skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Milestone report: The simulation of radiation driven gas diffusion in UO 2 at low temperature

Abstract

Below 1000 K it is thought that fission gas diffusion in nuclear fuel during irradiation occurs through atomic mixing due to radiation damage. This is an important process for nuclear reactor performance as it affects fission gas release, particularly from the periphery of the pellet where such temperatures are normal. Here we present a molecular dynamics study of Xe and Kr diffusion due to irradiation. Thermal spikes and cascades have been used to study the electronic stopping and ballistic phases of damage, respectively. Our results predict that O and Kr exhibit the greatest diffusivity and U the least, while Xe lies in between. It is concluded that the ballistic phase does not sufficiently account for the experimentally observed diffusion. Preliminary thermal spike calculations indicate that the electronic stopping phase generates greater fission gas displacement than the ballistic phase, although further calculation must be carried out to confirm this. A good description of the system by the empirical potentials is important over the very wide temperatures induced during thermal spike and damage cascade simulations. This has motivated the development of a parameter set for gas-actinide and gas-oxygen interactions that is complementary for use with a recent many-body potential set. A comprehensivemore » set of density functional theory (DFT) calculations were used to study Xe and Kr incorporation at a number of sites in CeO 2, ThO 2, UO 2 and PuO 2. These structures were used to fit a potential, which was used to generate molecular dynamics (MD) configurations incorporating Xe and Kr at 300 K, 1500 K, 3000 K and 5000 K. Subsequent matching to the forces predicted by DFT for these MD configurations was used to refine the potential set. This fitting approach ensured weighted fitting to configurations that are thermodynamically significant over a broad temperature range, while avoiding computationally expensive DFT-MD calculations. The resultant gas potentials were validated against DFT binding energies and are suitable for simulating combinations of Xe and Kr in solid solutions of CeO 2, ThO 2, UO 2 and PuO 2, providing a powerful tool for the atomistic simulation of conventional nuclear reactor fuel UO 2 as well as advanced MOX fuels.« less

Authors:
 [1];  [2];  [3];  [2];  [2];  [4];  [1];  [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  2. Imperial College, London (United Kingdom)
  3. Univ. of New South Wales (Australia)
  4. Independent Consultant (United Kingdom)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE Office of Nuclear Energy (NE)
OSTI Identifier:
1330173
Report Number(s):
LA-UR-16-23474
TRN: US1700436
DOE Contract Number:  
AC52-06NA25396
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; 22 GENERAL STUDIES OF NUCLEAR REACTORS; URANIUM DIOXIDE; MIXED OXIDE FUELS; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE RANGE 1000-4000 K; TEMPERATURE RANGE OVER 4000 K; PLUTONIUM OXIDES; FISSION PRODUCTS; DENSITY FUNCTIONAL METHOD; CERIUM OXIDES; THORIUM OXIDES; SOLID SOLUTIONS; MOLECULAR DYNAMICS METHOD; DIFFUSION; POTENTIALS; COMPUTERIZED SIMULATION; THERMAL SPIKES; OXYGEN; BINDING ENERGY; IRRADIATION; FISSION PRODUCT RELEASE; MANY-BODY PROBLEM; RADIATION EFFECTS; FUEL PELLETS; KRYPTON; XENON; URANIUM

Citation Formats

Cooper, Michael William, Kuganathan, Navaratnarajah, Burr, Patrick A, Rushton, Michael J., Grimes, Robin W, Turbull, James Anthony, Stanek, Christopher Richard, and Andersson, Anders David. Milestone report: The simulation of radiation driven gas diffusion in UO2 at low temperature. United States: N. p., 2016. Web. doi:10.2172/1330173.
Cooper, Michael William, Kuganathan, Navaratnarajah, Burr, Patrick A, Rushton, Michael J., Grimes, Robin W, Turbull, James Anthony, Stanek, Christopher Richard, & Andersson, Anders David. Milestone report: The simulation of radiation driven gas diffusion in UO2 at low temperature. United States. doi:10.2172/1330173.
Cooper, Michael William, Kuganathan, Navaratnarajah, Burr, Patrick A, Rushton, Michael J., Grimes, Robin W, Turbull, James Anthony, Stanek, Christopher Richard, and Andersson, Anders David. Mon . "Milestone report: The simulation of radiation driven gas diffusion in UO2 at low temperature". United States. doi:10.2172/1330173. https://www.osti.gov/servlets/purl/1330173.
@article{osti_1330173,
title = {Milestone report: The simulation of radiation driven gas diffusion in UO2 at low temperature},
author = {Cooper, Michael William and Kuganathan, Navaratnarajah and Burr, Patrick A and Rushton, Michael J. and Grimes, Robin W and Turbull, James Anthony and Stanek, Christopher Richard and Andersson, Anders David},
abstractNote = {Below 1000 K it is thought that fission gas diffusion in nuclear fuel during irradiation occurs through atomic mixing due to radiation damage. This is an important process for nuclear reactor performance as it affects fission gas release, particularly from the periphery of the pellet where such temperatures are normal. Here we present a molecular dynamics study of Xe and Kr diffusion due to irradiation. Thermal spikes and cascades have been used to study the electronic stopping and ballistic phases of damage, respectively. Our results predict that O and Kr exhibit the greatest diffusivity and U the least, while Xe lies in between. It is concluded that the ballistic phase does not sufficiently account for the experimentally observed diffusion. Preliminary thermal spike calculations indicate that the electronic stopping phase generates greater fission gas displacement than the ballistic phase, although further calculation must be carried out to confirm this. A good description of the system by the empirical potentials is important over the very wide temperatures induced during thermal spike and damage cascade simulations. This has motivated the development of a parameter set for gas-actinide and gas-oxygen interactions that is complementary for use with a recent many-body potential set. A comprehensive set of density functional theory (DFT) calculations were used to study Xe and Kr incorporation at a number of sites in CeO2, ThO2, UO2 and PuO2. These structures were used to fit a potential, which was used to generate molecular dynamics (MD) configurations incorporating Xe and Kr at 300 K, 1500 K, 3000 K and 5000 K. Subsequent matching to the forces predicted by DFT for these MD configurations was used to refine the potential set. This fitting approach ensured weighted fitting to configurations that are thermodynamically significant over a broad temperature range, while avoiding computationally expensive DFT-MD calculations. The resultant gas potentials were validated against DFT binding energies and are suitable for simulating combinations of Xe and Kr in solid solutions of CeO2, ThO2, UO2 and PuO2, providing a powerful tool for the atomistic simulation of conventional nuclear reactor fuel UO2 as well as advanced MOX fuels.},
doi = {10.2172/1330173},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Oct 24 00:00:00 EDT 2016},
month = {Mon Oct 24 00:00:00 EDT 2016}
}

Technical Report:

Save / Share: