Thermal-Fluids Modeling of ATR Experimentsof ATR ExperimentsPaul MurrayExperiment Design and Analysis

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Experiment Design and AnalysisIdaho National LaboratoryIdaho Falls, ID

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ATR NSUF User’s Week Experimenter CourseJune 20, 2012w

Outline• Preliminaries

ATR d i di ti iti– ATR core and irradiation positions– Thermal-fluids modeling software

• Capsule experiments– Thermal modeling of the UCSB-2 experiment– Comparison of measured and calculated temperatures– Gas gap temperature control in capsule experiments

• Pressurized water loop experiments– Thermal-fluids modeling of the EPRI loop experiment– Comparison of various thermal-fluids models

• Fuel plate experiments– Thermal-fluids modeling of the RERTR-12 experiment– Comparison to analytical heat transfer modelsy

ATR core cross-section

Fuel assemblies (40) Outer shim

control drums

A-positions (16)

Neck shim control rods

I-positions (24)

Flux traps

B-positions (12)

H-positions (14)

Flux traps (9)

Thermal-fluids modeling software• FLUENT

Fl id d i d h t t f– Fluid dynamics and heat transfer• ABAQUS

– Solid mechanics and heat transfer• RELAP5

– Two-phase flow and heat transfer in reactor systems

Example 1 – UCSB-2 lead-out experiment• Experiment capsule design

Pressure tube

H li /Thermocouples

Exhaust line

Helium/argon gas gap

Gas lines

SpecimensOuter sealing tube

Inner capsule

Example 1 – UCSB-2 lead-out experiment• Low alloy carbon steel specimens irradiated at 250°C to 310°C• Instrumented with 28 thermocouples• Active temperature control using helium-argon control gas

6

Example 1 – UCSB-2 lead-out experiment• Location of thermocouples

TC-13TC-14

TC-15TC-16

TC-17TC-18

TC-19TC-21TC-22TC-24

TC-23TC-25TC-26

TC-27TC-28 TC-20

TC-1TC-2TC-4

TC-3TC-5TC-7TC-6TC-8

TC-9TC-10

TC-11TC-12

Example 1 – UCSB-2 lead-out experiment• Model geometry and calculated temperature distribution

Example 1 – UCSB-2 lead-out experiment• Calculated temperature of specimens and thermocouples using design gas mixture

350

300

350Specimen

Thermocouple

250

(deg

rees

C)

150

200

Tem

pera

ture

(

100

T

501 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Thermocouple Number

Example 1 – UCSB-2 lead-out experiment• Comparison of measured and calculated TC temperature using actual gas mixtures

350

300

350Measured

Calculated

250

degr

ees

C)

150

200

Tem

pera

ture

(d

100

T

501 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Thermocouple Number

Example 1 – UCSB-2 lead-out experiment• Error bars corresponding to ±0.002 inch uncertainty in gas gaps

350

300

350Measured

Calculated

250

(deg

rees

C)

150

200

Tem

pera

ture

(

100

T

501 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Thermocouple Number

Temperature control in capsule experiments• Gas gap temperature controlled capsule experiments

St ti l i t ith fi d t t t l– Static capsule experiment with fixed temperature control gas– Lead-out experiment with variable temperature control gas

• Factors affecting temperature variation– Heating rate– Gas gap size– Specimen size– Axial position in core– Reactor power variations

• Methods to control temperature variation– Specimen isolation– Dimensional tolerances– Active temperature control

Example 2 – pressurized water loop• In-pile tube and out-of-pile facility for loop 2A-C

Example 2 – pressurized water loop• In-core section of in-pile tube containing specimens and holder

Envelope tubePressure tube

Flow tube

Example 2 – EPRI loop experiment• Irradiate nickel-base alloys and stainless steel compact tension (CT)

specimens at 288°Cspecimens at 288 C• Coolant flow 10 – 60 gpm• Coolant pressure 1800 – 2200 psig• Coolant temperature 200°C – 300°C

Example 2 – EPRI loop experiment• Model geometry of CT specimens

Coolant flow

CT specimen

Inner wall of specimen holder

Example 2 – EPRI loop experiment• Temperature contours at specimen interior• Peak temperature is 60°C greater than coolant temperature

Example 2 – EPRI loop experiment• Temperature as a function of axial position relative to core mid-plane

300

280

300

260

re (d

eg C

)

240

Tem

pera

tu

Specimen Temperature Bottom Holder - ABAQUSSpecimen Temperature Bottom Holder - RELAP5Specimen Temperature Lower Center Holder - ABAQUSSpecimen Temperature Lower Center Holder - RELAP5S i T t U C t H ld ABAQUS

