Workshop on Advanced Reactors With Innovative Fuels

ARWIFARWIF--20052005KAERIKAERIKAERI

MATERIALS PROPERTIES AND FUEL PERFORMANCE OF THE DUPIC

FUEL

MATERIALS PROPERTIES AND MATERIALS PROPERTIES AND FUEL PERFORMANCE OF THE DUPICFUEL PERFORMANCE OF THE DUPIC

FUELFUEL

Ho Jin Ho Jin RyuRyu, , JeJe Sun Moon, Sun Moon, KweonKweon Ho Kang, Ho Kang, KeeKeeChan Song, and Chan Song, and MyungMyung SeungSeung YangYang

1616--18 Feb. 2005, Oak Ridge, Tennessee18 Feb. 2005, Oak Ridge, Tennessee

ContentsContents

Introduction to the DUPIC Fuel Cycle

Material Properties of the DUPIC Fuel Pellet

Performance Analysis of the DUPIC Fuel

Irradiation Test of the DUPIC Fuel

Introduction to the DUPIC Fuel Cycle

Material Properties of the DUPIC Fuel Pellet

Performance Analysis of the DUPIC Fuel

Irradiation Test of the DUPIC Fuel

Concept of DUPICConcept of DUPIC* DUPIC : Direct use of spent PWR fuel in CANDU reactors

CANDU

Spent CANDU/DUPIC Fuel

LWR

Spent LWR Fuel

Uranium Saving

No Disposal Less Disposal

CANDU once-through

DUPIC

PWR once-through

DUPIC Fuel Fab

On-site Storage

Natural Uranium

AFR Storage

Permanent Disposal

On-site Storage

Permanent Disposal

Fabrication Process of DUPICFabrication Process of DUPIC

Skeleton

Volatiles

Cladding Hulls

Volatiles & Semi-volatiles

Spent PWR Fuel

DUPIC Fuel Bundle

Structural Parts

Oxidation/Reduction (OREOX)

Pelletizing/Sintering

Cut to Size

Fuel Rods

Welding

Decladding

DUPIC Fuel Rods

Technical Challenges

– Remote fabrication

– Remote handling

– Performance verification of the DUPIC fuel

Material Properties CharacterizationMaterial Properties Characterization

Simulated DUPIC fuel– Due to high radioactivity of spent fuel– Inactive isotope for fission product elements

Thermal Properties – Thermal conductivity– Thermal expansion coefficient

Mechanical Properties– Creep rate– Young’s modulus

Diffusion Coefficient of Fission Gas (Xe)

Thermal PropertiesThermal Properties

0 400 800 1200 1600 2000 2400-0.5

0.0

0.5

1.0

1.5

2.0

2.5 DUPIC fuel UO2

dL/L

, %

Temperature, K0 300 600 900 1200 1500 1800

2

4

6

8

10 UO2 DUPIC fuel

Ther

mal

Con

duct

ivity

, W/m

K

Temperatue, K

Thermal ConductivityMeasured by Laser Flash Method

DUPIC < UO2

A=0.0944, B=2.027X10-4, C=4.715X109, D=16,361

Thermal ExpansionMeasured by Dilatometer (DIL 402C)

DUPIC > UO2

∆L/ L0, % = - 0.3854 + 1.130 × 10-3 T + 1.095 × 10-7 T20 2

1 expDC DK

A BT T T⎛ ⎞= + −⎜ ⎟+ ⎝ ⎠

Mechanical Properties Mechanical Properties

Creep RateMeasured by Compressive Creep Test

DUPIC < UO2

Young’s ModulusMeasured by Resonance Ultrasound Spectroscopy

DUPIC > UO2

0.045 0.050 0.055 0.060 0.065 0.070 0.075

180

185

190

195

200

Youn

g's

Mod

ulus

, GPa

Porosity

DUPIC UO2

0.50 0.52 0.54 0.56 0.58

1E-8

1E-7

1E-6

1E-5

1E-4

UO2 DUPIC

Cre

ep R

ate,

hr-1

1000/T, K-1

Fission Gas Diffusion PropertyFission Gas Diffusion Property

0.00052 0.00054 0.00056 0.00058 0.000601E-18

1E-17

1E-16

Effective

Diffusivity (m

2/sec)

1/T(K)

UO2

D U PIC

Trace Irradiation in the HANARO reactor– Post-irradiation annealing : 1400 ~1600oC– Diffusion coefficient of Xe-133 : UO2 > DUPIC– Cation vacancy concentration change by fission products (trivalent)

He+

4% H2

T.CHeater

Ge-Detector

UO2

Vacuum Pump

Vent

Liquid N2

Oxygen Sensor

Al2O3

[ ]21.3 10 exp 307appD RT−= × −

[ ]44.4 10 exp 227appD RT−= × −

Basic Sensitivity AnalysisBasic Sensitivity Analysis

Fuel Performance Code: ELESTRES (AECL)Modifying ELESTRES’ material models for the DUPIC

0 5000 10000

400

600

800

1000

1200

1400

1600

1800

2000

Centerline Temperature (K)

Burnup (MWd/t)

UO2

therm al conductivity

enrichm ent

therm al expansion

flux depression

elastic stiffness

yield strength

creep

diffusion coefficient

0 5000 10000

-0.5

0.0

0.5

1.0

1.5

2.0

Sheath Plastic Strain (%)

Burnup (MWd/t)

UO2

therm al cond uctivity

enrichm ent

therm al exp ansio n

flux dep ression

elastic stiffness

yield streng th

creep

d iffusion co efficient

Centerline TemperatureCenterline Temperature Sheath Plastic Strain Sheath Plastic Strain

Basic Sensitivity AnalysisBasic Sensitivity Analysis

0 5000 10000

0

2

4

6

8

10

12

14

16

18

20

Internal Pressure (MPa)

Burnup(MWd/t)

UO2

th erm al c o n d u c tivity

en ric h m en t

th erm al exp an sio n

flu x d ep ressio n

elastic stiffn ess

yield stren g th

c reep

d iffu sio n c o effic ien t

0 5000 10000

0

5

10

15

20

25

30

35

Fission G

as Release (%)

Burnup (MWd/t)

UO2

th erm al c o n d uc tivity

en ric hm en t

th erm al exp an sio n

flux d ep ressio n

elastic stiffn ess

yield stren g th

c reep

d iffusio n co efficien t

Fission Gas ReleaseFission Gas Release Internal Gas PressureInternal Gas Pressure

The change of thermal conductivity influences most strongly on fuel performance of the DUPIC fuel.

Performance AnalysisPerformance Analysis

0 5000 10000 15000 20000

0

10

20

30

40

50

Reference High Power Nominal Design PowerE

lement lin

ear power (kW/m

)

Burnup (MWd/t)0 5000 10000 15000 20000

500

1000

1500

2000

Temperature (K)

Burnup (MWd/t)

Reference High Power Nominal Design Power

Performance Evaluation by Calculated Power Envelop– Reference High Power Envelop– Nominal Design Power Envelop

Higher Temperature than UO2 but less than melting temp.– ~3000 K

Performance AnalysisPerformance Analysis

Higher fission gas release: – Due to lower thermal conductivity and resulting higher temperature– Results in higher internal gas pressure than coolant pressure– Gap open and outward creep of clad

Internal gas pressure should be reduced.

0 5000 10000 15000 200000

10

20

FGR (%)

Burnup (MWd/t)

Reference High Power Nominal Design Power

0 5000 10000 15000 200000

5

10

15

Internal Pressure (MPa)

Burnup (MWd/t)

Reference High Power Nominal Design Power

Internal Gas PressureInternal Gas Pressure

One way to reduce the internal gas pressure is to give more volume for fission gases. – Plenum – Radial gap– Axial gap

0 5000 10000 15000 200000.0

0.5

1.0

1.5

Sheath Plastic Strain at Pelle

t End (%)

Burnup (MWd/t)

High Power without Plenum High Power with Plenum (0.5mm3

/K )

0 5000 10000 15000 200000

5

10

15

Internal Pressure (MPa)

Burnup (MWd/t)

High Power without Plenum

High Power with Plenum (0.5mm3/K )

