UO2CreepUpdate

Computes the secondary thermal and irradiation creep for UO2 LWR fuel. This material must be run in conjunction with ComputeMultipleInelasticStress.

Description

A model for combined secondary thermal creep and irradiation creep of UO fuel is available, with the creep rate modeled as a function of time, temperature, effective stress, density, grain size, fission rate, and oxygen-to-metal ratio (O/M). The constitutive relation is taken from the MATPRO FCREEP material model (Allison et al., 1993) and given as (1) where is the creep rate (1/s), is the effective (von Mises) stress (Pa), is the temperature (K), is the fuel density (percent of theoretical), is the grain size (, is the volumetric fission rate (fissions/-s), are the activation energies (J/mol), and is the universal gas constant (8.3145 J/mol-K).

The first term in Eq. (1) represents diffusional thermal creep and is applicable to low stress and low temperature conditions. The second term in Eq. (1) represents thermal dislocation or power-law creep and is applicable to high stress and high temperature conditions. Note that irradiation creep is included in both the first and third terms, as both are functions of the fission rate (). Irradiation enhances normal diffusional thermal creep (at elevated temperatures) as indicated in the first term. Irradiation creep also occurs at lower temperatures where thermal creep is not active, and is accounted for by the third term in Eq. (1). Material constants for the thermal creep terms are listed in Table 1.

Table 1: Parameters used in the UO Thermal Creep Model (Allison et al., 1993)

ParameterValueParameterValue

The activation energies for the thermal creep terms (Q and Q) are strongly dependent upon the fuel oxygen to metal ratio and, in MATPRO, are defined using the Arrhenius type relations where the energies are given in J/mole and (2) This function, Eq. (2), is plotted in Figure 1.

Figure 1: The function defining the dependence of the activation energies for thermal creep on the UO oxygen to metal ratio.

Transitional Stress

In MATPRO, a transition stress is defined to govern the transition between the first (low stress) and second (high stress) regions. When the applied stress is larger than the transition stress, the applied stress is used in the power-law relation and the transition stress is used in the linear creep relation. When the applied stress is lower than the transition stress, the applied stress is used in the linear relation and the power-law contribution is zero. Mai et al. (2010) investigated the MATPRO transition approach in comparison to experimental data and concluded that a better fit to the data could be achieved by simply ignoring the transition stress and applying both the low and high stress terms in all cases. This approach has been adopted in BISON.

MATPRO-Halden Creep Model

The low temperature irradiation creep (third term in Eq. (1)) requires further discussion. As the equation indicates, the original MATPRO formulation included exponential temperature dependence in this term. After a careful review of the MATPRO documentation and supporting literature, it is clear that this temperature dependency was based on a single experimental study (Brucklacher et al., 1973) involving only a very limited number of experiments. Additionally, this early study specified a relatively narrow applicability range for the correlation (523 K 773 K), which was not enforced in the MATPRO implementation. Several other studies, both early (Brucklacher and Dienst, 1972; Perrin, 1972; Solomon, 1973; Dienst, 1977) and more recent (Sakai et al., 2011; Sakai, 2013; Szoke and Tverberg, 2014), did not observe temperature dependency for low temperature irradiation creep, but reported creep rate variation as a function of only stress and fission rate. The most extensive data for irradiation creep of UO has been generated at the Halden Research Reactor, resulting in the following correlation (Sakai, 2013): (3) where A = .

The default model in BISON, which is referred to as the MATPRO-Halden model, replaces the third term in Eq. (1) with Eq. (3), thus removing temperature dependency. Note that the temperature dependent formulation can still be specified simply by providing the original MATPRO material constants (given in the table below) as input parameters.

Table 2: Irradiation creep material parameters for the original MATPRO model which included temperature dependence

ParameterValue
1/K

Example Input Syntax

[Materials<<<{"href": "../../../syntax/Materials/index.html"}>>>]
  [creep]
    type = UO2CreepUpdate<<<{"description": "Computes the secondary thermal and irradiation creep for UO2 LWR fuel. This material must be run in conjunction with ComputeMultipleInelasticStress.", "href": "UO2CreepUpdate.html"}>>>
    block<<<{"description": "The list of blocks (ids or names) that this object will be applied"}>>> = 1
    temperature<<<{"description": "Coupled temperature"}>>> = temp
    fission_rate<<<{"description": "Coupled fission rate"}>>> = fission_rate
    initial_grain_radius<<<{"description": "Fuel grain radius (m)"}>>> = 10.0e-6
    oxygen_to_metal_ratio<<<{"description": "Oxygen to metal ratio"}>>> = 2.0
  []
[]
(test/tests/solid_mechanics/uo2_creep/uo2_creep_irradiation.i)

UO2CreepUpdate must be run in conjunction with the inelastic strain return mapping stress calculator as shown below:

[Materials<<<{"href": "../../../syntax/Materials/index.html"}>>>]
  [radial_return_stress]
    type = ComputeMultipleInelasticStress<<<{"description": "Compute state (stress and internal parameters such as plastic strains and internal parameters) using an iterative process.  Combinations of creep models and plastic models may be used.", "href": "../ComputeMultipleInelasticStress.html"}>>>
    tangent_operator<<<{"description": "Type of tangent operator to return.  'elastic': return the elasticity tensor.  'nonlinear': return the full, general consistent tangent operator."}>>> = elastic
    inelastic_models<<<{"description": "The material objects to use to calculate stress and inelastic strains. Note: specify creep models first and plasticity models second."}>>> = 'creep'
    block<<<{"description": "The list of blocks (ids or names) that this object will be applied"}>>> = 1
  []
[]
(test/tests/solid_mechanics/uo2_creep/uo2_creep_irradiation.i)

Input Parameters

  • densityInitial fuel density

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Initial fuel density

  • temperatureCoupled temperature

    C++ Type:std::vector<VariableName>

    Unit:(no unit assumed)

    Controllable:No

    Description:Coupled temperature

Required Parameters

  • a77.78e-37Coefficient on irradiation creep term

    Default:7.78e-37

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Coefficient on irradiation creep term

  • absolute_tolerance1e-11Absolute convergence tolerance for Newton iteration

    Default:1e-11

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Absolute convergence tolerance for Newton iteration

  • acceptable_multiplier10Factor applied to relative and absolute tolerance for acceptable convergence if iterations are no longer making progress

    Default:10

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Factor applied to relative and absolute tolerance for acceptable convergence if iterations are no longer making progress

  • adaptive_substeppingFalseUse adaptive substepping, where the number of substeps is successively doubled until the return mapping model successfully converges or the maximum number of substeps is reached.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Use adaptive substepping, where the number of substeps is successively doubled until the return mapping model successfully converges or the maximum number of substeps is reached.

  • automatic_differentiation_return_mappingFalseWhether to use automatic differentiation to compute the derivative.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Whether to use automatic differentiation to compute the derivative.

  • base_nameOptional parameter that defines a prefix for all material properties related to this stress update model. This allows for multiple models of the same type to be used without naming conflicts.

    C++ Type:std::string

    Controllable:No

    Description:Optional parameter that defines a prefix for all material properties related to this stress update model. This allows for multiple models of the same type to be used without naming conflicts.

  • blockThe list of blocks (ids or names) that this object will be applied

    C++ Type:std::vector<SubdomainName>

    Controllable:No

    Description:The list of blocks (ids or names) that this object will be applied

  • boundaryThe list of boundaries (ids or names) from the mesh where this object applies

    C++ Type:std::vector<BoundaryName>

    Controllable:No

    Description:The list of boundaries (ids or names) from the mesh where this object applies

  • burnup_functionBurnup function

    C++ Type:BurnupFunctionName

    Unit:(no unit assumed)

    Controllable:No

    Description:Burnup function

  • constant_onNONEWhen ELEMENT, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps.When SUBDOMAIN, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped

    Default:NONE

    C++ Type:MooseEnum

    Options:NONE, ELEMENT, SUBDOMAIN

    Controllable:No

    Description:When ELEMENT, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps.When SUBDOMAIN, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped

  • declare_suffixAn optional suffix parameter that can be appended to any declared properties. The suffix will be prepended with a '_' character.

