Project Summary

Representative first wall/blanket design

The objective of this project is to develop an integrated computational model linking the materials physics scale with the component-level scale to simulate the thermomechanical response of the full first wall/blanket structures during fusion reactor operation. Phenomena of interest at the three modeling scales include:

  1. Fundamental properties (“Level 1”)
    1. Transmutant inventory changes
    2. Dose- and material chemistry-dependent PKA energy distributions
    3. Displacement cascades in isotopically-changing environments
    4. Chemical environment-dependent defect structures
    5. Irradiation defect distributions
    6. Tritium transport/trapping in chemically evolving environments
  2. Microstructural evolution (“Level 2”)
    1. Irradiation hardening, creep, and swelling
    2. Grain growth/recrystallization
    3. Tritium permeation and retention
  3. Component evaluation (“Level 3”)
    1. Integrated thermomechanical evolution of selected design(s)
    2. Design findings/recommendations

We will also carry out assessments of the uncertainties associated with various phenomena to inform the integrated models.

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Publications and Presentations

Our most recent publications include…

Publications

  • Li, Y., Maron, M., Baker, K., Flores, B. R., Black, T., Hollenbeck, J., Lalani, I., Ghoniem, N., & Po, G. (2026). Coupled cluster and dislocation dynamics modeling of microstructure evolution in irradiated materials. Journal of the Mechanics and Physics of Solids, 206, 106366. https://doi.org/10.1016/j.jmps.2025.106366
    Abstract

    We develop here a coupled cluster and dislocation dynamics framework to study the microstructure evolution of irradiated materials. The framework not only accounts for the three dimensional diffusion of radiation-generated clusters, but also their interaction with dislocation networks and the resultant climb motion of discrete dislocations within finite crystals. The framework is solved with a superposition solution scheme, and is applied to investigate the evolution of the irradiation-induced dislocation loops in zirconium (Zr), considering the effects of various bias factors including the diffusion anisotropy difference (DAD) of interstitials and interstitial clusters, the dislocation bias of defects to discrete dislocation segments, and the production bias of defects from the radiation cascade. We find that the DAD is the most critical factor influencing the kinetics of the loop evolution in Zr, while the recombination/interaction of mobile defects can induce a strong spatial dependence of the loop evolution together with the DAD. The method is also adopted to study the evolution of interstitial 〈a〉 and vacancy 〈c〉 dislocation loop ensembles consistent with the microstructure observed during irradiation-induced growth of Zr. Our findings not only reveal the spatial dependence of the size and ellipticity of the dislocation loops, but also suggest a limit on the anisotropy factor of interstitials to reproduce the co-growth of 〈a〉 and 〈c〉 loops in zirconium, in good agreement with experimental observations and other simulation results.

    BibTeX
    @article{LI2026106366,
  title = {Coupled cluster and dislocation dynamics modeling of microstructure evolution in irradiated materials},
  journal = {Journal of the Mechanics and Physics of Solids},
  volume = {206},
  pages = {106366},
  year = {2026},
  issn = {0022-5096},
  url = {https://doi.org/10.1016/j.jmps.2025.106366},
  doi = {10.1016/j.jmps.2025.106366},
  author = {Li, Yang and Maron, Matthew and Baker, Kristopher and Flores, Benjamin Ramirez and Black, Thomas and Hollenbeck, James and Lalani, Inam and Ghoniem, Nasr and Po, Giacomo},
  keywords = {Cluster diffusion, Dislocation climb, Bias factors, Irradiation growth}
}
  • Peng, J., & Cereceda, D. (2025). Temperature-Dependent Mechanical and Electronic Properties of 3C-SiC: Insights From First-Principles Calculations. Journal of Applied Mechanics, 92(11), 111009. https://doi.org/10.1115/1.4069107
    Abstract

    The zinc-blende polytype of silicon carbide, known as 3C-SiC, is a promising ceramic material in high-temperature energy applications. However, the reported data on its mechanical and electronic properties, especially at elevated temperatures, are either lacking or scarce, with sizeable uncertainty. In this study, we present a comprehensive study on the temperature-dependent mechanical and electronic properties of 3C-SiC. First-principles calculations are combined with the quasi-harmonic approximation to investigate lattice properties at elevated temperature. We find that phonons dominate the temperature-dependent behavior. As temperature increases, all elastic constants exhibit a softening trend, and 3C-SiC becomes more elastically anisotropic. Our calculated degree of softening of elasticity is weaker than the values reported by previous studies. Moreover, the effects of thermal expansion and electron–phonon coupling on the electron band energy at elevated temperatures are investigated. The electron–phonon coupling dominates the temperature dependence of the band gap, where 3C-SiC maintains its wide gap at high temperature.

