velocity profil

laminar layer

turbulent layer

turbulent sublayer

y

TF1

α1dT/dy

wallδW

stationarydependence of temperature

instationarydependence of temperature

α2TF2

velocity profil

laminar layer

turbulent layer

turbulent sublayer

y

TF1

α1dT/dy

wallδW

stationarydependence of temperature

instationarydependence of temperature

α2TF2

TF,i+5

TF,i+3

TF,i+4

TF,i

TF,i+1

TF,i+2y

grid lines

grid points

temperatureboundary layer

points insidethe boundarylayer

dTdy W

TF∞

TF,i+5

TF,i+3

TF,i+4

TF,i

TF,i+1

TF,i+2y

grid lines

grid points

temperatureboundary layer

points insidethe boundarylayer

dTdy W

TF∞

Figure 15: CFD calculation, fluid/wall-transition modelling parameter

Velocity profile

Temperature profile

Figure 16: CFD calculations by different partners

T = 0.13 s

T = 2.32 s

T = 2.47 s

0

CEATRIO-U code

•K

VTTfluent

SPGfluent

FANP-Dfluent

DN 50:50

∅ 50 mm

∅ 50 mm

l3

l1

l1/2 main flowsecondary flow

Process the plant files

Test signal ranges

Calculate virtual signals

Integrate modules and fatigue assessment

Man-machine interface

Figure 17: Virtual sensors, software application

WP2

WP4WP1

WP5

VTTFANP-

FIWM

FNSMPA

JRC

FANP-D

CEA

TECN

SPG

Load

determination

Damage measurement

Figure 18: WP 3 partner roles

Stress

Crack init.

Crack prop.

WP 3

SPG

Tests

VTT

Crack prop. Crack prop. Crack prop.

WP 4 Verification test: EDF, JRC, VTT

Stress

Crack init.

Crack prop.

Crack init.

Stress

Crack init.

Stress Stress

Crack init.

WP 2.2: SPG experiments 1:1 T and 4:1 T CEA experiments

Numerical calculationsstarting with benchmark test

FANP CEA

Figure 19: Integrity evaluation (“forward” and “backward” approach)

“Fortum train”

VTT, FNS, TEC

VTT-CFD

Stress calculation

Temperature fields

Stress/fatigue assessment

Crack initiation

Crack propagation

Figure 20: “Fortum train” workflow, VTT, FNS, TEC

WP 3.1

WP 3.1

WP 2.3

WP 3.1

WP 3.1

Thermal shock experiment

WP 3.2

SteamgeneratorMain gate

valve

Topressuriser

Main circulationpump

Main gatevalve

HOT LEG

Reactor

Steamgenerator

COLD LEG

Topressuriser

Purification line nozzle

Fortum train: Mock-up

Figure 21: “Fortum train”, thermal shock experiment mock-up

Cold jet penetrating into the primary pipe

Steep oscillating temperature gradient in the round-off region of the T joint

300 ºC272244

188

21

16013210476

4820

HOT FLOW

CO

LD F

LOW

Figure 22: VTT, CFD analysis on pipe/nozzle connection

FEA: The full model (CFD + pressure)

218 880 elements241 863 nodes725 589 variables

8-node linear brick elements

• overpressure 122.6 bar• main pipe temperature 300 oC• cold-leg temperature 20 oC• turbulent cycle 50 Hz

Materialpropertiestemperaturedependant

Figure 23: “Fortum train”, FE model and loads

Elastic strain in global 1 direction

Max. strain = 0.18 % Min. strain = 0.08 %

Figure 24: “Fortum train”, stress analysis, elastic strains

Primary circuit pipe

Purification line nozzle

Figure 25: “Fortum train”, thermal shock experiment

First cracks occurred after more than 10 000 load cyclesFinal condition: crack length: 34.5 mm (estimated depth: 15 mm)

Figure 26: “Fortum train”, thermal shock experiment, crack monitoring

Figure 27: “FANP-D/F train” and “CEA train” workflow

“FANP-D/F train”

FANP-D: CFD calculation based on

CEA Fatherino II test data:

geometry, fluid mass flow

Time history of fluid temperatureTemperature fields

Numerical approach

Data transfer to FANP-FStress calculation

CEA: experiment

CEA: CFD calculation using TRIO-U code

CEA: measurement

CEAStress calculation

CEA Crack initiation/propagation

Temperature fields

“CEA train”

Fatherino II

DN 50:50

Data transfer to FANP-DCrack propagation

DN 50:50

Figure 28: “SPG/TEC/FHG train” workflow

“SPG/FHG/TEC train”

SPG – experiments

Measurement of fluid temperature

Measurement of outside temperature

Determination of heat-transfer coefficient

Stress calculation

DN 80:20

Glass

TEC

FHG

Crack initiation

Crack propagation

DN 50:50

Steel

DN 100:100

A B

Electrical conductivity measurements(conductivity analogous to temperature)

Data transfer to

Figure 29: TEC, stress/crack analysis based on SPG Data

Results of experiments carried out by Siempelkamp

Additional data (material properties etc.) Finite element calculations

Temperature results over time

Stress results over time

Characterisation of cyclic stresses

Rain-flow counting method

Determination of crack initiation and crack

propagation

S-N curve

Fatigue CGR

Figure 30: TEC, experimental versus analytical results

1 mm. Model

50.0

55.0

60.0

65.0

70.0

75.0

80.0

85.0

90.0

100 110 120 130 140 150 160 170 180 190 200

t (s)

