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Thermal Design and Analysis of Capsule Experiments in the ATR

Paul MurrayATR Experiment Design and AnalysisIdaho National Laboratory

NSUF User Meeting

June 22, 2015

Temperature Indications and Comparison to Simulation

2

Contents• Introduction – static and active temperature control• EPRI static capsule experiment

– Experiment design– Temperature indicators (melt wires and SiC)– Reactor power history– Melt wire temperature indications– SiC temperature indications– Heat transfer simulations– Irradiation temperature estimates

• UCSB lead-out capsule experiment– Experiment design– Heat transfer simulations– Temperature measurements

ATR core cross-section

EPRI experiment

UCSB experiment

Capsule experiments• A gas gap of known thermal resistance is used to attain the desired

specimen temperature• Gas gap temperature controlled capsule experiments

– Static capsule experiment with fixed temperature control gas– Lead-out experiment with variable temperature control gas

Pressure tube

Helium/argon/neon gas gap

SpecimensSpecimen holder

Reactor coolant 50°C, 360 psig

5

EPRI static capsule experiment

• Capsule containing zirconium alloy specimens is irradiated in the A-16 position in the ATR northwest lobe

• Experiment is designed to study irradiation induced growth of zirconium alloys

6

Experiment design• 50 specimens (10 stacks of 5) are contained in a helium-filled

pressure-retaining stainless steel capsule• Gas gap temperature control is designed to maintain specimen

temperature at 285ºC ±10ºC

Spacer

Specimens

Holder

Capsule

7

Temperature indicators• Six melt wires (labelled A – E) and two SiC rods (labelled F) located in

dowel holes at top and bottom of specimen holder

Melt wire label

Location of melt wire in specimen holder

Composition of melt wire

Melting temperature

A Top Right 100% Sn 231.8°CD Top Right 80% Au 20% Sn 279.5°CC Top Left 90% Pb 10% Sb 252.4°CB Bottom Right 95% Sn 5% Sb 238.6°CE Bottom Right 90% Pb 5% Ag 5% Sn 302.9°CC Bottom Left 90% Pb 10% Sb 252.4°C

F

C

C

F

B

E

D

A

Top

Bottom

Dowel holes

Capsule

Holder

Specimens

8

Temperature indicators• Melt wires are encapsulated in helium-filled quartz tubes; post-

irradiation visual inspection is used to determine if melting occurred• Measured change in SiC electrical resistance resulting from post-

irradiation annealing is used to estimate irradiation temperature

Interior of annealing furnace

Apparatus for resistance measurement

SiC

9

Reactor power history

Cycle Average Lobe Power (MW) EFPD

149A 18.0 37149B 18.0 54150B 18.0 42151A 18.9 60151B 18.9 56152B 18.9 52

• SiC indicates temperature corresponding to average power during the final irradiation cycle

• Melt wire indicates temperature corresponding to peak power during the irradiation

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Reactor power history

11/27/2

012

12/5/2

012

12/13/2

012

12/21/2

012

12/29/2

012

1/6/2

013

1/14/2

013

1/22/2

01318.5

18.6

18.7

18.8

18.9

19

19.1

19.2

19.3

19.4

19.5Cycle 152B NW Lobe Power

Date

Pow

er (M

W)

19.44 MW

• Peak lobe power 19.44 MW occurred during cycle 152B on 12/06/2012

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Melt wire temperature indications• All melt wires at top of holder showed clear indications of melting• Peak irradiation temperature at top of the holder is equal to or

greater than 279.5°C (melting temperature of 80 Au 20 Sn)

Composition of melt wire

Melting temperature

Melted during irradiation

100% Sn 231.8°C Yes80% Au 20% Sn 279.5°C Yes90% Pb 10% Sb 252.4°C Yes95% Sn 5% Sb 238.6°C Yes90% Pb 5% Ag 5% Sn 302.9°C No90% Pb 10% Sb 252.4°C Yes

