application of lifetime management for mechanical systems ... · symp. on npp life management,...

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1 2nd Intern. Symp. on NPP Life Management, 15.-18. October 2007, Shanghai, China

Application of Lifetime ManagementApplication of Lifetime Managementfor Mechanical Systems, Structuresfor Mechanical Systems, Structures

and Components (SSC)and Components (SSC)in Nuclear Power Plantsin Nuclear Power Plants

E.E.RoosRoos, K., K.--H.H.HerterHerter, X.Schuler , X.Schuler MPA Stuttgart University, GermanyMPA Stuttgart University, Germany

W.W.HienstorferHienstorferTTÜÜV SV SÜÜD ET, D ET, FilderstadtFilderstadt, Germany, Germany

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� Introductory remarks

� Current activities

� Methodology

� Procedures for application

� Summary

ContentsContents

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Introductory remarksIntroductory remarksTheThe GermanGerman atomic energy act requires thatatomic energy act requires that“... every necessary precaution has been taken in the light ofexisting scientific knowledge and technology to prevent damage resulting from construction and operation of the installation. ...”This has been realised in guidelines and in the nuclear standards.� Safety resp. the quality of the systems, structures and components (SSC) is provided by the design, the material and manufactureing.

� The quality of the SSC shall be guaranteed and documented through-out the lifetime (extensive quality assurance during manufacture, construction, and operation).

� Operational parameters of the stressors relevant to the integrity of the SSC are monitored.

� Operational experience is recorded and evaluated safety related.

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Introductory remarksIntroductory remarks

for mechanical components

for mechanical components

Guidelines and standards contain all the demands for safe operation throughout the life time (life time management), for control of the ageing phenomena (ageing management - AM) as well as for the proofof integrity (for mechanical SSC). Within this approach AM is a key element.

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Introductory remarksIntroductory remarksDefinitionsDefinitionsLife time management - integration of ageing management andeconomic planning for SCC in order to

� optimise the operation, the maintenance and the life time of the plants

� maintain an accepted level of safety and performance as well as � maximize return on investment over the life time of the plant

Ageing - time-dependent gradually change of features andproperties related to their function

� the engineering (mechanical SSC, buildings, electrical equipment)

� the systems and control devices relevant to the operation of the plant

� the specifications and the documents as well as� the operating staff

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Introductory remarksIntroductory remarksDefinitionsDefinitionsAgeing management (AM) - engineering and organisational actions to guarantee safe operation during the life time including control of the ageing phenomena. Guarantee the safe operationof the SSC for the life time by engineering measures andmaintenance actions to control within acceptable limits ageing phenomena.Ageing phenomena� Conceptual (modification of requirements of safety and philosophy)

� Technological (latest results on possible in-service damage mechanisms, on material resp. properties of components, on test methods, on analysis methods, on assessment methods, etc.)

� Material-mechanical or physical (in-service ageing mechanisms generally caused by the material resp. change in material characteristics, by the operational loads and by the operational environmental conditions up to now)

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Introductory remarksIntroductory remarksDefinitionsDefinitionsTechnological and material-mechanical ageing denotes all technical andorganisational measures that guarantee the recording, monitoring andcontrol of all possible in-service damage mechanisms.Within the proof of integrity it has to be demonstrated that the bearing capacity is given for all relevant operational loads as well as accidental loads for the life time taking into account the specified or monitored number of load-cycles. These definitions and considerations agree well with the international procedures.

In the following the focus is on� material-mechanical ageing � proof of integrity

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Introductory remarksIntroductory remarksRetrospective viewRetrospective view -- Essential Essential aktivitiesaktivities in Germany in in Germany in the pastthe past

Source: GRS (2003) Cologne

GRS activities

Operational conditions Higher load levels under

beyond design conditions

� Ageing � Obsolescence� Conservationof knowledge

Plant specific reports of the plant operators

SR 441ALSTER I

SVA seminar

Determination and assessment of ageing parameters influencing the reliability of technical components

Overall aspects of ageing management

SR 2223 SR 2319 SR 2423

VdTÜV position paperTÜV ET-BW

report RSKprinciple paper

Subject specific RSKcomment

TÜV-Nord position paper

ESN position paper

„List of topics“ VGB report

BfS report

KTA winter seminar

AK „Aufsicht-RB“

Source: GRS (2003) Cologne

GRS activities

Operational conditions Higher load levels under

beyond design conditions

� Ageing � Obsolescence� Conservationof knowledge

Plant specific reports of the plant operators

SR 441ALSTER I

SVA seminar

Determination and assessment of ageing parameters influencing the reliability of technical components

