The INNOGRAPH-1C low dose irradiation experiment

extending the HTR graphite materials properties curves at 750°C

Maurits Heijna

INGSM

15-18 September 2014

Hangzhou

215th INGSM

Hangzhou, China

European HTR graphite program

2001-2006

2006-2011

2011-2015

(V)HTR: (Very) High Temperature Reactor

Goal of INNOGRAPH irradiations:• Get design curves of modern nuclear

graphite grades and select best candidate for (V)HTR

• Add to understanding of graphite irradiation behaviour

315th INGSM

Hangzhou, China

INNOGRAPH irradiation experiments

415th INGSM

Hangzhou, China

INNOGRAPH irradiation experiments

INNOGRAPH-1C: low dose irradiation at 750°C

515th INGSM

Hangzhou, China

Manufacturer Grade Coke Process

IG-110 petroleum iso-moulding

IG-430 pitch iso-moulding

NBG-10 pitch extrusion

NBG-17 pitch vibro-moulding

NBG-18 pitch vibro-moulding

NBG-25 petroleum iso-moulding

PCEA petroleum extrusion

PCIB petroleum iso-moulding

PPEA pitch extrusion

LPEB needle extrusion

LPIB needle iso-moulding

Graphite grades in INNOGRAPH

Variation in manufacturing process, coke, and grain size

615th INGSM

Hangzhou, China

INNOGRAPH experiment design

• 8 drums to hold samples

• Geometry allows grain orientation identification

• In the order of 180-220 samples per experiment

• Each experiment contains 24 thermocouples and 9 dosimeter sets

15th INGSM Hangzhou, China

INNOGRAPH experiment design

• INNOGRAPH-1B and -2B have been assembled in the NRG hot-cells

• Samples include irradiated samples from INNOGRAPH-1A and -2A

• INNOGRAPH-1C: virgin samples only, table top assembly

815th INGSM

Hangzhou, China

INNOGRAPH-1C irradiation

• 3 cycles in high flux position in High Flux Reactor (HFR, 45 MW)

• Helium gas environment

915th INGSM

Hangzhou, China

Irradiation temperature control

On-line temperature control by gas mixture control and vertical displacement unit

1015th INGSM

Hangzhou, China

Post-Irradiation Examination

PIE measurements:• Dimensional change• Mass & density• Young’s modulus• Thermal conductivity• Thermal Expansion• Measurement set-ups in

Box and Hot Cell

Sample recovery

Measurements

Drum recovery

1115th INGSM

Hangzhou, China

0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.0-10

-5

0

5

10

15

20

grade C, low dose grade C, high dose grade D, low dose grade D, high dose

V/V

0 (%

)

dpa

0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.0-10

-5

0

5

10

15

20 grade A, low dose grade A, high dose grade B, low dose grade B, high dose

V/V

0 (%

)

dpa

Volume change (Tirr=750°C)

Extrusion Iso-moulding

1215th INGSM

Hangzhou, China

0.0 0.5 1.0 1.5 2.0 2.5 3.0-1.0

-0.8

-0.6

-0.4

-0.2

0.0

grade C grade D

V/V

0 (%

)

dpa

Volume change (Tirr=750°C)

0.0 0.5 1.0 1.5 2.0 2.5 3.0-1.0

-0.8

-0.6

-0.4

-0.2

0.0

grade A grade B

V/V

0 (%

)

dpa

Extrusion Iso-moulding

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Hangzhou, China

Dynamic Young’s Modulus

Extrusion Iso-moulding

Measured by velocity-of-sound

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Hangzhou, China

Dynamic Young’s Modulus

Extrusion Iso-moulding

Measured by velocity-of-sound

1515th INGSM

Hangzhou, China

Dynamic Young’s Modulus

Extrusion Iso-moulding

Measured by velocity-of-sound

1615th INGSM

Hangzhou, China

0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.02.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

grade C, AG grade C, WG grade D, AG grade D, WG

CT

E30

-750

°C (

x1

0-6 K

-1)

dpa

0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.02.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

grade A, AG grade A, WG grade B, AG grade B, WG

CT

E30

-750

°C (

x1

0-6 K

-1)

dpa

Thermal expansion

Extrusion Iso-moulding

Measurement range used: 30°C-750°C

1715th INGSM

Hangzhou, China

0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.02.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

grade C, AG grade C, WG grade D, AG grade D, WG

CT

E30

-750

°C (

x1

0-6 K

-1)

dpa

0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.02.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

grade A, AG grade A, WG grade B, AG grade B, WG

CT

E30

-750

°C (

x1

0-6 K

-1)

dpa

Thermal expansion

Extrusion Iso-moulding

Measurement range used: 30°C-750°C

1815th INGSM

Hangzhou, China

0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.02.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

grade C, AG grade C, WG grade D, AG grade D, WG

CT

E30

-750

°C (

x1

0-6 K

-1)

dpa

0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.02.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

grade A, AG grade A, WG grade B, AG grade B, WG

CT

E30

-750

°C (

x1

0-6 K

-1)

dpa

Thermal expansion

Extrusion Iso-moulding

Measurement range used: 30°C-750°C

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Hangzhou, China

Thermal conductivity vs temperature

Measured by Laser Flash Analysis (LFA)

2015th INGSM

Hangzhou, China

Thermal conductivity vs dpa

Extrusion Iso-moulding

Measured at 750°C

2115th INGSM

Hangzhou, China

Thermal conductivity vs dpa

Extrusion Iso-moulding

Measured at 750°C

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Hangzhou, China

Thermal conductivity vs dpa

Extrusion Iso-moulding

Measured at 750°C

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Hangzhou, China

Conclusions

• Materials properties curves at 750°C extended to low dpa for HTR graphite grades

• Little happens at low dpa– Volume change– Although indicative for behaviour at higher dose

• A lot happens at low dpa– CTE, DYM, thermal conductivity

• To be answered: what grade is best for (V)HTR?