Fabrication Process Selection through the Miniplate …dels.nas.edu/resources/static-assets/nrsb/miscellaneous/U-Mo-Fuel...Medium Power Test in South Flux Trap 25 • NBSR – MURR-1

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Fabrication Process Selection through the Miniplate-1 (MP-1) Experiment I. Glagolenko, N. Woolstenhulme, B. Rabin, D. Keiser, M. Meyer, B. Nielson, J. Parry, M. Lillo, G. Roth, W. Jones, J. Wiest, and S. Snow, INL G. Hofman and E. Wilson, ANL D. Senor, PNNL C. Richardson, B&W 02/26/15

Needed LEU fuel for conversion of five US High Power Research Reactors (US HPRR)

US High Performance Research Reactor (US HPRR)

Regulatory Agency

1 Massachusetts Institute of Technology Reactor (MITR) Nuclear Regulatory

Commission (NRC)

2 Missouri University Research Reactor (MURR) 3 National Bureau of Standards Reactor (NBSR) 4 High Flux Isotope Reactor (HFIR) Department of

Energy (DOE) 5 Advanced Test Reactor (ATR)

Challenge: one type of fuel for different end-use applications

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Selected Design Monolithic LEU U-10Mo fuel with Zr diffusion barrier

August 2009: Favorable performance in the limited number of irradiation tests:

9 miniplates (RERTR-9,-10) 2 large size plates (AFIP-2 and AFIP-3)

Additional data became available for this fuel design later: 56 miniplates (RERTR-12), 11 larger size plates (AFIP-4, AFIP-6, AFIP-6-MKII, AFIP-7)

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Al-6061 cladding U-Mo monolithic foil

(0.2 – 0.635 mm thick)

Co-rolled Zr barrier (0.0254 mm thick)

Plate (1.1 mm – 2.54 mm thick)

Reference Fuel fabrication process Bench scale reference process developed at INL • Down-blending and alloying • U-Mo casting and coupon preparation • Hot rolling of U-Mo with Zr barrier in a welded can assembly • De-canning of the U-Mo/Zr foil • Annealing of the foil, if desired • Cold rolling of the foil to final thickness • Foil shearing • Foil cleaning • Bonding of the foil and cladding at 560 °C using Hot Isostatic Press (HIP)

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Challenges Scaling of the fabrication process

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Not commercially viable: low yield inefficient poor uranium

resource utilization high cost of waste

reprocessing

INL bench-scale reference fabrication

process

Large scale reference fabrication

process Scale-up

2.54 cm × 10.16 cm 10.06 cm× 125.73 cm

Key to Success

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Successful Fuel Product

Efficient and Economical Fabrication

Process

Acceptable Irradiation

Performance

New Focus Develop commercially viable fabrication process

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Fuel Fabrication Capability (FFC) is in charge

Stage Gate Approach in Fabrication Process Selection Improve yield

Minimize waste Reduce cost

Optimize existing (baseline) fabrication process

Develop/implement alternative fabrication methods

Detailed information about FFC activities is in Doug Burkes’s

presentation on Friday

Examples of Fabrication method Improvements

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• Reduction of U-waste by changing Zr barrier application method

• Reduction of cost by switching to can-less HIP

Key: new fabrication technologies have to be demonstrated at large scale

No barrier

Zr barrier application

Co-rolling

Plasma spray

Electro-plating

Cladding bonding

Hot Isostatic Press (HIP)

Can-less HIP

New Focus

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MP-1 test is a platform for achieving this mission

Base Fuel Designs

• no fuel grading

• no poisons

Reactors MURR, MIT,

NBSR

Single Fab. Process

Compatible with ATR/HFIR

Commercial Viability Deploy and demonstrate

commercially viable fabrication methods at large

scale far in advance of irradiation tests

Adequate Irradiation Performance

Demonstrate irradiation performance as a function

of fabrication process

Downselect Select fabrication process

suitable to be qualified for LEU conversion

Evaluation of Fuel Performance: Miniplate-1 (MP-1) irradiation test

• Fabrication process downselect test • All test specimens manufactured using fabrication processes that meet

“commercial viability” requirements • Miniplate scale • Base fuel designs • Prototypic irradiation conditions/plate geometries • Focus on evaluation of irradiation performance against a set of

established criteria • Development of key relationships:

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Fabrication process

Microstructure/ properties

Irradiation performance

Role of MP-1 in US HPRR Fuel Development Program

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Base Fuel Qualification

Report submitted to NRC

MP-1 Screening/downselect test, miniplate scale

MP-2 Fuel qualification test

miniplate scale

FSP-1 Fuel qualification test full-size plate scale

ET-1 Fuel qualification test

fuel element scale

Base fuel fabrication process selected for qualification Fuel specification defined

