IAEA Fatigue Assessment in LWR for LTO Fatigue Assessment in LWR for LTO Tools & Methods for Advanced Thermal Loads Specification Engineering & Technology (DTI) Dr. Kerstin Gauter

IAEAFatigue Assessment in LWR for LTOTools & Methods for Advanced Thermal Loads Specific ation

Engineering & Technology (DTI)

Dr. Kerstin GauterAREVA Specialist Thermal HydraulicsR&D Project Leader New Numerical Methods for Ageing Determination

Dr. Gerhard SchlichtAREVA Expert Thermo- and Fluid Dynamics

Dr. Thomas FuchsSection Manager Numerical Methods, Thermal Loads, and Ageing Management in PWR System EngineeringTechnical Product Manager and Chief Developer Advanced Cooling SystemsAREVA Expert Thermo- and Fluid Dynamics

Erlangen, 6.-8. July 2016

All rights are reserved, see liability notice.

Advanced Thermal Loads SpecificationBenefit

Fast, reliable & reproducible data evaluation

Fatigue (re)calculation based on (more) realistic l oad scenarios

Avoidance of premature component exchange (REKU > 7 M€)

Availability control / prevention of extra outages

Continuous fatigue analysis & extrapolation to cumu lative usage into future

� Early detection of failures

� Early detection of significant partial fatigue usag e

� Early counter measures with the aim of fatigue usag e reduction

Action plan in case of calculated design CUF > 1.0

Optimization of operation modes (e.g. load following operation)

Integrated / modular load assessment and reduction concept

Property of AREVA GmbH, all rights are reserved. Liability restricted, see notice.

IAEA-Workshop Methods for Advanced Thermal Loads Specification – Fuchs / Gauter – July 2016 – AREVA - AL: N - ECCN: N©AREVA - p.2


AREVA Fatigue Concept - AFC




Contare –Data

Evaluation60

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Time / s




CONTARESteps of Analysis

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Step 1: Define load relevant Flanks : Schematic characterization of raw data

Step 2: Load cycles : Paired flanks for simple type of model transients:

Step 3: Model transients : Enveloping load cycles

grad T∆T

optim

izat

ion



CONTAREContext and Features



Context� Data evaluation: Analysis of temperature data over time for thermal loads

(alternatively p, m_dot, …)� Preprocessing data for (cycle & stress based) fatigue analysis (ageing management)

Features� Counting thermal occurrences in combination with a sophisticated data interpretation

and data tracking, e.g. time history and other characteristic parameters• superposing mechanical & thermal loads at same time, not the respective maxima

� Automatic (numerical) examination • very large amounts of data (e.g. all past operational loads) in a very short time• reproducible results

� Detection of enveloping loads in case of a fleet� Efficient reduction of data volume by grouping into model/reference transients� Adjustable user-defined model transients and level of detail� More realistic load specifications because of more detailed examination � Stand-alone tool or in combination with AFC and/or calculations � versatile tool


CONTAREConclusion

Measurement Evaluation Specification

Technical items� Identification of critical events� Realistic prediction of service life � Optimization of plant operation modes� Compatibility to FAMOSi or any other instrumentation system

Contare results � Fast, reliable & reproducible data evaluation / data reduction� Detailed and accurate loads specifications� User defined degree of accuracy� Load counting + tracking time history and characteristic parameters




Transfer Functions –Virtual

Measurements




Transfer FunctionsMarket Needs



Customer Problem, Objective or Need

� Problem: Determination of thermal loads in pipes or components at • locations not equipped with measurement devices • locations inaccessible for measurements, such as component internals

� Even though customer retrofitted an advanced monitoring system (e.g. FAMOSi), the years before the adaption remain unknown

� Only very expensive systems feature such sophisticated analysis tools (Transfer Functions applicable to all systems / locations)

� Standard method in the 1980s: Definition of conservative thermal transients, � largely overestimated thermal loads

� Components have been designed for 40 years lifetime – extension to 60 years requires hardware replacement / redesign or re-calculation of more realistic thermal loads


Transfer Functions Consider System Influence

Using thermal inertia: No simple mirroring of penalizing (step) function at “A” to location “B”

