Early Progress on Additive Manufacturing of Nuclear Fuel Materials

Transcription

1 Early Progress on Additive Manufacturing of Nuclear Fuel Materials Andrew Bergeron, Brent Crigger Cathy Thiriet (presenter) 2018 October 30-1-

2 Outline Background Stereolithography 3D printing method (SLA) Materials Results Discussion and Conclusions -2-

3 Background 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 UO 2 -based fuel Additive manufacturing of ThO 2 investigated using a commercially available stereolithography-based 3D printer and photopolymer resin. -3-

4 Background (continued) Additive Manufacturing According to ASTM Standard F a, 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 -4-

5 Background (continued) Additive Manufacturing Technologies Material extrusion Directed energy deposition Binder jetting Material jetting Powder bed fusion Vat polymerization (Stereolithography) -5-

6 Stereolithography 3D printing method -6-

7 Stereolithography 3D printing method Additive manufacturing technology based on vat photopolymerization Formlabs Form 2-7-

8 Stereolitography 3D printing method Manufacturing steps 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) 3D Printed ThO 2 cubes UV light curing box -8-

9 Materials Description and preparation steps for SLA 3D printing Commercially available photopolymer resin (Genesis resin from Tethon 3D) combined with thorium dioxide powder ThO 2 powder physical specifications and element chemical analysis Particle shape Particle size Surface area Mostly spherical 2.0 µm (7.3 µm) m2 g-1 Resin and ThO 2 powder mixing in low intensity turbula shaker/mixer in 3:10 weight ratio (27 ThO 2 vol. %) -9-

10 3D printed hollow thoria cubes Results z Thoria cube after printing Parts on build platform with arrow indicating build direction After support removal and sintering -10-

11 3D printed hollow thoria cubes Results Cube Step X (mm) Y (mm) Z (mm) 1 Pre-sintering Sintered density (g cm -3 ) % theor. density Post-sintering Pre-sintering Post-sintering 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% d theor. ) -11-

12 3D printed hollow thoria cubes Results Composite cross-sectional image of a 3D-printed cube face Arrows indicate cracks parallel and normal to build lines 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 -12-

13 Discussion and Conclusions Additive manufacturing successfully applied to produce ThO 2 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. -13-

14 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) 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 thoriumuranium mixed oxides, JNM 500 (2018) A. Quastel, C. Thiriet, Chemical diffusion coefficient of oxygen in thoria based fuel with 3 and 8 weight % urania, JNM 512 (2018) 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)O 2 fuel at Canadian Nuclear Laboratories, JNM 508 (2018) D. Woods, M. Saoudi, C. Mayhew, R. Ham-Su, Characterization of Plutonium distribution in ThO 2 -PuO 2 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 M. Saoudi, J. Mouris, L. Fu, K. Stoev, Laser flash method for measuring thermal diffusivity of liquids, poster presented at NuMat, Seattle, 2018 Oct

15 Thank you. Merci. Questions? Contact information: Andrew Bergeron -15-