About this Abstract | 
  
   
    | Meeting | 
    MS&T24: Materials Science & Technology
       | 
  
   
    | Symposium 
       | 
    Thermodynamics of Materials in Extreme Environments
       | 
  
   
    | Presentation Title | 
    Defect Thermodynamics and Its Role in the Irradiation Response of Nuclear Fuels | 
  
   
    | Author(s) | 
    David  Andersson, Michael  Cooper, Benjamin  Liu, Conor  Galvin, Anton  Schneider, William  Neilson, Christopher  Matthews | 
  
   
    | On-Site Speaker (Planned) | 
    David  Andersson | 
  
   
    | Abstract Scope | 
    
Equilibrium thermodynamics in nuclear fuels sets conditions that impact the response to irradiation. This occurs by providing driving forces for returning the system to equilibrium, controlling defect clustering and determining at what temperature the system transitions from being dominated by irradiation transport to thermal transport processes. Three ceramic nuclear fuels are investigated: uranium oxide (UO2), uranium oxycarbides (UCO) used in TRISO particles and uranium nitride (UN). First, the equilibrium defect thermodynamics will be established using density functional theory and empirical potential calculations. Next, the link to the irradiation response is studied by using the cluster dynamics code Centipede. In addition to the thermodynamic properties, this code captures defect production, self-interactions, sink-reactions, clustering, and kinetic properties governing the response to irradiation. Finally, the resulting defect thermodynamic and diffusion properties will be connected to in-reactor performance at the engineering scale through their role in swelling, release of fission gases, creep, and densification.  |