220Specimen Temperature Upper Center Holder - ABAQUSSpecimen Temperature Upper Center Holder - RELAP5Specimen Temperature Top Holder - ABAQUSSpecimen Temperature Top Holder- RELAP5Coolant Temperature - ABAQUSCoolant Temperature - RELAP5

200

Position Relative to Core Mid-Plane (inches)

Example 2 – EPRI loop experiment• RELAP5 model of in-vessel components• Operating conditions needed to attain

turn-around

• Operating conditions needed to attain 288°C specimen temperature

300 flow channels

hanger rod and adapter

200

250

300

pera

ture

(C) inside and

outside flow tube

flow channels inside holders

holderspressure tube envelope tube

flow tube

insulating

100

150

200

Coo

lant

Tem

p

specimens

insulating gas gap

50

100

20 30 40 50 60

Inle

t

Center Flux Trap Power (MW)

test stop

inletoutlet

Example 3 – RERTR-12 fuel experiment• Irradiate uranium-10%molybdenum alloy fuel plates• Experiment contains 4 capsules, each capsule contains 8 fuel plates

Example 3 – RERTR-12 fuel experiment• Coolant conditions (2 pumps)

360 i i l t– 360 psig inlet pressure– 52°C inlet temperature– 73 psi core pressure drop

43 fl th h l– 43 gpm flow through capsule• Comparison of measured and calculated flow

50

m)

30

40

Cap

sule

(gpm

0

10

20

Flow

Insi

de

Flow Rate (experimental friction loss factor)Flow Rate (RELAP5)

0 20 40 60 80Pressure Drop (psi)

Example 3 – RERTR-12 fuel experiment• Model geometry of a RERTR capsule containing 8 plates

Example 3 – RERTR-12 fuel experiment• CFD simulations of plate surface temperature and heat flux

Example 3 – RERTR-12 fuel experiment• CFD simulations of coolant temperature and plate centerline temperature

Example 3 – RERTR-12 fuel experiment• Comparison of temperatures from CFD simulation and Petukhov correlation

130

140

150Plate 1 surface facing exterior coolant channel

130

140

150Plate 1 surface facing interior coolant channel

90

100

110

120

mpe

ratu

re (C

)

Plate - FLUENTPlate - Analytical

90

100

110

120

130

pera

ture

(C)

Plate - FLUENTPlate - Analytical

50

60

70

80Tem Coolant - FLUENT

Coolant - Analytical

50

60

70

80

90

Tem

p Plate AnalyticalCoolant - FLUENTCoolant - Analytical

500 2 4 6 8 10

Position along plate surface (cm)

500 2 4 6 8 10

Position along plate surface (cm)

Example 3 – RERTR-12 fuel experiment• Comparison of temperatures from CFD simulation and Petukhov correlation

130

140

150Plate 5 surface facing exterior coolant channel

130

140

150Plate 5 surface facing interior coolant channel

90

100

110

120

mpe

ratu

re (C

)

Plate - FLUENT

Plate - Analytical

Coolant - FLUENT 90

100

110

120

mpe

ratu

re(C

)

Plate - FLUENT

Plate - Analytical

Coolant - FLUENT

50

60

70

80

10 12 14 16 18 20

Tem

Coolant - Analytical

50

60

70

80

10 12 14 16 18 20

Tem Coolant - Analytical

10 12 14 16 18 20Position along plate surface (cm)

10 12 14 16 18 20Position along plate surface (cm)

Example 3 – RERTR-12 fuel experiment• Comparison of interior plate temperature from CFD simulation and analytical solution

160

170

180Center of Plate 1

FLUENT160

170

180Center of Plate 5

FLUENT

140

150

160

pera

ture

(C) Analytical

140

150

160

pera

ture

(C) Analytical

110

120

130

Tem

p

110

120

130

Tem

p

100-0.10 -0.05 0.00 0.05 0.10

Position through plate thickness (cm)

100-0.10 -0.05 0.00 0.05 0.10

Position through plate thickness (cm)

Summary• Thermal-fluids modeling of ATR experiments

FLUENT CFD l i– FLUENT CFD analysis– ABAQUS thermal analysis– RELAP5 hydrodynamic system analysis

• Three examples of ATR experiments– UCSB-2 lead-out capsule experiment– EPRI pressurized water loop experiment

f– RERTR-12 fuel plate experiment• Temperature control of ATR experiments