Sn80Au 20Sn

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Melt wire temperature indications• One melt wire (90 Pb 5 Ag 5 Sn) at bottom of holder did not melt;

other wires showed clear indications of melting• Peak irradiation temperature at bottom of holder is less than

302.9°C (melting temperature of 90 Pb 5 Ag 5 Sn)

Composition of melt wire

Melting temperature

Melted during irradiation

100% Sn 231.8°C Yes80% Au 20% Sn 279.5°C Yes90% Pb 10% Sb 252.4°C Yes95% Sn 5% Sb 238.6°C Yes90% Pb 5% Ag 5% Sn 302.9°C No90% Pb 10% Sb 252.4°C Yes

90Pb 5Ag 5Sn 95Sn 5Sb

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SiC temperature indications• Indicated irradiation temperature at top of holder is 258°C ±10°C

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SiC temperature indications• Indicated irradiation temperature at bottom of holder is 279°C ±10°C

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Heat transfer simulation at 18.9 MW

16

Heat transfer simulation at 19.4 MW

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Temperature indications and results of simulation

Reactor Lobe Power

Indicated Irradiation

Temperature of SiC

Indicated Irradiation

Temperature of Melt Wires

Calculated Irradiation

Temperature of SiC

Calculated Irradiation

Temperature of Melt Wires

Calculated Irradiation

Temperature of Specimens

18.0 MW 275°C - 291°C

18.9 MW

258°C ± 10°C (top)

279°C ± 10°C (bottom)

261°C - 269°C (top)

266°C - 271°C (bottom)

284°C - 301°C

19.4 MW> 279.5°C (top)

< 302.9°C (bottom)

277°C (top)279°C

(bottom)290°C - 307°C

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Irradiation temperature estimates

Cycle Average Lobe Power (MW)

Estimated Irradiation

Temperature149A 18.0 275°C - 291°C149B 18.0 275°C - 291°C150B 18.0 275°C - 291°C151A 18.9 284°C - 301°C151B 18.9 284°C - 301°C152B 18.9 284°C - 301°C

UCSB lead-out capsule experiment

• Capsule containing low alloy carbon steel specimens is irradiated in the I-22 position in the ATR southeast lobe

• Capsule is instrumented with 28 thermocouples• Active gas gap temperature control using helium-argon control gas

is designed to maintain specimen temperature at 250°C to 310°C

Experiment design• Numerous multi-purpose disc specimens, compact tension specimens,

and tensile specimens contained in a thin-walled sleeve• Thermocouples and gas lines located in a sealing tube assembly that

contains the specimen packets • Helium-argon control gas mixture is adjusted based on temperature

feedback from thermocouples

Gas lines and TCs

Sealing tube assemblySpecimens

Sleeve

Experiment design• Specimens arranged in packets according to desired irradiation

temperature• Three gas zones with variable gas gaps• Selected thermocouples in each zone used for temperature control

Bottom zone Top zoneMiddle zone

Heat transfer simulation

1 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 2850

100

150

200

250

300

350

Specimen

Thermocouple

Thermocouple Number

Te

mp

era

ture

(d

eg

ree

s C

)

• Simulation using a 50% He – 50% Ar control gas mixture used to establish thermocouple setpoints at approximately 276°C

Control TCs

Heat transfer simulation• Simulation using actual control gas mixture on 6/20/2011

(bottom zone 42% He, middle zone 62% He, top zone 48% He)

Temperature measurements

1 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 2850

100

150

200

250

300

350

Measured

Calculated

Thermocouple Number

Te

mp

era

ture

(d

eg

ree

s C

)

• Simulation using actual control gas mixture during irradiation

Temperature measurements• Error bars correspond to ±0.002 inch uncertainty in gas gaps

1 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 2850

100

150

200

250

300

350

Measured

Calculated

Thermocouple Number

Te

mp

era

ture

(d

eg

ree

s C

)

Summary• EPRI static capsule experiment

– Passive temperature indication• UCSB lead-out experiment

– Active temperature indication• Comparison of temperature indications to heat transfer simulations

– Temperature uncertainty is approximately ±30°C for a materials irradiation at 300°C