    C++ Type:MaterialPropertyName

    Unit:(no unit assumed)

    Controllable:No

    Description:An optional suffix parameter that can be appended to any declared properties. The suffix will be prepended with a '_' character.

  • fission_rateCoupled fission rate

    C++ Type:std::vector<VariableName>

    Unit:(no unit assumed)

    Controllable:No

    Description:Coupled fission rate

  • initial_grain_radius1e-05Fuel grain radius (m)

    Default:1e-05

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Fuel grain radius (m)

  • max_inelastic_increment0.0001The maximum inelastic strain increment allowed in a time step

    Default:0.0001

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:The maximum inelastic strain increment allowed in a time step

  • maximum_number_substeps25The maximum number of substeps allowed before cutting the time step.

    Default:25

    C++ Type:unsigned int

    Controllable:No

    Description:The maximum number of substeps allowed before cutting the time step.

  • oxygen_to_metal_ratio2Oxygen to metal ratio

    Default:2

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Oxygen to metal ratio

  • po2_fraction0Weight fraction of PO2

    Default:0

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Weight fraction of PO2

  • q30Activation energy for irradiation creep, divided by gas constant (1/K)

    Default:0

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Activation energy for irradiation creep, divided by gas constant (1/K)

  • relative_tolerance1e-08Relative convergence tolerance for Newton iteration

    Default:1e-08

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Relative convergence tolerance for Newton iteration

  • use_substep_integration_errorFalseIf true, it establishes a substep size that will yield, at most,the creep numerical integration error given by substep_strain_tolerance.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:If true, it establishes a substep size that will yield, at most,the creep numerical integration error given by substep_strain_tolerance.

  • use_substeppingNONEWhether and how to use substepping

    Default:NONE

    C++ Type:MooseEnum

    Options:NONE, ERROR_BASED, INCREMENT_BASED

    Controllable:No

    Description:Whether and how to use substepping

Optional Parameters

  • apply_strainTrueFlag to apply strain. Used for testing.

    Default:True

    C++ Type:bool

    Controllable:No

    Description:Flag to apply strain. Used for testing.

  • control_tagsAdds user-defined labels for accessing object parameters via control logic.

    C++ Type:std::vector<std::string>

    Controllable:No

    Description:Adds user-defined labels for accessing object parameters via control logic.

  • effective_inelastic_strain_nameeffective_creep_strainName of the material property that stores the effective inelastic strain

    Default:effective_creep_strain

    C++ Type:std::string

    Controllable:No

    Description:Name of the material property that stores the effective inelastic strain

  • enableTrueSet the enabled status of the MooseObject.

    Default:True

    C++ Type:bool

    Controllable:Yes

    Description:Set the enabled status of the MooseObject.

  • implicitTrueDetermines whether this object is calculated using an implicit or explicit form

    Default:True

    C++ Type:bool

    Controllable:No

    Description:Determines whether this object is calculated using an implicit or explicit form

  • seed0The seed for the master random number generator

    Default:0

    C++ Type:unsigned int

    Controllable:No

    Description:The seed for the master random number generator

  • substep_strain_tolerance0.1Maximum ratio of the initial elastic strain increment at start of the return mapping solve to the maximum inelastic strain allowable in a single substep. Reduce this value to increase the number of substeps

    Default:0.1

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Maximum ratio of the initial elastic strain increment at start of the return mapping solve to the maximum inelastic strain allowable in a single substep. Reduce this value to increase the number of substeps

  • use_displaced_meshFalseWhether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Whether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

Advanced Parameters

  • internal_solve_full_iteration_historyFalseSet true to output full internal Newton iteration history at times determined by `internal_solve_output_on`. If false, only a summary is output.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Set true to output full internal Newton iteration history at times determined by `internal_solve_output_on`. If false, only a summary is output.

