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Title: Modeling defect and fission gas properties in U-Si fuels

Abstract

Uranium silicides, in particular U 3Si 2, are being explored as an advanced nuclear fuel with increased accident tolerance as well as competitive economics compared to the baseline UO2 fuel. They benefit from high thermal conductivity (metallic) compared to UO 2 fuel (insulator or semi-conductor) used in current Light Water Reactors (LWRs). The U-Si fuels also have higher fissile density. In order to perform meaningful engineering scale nuclear fuel performance simulations, the material properties of the fuel, including the response to irradiation environments, must be known. Unfortunately, the data available for USi fuels are rather limited, in particular for the temperature range where LWRs would operate. The ATF HIP is using multi-scale modeling and simulations to address this knowledge gap.

Authors:
ORCiD logo [1]; ORCiD logo [1];  [2];  [2];  [3];  [4];  [5];  [6]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  2. Univ. of South Carolina, Columbia, SC (United States)
  3. Westinghouse Electric Sweden, Vasteras (Sweden)
  4. Westinghouse Electric Company LLC, Cranberry Woods, PA (United States)
  5. Missouri Univ. of Science and Technology, Rolla, MO (United States)
  6. Imperial College, London (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:
1352406
Report Number(s):
LA-UR-17-23072
DOE Contract Number:
AC52-06NA25396
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS

Citation Formats

Andersson, Anders David Ragnar, Stanek, Christopher Richard, Noordhoek, Mark J., Besmann, Theodore M., Middleburgh, Simon C., Lahoda, E. J., Chernatynskiy, Aleksandr, and Grimes, Robin W. Modeling defect and fission gas properties in U-Si fuels. United States: N. p., 2017. Web. doi:10.2172/1352406.
Andersson, Anders David Ragnar, Stanek, Christopher Richard, Noordhoek, Mark J., Besmann, Theodore M., Middleburgh, Simon C., Lahoda, E. J., Chernatynskiy, Aleksandr, & Grimes, Robin W. Modeling defect and fission gas properties in U-Si fuels. United States. doi:10.2172/1352406.
Andersson, Anders David Ragnar, Stanek, Christopher Richard, Noordhoek, Mark J., Besmann, Theodore M., Middleburgh, Simon C., Lahoda, E. J., Chernatynskiy, Aleksandr, and Grimes, Robin W. Fri . "Modeling defect and fission gas properties in U-Si fuels". United States. doi:10.2172/1352406. https://www.osti.gov/servlets/purl/1352406.
@article{osti_1352406,
title = {Modeling defect and fission gas properties in U-Si fuels},
author = {Andersson, Anders David Ragnar and Stanek, Christopher Richard and Noordhoek, Mark J. and Besmann, Theodore M. and Middleburgh, Simon C. and Lahoda, E. J. and Chernatynskiy, Aleksandr and Grimes, Robin W.},
abstractNote = {Uranium silicides, in particular U3Si2, are being explored as an advanced nuclear fuel with increased accident tolerance as well as competitive economics compared to the baseline UO2 fuel. They benefit from high thermal conductivity (metallic) compared to UO2 fuel (insulator or semi-conductor) used in current Light Water Reactors (LWRs). The U-Si fuels also have higher fissile density. In order to perform meaningful engineering scale nuclear fuel performance simulations, the material properties of the fuel, including the response to irradiation environments, must be known. Unfortunately, the data available for USi fuels are rather limited, in particular for the temperature range where LWRs would operate. The ATF HIP is using multi-scale modeling and simulations to address this knowledge gap.},
doi = {10.2172/1352406},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Apr 14 00:00:00 EDT 2017},
month = {Fri Apr 14 00:00:00 EDT 2017}
}

Technical Report:

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  • Uranium silicides, in particular U 3Si 2, are being explored as an advanced nuclear fuel with increased accident tolerance as well as competitive economics compared to the baseline UO 2 fuel. They benefit from high thermal conductivity (metallic) compared to UO 2 fuel (insulator or semi-conductor) used in current Light Water Reactors (LWRs). The U-Si fuels also have higher fissile density. In order to perform meaningful engineering scale nuclear fuel performance simulations, the material properties of the fuel, including the response to irradiation environments, must be known. Unfortunately, the data available for USi fuels are rather limited, in particular formore » the temperature range where LWRs would operate. The ATF HIP is using multi-scale modeling and simulations to address this knowledge gap.« less
  • Accident tolerant fuels (ATF) are being developed in response to the Fukushima Daiichi accident in Japan. One of the options being pursued is U-Si fuels, such as the U 3Si 2 and U 3Si 5 compounds, which benefit from high thermal conductivity (metallic) compared to the UO 2 fuel (insulator or semi-conductor) used in current Light Water Reactors (LWRs). The U-Si fuels also have higher fissile density. In order to perform meaningful engineering scale nuclear fuel performance simulations, the material properties of the fuel, including the response to irradiation environments, must be known. Unfortunately, the data available for U-Si fuelsmore » are rather limited, in particular for the temperature range where LWRs would operate. The ATF HIP is using multi-scale modeling and simulations to address this knowledge gap. The present study investigates point defect and fission gas properties in U 3Si 2, which is one of the main fuel candidates, using density functional theory (DFT) calculations. Based on a few assumption regarding entropy contributions, defect and fission diffusivities are predicted. Even though uranium silicides have been shown to amorphize easily at low temperature, we assume that U 3Si 2 remains crystalline under the conditions expected in Light Water Reactors (LWRs). The temperature and dose where amorphization occurs has not yet been well established.« less
  • Since the events at the Fukushima-Daiichi nuclear power plant in March 2011 significant research has unfolded at national laboratories, universities and other institutions into alternative materials that have potential enhanced accident tolerance when compared to traditional \uo~fuel zircaloy clad fuel rods. One of the potential replacement fuels is uranium silicide (\usi) for its higher thermal conductivity and uranium density. The lower melting temperature is of potential concern during postulated accident conditions. Another disadvantage for \usi~ is the lack of experimental data under power reactor conditions. Due to the aggressive development schedule for inserting some of the potential materials into leadmore » test assemblies or rods by 2022~\cite{bragg-sitton_2014} multiscale multiphysics modeling approaches have been used to provide insight into these materials. \\ \noindent The purpose of this letter report is to highlight the multiscale modeling effort for \usi~fuel as part of the Nuclear Energy Advanced Modeling and Simulation (NEAMS) Accident Tolerant Fuel (ATF) High Impact Problem (HIP). This fiscal year two new models for \usi~fuel have been incorporated into the BISON fuel performance code~\cite{Williamson2012} based upon lower length scale simulations using the GRASS-SST rate theory code. The models are briefly described in the following sections.« less
  • The present work intends to develop a computer simulation model that specifically addresses the typical characteristics of carbide fuels. The model will be based entirely on the migration of freely diffusing single gas atoms as a transport mechanism of fission gas to grain boundaries and subsequently to release. A solution will be sought for the distribution of intragranular as well as intergranular concentration of gas atoms and gas bubbles. Several theoretical as well as experimental works that have appeared in the literature will be reviewed and where applicable the results will be incorporated in the model. In any case, amore » broad sensitivity study will be performed with the model using varying values of these parameters in an attempt to better identify their significance in terms of their magnitude and their interrelation with fuel properties and reactor irradiation conditions. A comparison between the results of the computation and the available experimental data can hopefully be used as a basis to select the proper values of the parameters.« less
  • Advanced fast reactor systems being developed under the DOE's Advanced Fuel Cycle Initiative are designed to destroy TRU isotopes generated in existing and future nuclear energy systems. Over the past 40 years, multiple experiments and demonstrations have been completed using U-Zr, U-Pu-Zr, U-Mo and other metal alloys. As a result, multiple empirical and semi-empirical relationships have been established to develop empirical performance modeling codes. Many mechanistic questions about fission as mobility, bubble coalescience, and gas release have been answered through industrial experience, research, and empirical understanding. The advent of modern computational materials science, however, opens new doors of development suchmore » that physics-based multi-scale models may be developed to enable a new generation of predictive fuel performance codes that are not limited by empiricism.« less