Orthogonal Array DesignOrthogonal Array Design

Assignment of the levels to the factors

* within manufacturing spec.

levelgap

clearance(µm)

pellet density(g/cm3)

grain size(µm)

1 40 10.30 5

2 80 10.45 15

3 120 10.60 25

3 level OAD Table, L9(34)

factors

Run gap clearance

pellet density

error grain size

1 1 1

2

3

1

2

3

1

2

3

1 1

2 1 2 2

3 1 3 3

4 2 2 3

5 2 3 1

6 2 1 2

7 3 3 2

8 3 1 3

9 3 2 1

LevelLevel--average Response Graphsaverage Response Graphs

1 2 30

5

10

15

Gas

Pre

ssur

e (M

Pa)

Level

Gap Clearance Density Grain Size

Safety Limiting Parameters– centerline temperature– Internal gas pressure– hoop strain

gap & grain ↑, density ↓

1 2 30.5

1.0

1.5

2.0

Hoo

p St

rain

(%)

Level

Gap Clearance Density Grain Size

1 2 31900

1950

2000

2050

2100

Cen

tral T

empe

ratu

re (K

)

Level

Gap Clearance Density Grain Size

Safety MarginSafety Margin

Comparison of Fabrication Factors’ Set– Large gap, large grain, low density– Small gap, small grain, high density

Safety Margin Standards– Central temperature: melting temp.– Internal pressure: coolant pressure– Hoop strain: 1%

0

1

2

3

Hoop Strain Internal Pressure

Safety M

argin R

atio

Central Temperature

large gap & grain / low density small gap & grain / high density

Irradiation Test of DUPIC FuelIrradiation Test of DUPIC FuelIrradiation Test in HANARO Research Reactor (KAERI)– Spent Fuel: discharged from Gori-1 LWR at 27,300 MWd/tU– U-235: 1.06%, Pu: 0.51%– Linear power: ~38 kW/m

– Discharge burnup : ~6,700 MWd/t

– Instrumentation : temp. & SPND

Measured and Calculated TemperatureMeasured and Calculated Temperature

Good agreement between measured centerline temperature and estimated one calculated by performance evaluation codes

0

200

400

600

800

1000

1200

1400

1600

0 500 1000 1500 2000 2500

B u rn up , M WD /tHM

Cen

ter T

empe

ratu

re,

o C

M easuredK AOSIN FR A

0

5

10

15

20

25

30

35

40

45

0 500 1000 1500 2000 2500

Burnup, MWD/tHM

Line

ar P

ower

, kW

/m

Rod #1Rod #2Rod #3

International CollaborationInternational CollaborationKOREA-CANADA-US-IAEA– 3 DUPIC Fuel Rod Fabrication (AECL)– Irradiation Test in the NRU Reactor– BB03: 2000. Sep. (10 MWd/kgHM)– BB04: 2001. Dec. (16 MWd/kgHM)– BB02: 2003. Dec. (21 MWd/kgHM)

Performance Para. BB03 BB04

Midplane Burnup 10 MWd/kgHM 16 MWd/kgHM

Max. Power ~49 kW/m ~50 kW/m

Max. Ridge Height 0.021 mm 0.029 mm

Residual Sheath Strain(Pellet Interface)

0.2 % to 0.3 % 0.2 % to 0.6 %

Gas Volume 12.6 ml at STP 16.0 ml at STP

ConclusionsConclusions

The material properties of the DUPIC fuel pellet were measured to be used in the fuel performance code for the DUPIC fuel.

The fuel performance of the DUPIC fuel shows that the DUPIC fuel requires adjustments of fabrication parameters to guarantee safety margin during the in-reactor operation.

The irradiated DUPIC fuel shows good performance in agreement with estimation by performance evaluation codes using material properties for the DUPIC fuel.

The material properties of the DUPIC fuel pellet were measured to be used in the fuel performance code for the DUPIC fuel.

The fuel performance of the DUPIC fuel shows that the DUPIC fuel requires adjustments of fabrication parameters to guarantee safety margin during the in-reactor operation.

The irradiated DUPIC fuel shows good performance in agreement with estimation by performance evaluation codes using material properties for the DUPIC fuel.