Radiation damage effects in zirconia

Sickafus, Kurt E.; Matzke, Hj.; Hartmann, Thorsten; Yasuda, Kazuhiro; Valdez, James A.; Chodak, P.; Nastasi, M.; Verrall, R.A.

doi:10.1016/s0022-3115(99)00041-0

Cited by 334 publications

(166 citation statements)

References 35 publications

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“…Our focus is on cation vacancy diffusion as this will be the rate limiting specie controlling phenomena such as diffusion-controlled creep. We use the Kinetic Monte Carlo (KMC) method 23,24 to calculate the uranium diffusivity at relevant fuel temperatures.…”

Section: Introductionmentioning

confidence: 99%

Impact of homogeneous strain on uranium vacancy diffusion in uranium dioxide

et al. 2015

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We present a detailed mechanism of, and the effect of homogeneous strains on, the migration of uranium vacancies in UO2. Vacancy migration pathways and barriers are identified using density functional theory (DFT) and the effect of uniform strain fields are accounted for using the dipole tensor approach. We report complex migration pathways and non-cubic symmetry associated with the uranium vacancy in UO2 and show that these complexities need to be carefully accounted for to predict the correct diffusion behavior of uranium vacancies. We show that under homogeneous strain fields, only the dipole tensor of the saddle with respect to the minimum is required to correctly predict the change in the energy barrier between the strained and the unstrained case. Diffusivities are computed using kinetic Monte Carlo (KMC) simulations for both neutral and fully charged state of uranium single and di-vacancies. We calculate the effect of strain on migration barriers in the temperature range 800 -1800 K for both vacancy types. Homogeneous strains as small as 2% have a considerable effect on diffusivity of both single and di-vacancies of uranium, with the effect of strain being more pronounced for single vacancies than di-vacancies. In contrast, the response of a given defect to strain is less sensitive to changes in the charge state of the defect. Further, strain leads to anisotropies in the mobility of the vacancy and the degree of anisotropy is very sensitive to the nature of the applied strain field for strain of equal magnitude. Our results suggest that the influence of strain on vacancy diffusivity will be significantly greater when single vacancies dominate the defect structure, such as sintering, while the effects will be much less substantial under irradiation conditions where di-vacancies dominate.

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Section: Introductionmentioning

confidence: 99%

Impact of homogeneous strain on uranium vacancy diffusion in uranium dioxide

et al. 2015

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“…Fracture is attributed to the contribution of several factors, such as (1) compressive stresses in the oxide due to volumetric expansion during oxidation (Pillar-Bedworth ratio of 1.56), 2 (2) tensile stresses in the oxide layer due to thermal and irradiation induced expansion on the fuel side, and (3) dynamic embrittlement caused by hydride precipitation. [8][9][10][11][12] Due to the highly complex and synergistic nature of corrosion kinetics, with coupled oxygen/hydrogen transport, diffusion/ reaction kinetics, temperature effects, and complex oxide microstructures, to name but a few, a multipronged approach that includes modeling as an essential element must be adopted to improve our understanding of the process.…”

Section: Zr Smentioning

confidence: 99%

Integrated Computational Modeling of Water Side Corrosion in Zirconium Metal Clad Under Nominal LWR Operating Conditions

Aryanfar

Thomas

Ven

et al. 2016

JOM

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A mesoscopic chemical reaction kinetics model to predict the formation of zirconium oxide and hydride accumulation light-water reactor (LWR) fuel clad is presented. The model is designed to include thermodynamic information from ab initio electronic structure methods as well as parametric information in terms of diffusion coefficients, thermal conductivities and reaction constants. In contrast to approaches where the experimentally observed time exponents are captured by the models by design, our approach is designed to be predictive and to provide an improved understanding of the corrosion process. We calculate the time evolution of the oxide/metal interface and evaluate the order of the chemical reactions that are conducive to a t 1/3 dependence. We also show calculations of hydrogen cluster accumulation as a function of temperature and depth using spatially dependent cluster dynamics. Strategies to further cohesively integrate the different elements of the model are provided.

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“…[15][16][17][18] The low-thermal conductivity of ZrO 2 can be accommodated through the use of annular fuel, which reduces centerline temperatures to within standard LWR envelopes. SiC coated particle fuel with PuO 2 …”

Section: Feasibility Of Burning Prfs In Lwrsmentioning

confidence: 99%

Using Proliferation-Resistant Fuels to Manage Global Plutonium Inventories: Going Beyond the Spent-Fuel Standard

Chodak¹

1999

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The National Academy of Sciences has stated that the growing global stocks of civil and weapons plutonium represent a "clear and present danger." Proliferation-resistant fuels (PRFs) have been proposed by researchers in several countries including France, Italy, Switzerland, Japan and the United States (US) as an effective sink for this plutonium. In place of the UO 2 in mixed uranium-plutonium dioxide (MOX), PRFs blend a nonfertile-oxide-diluant and burnable poisons with PuO 2 . The resultant ceramic is more chemically durable than MOX; consequently, the plutonium cannot be recovered by standard Plutonium-Uranium Reduction Extraction (PUREX) processing and is a more durable waste form than MOX. In the absence of the in situ production of 239 Pu or 233 U found in MOX and thorium fuels, respectively, an extremely deep burn of the plutonium is possible, producing a spent fuel that goes well beyond the spent-fuel standard. Calculations have shown that the reactivity behavior of these fuels can be tailored through the appropriate incorporation of burnable poisons to enable their use in existing lightwater reactors without hardware or operational modifications. Depending on the fuel management strategy employed, PRFs destroy 60-80 wt % of their total plutonium charge, more than twice the consumption possible with MOX fuel. In addition, the isotopics of the residual spent plutonium are >50 wt % 242 Pu, <20 wt % fissile plutonium, and >3 wt % 238 Pu as compared with <15 wt % 242 Pu, >70 wt % fissile plutonium, and <1 wt % 238 Pu for spent MOX. Spent PRF is, therefore, a substantially less attractive source for weapons material than spent MOX. A once-through, one-third PRF core consumes 90 kg of plutonium, whereas a one-third MOX core produces 70 kg. Thus, PRFs can be used to reduce plutonium inventories and the overall proliferation risk posed by commercial fuel cycles. It is recommended that the US Department of Energy develop PRFs on a not-to-interfere basis with the ongoing Material Disposition MOX program. Development of PRFs as a follow on to MOX for burning excess weapons plutonium could be leveraged to promote PRF consumption of global separated civilplutonium stocks. Thus, the US could take an active leadership role to enhance the proliferation resistance of commercial nuclear fuel cycles.

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Radiation damage effects in zirconia

Cited by 334 publications

References 35 publications

Impact of homogeneous strain on uranium vacancy diffusion in uranium dioxide

Impact of homogeneous strain on uranium vacancy diffusion in uranium dioxide

Integrated Computational Modeling of Water Side Corrosion in Zirconium Metal Clad Under Nominal LWR Operating Conditions

Using Proliferation-Resistant Fuels to Manage Global Plutonium Inventories: Going Beyond the Spent-Fuel Standard

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