Detailed information about base fuel qualification is in

Nic Woolstenhulme’s presentation on

Friday

MP-1 Designing by the Rules • Design to meet safety and program requirements • Be prototypic as much as feasible:

– use LEU instead of HEU – prototypic geometries (fuel meat/cladding thickness) – commercial fab processes – prototypic irradiation conditions

• Obtain statistical confidence to enable good downselect decision • Reduce the risk of in-reactor failure as much as possible

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MP-1 Fabrication Requirements • Miniplates are manufactured by commercial supplier (B&W) using

commercially viable processes: – optimized baseline – alternative

• MP-1 fuel specification requires demonstration of selected fabrication processes at full scale

• Miniplates are representative of the full scale products and meet established fuel specification

• Entry requirement for MP-1 test – Fabrication processes meet Technology Readiness Level 4 (TRL- 4)

• economics (capital and life cycle cost) • technical maturity • suitability for implementation • lead time for deployment

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MP-1 Matrix (Evolving)

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Fabrication Process Variables

Fuel

Specimens

Coupon fabrication

Zr barrier application

Fuel foil edge conditions

Cladding bonding

Optimized FY16 baseline

Billet casting and bare rolling

No barrier

Co-rolling

Plasma spray

Electro-plating

Not-covered (co-roll, plasma-spray)

Hot Isostatic Press (HIP)

Can-less HIP

Covered (electroplating)

Reference Fuel

Specimens

MP-1 Selecting plate geometries and irradiation conditions for testing

Five Reactors: • Variety of plate designs (fuel meat/cladding thicknesses) coupled with

unique operating conditions • Striving to be prototypic

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Plate 19

Plate 15

Plate 19

Plate 15

Dispersion • The same fuel meat thickness • Plate with the highest power density

is the plate with the highest heat flux

Monolithic • Multiple fuel foil thicknesses • Plate 19 – highest power density • Plate 15 – highest heat flux

Reactor plates limiting operating conditions vs. MP-1 targets

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MP-1 high power target: 0.0085”, 0.05”

MP-1 medium power target: 0.0085”, 0.05” MP-1 low

power target: 0.025”, 0.05”

ATR- thick foil: 0.016”, 0.05”

ATR-thin foil: 0.008”, 0.05”

MURR-thin foil: 0.009”, 0.044”

MURR-thick foil:

0.020”, 0.044”

NBSR: 0.0085”, 0.05”

MITR-thin foil: 0.013”, 0.049” MITR-thick foil:

0.025”, 0.049” 0

10

20

30

40

50

0 1 2 3 4 5 6 7 8

Plat

e pe

ak p

ower

(r

eact

or s

peci

fic n

ode)

, kW

/cc

Plate peak burnup (reactor specific node), × E21 fiss/cc

Selection of plate geometries / irradiation conditions for MP-1

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ATR, (HFIR)

thickest meat low power,

med-burnup

thin meat med power,

highest burnup

thin meat highest power,

low-to-med burnup

NBSR, MURR-1 MURR-22, MITR

Fab Process #1

Fab Process #2

Fab Process #3 Test Condition #1

low power, med-burnup

Test Condition #2 medium power,

high burnup

Test Condition #3

high power, low-to-med burnup

And the Winner is … Fab Process X !!! EXPERT JURY

Geometry #1 thick meat

Geometry #2 thin meat

Geometry #2 thin meat

. . .

Essence of MP-1

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Fabrication + Performance Requirements

MP-1 Matrix Specimen Category

Coupon Fab Method

Foil Trimming

Clad Bonding

Fuel Meat, Plate

thickness (inches)

Power, Burnup

Zirconium Application and Edge Condition

Co-roll Plasma Spray Electroplating No Zirconium (Uncovered) (Uncovered) (Covered)

Fabrication Process Variables

FY16 Optimized Baseline

(Billet Cast and Bare

Roll)

Slitting

HIP

0.0085, 0.049 52.5, 5.5 FFC-1-1 FFC-5-1 FFC-6-1

0.0085, 0.049 17.6, 7.6 FFC-1-2 FFC-5-2 FFC-6-2 FFC-4-2

0.025, 0.049 7.7, 4.0 FFC-1-3 FFC-5-3 FFC-6-3 FFC-4-3

Alternate (Canless

HIP)

0.0085, 0.049 52.5, 5.5 FFC-8-1 FFC-7-1 FFC-9-1

0.0085, 0.049 17.6, 7.6 FFC-8-2 FFC-7-2 FFC-9-2 FFC-12-2

0.025, 0.049 7.7, 4.0 FFC-8-3 FFC-7-3 FFC-9-3 FFC-12-3

Reference Process (modified geometry)