    BibTeX
    @article{10.1115/1.4069107,
  author = {Peng, Jie and Cereceda, David},
  title = {Temperature-Dependent Mechanical and Electronic Properties of 3C-SiC: Insights From First-Principles Calculations},
  journal = {Journal of Applied Mechanics},
  volume = {92},
  number = {11},
  pages = {111009},
  year = {2025},
  month = aug,
  issn = {0021-8936},
  doi = {10.1115/1.4069107},
  url = {https://doi.org/10.1115/1.4069107},
  eprint = {https://asmedigitalcollection.asme.org/appliedmechanics/article-pdf/92/11/111009/7519253/jam-25-1191.pdf}
}
  • Ullah, R., Morgan, D. D., & Szlufarska, I. (2025). Mg and native defects in cubic silicon carbide from first principles. Journal of Physics D: Applied Physics, 58(26), 265302. https://doi.org/10.1088/1361-6463/ade263
    Abstract

    The diffusion of Mg defects in 3C-SiC is studied using the density functional theory. Mg has the highest burn-in rate as a transmutant in 3C-SiC when it is placed in high-energy neutron irradiation environment of a fusion reactor. The presence and evolution of transmutant defects impact thermal and mechanical properties of this important structural material. This study is focused on understanding the structure, stability, and evolution of Mg defects and the interaction of Mg with native defects in 3C-SiC. Our calculations of diffusion coefficients for different Mg defects suggest that Mg is likely to diffuse faster in pristine 3C-SiC than in the damaged one, in agreement with earlier experimental observations.

    BibTeX
    @article{Ullah_2025,
  doi = {10.1088/1361-6463/ade263},
  url = {https://doi.org/10.1088/1361-6463/ade263},
  year = {2025},
  month = jun,
  publisher = {IOP Publishing},
  volume = {58},
  number = {26},
  pages = {265302},
  author = {Ullah, Rafi and Morgan, Dane D and Szlufarska, Izabela},
  title = {Mg and native defects in cubic silicon carbide from first principles},
  journal = {Journal of Physics D: Applied Physics}
}

Presentations

  • Marian, J. (2025). Integrated Thermomechanical Model of First Wall Components Under Evolving Chemistry and Microstructure During Fusion Reactor Operation: ThermChem-FW. invited talk, 2025 SciDAC-5 Principal Investigator (PI) Meeting, Rockville, Maryland. https://thermchem-fw.github.io/assets/documents/2025-09-marian-scidac-pi-meeting.pdf
    BibTeX
    @misc{2025-09-marian-scidac-pi-meeting,
  author = {Marian, Jaime},
  howpublished = {invited talk, 2025 SciDAC-5 Principal Investigator (PI) Meeting, Rockville, Maryland},
  title = {Integrated Thermomechanical Model of First Wall Components Under Evolving Chemistry and Microstructure During Fusion Reactor Operation: ThermChem-FW},
  year = {2025},
  month = {16--18 September}
}
  • Abaalkhail, A. K., Dudhatra, H., German, P., Marian, J., Spencer, B., & Po, G. (2025). A Microstructure-Based Viscoplastic Model of FW & Blanket Fusion Materials. poster, ICFRM-22: International Conference on Fusion Reactor Materials, Shizuoka, Japan, Sep 28–Oct 3, 2025.
    BibTeX
    @misc{abaalkhail2025-fw-blanket,
  author = {Abaalkhail, Abdulmohssen K. and Dudhatra, Harsh and German, Peter and Marian, Jamie and Spencer, Benjamin and Po, Giacomo},
  howpublished = {poster, ICFRM-22: International Conference on Fusion Reactor Materials, Shizuoka, Japan, Sep 28--Oct 3, 2025},
  title = {A Microstructure-Based Viscoplastic Model of {FW} \& Blanket Fusion Materials},
  year = {2025},
  month = {28 Sep -- 3 Oct}
}
  • Marian, J., & Trelewicz, J. (2024). Integrated Thermomechanical Model of First Wall Components Under Evolving Chemistry and Microstructure During Fusion Reactor Operation: ThermChem-FW. invited talk, 2024 SciDAC-5 Principal Investigator (PI) Meeting, Rockville, Maryland. https://thermchem-fw.github.io/assets/documents/2024-07-marian-scidac-pi-meeting.pdf
    BibTeX
    @misc{2024-07-marian-scidac-pi-meeting,
  author = {Marian, Jaime and Trelewicz, Jason},
  howpublished = {invited talk, 2024 SciDAC-5 Principal Investigator (PI) Meeting, Rockville, Maryland},
  title = {Integrated Thermomechanical Model of First Wall Components Under Evolving Chemistry and Microstructure During Fusion Reactor Operation: ThermChem-FW},
  year = {2024},
  month = {16--18 July}
}

