AxialRelocationAction

Description

This AxialRelocation action generates the AuxVariables, AuxKernels, Materials, UserObjects, and Postprocessors required for simulating axial fuel relocation that may occur in LWR fuel rods during a Loss of Coolant Accident(LOCA). See the description, example use, and parameters on the AxialRelocation action system page.

Multiple Fuel Rods

Currently the AxialRelocationAction, when used with the Layered2DMeshGenerator, can be used to simulate identical multiple fuel pins. In doing so, names and numbering for blocks and sidesets are required to be unique. This is achieved through the input parameters name_prefix and id_offset ensuring unique names and numbering for possible otherwise identical fuel rods.

An example of constructing multiple fuel rods:

[AxialRelocation<<<{"href": "../../syntax/AxialRelocation/index.html"}>>>]
  [righthand]
    rod_ave_lin_pow<<<{"description": "Rod average linear power function."}>>> = power
    formulation<<<{"description": "The layered formulation being used in the simulation."}>>> = layered2D
    axial_direction<<<{"description": "The axial direction of the model."}>>> = z
    fuel_blocks<<<{"description": "The list of names of the blocks (subdomains) for the fuel pellets."}>>> = 'righthand_fuel'
    clad_blocks<<<{"description": "The list of names of the block (subdomain) for the cladding."}>>> = 'righthand_clad'
    contact_pressure_variable<<<{"description": "The contact pressure variable."}>>> = contact_pressure
    out_of_plane_strain_variable<<<{"description": "The out-of-plane strain nodal variable."}>>> = strain_zz_0
    penetration_variable<<<{"description": "The penetration variable."}>>> = penetration
    pulver_packing_fraction<<<{"description": "The packing fraction of the smaller pulvers of fuel."}>>> = 0.75
    fragment_packing_fraction<<<{"description": "The packing fraction of large fragments of fuel."}>>> = 0.75
    clad_inner_volume_addition<<<{"description": "An additional volume to be included in the internal volume calculation. A time-dependent function is expected."}>>> = 0
    burnup_variable<<<{"description": "The burnup variable."}>>> = burnup
    axial_relocation_output_options<<<{"description": "The layered quantities to be output from the axial relocation userobject."}>>> = MASS_FRACTION
    mesh_generator<<<{"description": "The name of the generator to use as the prefix for mesh meta data properties."}>>> = layered2D_mesh_1
    translation_vector<<<{"description": "The value to use for the translation. The xyz coordinates are applied in each direction respectively."}>>> = '1 0 0'
    name_prefix<<<{"description": "If provided, prefix the built in boundary names with this string"}>>> = 'righthand'
    id_offset<<<{"description": "This offset is added to the generated boundary IDs"}>>> = 10
  []
  [lefthand]
    rod_ave_lin_pow<<<{"description": "Rod average linear power function."}>>> = power
    formulation<<<{"description": "The layered formulation being used in the simulation."}>>> = layered2D
    axial_direction<<<{"description": "The axial direction of the model."}>>> = z
    fuel_blocks<<<{"description": "The list of names of the blocks (subdomains) for the fuel pellets."}>>> = 'lefthand_fuel'
    clad_blocks<<<{"description": "The list of names of the block (subdomain) for the cladding."}>>> = 'lefthand_fuel'
    contact_pressure_variable<<<{"description": "The contact pressure variable."}>>> = contact_pressure
    out_of_plane_strain_variable<<<{"description": "The out-of-plane strain nodal variable."}>>> = strain_zz_0
    penetration_variable<<<{"description": "The penetration variable."}>>> = penetration
    pulver_packing_fraction<<<{"description": "The packing fraction of the smaller pulvers of fuel."}>>> = 0.75
    fragment_packing_fraction<<<{"description": "The packing fraction of large fragments of fuel."}>>> = 0.75
    clad_inner_volume_addition<<<{"description": "An additional volume to be included in the internal volume calculation. A time-dependent function is expected."}>>> = 0
    burnup_variable<<<{"description": "The burnup variable."}>>> = burnup
    axial_relocation_output_options<<<{"description": "The layered quantities to be output from the axial relocation userobject."}>>> = MASS_FRACTION
    mesh_generator<<<{"description": "The name of the generator to use as the prefix for mesh meta data properties."}>>> = layered2D_mesh_2
    translation_vector<<<{"description": "The value to use for the translation. The xyz coordinates are applied in each direction respectively."}>>> = '-1 0 0'
    name_prefix<<<{"description": "If provided, prefix the built in boundary names with this string"}>>> = 'lefthand'
    id_offset<<<{"description": "This offset is added to the generated boundary IDs"}>>> = 30
  []
[]
(examples/axial_relocation/layered2D/single_balloon/single_balloon_two_rods.i)
warningwarning:For LWR Use Only

This action is designed for use with only Light Water Reactor simulations run with a mesh generated by Layered1DMeshGenerator or Layered2DMeshGenerator.

commentnote

Note that when pulverization_criterion_type = ANALYTICAL or pulverization_criterion_type = PHASE_FIELD, then a UO2Sifgrs block is required to be in the input file. This is to be able to use UO2PulverizationMesoscale, which is automatically created by AxialRelocationAction.