Nuclear Material BCs

Action for creating boundary conditions associated with NuclearMaterials and arrays of Layered2D fuel rods.

Description of Created Blocks

This NuclearMaterialBCs action generates a set of thermal and mechanical boundary conditions for use in reducing the input file size for arrays of fuel rods for LWR simulation.

warning:For LWR Use Only

This action is designed for use with only arrays of light water reactor fuel rods using Layered2D meshes.

User-based Interface

To reduce the length and complexity of necessary blocks for simulations, a standard set of boundary conditions are optionallly created when analyzing an array of fuel rods. An array of fuel rods is created with the Layered2DArray mesh generator. The use of compress_boundary_ids = true with Layered2DArray is required.

The thermal and mechanical boundary conditions, along with helper classes, are created internally based on the bc_types parameter under the NuclearMaterials block. The options to this parameter are Temperature, Displacement, PlenumPressure, and SystemPressure.

Temperature

The Temperature option to bc_types will create a Dirichlet thermal boundary condition on the outside surface of the cladding. When this option is active, the parameter temperature_bc_function must also be given.

Displacement

The Displacement option to bc_types will create Dirichlet displacement boundary conditions on the symmetry surfaces of the fuel rods in the array. No additional parameters are required.

PlenumPressure

The PlenumPressure option to bc_types will create individual plenum pressure boundary conditions for each rod in the array. When this option is active, the parameters initial_plenum_pressure and pitch must also be given. The classes needed to calculate layered plenum temperature and layered plenum volume are also created.

SystemPressure

The SystemPressure option to bc_types will create a set of Pressure boundary conditions on the exterior surfaces of the fuel rods. When this option is active, the parameter system_pressure_function must also be given.

Example Input Syntax

[NuclearMaterials<<<{"href": "../index.html"}>>>]
  fission_operation<<<{"description": "Type of fission occuring in this simulation."}>>> = normal
  physics<<<{"description": "Type(s) of physics used on this block."}>>> = 'mechanics thermal'
  strain<<<{"description": "Strain formulation"}>>> = FINITE
  initial_temperature<<<{"description": "Initial temperature in Kelvins."}>>> = ${initial_temperature}
  stress_free_temperature<<<{"description": "Reference temperature for thermal eigenstrain calculation"}>>> = ${initial_temperature}
  temperature<<<{"description": "Coupled temperature: Used in multiple models"}>>> = temperature
  temperature_bc_function<<<{"description": "The function to use for the temperature boundary condition."}>>> = temperature_func
  bc_types<<<{"description": "The types of boundary conditions to create with NuclearMaterials and arrays of Layered2D fuel rods."}>>> = 'Displacement PlenumPressure SystemPressure Temperature'
  contact_types<<<{"description": "The types of contact constraints to create with NuclearMaterials and arrays of Layered2D fuel rods."}>>> = 'fuel_cladding'
  fuel_pin_geometry<<<{"description": "Name of the UserObject that reads the pin geometry from the mesh."}>>> = fred
  initial_plenum_pressure<<<{"description": "The initial pressure in the plenum."}>>> = 4.0e6
  system_pressure_function<<<{"description": "The function to use for the pressure on the exterior of the cladding."}>>> = system_pressure
  axial_direction<<<{"description": "The direction perpendicular to the circular cross section."}>>> = z
  [UO2<<<{"href": "../UO2/index.html"}>>>]
    [pellets]
      block<<<{"description": "The list of ids of the blocks (subdomain) that the stress divergence kernels will be applied to"}>>> = fuel
      uo2_models<<<{"description": "Type(s) of physics models used on this block.   The choices are: Burnup Elastic Creep Relocation Swelling ThermalExpansion HighBurnupStructureFormation"}>>> = 'elastic relocation swelling thermalexpansion'
      burnup_function<<<{"description": "Burnup function"}>>> = illinois
      axial_power_profile<<<{"description": "The axial power peaking function."}>>> = axial_power_factor
      density<<<{"description": "The initial fuel density."}>>> = ${fuel_density}
      extra_vector_tags<<<{"description": "The tag names for extra vectors that residual data should be saved into"}>>> = 'ref'
    []
  []
  [ZirconiumAlloy<<<{"href": "../ZirconiumAlloy/index.html"}>>>]
    [clad]
      block<<<{"description": "The list of ids of the blocks (subdomain) that the stress divergence kernels will be applied to"}>>> = clad
      cladding_models<<<{"description": "Type(s) of physics models used on this block.   The choices are: Creep Elastic Plasticity ZryOxidation IrradiationGrowth ThermalExpansion ZrPhase ZryCladdingFailure"}>>> = 'elastic creep thermalexpansion irradiationgrowth'
      extra_vector_tags<<<{"description": "The tag names for extra vectors that residual data should be saved into"}>>> = 'ref'
    []
  []
[]

