FissionRateAuxLWR

Computes fission rate based on common LWR parameters.

Description

FissionRateAuxLWR is designed to calculate fission rate given rod averaged linear power and pellet dimensions.

Example Input Syntax

[AuxKernels<<<{"href": "../../syntax/AuxKernels/index.html"}>>>]
  [fissionrate]
    type = FissionRateGeneral<<<{"description": "Provides various implementations which allow the user to set the fission rate.", "href": "FissionRateGeneral.html"}>>>
    fission_rate_formulation<<<{"description": "The active fission rate formulation."}>>> = LWR
    variable<<<{"description": "The name of the variable that this object applies to"}>>> = fission_rate
    rod_ave_lin_pow<<<{"description": "The rod power history function."}>>> = rod_ave_lin_pow
    axial_power_profile<<<{"description": "The axial power profile function."}>>> = rod_axial_profile
    pellet_diameter<<<{"description": "Fuel pellet diameter in meters."}>>> = 1.128379169
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_begin'
    block<<<{"description": "The list of blocks (ids or names) that this object will be applied"}>>> = 2
  []
[]

Input Parameters

pellet_diameterFuel pellet diameter in meters.
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Fuel pellet diameter in meters.
variableThe name of the variable that this object applies to
C++ Type:AuxVariableName
Unit:(no unit assumed)
Controllable:No
Description:The name of the variable that this object applies to

Required Parameters

axial_power_profileThe axial power profile function.
C++ Type:FunctionName
Unit:(no unit assumed)
Controllable:No
Description:The axial power profile function.
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
check_boundary_restrictedTrueWhether to check for multiple element sides on the boundary in the case of a boundary restricted, element aux variable. Setting this to false will allow contribution to a single element's elemental value(s) from multiple boundary sides on the same element (example: when the restricted boundary exists on two or more sides of an element, such as at a corner of a mesh
Default:True
C++ Type:bool
Controllable:No
Description:Whether to check for multiple element sides on the boundary in the case of a boundary restricted, element aux variable. Setting this to false will allow contribution to a single element's elemental value(s) from multiple boundary sides on the same element (example: when the restricted boundary exists on two or more sides of an element, such as at a corner of a mesh
energy_per_fission3.28451e-11Energy per fission in J/fission.
Default:3.28451e-11
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Energy per fission in J/fission.
execute_onLINEAR TIMESTEP_ENDThe list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html.
Default:LINEAR TIMESTEP_END
C++ Type:ExecFlagEnum
Options:XFEM_MARK, NONE, INITIAL, LINEAR, NONLINEAR_CONVERGENCE, NONLINEAR, POSTCHECK, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM, PRE_DISPLACE
Controllable:No
Description:The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html.
fuel_volume_ratio1Reduction factor for deviation from right circular cylinder fuel. The ratio of actual volume to right circular cylinder volume.
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Reduction factor for deviation from right circular cylinder fuel. The ratio of actual volume to right circular cylinder volume.
pellet_inner_diameter0Pellet inner diameter in meters for an annular pellet.
Default:0
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Pellet inner diameter in meters for an annular pellet.
radial_power_profileThe radial power profile function.
C++ Type:FunctionName
Unit:(no unit assumed)
Controllable:No
Description:The radial power profile function.
rod_ave_lin_powThe rod power history function.
C++ Type:FunctionName
Unit:(no unit assumed)
Controllable:No
Description:The rod power history function.
value1
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No

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.
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Controllable:Yes
Description:Set the enabled status of the MooseObject.
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
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

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

(test/tests/fission_rate_LWR/LWR_deprecated.i)

Child Objects

(include/auxkernels/FissionRateMOX.h)

(test/tests/fission_rate_LWR/fission_to_thermal_power_deprecated.i)