Other Documents

  • Marian, J., Trelewicz, J., Szlufarska, I., Po, G., Cereceda, D., Cusentino, M. A., Sargsyan, K., Setyawan, W., Bernholdt, D., Humrickhouse, P., Permann, C., & Spencer, B. (2023). Integrated Thermomechanical Model of First Wall Components Under Evolving Chemistry and Microstructure During Fusion Reactor Operation (ThermChem-FW). Proposal to the U. S. Dept. of Energy, Office of Science, Office of Fusion Energy Sciences and Office of Advanced Scientific Computing Research, funding opportunity announcement DE-FOA-0002924, Scientific Discovery Through Advanced Computing (SCiDAC) - FES Partnerships. https://thermchem-fw.github.io/assets/documents/thermochem-fw-proposal-2023.pdf
    BibTeX
    @misc{thermochem-fw-proposal-2023,
  author = {Marian, Jaime and Trelewicz, Jason and Szlufarska, Izabela and Po, Giacomo and Cereceda, David and Cusentino, Mary Alice and Sargsyan, Khachik and Setyawan, Wahyu and Bernholdt, David and Humrickhouse, Paul and Permann, Cody and Spencer, Benjamin},
  howpublished = {Proposal to the U. S. Dept. of Energy, Office of Science, Office of Fusion Energy Sciences and Office of Advanced Scientific Computing Research, funding opportunity announcement DE-FOA-0002924, Scientific Discovery Through Advanced Computing (SCiDAC) - FES Partnerships},
  title = {Integrated Thermomechanical Model of First Wall Components Under Evolving Chemistry and Microstructure During Fusion Reactor Operation  (ThermChem-FW)},
  year = {2023},
  note = {Note: this version does not include scope changes in response to budget changes at award time.}
}

See all…

Team

Institution Principal Investigator(s)* Additional Personnel
UCLA logo Jaime Marian (FES, Lead PI) Abhijeet Gangan, Alan He, Shao-Ching Huang, Scarlett Liang, Lily Wang, Jinxin Yu
INL logo Cody Permann (ASCR) Peter German, Benjamin Spencer

Alumni: Dewen Yushu
ORNL logo David E. Bernholdt (ASCR)
Paul Humrickhouse (FES)		 Monica Gehrig, Moataz Harb, Danny Schappel, Sergey Yakubov
PNNL logo Wahyu Setyawan (FES) Yucheng Fu
SNL logo Mary Alice Cusentino (FES)
Khachik Sargsyan (ASCR)		 Cristian Lacey
Stony Brook U logo Jason Trelewicz (FES) Yusheng Jin, Anus Manzoor, Yedu Neelam, Spencer Thomas
U Miami logo Giacomo Po (FES) Abdulmohssen Abaalkhail, Harsh Dudhatra
U Wisconsin logo Izabela Szlufarska (FES) Dane Morgan, Maceij Polak, Chen Shen

Alumni: Rafi Ullah
Villanova U logo David Cereceda (FES) Alumni: Jie Peng

* PIs are listed for the Fusion Energy Sciences (FES) and Advanced Scientific Computing Research (ASCR) funding components, as appropriate. The first person listed is the institutional PI.

This project is part of the Scientific Discovery through Advanced Computing (SciDAC) program, and is jointly sponsored by the Fusion Energy Sciences (FES) and Advanced Scientific Computing Research (ASCR) programs within the U.S. Department of Energy Office of Science. The project is part of the fifth funding cycle of the SciDAC program, under FOA DE-FOA-0002924. The project’s period of performance is 2023-09-22/2027-09-21.

DOE Office of Science logo