Input Parameters

active__all__ If specified only the blocks named will be visited and made active
Default:__all__
C++ Type:std::vector<std::string>
Controllable:No
Description:If specified only the blocks named will be visited and made active
add_variablesFalseAdd the displacement variables
Default:False
C++ Type:bool
Controllable:No
Description:Add the displacement variables
automatic_eigenstrain_namesTrueCollects all material eigenstrains and passes to required strain calculator within the solid mechanics physics internally.
Default:True
C++ Type:bool
Controllable:No
Description:Collects all material eigenstrains and passes to required strain calculator within the solid mechanics physics internally.
bc_typesThe types of boundary conditions to create with NuclearMaterials and arrays of Layered2D fuel rods.
C++ Type:MultiMooseEnum
Options:Displacement, PlenumPressure, SystemPressure, Temperature
Controllable:No
Description:The types of boundary conditions to create with NuclearMaterials and arrays of Layered2D fuel rods.
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
d1_functionFunction to be multiplied by d1
C++ Type:std::vector<FunctionName>
Unit:(no unit assumed)
Controllable:No
Description:Function to be multiplied by d1
d1_function_variableVariable to be used when evaluating d1_function. If not given, time will be used.
C++ Type:std::vector<std::string>
Controllable:No
Description:Variable to be used when evaluating d1_function. If not given, time will be used.
decomposition_methodEigenSolutionMethods to calculate the finite strain and rotation increments
Default:EigenSolution
C++ Type:MooseEnum
Options:TaylorExpansion, EigenSolution, HughesWinget
Controllable:No
Description:Methods to calculate the finite strain and rotation increments
diffusion_1st_activation_energiesDiffusion activation energies.
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:Diffusion activation energies.
diffusion_1st_coefficients1st diffusion coefficient.
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:1st diffusion coefficient.
diffusion_2nd_activation_energiesSecond diffusion activation energy
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:Second diffusion activation energy
diffusion_2nd_coefficients2nd diffusion coefficient
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:2nd diffusion coefficient
displacementsThe displacements appropriate for the simulation geometry and coordinate system: Used in density and strain models
C++ Type:std::vector<VariableName>
Unit:(no unit assumed)
Controllable:No
Description:The displacements appropriate for the simulation geometry and coordinate system: Used in density and strain models
element_decay_constantsRadioactive decay constant for elements tracked
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:Radioactive decay constant for elements tracked
element_scalingRelative scaling of element percentages
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:Relative scaling of element percentages
elements_initial_concentrationRelative ratio of element concentration
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:Relative ratio of element concentration
elements_trackedThe elements tracked within TRISO simulations.
C++ Type:MultiMooseEnum
Options:Ag, Cs, Sr
Controllable:No
Description:The elements tracked within TRISO simulations.
extra_vector_tagsThe tag names for extra vectors that residual data should be saved into
C++ Type:std::vector<TagName>
Controllable:No
Description:The tag names for extra vectors that residual data should be saved into
familyLAGRANGESpecifies the family of FE shape functions to use for this variable.
Default:LAGRANGE
C++ Type:std::string
Controllable:No
Description:Specifies the family of FE shape functions to use for this variable.
flux_factor1Constant multiplied against the function, rod average linear power, or q_variable.
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Constant multiplied against the function, rod average linear power, or q_variable.
flux_functionThe function that describes the fast neutron flux
C++ Type:FunctionName
Unit:(no unit assumed)
Controllable:No
Description:The function that describes the fast neutron flux
fuel_pin_geometryName of the UserObject that reads the pin geometry from the mesh.
C++ Type:UserObjectName
Controllable:No
Description:Name of the UserObject that reads the pin geometry from the mesh.
generate_outputAdd scalar quantity output for stress and/or strain
C++ Type:MultiMooseEnum
Options:cauchy_stress_xx, cauchy_stress_xy, cauchy_stress_xz, cauchy_stress_yx, cauchy_stress_yy, cauchy_stress_yz, cauchy_stress_zx, cauchy_stress_zy, cauchy_stress_zz, creep_strain_xx, creep_strain_xy, creep_strain_xz, creep_strain_yx, creep_strain_yy, creep_strain_yz, creep_strain_zx, creep_strain_zy, creep_strain_zz, creep_stress_xx, creep_stress_xy, creep_stress_xz, creep_stress_yx, creep_stress_yy, creep_stress_yz, creep_stress_zx, creep_stress_zy, creep_stress_zz, deformation_gradient_xx, deformation_gradient_xy, deformation_gradient_xz, deformation_gradient_yx, deformation_gradient_yy, deformation_gradient_yz, deformation_gradient_zx, deformation_gradient_zy, deformation_gradient_zz, elastic_strain_xx, elastic_strain_xy, elastic_strain_xz, elastic_strain_yx, elastic_strain_yy, elastic_strain_yz, elastic_strain_zx, elastic_strain_zy, elastic_strain_zz, mechanical_strain_xx, mechanical_strain_xy, mechanical_strain_xz, mechanical_strain_yx, mechanical_strain_yy, mechanical_strain_yz, mechanical_strain_zx, mechanical_strain_zy, mechanical_strain_zz, pk1_stress_xx, pk1_stress_xy, pk1_stress_xz, pk1_stress_yx, pk1_stress_yy, pk1_stress_yz, pk1_stress_zx, pk1_stress_zy, pk1_stress_zz, pk2_stress_xx, pk2_stress_xy, pk2_stress_xz, pk2_stress_yx, pk2_stress_yy, pk2_stress_yz, pk2_stress_zx, pk2_stress_zy, pk2_stress_zz, plastic_strain_xx, plastic_strain_xy, plastic_strain_xz, plastic_strain_yx, plastic_strain_yy, plastic_strain_yz, plastic_strain_zx, plastic_strain_zy, plastic_strain_zz, small_stress_xx, small_stress_xy, small_stress_xz, small_stress_yx, small_stress_yy, small_stress_yz, small_stress_zx, small_stress_zy, small_stress_zz, strain_xx, strain_xy, strain_xz, strain_yx, strain_yy, strain_yz, strain_zx, strain_zy, strain_zz, stress_xx, stress_xy, stress_xz, stress_yx, stress_yy, stress_yz, stress_zx, stress_zy, stress_zz, effective_plastic_strain, effective_creep_strain, firstinv_stress, firstinv_cauchy_stress, firstinv_pk1_stress, firstinv_pk2_stress, firstinv_small_stress, firstinv_strain, hydrostatic_stress, hydrostatic_cauchy_stress, hydrostatic_pk1_stress, hydrostatic_pk2_stress, hydrostatic_small_stress, intensity_stress, intensity_cauchy_stress, intensity_pk1_stress, intensity_pk2_stress, intensity_small_stress, l2norm_mechanical_strain, l2norm_stress, l2norm_cauchy_stress, l2norm_pk1_stress, l2norm_strain, l2norm_elastic_strain, l2norm_plastic_strain, l2norm_creep_strain, max_principal_mechanical_strain, max_principal_stress, max_principal_cauchy_stress, max_principal_pk1_stress, max_principal_pk2_stress, max_principal_small_stress, max_principal_strain, maxshear_stress, maxshear_cauchy_stress, maxshear_pk1_stress, maxshear_pk2_stress, maxshear_small_stress, mid_principal_mechanical_strain, mid_principal_stress, mid_principal_cauchy_stress, mid_principal_pk1_stress, mid_principal_pk2_stress, mid_principal_small_stress, mid_principal_strain, min_principal_mechanical_strain, min_principal_stress, min_principal_cauchy_stress, min_principal_pk1_stress, min_principal_pk2_stress, min_principal_small_stress, min_principal_strain, secondinv_stress, secondinv_cauchy_stress, secondinv_pk1_stress, secondinv_pk2_stress, secondinv_small_stress, secondinv_strain, thirdinv_stress, thirdinv_cauchy_stress, thirdinv_pk1_stress, thirdinv_pk2_stress, thirdinv_small_stress, thirdinv_strain, triaxiality_stress, triaxiality_cauchy_stress, triaxiality_pk1_stress, triaxiality_pk2_stress, triaxiality_small_stress, volumetric_mechanical_strain, volumetric_strain, vonmises_stress, vonmises_cauchy_stress, vonmises_pk1_stress, vonmises_pk2_stress, directional_stress, directional_strain, axial_stress, axial_strain, axial_plastic_strain, axial_creep_strain, axial_elastic_strain, hoop_stress, hoop_strain, hoop_plastic_strain, hoop_creep_strain, hoop_elastic_strain, radial_stress, radial_strain, spherical_hoop_stress, spherical_hoop_strain, spherical_hoop_plastic_strain, spherical_hoop_creep_strain, spherical_hoop_elastic_strain, spherical_radial_stress, spherical_radial_strain
Controllable:No
Description:Add scalar quantity output for stress and/or strain
inactiveIf specified blocks matching these identifiers will be skipped.
C++ Type:std::vector<std::string>
Controllable:No
Description:If specified blocks matching these identifiers will be skipped.
incrementalFalseUse incremental or total strain
Default:False
C++ Type:bool
Controllable:No
Description:Use incremental or total strain
initial_plenum_pressureThe initial pressure in the plenum.
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The initial pressure in the plenum.
orderFIRSTSpecifies the order of the FE shape function to use for this variable.
Default:FIRST
C++ Type:MooseEnum
Options:CONSTANT, FIRST, SECOND, THIRD, FORTH
Controllable:No
Description:Specifies the order of the FE shape function to use for this variable.
physicsType(s) of physics used on this block.
C++ Type:MultiMooseEnum
Options:Mechanics, Thermal
Controllable:No
Description:Type(s) of physics used on this block.
pitchPitch between rods.
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Pitch between rods.
poissons_ratioPoisson's ratio for the material.
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Poisson's ratio for the material.
strainSMALLStrain formulation
Default:SMALL
C++ Type:MooseEnum
Options:SMALL, FINITE
Controllable:No
Description:Strain formulation
stress_free_temperatureReference temperature for thermal eigenstrain calculation
C++ Type:std::vector<VariableName>
Unit:(no unit assumed)
Controllable:No
Description:Reference temperature for thermal eigenstrain calculation
system_pressure_functionThe function to use for the pressure on the exterior of the cladding.
C++ Type:FunctionName
Unit:(no unit assumed)
Controllable:No
Description:The function to use for the pressure on the exterior of the cladding.
temperatureCoupled temperature: Used in multiple models
C++ Type:std::vector<VariableName>
Unit:(no unit assumed)
Controllable:No
Description:Coupled temperature: Used in multiple models
temperature_bc_functionThe function to use for the temperature boundary condition.
C++ Type:FunctionName
Unit:(no unit assumed)
Controllable:No
Description:The function to use for the temperature boundary condition.
use_automatic_differentiationFalseFlag to use automatic differentiation (AD) objects when possible
Default:False
C++ Type:bool
Controllable:No
Description:Flag to use automatic differentiation (AD) objects when possible
volumetric_locking_correctionFalseFlag to correct volumetric locking
Default:False
C++ Type:bool
Controllable:No
Description:Flag to correct volumetric locking
youngs_modulusYoung's modulus of the material.
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Young's modulus of the material.

