Early Progress on Additive Manufacturing of Nuclear Fuel ......2018/10/30 · • A. Quastel, C. Thiriet, “hemical diffusion coefficient of oxygen in thoria based fuel with 3 and

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Early Progress on Additive Manufacturing of

Nuclear Fuel MaterialsAndrew Bergeron, Brent CriggerCathy Thiriet (presenter) 2018 October 30


Outline

• Background

• Stereolithography 3D printing method (SLA)

• Materials

• Results

• Discussion and Conclusions


• Advanced nuclear fuel concepts are being developed:

• Better fuel performance

• Proliferation resistance

• Increased safety and accident tolerance

• Recycled or are recyclable

• Fuel designs may be based on advanced materials, have inhomogeneous structures, or have complex geometries

• Many cannot be fabricated via conventional processes applied to traditional UO2-based fuel

Additive manufacturing of ThO2 investigated using a commercially available stereolithography-based 3D printer and photopolymer resin.

Background


Background (continued)Additive Manufacturing

According to ASTM Standard F2793-12a,

“Additive Manufacturing” is:

“the process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies, such as

traditional machining”

This is generally synonymous with “3D printing”


Background (continued)Additive Manufacturing Technologies

• Material extrusion

• Directed energy deposition

• Binder jetting

• Material jetting

• Powder bed fusion

• Vat polymerization (Stereolithography)


Stereolithography 3D printing method


Stereolithography 3D printing methodAdditive manufacturing technology based on vat photopolymerization

Formlabs Form 2


1. 3D CAD model drawing and slicing

2. Parts printing (~3.5 h duration)

3. Printed part washing with isopropyl alcohol to remove any excess resin

4. UV light curing to complete the polymerization of resin

5. Support structure cutting off

6. Resin burnout (air, 400°C for 2h)

7. Sintering (air, 1700°C for 2h)

Stereolitography 3D printing methodManufacturing steps

UV light curing box

3D Printed ThO2 cubes


• Commercially available photopolymer resin (Genesis resin from Tethon 3D) combined with thorium dioxide powder

• ThO2 powder physical specifications and element chemical analysis

• Resin and ThO2 powder mixing in low intensity turbulashaker/mixer in 3:10 weight ratio (27 ThO2 vol. %)

MaterialsDescription and preparation steps for SLA 3D printing

Particle shape Particle size Surface area

Mostly spherical 2.0 µm (7.3 µm) 6.865 m2·g-1


3D printed hollow thoria cubesResults

Thoria cube after printing After support removal and sintering

Parts on build platform with arrow indicating build direction

z


• Dimensions of the printed cubes slightly larger than the dimensions of the 3D model with a max. measured deviation of about 3%

• Linear shrinkage during sintering in the range of 18-23%

• Surface roughness from 4 to 7 µm Ra depending on the orientation of the measurement path in relation to the build lines of the cube

• Measured density ~90% of the theoretical density (nuclear fuels >95% dtheor.)


Cube Step X (mm) Y (mm) Z (mm)Sintered

density (g·cm-3)% theor. density

1 Pre-sintering 10.15 10.24 10.22

Post-sintering 8.31 8.34 8.41 9.177 91.7

2 Pre-sintering 10.12 10.31 10.15

Post-sintering 7.95 7.98 7.97 8.971 89.7


• Apparent layered structure of the cube in the top left corner of the image, cracking

• Strains arising from shrinkage due to thermally-induced polymerization of residual monomer resin on heating?

• Carbon content in sintered part lower than starting powder and no tin photocurable resin material removed from the sintered part


Composite cross-sectional image of a 3D-printed cube face

Arrows indicate cracks parallel and normal to build lines


• Additive manufacturing successfully applied to produce ThO2

part with complex geometries using a commercially available stereolithography-based 3D printer and photopolymer resin.

• Improvements need to be made to

• increase sintered density of the printed parts,

• decrease surface roughness,

• decrease number of internal cracks, and

• mitigate non-uniform distortion during sintering

• Additive manufacturing eliminates the geometric constraints of conventional fuel manufacturing which may enable fuel designers to define fuel geometries optimized for improved fuel performance and safety.

Discussion and Conclusions


Selection of recent CNL publications• A. Bergeron, J. Crigger, “Early Progress on Additive Manufacturing of Nuclear Fuel Materials”,

presentation at TopFuel, Prague, 2018 Oct 04; Brief publication in JNM 508 (2018) 344-347

• M. Floyd, B. Bromley, J. Pencer, “A Canadian perspective on progress in thoria fuel Science and Technology”, CNL Nuclear Review 6[1] (2017) 1-17

• M. Saoudi, D. Staicu, J. Mouris, A. Bergeron et al., “Thermal diffusivity and conductivity of thorium-uranium mixed oxides”, JNM 500 (2018) 381-388

• A. Quastel, C. Thiriet, “Chemical diffusion coefficient of oxygen in thoria based fuel with 3 and 8 weight % urania”, JNM 512 (2018) 31-36

• A. Bergeron, D. Manara, O. Beneš, R. Eloirdi et al., “Thermodynamic modelling of thoria-urania and thoria-plutonia fuels: Description of the Th-U-Pu-O quaternary system”, accepted paper in JNM

• K. Leeder, S. Yatabe, M.R. Floyd, G. Cota-Sanchez, R. Beier, C. Mayhew, “Fabrication and characterization of (Th, Pu)O2 fuel at Canadian Nuclear Laboratories”, JNM 508 (2018) 599-608

• D. Woods, M. Saoudi, C. Mayhew, R. Ham-Su, “Characterization of Plutonium distribution in ThO2-PuO2 mixed oxides by electron probe microanalysis”, CNL Nuclear Review (2018)

• A. Barry, A. Bergeron, T. Stoddard, B. Crigger et al., “Fluoride volatility experiments on irradiated thoria fuel at Canadian Nuclear Laboratories”, Journal of Fluorine Chemistry 214 (2018) 8-12

• D. Cluff, K. Podila, B. Hyland, “Development of molten salt capabilities at Canadian Nuclear Laboratories”, presentation at MSR Workshop, Oak Ridge, 2018 Oct 03-04

• M. Saoudi, J. Mouris, L. Fu, K. Stoev, “Laser flash method for measuring thermal diffusivity of liquids”, poster presented at NuMat, Seattle, 2018 Oct 14-18


Thank you. Merci.Questions?

Contact information:

Andrew Bergeron

[email protected]

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Early Progress on Additive Manufacturing of Nuclear Fuel ......2018/10/30 · • A. Quastel, C. Thiriet, “hemical diffusion coefficient of oxygen in thoria based fuel with 3 and