Overall aspects of ageing management

SR 2223 SR 2319 SR 2423

VdTÜV position paperTÜV ET-BW

report RSKprinciple paper

Subject specific RSKcomment

TÜV-Nord position paper

ESN position paper

„List of topics“ VGB report

BfS report

KTA winter seminar

AK „Aufsicht-RB“

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Introductory remarksIntroductory remarksRetrospective viewRetrospective view -- Essential Essential aktivitiesaktivities in Germanyin Germany

RSK recommendationand subject specificRSK comments for

ageing management

2002 2003 2004 2005 2006 2007

Decision of the Nuclear Safety Standards

Commission (KTA) to prepare a new nuclear safety standard KTA 2301 „Ageing

Management of NPP“

On 26 April 2002 the "Act onthe structured phase-out of

the utilisation of nuclear energy for the commercial generation of electricity"

entered into force.

RSK recommendationand subject specificRSK comments for

ageing management

2002 2003 2004 2005 2006 2007

Decision of the Nuclear Safety Standards

Commission (KTA) to prepare a new nuclear safety standard KTA 2301 „Ageing

Management of NPP“

On 26 April 2002 the "Act onthe structured phase-out of

the utilisation of nuclear energy for the commercial generation of electricity"

entered into force.

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Current Current activites activites

RSK RSK -- CommentsComments andand RecommendationRecommendation on on „„Management ofManagement ofAgeing ProcessesAgeing Processes at NPPat NPP““ ((JulyJuly 22, 2004)22, 2004)

� An effective AM concept shall to be implemented for the SSC with regard to the safety-related relevance.

� The plant relevant ageing mechanisms shall to be identified and pursued.

� AM shall to be implemented as a permanent task on a highmanagement level in connection with the management responsible for safety.

� An annual report on AM shall be submitted to the competent supervisory authority of the different German states.

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Current Current activites activites PrepareingPrepareing aa new Safetynew Safety Standard KTA 2301Standard KTA 2301„„AgeingAgeing Management of NPPManagement of NPP““

Contents of the KTA 2301� Fundamentals� Scope� General principles� Application to mechanical SSC� Application to buildings and structures� Application to electrical and I&C SSC� Application to operating supplies

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MethodolgyMethodolgy

BasicBasic PrinciplesPrinciples ofof AgeingAgeing ManagementManagement� An effective AM is the basis to preclude possible losses of qualityand is distinguished by well-aimed countermeasures on a broad knowledge base.

� Shall be applied to mechanical SSC, to structural SSC (buildings),to electrical and I&C SSC and to operating supplies.

� General aspects are � Component selection and grouping (based on the safety relevance)� Evaluation of possible degradation/ageing mechanisms in opeation� Control the relevant degradation/ageing mechanisms all the life time� Evaluation of the efficiency of the AM

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BasicBasic PrinciplesPrinciples ofof AgeingAgeing ManagementManagement� Grouping of the SSC depends on the safety relevance:� Group 1 - SSC shall not fail all the life time (proof of integrity -

“proactive approach” prevents damage)� Group 2 - SSC may fail in a single case, but a common mode

failure shall be excluded (preventive maintenance)� Group 3 - the SSC may fail, no specific requirments

� A proactive knowledge-based ageing management shall be implemented process oriented, based on e.g. a PDCA cycle (Plan – Do – Check – Act).

� The efficiency of the AM shall be evaluated/qualified in periodical intervals.

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LifeTime

ManagementAg

e ing

Mana

gem e

nt

Proo f

o fIn t

e grity

Failure of a single component is allowed,

common-mode-failure shall be excluded(group 2)

Failure of a componentshall be excluded

(group 1)

No specific requirement for thequality of the components for the

ongoing operation(group 3)

LifeTime

ManagementAg

e ing

Mana

gem e

nt

Proo f

o fIn t

e grity

Failure of a single component is allowed,

common-mode-failure shall be excluded(group 2)

Failure of a componentshall be excluded

(group 1)

No specific requirement for thequality of the components for the

ongoing operation(group 3)

Classification Classification of of thethe mechanicalmechanical componentscomponents

Group 1: Failure of the SSC shall to be excluded to avoid subsequent damage. The required quality shall be guaranteed for the total life time. The causes of possible in-service damage mechanisms shall be monitoredand controlled (proof of integrity). Group 2: For redundant SSC the failure of singlepart is allowable from the safety relevant point ofview. However, common mode failure shall beexcluded. In single cases the present quality mayfall short of the required quality, for that therequired quality shall be restored. The con-sequences of possible in-service damagemechanisms shall be monitored. (preventivemaintenance, time- or condition-oriented).