Optional Parameters

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.

Advanced Parameters

(test/tests/layered2D/arrayAction.i)

#
# Simple 2x2 array (four quarter rods)
# The 0_0, 1_0, and 1_1 rods have the same power and should give identical results.
# The 0_1 rod has a higher power
#

pitch = 0.0126
fuel_density = 10431.0
initial_temperature = 293

[GlobalParams]
  order = SECOND
  family = LAGRANGE
  displacements = 'disp_x disp_y'
  number_of_rows = 2
  number_of_columns = 2
  pitch = ${pitch}
  #rod_ave_lin_pow = 'power1 power1 power2 power1'
[]

[Problem]
  type = ReferenceResidualProblem
  reference_vector = 'ref'
  extra_tag_vectors = 'ref'
  group_variables = 'disp_x disp_y;
  scalar_strain_zz_0_0_pellets0 scalar_strain_zz_1_0_pellets0 scalar_strain_zz_0_1_pellets0 scalar_strain_zz_1_1_pellets0;
  scalar_strain_zz_0_0_clad0 scalar_strain_zz_1_0_clad0 scalar_strain_zz_0_1_clad0 scalar_strain_zz_1_1_clad0
  scalar_strain_zz_0_0_clad1 scalar_strain_zz_1_0_clad1 scalar_strain_zz_0_1_clad1 scalar_strain_zz_1_1_clad1;'
[]

[Mesh]
  [Layered2DArray]
    axial_direction = z
    num_sectors = 10
    slices_per_block = 1
    clad_thickness = 0.56e-3
    clad_gap_width = 8e-5
    fuel_height = 0.1
    include_plenum = true
    plenum_height = 0.05
    pellet_bottom_coor = 0.0
    pellet_outer_radius = 0.0041
    pellet_mesh_density = coarse
    clad_mesh_density = coarse
    compress_boundary_ids = true
    id_offset = 100
  []
  partitioner = centroid
  centroid_partitioner_direction = z
  patch_update_strategy = iteration #auto
[]