Old Reference Shear HIP

0.0085, 0.049 52.5, 5.5 FD-11-1

0.0085, 0.049 17.6, 7.6 FD-11-2

0.025, 0.049 7.7, 4.0 FD-11-3

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• 4 replicates for each specimen type • 28 specimens in high power conditions • 36 specimens in medium power conditions • 36 specimens in low power conditions • Additional archives and substitutes

100 specimens total to be irradiated: 72 LEU + 28 HEU

LEU Advantages

• Prototypic enrichment • Prototypic fabrication line • Representative power

history • Less spread in power

among specimens in the flux trap

• Less spread in burnup

Consequences

• Longer irradiation time • Need for higher flux flux

trap (NBSR case) • Harder to match target

power = can’t use enrichment to adjust power

• Limited number of suitable test positions within one test train

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ATR- and HFIR-like conditions still require HEU!

MP-1 Test Capsule Hf suppressors to reduce power peaking

Benefits Reduces power

peaking to allow thermal safety requirements for experiment insertion to be met

Helps to avoid failures at non-prototypic conditions

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Courtesy of Jim Wiest

Courtesy of Nic Woolstenhulme

MP-1 Hardware Design Large-B Position

Irradiation Vehicle

South Flux Trap Irradiation Vehicle

• Two side-by-side channels, a.k.a ‘double barrel design’

• Fits more specimens at the same axial flux level → with the same power

• Provides more efficient cooling configuration for high power specimens

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B-12 B-10

B-11 South Flux Trap (SFT)

MP-1 Test Positions in ATR

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Low Power Test in Large B Test Position

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• MITR – MURR-22 condition • All plates are LEU • With Hf suppressors • Up to 26% higher than bounding

conversion element power • Number of useful positions (in red)

per one large B test train = 14 • Need to fit 36 specimens 3 large

B test trains • Each specimen type is isolated in

individual capsule • 5-6 cycles to reach target burnup

Courtesy of Nic Woolstenhulme

Medium Power Test in South Flux Trap

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• NBSR – MURR-1 condition • All plates are LEU • Without Hf suppressors • Up to 58% higher than conversion

element bounding power • Number of useful positions (in red) = 32 • Need to fit 36 specimens 4 mini-

plates short • Specimens without Zr barrier are

isolated in individual capsule • Two specimen types are in one capsule • 6-7 cycles to reach target burnup

Courtesy of Nic Woolstenhulme

High Power Test in South Flux Trap

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• ATR condition • All plates are HEU (A% and B%) • With Hf suppressors • Number of useful positions (in red) = 32 • Need to fit 28 specimens • No specimens without Zr barrier • ~ 1 cycle to reach target burnup

Courtesy of Nic Woolstenhulme

Irradiation Schedule

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Test Test Position ATR Cycles 1 2 3 4 5 6 7 8

CIC

Low Power Three large B’s X X X X X X

Medium Power South Flux Trap X X X X X X X High Power South Flux Trap X

Channel gap probe measurements and data

interpretation

As-run analysis for the previous cycle and

projections for the next cycle

Risk assessment against ‘requirements based exit criteria’

‘Go/no go’decision per capsule basis

In-between cycles

Irradiation Performance

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Mechanical Integrity • no in-core blistering • blister threshold temperature is

known acceptable • no excessive swelling • no plate deformation or movement • thermo-physical properties affecting

geometric stability are known

Stable and Predictable Behavior

• no fission product release • no delamination (bond integrity) • no in-core blistering • blister threshold temperature is known

and acceptable • no warping or buckling • fuel microstructure is stable • mechanical properties are known and

acceptable • mechanical stresses are known • thermo-physical properties affecting

mechanical integrity are known • no excessive cladding corrosion • limits for fabrication defects are

established

• swelling is known and acceptable

• fuel microstructure is stable, no obvious precursors to failure

– large gas bubbles

– interconnected porosity

• thermo-physical properties affecting fuel stability are known

• blister threshold temperature is known and acceptable

Geometric Stability

Acceptable Irradiation

Performance Geometric Stability

Mechanical Integrity

Stable and Predictable Behavior

Detailed information about PIE activities is in Adam Robinson’s

presentation on Friday

MP-1 Benefit to the Program • MP-1 will provide irradiation performance data for the fabrication

processes: – that have lower cost, produce less waste and are more efficient – that have been demonstrated to be scalable and commercially

viable – with good statistical confidence to enable solid fabrication process

down-select decision • MP-1 will deliver fuel/fabrication process for future fuel qualification and

ultimate reactor conversion

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