Group 3: There are no defined standardsof the qualityof the SSC concerning thesucceeding operation (failure-oriented maintenance).

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152ndIntern. Symp. on NPP Life Management, 15.-18. October 2007, Shanghai, China

Procedure for application Procedure for application

ProofProofof ofintegrity for components

integrity for componentsof of groupgroup1 1

Preventive maintenance for componentsPreventive maintenance for componentsof

of groupgroup2 2

FailureFailure- -oriented maintenance for components

oriented maintenance for componentsof ofgroupgroup3 3

Physicalageing

Physicalageing

Qualityafter

Design

Qualityafter

DesignQualityafterManufacture

(as-built)

QualityafterManufacture

(as-built)As-built Qualityaftersome time

of operation

As-built Qualityaftersome time

of operationComponent

failureComponent

failureSubse-quent

damage

Subse-quent

damage

Group 1

Requirement according to specifications; Specific design (Material, Fabrication, Shape, Dimensions, Loadings, postulated flaws)


Material selected, as-built shape and dimensions,detected findings


Leakage,Break,Wear,Friction, ...


Subsequent failure of redundant components, damage of adjoining systems, flooding, …


Loading, Environment, Change of material characteristics

Loading, Environment, Change of material characteristicsFatigue, Crack initiation, Crack growth, Leakage, increased friction, ...

Fatigue, Crack initiation, Crack growth, Leakage, increased friction, ...

Causes Causes

Consequences Consequences

Proof of Integrity

Preventive MaintenanceFailure oriented Maintenance

Conceptualageing

Conceptualageing

Technologicalageing

TechnologicalageingGroup 2

Group 3

Physicalageing

Physicalageing

Qualityafter

Design

Qualityafter

DesignQualityafterManufacture

(as-built)

QualityafterManufacture

(as-built)As-built Qualityaftersome time

of operation

As-built Qualityaftersome time

of operationComponent

failureComponent

failureSubse-quent

damage

Subse-quent

damage

Group 1









Loading, Environment, Change of material characteristics

Loading, Environment, Change of material characteristicsFatigue, Crack initiation, Crack growth, Leakage, increased friction, ...

Fatigue, Crack initiation, Crack growth, Leakage, increased friction, ...

Causes Causes

Consequences Consequences

Proof of Integrity

Preventive MaintenanceFailure oriented Maintenance

Conceptualageing

Conceptualageing

Technologicalageing

TechnologicalageingGroup 2

Group 3

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Procedure for application Procedure for application ProofProof ofof integrity for componentsintegrity for components ofof groupgroup 11Demonstrate and guarantee that the load bearing capacity is given forall relevant operational loads as well as accidental loads for the life time taking into account the specified or monitored number of load-cycles.� Documentation and assessment of the actual (as-built) state of quality according to the respective requirements (shall be in accordance with the particular requirements in guidelines, codes and standards). � The required quality shall be guaranteed for the total life time by:� Identification and monitoring of the causes of possible in-service damage mechanisms and assessment of the data recorded.� Monitoring of the consequences of possible in-service damage mechanisms.� Follow-up of the state of present knowledge.

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Monitoring of the consequences of operational damage mechanisms to be assumed

(e.g. non destructive testing, monitoring of loos parts, destructive testing)

Phase 1.1Assessment of the present design

Phase 1.2Determination of the relevant

loading conditions

Phase 1.4Redundant measures(e.g. detailled analyses,additional monitoring)

Requirementsof the „Basis Safety“

are fullfilled ?Specifiedloads arekept ?

Phase 1.5Evaluation of the actual state of quality

Identification and monitoring of the causes possible operational damage mechanisms

mechanical and thermal water chemistryloads

Evaluation of the loads and strengthe.g. stress analysis, fatigue analysis,

fracture mechanics analyssis

Determination of measures to monitor the consequences of operational damage mechanisms

areas of test testrelevance method interval

Evaluation of thegeneral concept Closed concept

Additional measures

no

yes

Chan

geso

fthe s

tateo

fthea

rt

Phase 1.3Determination of

operational damage mechanisms

no

yes

positiv

Phase 2

Phase 1

Phase 3

Phase 4

Phase 5

Pres

ent Q

uality

G u a

r a n

t e e

O p e

r a t i

o n

Monitoring of the consequences of operational damage mechanisms to be assumed

(e.g. non destructive testing, monitoring of loos parts, destructive testing)

Phase 1.1Assessment of the present design

Phase 1.2Determination of the relevant

loading conditions

Phase 1.4Redundant measures(e.g. detailled analyses,additional monitoring)

Requirementsof the „Basis Safety“

are fullfilled ?Specifiedloads arekept ?

Phase 1.5Evaluation of the actual state of quality

Identification and monitoring of the causes possible operational damage mechanisms

mechanical and thermal water chemistryloads

Evaluation of the loads and strengthe.g. stress analysis, fatigue analysis,

fracture mechanics analyssis

Determination of measures to monitor the consequences of operational damage mechanisms

areas of test testrelevance method interval

Evaluation of thegeneral concept Closed concept

Additional measures

no

yes

Chan

geso

fthe s

tateo

fthea

rt

Phase 1.3Determination of

operational damage mechanisms

no

yes

positiv

Phase 2Phase 2

Phase 1Phase 1

Phase 3Phase 3

Phase 4Phase 4

Phase 5Phase 5

Pres

ent Q

uality

G u a

r a n

t e e

O p e

r a t i

o nProof Proof of of integrityintegrity

for components ofgroup 1according to KTA safety standard 3201.4

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Preventive maintenance for componentsPreventive maintenance for components ofof groupgroup 22

� The present state of quality shall be kept and guaranteed for the succeeding operation.

� In single cases the present quality may fall short of the required quality, for that the required quality shall be restored.

� Relevant failures have to be checked (monitoring of consequences of operational damage mechanisms).

� Consequential failures are of now effect in view of safety relevance.

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Preventive maintenance for componentsPreventive maintenance for components ofof groupgroup 22State of quality according to particular requirements: � Requirements on the material and construction (design and calculation) including manufacture (shall be in accordance with the guidelines, codes and standards)

� Results of tests performed (state of findings of manufacture, NDT)� Operational experience (mode of operation, results of operational in-service monitoring, failure investigations, NDT, maintenance measures)

Operational in-service monitoring and maintenance measures:� Maintenance (measures to keep the nominal condition)� Inspection and measurement (measures and actions to determine and asses the actual as-built status)

� Repair work (measures to restore the required state of quality)

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Procedure for application Procedure for application PDCAPDCA--CycleCycle ((DemingDeming--ProcessProcess)) TechnicalTechnical andandorganisational measures organisational measures

correction measures (managing ageing

effects)

ACT

Coordination(ageing management program)

PLAN

preventive measures(managing ageing

mechanism)

DO

monitoring, analysis andevaluation

(detecting and assessingageing of the effects)

CHECK

Improve AMPeffectiveness

Correct unacceptable degradation

Check for degradation

Minimize expected degradation

Group 1 SSC

DATA BASIS

Group 2 SSC

Group 3 SSC

correction measures (managing ageing

effects)

ACTcorrection measures (managing ageing

effects)

ACT

Coordination(ageing management program)

PLANCoordination

(ageing management program)

PLAN

preventive measures(managing ageing

mechanism)

DOpreventive measures(managing ageing

mechanism)

DO

monitoring, analysis andevaluation

(detecting and assessingageing of the effects)

CHECKmonitoring, analysis and

evaluation (detecting and assessingageing of the effects)

CHECK

Improve AMPeffectiveness

Correct unacceptable degradation

Check for degradation

Minimize expected degradation

Group 1 SSC

DATA BASIS

Group 2 SSC

Group 3 SSC

Group 1 SSCGroup 1 SSC

DATA BASISDATA BASIS



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SummarySummary

� Guidelines and standards contain the requirements for a safe operation throughout the life time (life time management), for the control of the ageing phenomena (ageing management) for the SSC

� Various engineering measures are required depending on the safety relevance (for mechanicl SSC, e.g. proof ofintegrity for components of group 1, preventive maintenancefor components of group 2)

� The practical implementation and application is in progress� A new Safety Standard KTA 2301„Ageing Management of NPP“ is under preparation

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End of presentation End of presentation

Many thanks for your attention

MaterialprMaterialprüüfungsanstalt Universitfungsanstalt Universitäät Stuttgart t Stuttgart (MPA Stuttgart, Otto(MPA Stuttgart, Otto--GrafGraf--Institut (FMPA))Institut (FMPA))

Postfach 801140, DPostfach 801140, D--70511 Stuttgart70511 StuttgartInternet: http://Internet: http://wwwwww..mpampa.uni.uni--stuttgartstuttgart.de.de

EE--Mail:Mail: wwwwww@@mpampa.uni.uni--stuttgartstuttgart.de.de

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