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Title: Mechanistic materials modeling for nuclear fuel performance

Abstract

Fuel performance codes are critical tools for the design, certification, and safety analysis of nuclear reactors. However, their ability to predict fuel behavior under abnormal conditions is severely limited by their considerable reliance on empirical materials models correlated to burn-up (a measure of the number of fission events that have occurred, but not a unique measure of the history of the material). In this paper, we propose a different paradigm for fuel performance codes to employ mechanistic materials models that are based on the current state of the evolving microstructure rather than burn-up. In this approach, a series of state variables are stored at material points and define the current state of the microstructure. The evolution of these state variables is defined by mechanistic models that are functions of fuel conditions and other state variables. The material properties of the fuel and cladding are determined from microstructure/property relationships that are functions of the state variables and the current fuel conditions. Multiscale modeling and simulation is being used in conjunction with experimental data to inform the development of these models. Finally, this mechanistic, microstructure-based approach has the potential to provide a more predictive fuel performance capability, but will require a teammore » of researchers to complete the required development and to validate the approach.« less

Authors:
 [1];  [2];  [3];  [4];  [4];  [2];  [2];  [4]
  1. Pennsylvania State Univ., University Park, PA (United States). Dept. of Mechanical and Nuclear Engineering
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. Univ. of Florida, Gainesville, FL (United States). Dept. of Materials Science and Engineering
  4. Idaho National Lab. (INL), Idaho Falls, ID (United States). Fuel Modeling and Simulation
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Idaho National Lab. (INL), Idaho Falls, ID (United States); Pennsylvania State Univ., University Park, PA (United States)
Sponsoring Org.:
USDOE Office of Nuclear Energy (NE); USDOE National Nuclear Security Administration (NNSA)
Contributing Org.:
Univ. of Florida, Gainesville, FL (United States)
OSTI Identifier:
1369201
Alternate Identifier(s):
OSTI ID: 1415338
Report Number(s):
LA-UR-17-21472
Journal ID: ISSN 0306-4549
Grant/Contract Number:
AC52-06NA25396; AC07-05ID14517; 12-4728
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Annals of Nuclear Energy (Oxford)
Additional Journal Information:
Journal Name: Annals of Nuclear Energy (Oxford); Journal Volume: 105; Journal ID: ISSN 0306-4549
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; 11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; Fuel performance modeling; Multiscale modeling and simulation

Citation Formats

Tonks, Michael R., Andersson, David, Phillpot, Simon R., Zhang, Yongfeng, Williamson, Richard, Stanek, Christopher R., Uberuaga, Blas P., and Hayes, Steven L.. Mechanistic materials modeling for nuclear fuel performance. United States: N. p., 2017. Web. doi:10.1016/j.anucene.2017.03.005.
Tonks, Michael R., Andersson, David, Phillpot, Simon R., Zhang, Yongfeng, Williamson, Richard, Stanek, Christopher R., Uberuaga, Blas P., & Hayes, Steven L.. Mechanistic materials modeling for nuclear fuel performance. United States. doi:10.1016/j.anucene.2017.03.005.
Tonks, Michael R., Andersson, David, Phillpot, Simon R., Zhang, Yongfeng, Williamson, Richard, Stanek, Christopher R., Uberuaga, Blas P., and Hayes, Steven L.. Wed . "Mechanistic materials modeling for nuclear fuel performance". United States. doi:10.1016/j.anucene.2017.03.005. https://www.osti.gov/servlets/purl/1369201.
@article{osti_1369201,
title = {Mechanistic materials modeling for nuclear fuel performance},
author = {Tonks, Michael R. and Andersson, David and Phillpot, Simon R. and Zhang, Yongfeng and Williamson, Richard and Stanek, Christopher R. and Uberuaga, Blas P. and Hayes, Steven L.},
abstractNote = {Fuel performance codes are critical tools for the design, certification, and safety analysis of nuclear reactors. However, their ability to predict fuel behavior under abnormal conditions is severely limited by their considerable reliance on empirical materials models correlated to burn-up (a measure of the number of fission events that have occurred, but not a unique measure of the history of the material). In this paper, we propose a different paradigm for fuel performance codes to employ mechanistic materials models that are based on the current state of the evolving microstructure rather than burn-up. In this approach, a series of state variables are stored at material points and define the current state of the microstructure. The evolution of these state variables is defined by mechanistic models that are functions of fuel conditions and other state variables. The material properties of the fuel and cladding are determined from microstructure/property relationships that are functions of the state variables and the current fuel conditions. Multiscale modeling and simulation is being used in conjunction with experimental data to inform the development of these models. Finally, this mechanistic, microstructure-based approach has the potential to provide a more predictive fuel performance capability, but will require a team of researchers to complete the required development and to validate the approach.},
doi = {10.1016/j.anucene.2017.03.005},
journal = {Annals of Nuclear Energy (Oxford)},
number = ,
volume = 105,
place = {United States},
year = {Wed Mar 15 00:00:00 EDT 2017},
month = {Wed Mar 15 00:00:00 EDT 2017}
}

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  • A parametric model predicting the performance of a solid polymer electrolyte, proton exchange membrane (PEM) fuel cell has been developed using a combination of mechanistic and empirical modeling techniques. This paper details the mechanistic model development. Mass transport properties are considered in the mechanistic development via Stefan-Maxwell equations. Thermodynamic equilibrium potentials are defined using the Nernst equation. Activation overvoltages are defined via a Tafel equation, and internal resistance are defined via the Nernst-Planck equation, leading to a definition of ohmic overvoltage via an Ohm's law equation. The mechanistic model cannot adequately model fuel cell performance, since several simplifying approximations havemore » been used in order to facilitate model development. Additionally, certain properties likely to be observed in operational fuel cells, such as thermal gradients, have not been considered. Nonetheless, the insights gained from the mechanistic assessment of fuel cell processes were found to give the resulting empirical model a firmer theoretical basis than many of the models presently available in the literature. Correlation of the empirical model to actual experimental data was very good.« less
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