Calculated response at “B” with smaller (physical) amplitudes and gradients


pipe line to measuring point

length : 45 m

Inner-Diameter : 0.0900 m

Wall thickness : 0.0125 m

A

BIAEA-Workshop Methods for Advanced Thermal Loads Specification – Fuchs / Gauter – July 2016 – AREVA - AL: N - ECCN: N©AREVA - p.10

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Realistic ∆T & grad(T) reduction»


Contare + Transfer FunctionSophisticated AREVA Approach

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Time / s

Consideration of thermal response of piping system

More physical transient specifications due to sophisticated pre-/post-processing, e.g. CONTARE (gradients instead of step function)


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pera

ture

/ °C

Time / s

pipe line to measuring point

length : 45 m

Inner-Diameter : 0.0900 m

Wall thickness : 0.0125 m

A

BIAEA-Workshop Methods for Advanced Thermal Loads Specification – Fuchs / Gauter – July 2016 – AREVA - AL: N - ECCN: N©AREVA - p.11



PZR

MCL

PZR outer wall

PZR inner wall

MCL outer wall (light blue)MCL inner wall (dark blue)

Transfer Functions Consider System Influence

Surge Line:

Consideration of thermal response of piping system & history

� Sharply declining fluid temperature profile at main coolant line (light green)

� Slightly declining fluid temperature profile at pressurizer (red)

�� Substantial reduction of temperature gradient




Essential Side Topic: Transient Thermal Analysis of Large Heat Exchangers


MCL CVCSTube flow

Shell flow

t0: valves closed, idle state

t1 = 1781 s tube side inflow

from MCL at 300°C

t2 = 2395 s shell side inflowfrom CVCS at 50°C

t3 > 2900 s steady state

conditions (fluid)

Tube sideShell sideShell wall


Transfer FunctionsConclusion

Time and cost factor geometric model: Simple and timesaving modeling of the complete systems (pipe sections, elbows and components) due to a sophisticated pre-processing tool (direct network implementation of a CFD model possible)

Direct coupling Transfer Functions with Contare as pre- or post-processing tool to categorize the transients (important in case of long term calculations � data reduction)

Simple version of the tool already available and tested in the scope of an existing facility

Sophisticated thermal hydraulic transfer function

� basis to derive functional transfer function (coupling with FAMOSi – low CPU performance)

� Simulation of complex systems (e.g. combination of piping and HX or other components)

Combination of Contare and transfer function is able to reduce the usage factor considerably (e.g. one order of magnitude)

More realistic fatigue usage by providing more realistic loads specifications, e.g. to prevent premature component exchange



»


Advanced Thermal Loads SpecificationLife Time Extension

Fatigue usage factor Allowable Limit

40

0

60Commissioning phase and

first 2 years

Fatigue growth based on penalizing / design

specifications

Time [years]

Consideration of more realistic / operational

specifications




Advanced Thermal Loads Specification



Thank you!For more information, please visit booth 3!



End of PresentationTools & Methods for Advanced Thermal Loads Specification


Dr. Kerstin GauterAREVA Specialist Thermal HydraulicsR&D Project Leader New Numerical Methods for Ageing Determination

Dr. Gerhard SchlichtAREVA Expert Thermo- and Fluid Dynamics

Dr. Thomas FuchsSection Manager Numerical Methods, Thermal Loads, and Ageing Management in PWR System EngineeringTechnical Product Manager and Chief Developer Advanced Cooling SystemsAREVA Expert Thermo- and Fluid Dynamics

Erlangen, 6.-8. July 2016



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Subject to change without notice, errors excepted. Illustrations may differ from the original. The statements and information in this brochure are for advertising purposes only and do not constitute an offer of contract. They shall neither be construed as a guarantee of quality or durability, nor as warranties of merchantability or fitness for a particular purpose. These statements, even if they are future-orientated, are based on information that was available to us at the date of publication. Only the terms of individual contracts shall be authoritative for type, scope and characteristics of our products and services.


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IAEA Fatigue Assessment in LWR for LTO Fatigue Assessment in LWR for LTO Tools & Methods for Advanced Thermal Loads Specification Engineering & Technology (DTI) Dr. Kerstin Gauter