[Functions]
  [power1]
    type = ParsedFunction
    expression = 'if(t<=0, 0, 10000)'
  []
  [power2]
    type = ParsedFunction
    expression = 'if(t<=0, 0, 20000)'
  []
  [axial_power_factor]
    type = ParsedFunction
    expression = '1'
  []
  [temperature_func]
    type = PiecewiseLinear
    x = '-200 0 180'
    y = '${initial_temperature} 300 320'
  []
  [pressure_ramp]
    type = PiecewiseLinear
    x = '-200 0'
    y = '0 1'
  []
  [system_pressure]
    type = CompositeFunction
    functions = '15.5e6 pressure_ramp'
  []
[]

[Burnup]
  [illinois]
    block = fuel
    axial_power_profile = axial_power_factor
    rpf_active = true
    num_radial = 11
    num_axial = 2
    a_lower = 0
    a_upper = 0.1
    fuel_inner_radius = 0
    fuel_outer_radius = .0041
    fuel_volume_ratio = 1.0
    density = ${fuel_density}
    average_burnup = average_burnup
    axial_direction = z
    order = CONSTANT
    family = MONOMIAL
  []
[]

[NuclearMaterials]
  fission_operation = normal
  physics = 'mechanics thermal'
  strain = FINITE
  initial_temperature = ${initial_temperature}
  stress_free_temperature = ${initial_temperature}
  temperature = temperature
  temperature_bc_function = temperature_func
  bc_types = 'Displacement PlenumPressure SystemPressure Temperature'
  contact_types = 'fuel_cladding'
  fuel_pin_geometry = fred
  initial_plenum_pressure = 4.0e6
  system_pressure_function = system_pressure
  axial_direction = z
  [UO2]
    [pellets]
      block = fuel
      uo2_models = 'elastic relocation swelling thermalexpansion'
      burnup_function = illinois
      axial_power_profile = axial_power_factor
      density = ${fuel_density}
      extra_vector_tags = 'ref'
    []
  []
  [ZirconiumAlloy]
    [clad]
      block = clad
      cladding_models = 'elastic creep thermalexpansion irradiationgrowth'
      extra_vector_tags = 'ref'
    []
  []
[]

[ThermalContact]
  [thermal_contact_0_0]
    type = GasGapHeatTransfer
    variable = temperature
    primary = 0_0_cladding_interior
    secondary = 0_0_fuel_outer_radial
    initial_moles = 0_0_initial_moles
    gas_released = 0_0_fission_gas_released
    quadrature = true
  []
  [thermal_contact_1_0]
    type = GasGapHeatTransfer
    variable = temperature
    primary = 1_0_cladding_interior
    secondary = 1_0_fuel_outer_radial
    initial_moles = 1_0_initial_moles
    gas_released = 1_0_fission_gas_released
    quadrature = true
  []
  [thermal_contact_0_1]
    type = GasGapHeatTransfer
    variable = temperature
    primary = 0_1_cladding_interior
    secondary = 0_1_fuel_outer_radial
    initial_moles = 0_1_initial_moles
    gas_released = 0_1_fission_gas_released
    quadrature = true
  []
  [thermal_contact_1_1]
    type = GasGapHeatTransfer
    variable = temperature
    primary = 1_1_cladding_interior
    secondary = 1_1_fuel_outer_radial
    initial_moles = 1_1_initial_moles
    gas_released = 1_1_fission_gas_released
    quadrature = true
  []
[]

[Executioner]
  type = Transient

  solve_type = PJFNK

  petsc_options = '-snes_ksp_ew'
  petsc_options_iname = '-pc_type -pc_factor_mat_solver_package'
  petsc_options_value = 'lu       superlu_dist'

  line_search = 'none'

  l_max_its = 100
  nl_max_its = 100
  nl_rel_tol = 1e-6
  nl_abs_tol = 1e-8
  l_tol = 1e-3
  start_time = -200
  n_startup_steps = 1
  end_time = 5e5
  dt = 2e2
  num_steps = 3
[]

[Outputs]
  [out]
    type = Exodus
    output_dimension = 3
    execute_on = 'initial timestep_end'
    show = 'burnup disp_x disp_y temperature'
    hide = 'conductivity_temperature paired_k_temperature paired_temperature qpoint_penetration strain_zz'
  []
[]

Description of Created Blocks
User - based Interface
Example Input Syntax
Input Parameters