  • internal_solve_output_onon_errorWhen to output internal Newton solve information

    Default:on_error

    C++ Type:MooseEnum

    Options:never, on_error, always

    Controllable:No

    Description:When to output internal Newton solve information

Debug Parameters

  • output_propertiesList of material properties, from this material, to output (outputs must also be defined to an output type)

    C++ Type:std::vector<std::string>

    Controllable:No

    Description:List of material properties, from this material, to output (outputs must also be defined to an output type)

  • outputsnone Vector of output names where you would like to restrict the output of variables(s) associated with this object

    Default:none

    C++ Type:std::vector<OutputName>

    Controllable:No

    Description:Vector of output names where you would like to restrict the output of variables(s) associated with this object

Outputs Parameters

  • prop_getter_suffixAn optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.

    C++ Type:MaterialPropertyName

    Unit:(no unit assumed)

    Controllable:No

    Description:An optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.

  • use_interpolated_stateFalseFor the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:For the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

Material Property Retrieval Parameters

Input Files

Child Objects

References

  1. C. M. Allison, G. A. Berna, R. Chambers, E. W. Coryell, K. L. Davis, D. L. Hagrman, D. T. Hagrman, N. L. Hampton, J. K. Hohorst, R. E. Mason, M. L. McComas, K. A. McNeil, R. L. Miller, C. S. Olsen, G. A. Reymann, and L. J. Siefken. SCDAP/RELAP5/MOD3.1 code manual, volume IV: MATPRO-A library of materials properties for light-water-reactor accident analysis. Technical Report NUREG/CR-6150, EGG-2720, Idaho National Engineering Laboratory, 1993.[BibTeX]
  2. D. Brucklacher and W. Dienst. Creep behavior of ceramic nuclear fuels under neutron irradiation. Journal of Nuclear Materials, 42(3):285–296, 1972. doi:10.1016/0022-3115(72)90079-7.[BibTeX]
  3. D. Brucklacher, W. Dienst, and F. Thummler. Creep behavior of oxide fuels under neutron irradiation, Paper 251. In Proceedings REAKTORTAGUNG 1973 des Deutschen Atomforums/KTG held in Karlsruhe, 413–416. Apr 10-13 1973.[BibTeX]
  4. W. Dienst. Irradiation induced creep of ceramic materials. Journal of Nuclear Materials, 65:1–8, 1977. doi:10.1016/0022-3115(77)90035-6.[BibTeX]
  5. A. T. Mai, W. F. Lyon, R. O. Montgomery, and R. S. Dunham. An evaluation of the MATPRO fuel creep model using the FALCON fuel analysis code. Trans. Am. Nucl. Soc., 102:888–889, 2010.[BibTeX]
  6. J. S. Perrin. Effect of irradiation on creep of UO_2-PuO_2. Journal of Nuclear Materials, 42:101–104, 1972.[BibTeX]
  7. K. Sakai. The fuel creep test IFA-701: results after four irradiation cycles. Technical Report HWR-1039, OECD Halden Reactor Project, 2013.[BibTeX]
  8. K. Sakai, H. Hanakawa, and T. Tverberg. Investigation of fission induced creep of UO2 and Cr-doped fuel in IFA-701. Technical Report HWR-1006, OECD Halden Reactor Project, 2011.[BibTeX]
  9. A. A. Solomon. Radiation induced creep of UO_2. American Ceramic Society, 56(3):164–171, 1973. doi:10.1111/j.1151-2916.1973.tb15435.x.[BibTeX]
  10. R. Szoke and T. Tverberg. Update on in-pile results from the fuel creep test IFA-701. Technical Report HWR-1092, OECD Halden Reactor Project, 2014.[BibTeX]