7. CONCRETE CONTAINMENT BUILDING AGEING
MANAGEMENT PROGRAMME.....................................................................................112
7.1. Understanding ageing ................................................................................................114
7.1.1. Awareness of generic concrete ageing issues ................................................114
7.1.2. Assemy pebkl lfayo nt documentation...........................................................116
7.2. Definitionf oc oncrete containment building AMP....................................................118
7.2.1. Interim ageing assessment..............................................................................119
7.2.2. Programme definition ....................................................................................119
7.3. Operation ..................................................................................................................121
7.4. Inspection, monitorind gnca ondition assessment......................................................121
7.4.1. Insped mcntiooann itoring .............................................................................121
7.4.2. Condition assessment.....................................................................................122
7.5. Maintenance............................................................................................................... 124
7.6. Optimizing.................................................................................................................127
References to Chapter 7............................................................................................................... 127
. 8 CONCLUSD IRONENACSO MMENDATIONS .............................................................129
8.1. Conclusions................................................................................................................129
8.2. Recommendations......................................................................................................130
APPENDIX I: CURRENT AGEING MANAGEMENT PRACTICES AND
OPERATING EXPERIEN FSCOEEV ERAL MEMBER STATES.........3..3..1.. .
APPENDIX II: AGEING EXPERIENCE OF NON-NUCLEAR
CONCRETE STRUCTURES...........................................................................145
CONTRIBUTORS TO DRAFTING AND REVIEW .................................................................157
1. INTRODUCTION
1.1. OBJECTIVE
e hT objectivef o this report ot si presente ht results eht fo Co-ordinated Research
Programme (CR ePhMt n)o anagemenf toA geingf oC oncrete Containment Buildings (CCBs)
addressing current practicesd na techniquesr of assessing fitness-for-servicehte dna
inspection, monitord inmnagi tigatiof oan geing degradatif ooCn CBs. This report aimots
provide a technical basis for developing and implementing a systematic ageing management
programmd neaa lsr oodf ialogue between nuclear power plant (NPP) operatord nrsa egulators
when dealing with age-related licensing issues.
1.2. BACKGROUND
1.2.1. Safety aspects of concrete containment building (CCB)
Concrete containment structures are designed to separate the reactor and other systems
and equipment important to safety from the outside environment. External and internal events
are considered in the design. External events include earthquake and severe weather
conditions (e.g. floods and tornadoes), as well as potential missile impingement (e.g. aircraft
and turbine blades). Critical internal events include loss-of-coolant accidents (LOGAs) and
high-energy-line breaks. The containment is designed to withstand the loadings resulting from
the above postulated events and represents the final physical barrier to radioactive material
befoe roehu ttrsei ldoeeat see nvironment. Potential age-related dega racdo anftcoiroen te
containment building, including its various subcomponents, must be effectively controlled to
ensus rrtiee quired leaktightnd esnstars uctural integrity.
1.2.2. Neer sodfy stematic ageing manageBmCCen fot
e dhTesign lf ieofex isting Ns PoaPwftse n che o3bs 0eo-tn4 0 years. However, current
economic presn suuotiro leie sttxiet esnd plant serv 0iyc6eea (rlisf etotal bea iqnug oted
target) and decommissioning strategies that involve use of the containment as a "safestore" for
0 y0e1ar os,t p mpeureia ofndo e s tchhoatnt tainment buildy hianam ogvptse e rform safety
fua ntci mrtiooefn ps eriod significantly greater than their initial design life.
Concra ed stuie rable mas pttiee drrnifaaol rmae nch scpatoe afnortt ainment function
in NPPs has been good. However, experience shows that ageing degradation of CCBs, often
caused or accelerated by factors such as faulty design, use of unsuitable or poor quality
materials, improper construction, exposure ot aggressive environments, excessive structural
loads, and accident conditions, could impair its safety functions and thus increase the risk to
public dhsnaefaaelttyh . Effectivs etih ea rgBeefioCnrgeC mre aqenuaohigrtteedm feont 1
ensure its fitness-for-service throughout the plant service life.
A numf eP boxpePi rrsoNtginrag mmes, ss puacehr iodic inspd etcednstniatoinan g ,
preventive and corrective maintenance, contribute to the ageing management of CCBs. The
effectivend enesafsf icB aiCegCne cfioyn g managee mbim enanpct rove ybidn tegratidnnag
'in the Electric Power Research Institute document Common Ageing Terminology (1993) ageing management is
e ehntdgei nfsieaneerd ing, operd amtnioaanins tenance acto ioctnos ntrol within acceptable limits ageing
degradation and wear out of systems, structures or components.
Review Pertinent Background
Materials and Documentation
CCB
Component Selection
Select Components
for Evaluation
1 1 | 1
Inspectiondna
Visual Field Laboratory Inspection/Surveillance
Surveillance
Examinations Testing Testing
Data
1 1 1 1
Curd Frneunatut re
Condition Assessment
Continued Service
Structural
Component Determination
Reliability
Determination
FIG. 1.1. Example of programme for evaluation of current condition and estimation of future
performance of concrete containment buildings.
modifying these programmes, as appropriate, within a systematic ageing management
programme (AMP), Figur 1.e1p resene tnaso pprw oothah ocet shsa e various programmes
would integrate ina tpo rograr mee ovcmhuafler tur eafntioto cn ond deenistthiiaomtn a ftioon
future performance of CCBs. Development of a systematic ageing management programme
eaihnnttde y erealkecmt ifooennf sotus ca ph rograme dmriase cussed lan tteihr is report.
1.2.3. IAEA programn msoaef ety Pa agPseNpine gfcots
o Tassist Member Stan tieusn derstanding age foinsyg stems, strucdtnuares
components (SSCs) important to safety and in effective ageing management of these SSCs,
the IAEAn i 1989 initiateda projecn ost afety aspP ePacNgt fsoe ing. This project integrates
information on the evaluation and management of safety aspects of NPP ageing generated by
Member States into a common knowledge base, and derives guidance and assists Member
States in the application of this guidance. Results of this work are documented in Refs [1.1-
1.7].
The Safety Practices publication Data Collection and Record Keeping for the
Management of Nuclear Power Plant Ageing [1.2] provides information on data requirements
r doa astayad fsnrc tedeocnm lolredac tikoe neping. General data nee edgsr,r owuapheicd h
into three categories (baseline data, operating history data, and maintenance history data), are
illusy trsbaetvede ral examf pocloems ponent-specific data requirements. Actual record
keeping systems, includinn gaa dvanced system eraa, lso describe ehpt dnui blication.
Managing physical ageiP PncN ogfo mponents importano tt safety requires predicting
and/or detecting when a plant component will have degraded to the point that the required
safety margins are threatened and taking appropriate corrective or mitigative actions. The
methodology for the management of ageing of NPP components important to safety is
documentedn i Ref. [1.3d ]nac onsistsf o three basic steps:
(1) Selecting,e sfharoftemt y perspective, plant componen wniths ich ageing should
be evaluated, by assessing the effects of ageing degradation on the ability of the
componeo npttes rform their design func dctniroeands iting existing programmes
and activities that manage ageing effectively.
(2) Performing ageing management studies for the selected components to
determine appropriate ageing management ace thitowTnos- .phased method
reviews current understanding, monitoring and mitigation of the components'
ageind gnai, dentifie ros develops effectid vnaep ractical technologdnay
practices for its monitoring and mitigation.
(3) Using results of the ageing management studies to take appropriate management
actions (i.e. improving existing operations and maintenance practices and the
design) and to improve relevant codes, standards and regulatory requirements.
Development of the above consensus guidance is beneficial in its own right because it
provides opportunit rioefps ractitioners from organizations with both dird eniacnt direct
responsibility for nuclear safety to address in an interactive environment important issues of
common interest and to learn from each other. However, it is the actual application of
guidance that has a positive impact on nuclear safety. The IAEA therefore devotes significant
effort in assisting Member States in the application of its guidance.