# Tests/demonstrates fission to thermal power conversion
#
# In some cases, the LHGR is specified as the thermal power generated within
# the fuel. To get the fission rate and burnup correct, this thermal power must be
# scaled upward to obtain the total fission power in the fuel. For Halden experiments
# the ratio of fission power to thermal power in the fuel is generally assumed to be
# 0.95.
#
# In this test, the power is specified as fuel thermal power (95 W/m) and so is scaled
# upward to 100 W/m as part of the power function definition. This total power is then
# partitioned as thermal power in the fuel (0.95) and thermal power in the clad
# (0.05) using the NeutronHeatSource kernel.
#
# Postprocessors show the fission power in the fuel and clad as 100 and 0, as
# expected. The fission power density in the fuel can be computed as:
#
#    Fdot = ALHR / (Energy_per_fission * Cross_sectional_area)
#         = 100 /  (3.2e-11 * pi * 0.56418958^2)
#         = 3.125e12 fissions/(m**3-s)
#
# Assuming a very high conductivity for the fuel and clad (1e6), both materials can be
# accurately described using a lumped-capacity thermal model. The temperature is
# then given by:
#
#     dT = (q * dt) / (rho * C * V)
#        = (q/l * dt) / (rho * C * A)
#
#       where:   T = temperature
#                t = time
#                q = heat rate
#                rho = density
#                C = specific heat
#                V = volume
#                l = length
#                A = cross-sectional area
#
#  For the fuel, at 2 s:
#     dT = (95 W/m * 2 s) / (1 kg/m^3 * 1 J/kg-K * pi * 0.56418958^2 m^2)
#        = 190 K
#
#  For the clad, at 2 s:
#     dT = (5 W/m * 2 s) / (1 kg/m^3 * 1 J/kg-K * pi * (0.8990605^2 - 0.7^2 m^2)
#        = 10 K
#
#  which is what is computed numerically
#
[GlobalParams]
  energy_per_fission = 3.2e-11
[]

[Mesh]
  coord_type = RZ
  [mesh]
    type = FileMeshGenerator
    file = fission_to_thermal_power.e
  []
[]

[Variables]
  [temp]
    order = FIRST
    family = LAGRANGE
    initial_condition = 500.0
  []
[]

[Functions]
  [rod_ave_lin_pow]
    type = PiecewiseLinear
    x = '0 2'
    y = '95 95'
    scale_factor = 1.052631579 # scale input thermal power to fission power (1/0.95)
  []

  [rod_axial_profile]
    type = ParsedFunction
    expression = '1.0'
  []
[]

[AuxVariables]
  [fission_rate]
    order = FIRST
    family = LAGRANGE
  []
[]

[Kernels]

  [heat]
    type = HeatConduction
    variable = temp
  []

  [ie]
    type = HeatConductionTimeDerivative
    variable = temp
  []

  [heat_source_fuel]
    type = NeutronHeatSource
    block = 2
    variable = temp
    rod_ave_lin_pow = rod_ave_lin_pow
    axial_profile = rod_axial_profile
    outer_diameter = 1.128379169
    inner_diameter = 0
    fraction = 0.95 # 95% of fission power deposited in fuel
  []

  [heat_source_clad]
    type = NeutronHeatSource
    block = 1
    variable = temp
    rod_ave_lin_pow = rod_ave_lin_pow
    axial_profile = rod_axial_profile
    outer_diameter = 1.7981211151463525
    inner_diameter = 1.4
    fraction = 0.05 # 5% of fission power deposited in clad
  []
[]

[AuxKernels]
  [fissionrate]
    type = FissionRateGeneral
    fission_rate_formulation = LWR
    variable = fission_rate
    rod_ave_lin_pow = rod_ave_lin_pow
    axial_power_profile = rod_axial_profile
    pellet_diameter = 1.128379169
    execute_on = 'initial timestep_begin'
    block = 2
  []
[]