Out

side

wal

l tem

pera

ture

(ºC

)Ansys results

F9 temperature gauge, 6 o'clock

Configuration analysed by FEM

3.9 kg/s

0.015 kg/s

∆Tmain leak ≅ 90 K

• Austenitic steel piping• Wall thickness

– experiments: 1 mm– calculations: 10 mm

This combination turned out to be the most damaging one

Figure 31: TEC, relevant T configuration analysed by FE analysis

ASME Code, Section III, Appendix I: Design fatigue curve for austenitic steels

101.3

81.170.9

60.850.7

40.530.4

20.3

0

20

40

60

80

100

120

140

160

180

200

1E+06 1E+07 1E+08 1E+09 1E+10 1E+11

Number of cycles, N

S a (M

Pa)

Sa (MPa)

32 EFPY; T16, 6 o'clockσax. = σcirc. (inner surface)

Fatigue analysis

046.0107.3107.1

7

6

=⋅⋅

=geFactorFatigueUsa

Figure 32: TEC; fatigue analysis of through-wall stresses; α experiment = 2000 W/(m²K)

Fatigue analysis

Figure 33: TEC; fatigue analysis of through-wall stresses; α Colburn = 16 700 W/(m²K)

ASME Code, Section III, Appendix I: Design fatigue curve for austenitic steels

30.6

61.2

91.8

122.4

153.0

183.6

214.2

244.8

275.4

306.0

0

50

100

150

200

250

300

350

1E+04 1E+05 1E+06 1E+07 1E+08 1E+09 1E+10 1E+11

Number of cycles, N

S a (M

Pa)

Sa (MPa)

32 EFPY; T10, 6 o'clock σax. = σcirc. (inner surface)h=16700 W/m^2*ºC

Temperature and stress for the SPG geometry

Figure 34: FHG, 3D-FE model for stress analysis and crack initiation/propagation

Figure 35: FHG, elastic-plastic analysis

Stress variation: elastic-plastic analysis

∆T = 250 °C

Da = 59 mm, t = 10 mm

α = 5 kW/(m2K), f = 0.1 Hz

High power density Hea ting m odulus

Model

High power density Heating modu lus

A lternate rotation

Ecrans

Hea tin g For me an

s tabi lisatio n

Hig h p owe r d e n sity H ea tin g

H ig h po we r d en sit y He a ting

A B

Hig h po we r d e nsit y He a tin g

H ig h po we r d e nsit y He a tin g

A B

INTHERPOL descrip tion EDF: WP4 test mock-up

Figure 36: EDF-INTHERPOL “turning cylinder” test

First cracks after 124 000 cycles

Weld

Figure 37: EDF, long-term damage test results

Figure 38: JRC test workflow, JRC, JSI, MPA, FHG

JRC

JRC test

316L model pipe components

Stress/fatigue

Crack initiation

Crack growth

JSI

Crazing

Crack initiation

MPA

Stress

Crack initiation

Crack propagation

FHG

Crack initiation

Crack propagation

Advanced material law WP

3.1

, 3.2

JRC thermal shock experiment (pipe specimen)

Instrumented specimenSpecimen geometry

Material: A316L austenitic steel

48 mm

14 mm20 mm

224 mm

F (axial load)

Tpipe

Tfluid

∆T = Tpipe-Tfluid

∆T = 380 KFirst cracks after 20 000 load cycles

Figure 39: JRC, long-term damage tests

Figure 40: JSI, micro-structure modeling, analysis of the JRC experiment

Figure 41: WP 4.2 Compilation of thermal load tests and additional MPA specimen experiment

Fortum mock-up test x

0,1

1,0

1,E+02 1,E+03 1,E+04 1,E+05 1,E+06N f(25)

e a

%ASME SS best estimate

ASME SS Design

Experimental curveLocal strain by FEA

Crack opening "strain"

Specimen thermal load

Fatigue assessment

MPAtests

HUTsmall

specimenFull-scalemock-up

Nocrack

teststopped

Crackdetected

Operational loadsby CFD & FEA

Figure 42: VTT, fatigue assessment according to experimental and analytic results

ASME designcurve

Mean curve

Figure 43: Overall integrity concept for safety-relevant structures in NPPs

Basic component/system quality by design and manufacturing

Evaluation of current component/system qualitystatus according to current quality requirements

Proactive surveillance/registration/recording of root causes of potential operational degradation mechanisms

• actual mechanical/thermal loads

Integrity evaluation using actual operational loading input

• e.g. stress analysis, fatigue analysis, fracture mechanics

Stipulating measures to monitor consequencesof operational degradation mechanisms

• stress/fatigue-relevant locations, NDE methods, NDE intervals

Reactive surveillance of consequences of potential operational degradation mechanisms

• e.g. non-destructive examinations, loose-part monitoring, destructive examinations of replaced parts

Proa

ctiv

e co

nsid

erat

ion

of re

leva

nt c

hang

es in

the

“sta

te o

f the

art

”

OK Evaluationresults

Additional measures

THERFAT

„Qua

lity

byfa

bric

atio

n &

des

ign“

„Spe

cifie

d or

mon

itore

dlo

adin

gs“

„Inte

grity

eva

luat

ion“

(stre

ss/fa

tigue

ana

lyse

s)

„Stip

ulat

ion

of a

ppro

pria

tesu

rvei

llanc

e m

easu

res“

„Red

unda

nt s

urve

illanc

eof

pot

entia

l deg

rada

tion

mec

hani

sms“

„Design quality“ „Redundant quality assurance“„Quality assurance during plant lifetime“

Operational degradation mechanisms

Integrity requirements:high, medium, low

Integrity building

Figure 44: Integrity concept: the “integrity building”