[Materials]
  [goo]
    type = HeatConductionMaterial
    block = '1 2'
    thermal_conductivity = 1.0e6
    specific_heat = 1.0
  []
  [density]
    type = ParsedMaterial
    block = '1 2'
    property_name = density
    expression = 1
  []
[]

[Executioner]
  type = Transient

  solve_type = 'PJFNK'

  petsc_options_iname = '-ksp_gmres_restart -pc_type -pc_hypre_type -pc_hypre_boomeramg_max_iter'
  petsc_options_value = '201                hypre    boomeramg      4'

  line_search = 'none'

  nl_rel_tol = 1e-6

  start_time = 0.0
  num_steps = 2
  dt = 1.0
[]

[Postprocessors]
  [fuel_fission_power]
    type = ElementIntegralPower
    variable = temp
    fission_rate = fission_rate
    block = 2
    execute_on = 'initial timestep_end'
  []

  [clad_fission_power]
    type = ElementIntegralPower
    variable = temp
    fission_rate = fission_rate
    block = 1
    execute_on = 'initial timestep_end'
  []
[]

[Outputs]
  exodus = true
[]

(test/tests/fission_rate_LWR/LWR_deprecated.i)

#The reason for this test is to determine if the fission rate is calculated correctly.  The fission rate is a function of
#rod average linear power (function named power here) in W/m - calculated via function PiecewiseLinear and  LinearInerpolation,
#the 2D axial power profile function (power factors as a function of axial position and time - calculated using the auxkernel FissionRateAux via the
#function PiecewiseBilinear and BilinearInterpolation, function named axial_power_factors here), pellet diameter (m), inner pellet diameter (m) if fuel is annular, f_fuel (fraction of total power),
#and fuel_volume_ratio (volume reduction factor due to pellet dishing i.e. if the pellet is not a right circular cylinder), and energy per fission.
#
#The mesh consists of 5 1x1x1 brick elements "stacked" in the y-direction.  The y-coordinate of nodes is 0, 1, 2, 3, 4, or 5.
#The power is 1 for the duration...after a ramp from 0 to 1 during the first time step.
#The power factors for this test are in the file powerfactors.csv, which as the following format
#
#0.25,1.25,2.25,3.5,4.25,4.75
#0,0,0,0,0,0,0
#1,1,1,1,1,1,1
#2,.5,.75,2.5,2.5,.75,.5
#3,.5,.7,.3,.1,1,.1
#4,.2,.9,.8,.7,1,.9
#5,.2,.9,.8,.7,1,.25
#
#Where the first row is a list of the axial positions where the power factors are defined.
#After the first row, the first column is a list of the times where the power factors are defined.
#All the other numbers are the power factors defined at the given axial position and time.
#For a given power, pellet diameter, and reduction factors (all described previously) the fission rate is calculated for every node at every time.
#The file powerfactors.csv is used/read by PiecewiseBilinear, which sends a vector (x) of the axial position values,
#a vector (y) of the times, a ColumnMajorMatrix (z) of the powerfactors to BilinearInterpolation, and a sample point (position,time).  The value returned
#is used in the fission rate calculation.
#
#An example:
#
#At time 2.25 and axial position z = 1 (node 20)...sample point = (1, 2.25), the value returned is 0.678125.  You can check this value by hand using the data provided.
#
#For this test, the fission rate has the same value as the power factor (for this example 0.678125).
#This is by design to make it easy to determine if the fission rate is being calculated correctly.
#Look at the output file for this test and plot the fission rate at node 20 (z-coordinate = 1).  At time = 2.25, the value should be 0.678125
#

[Mesh]
  [mesh]
    type = FileMeshGenerator
    file = 1x5x1.e
  []
[]

[Variables]
  [temp]
    order = FIRST
    family = LAGRANGE
    initial_condition = 1373.15
  []
[]

[AuxVariables]
  [fission_rate]
    order = FIRST
    family = LAGRANGE
  []
[]

[Functions]
  [power]
    type = PiecewiseLinear
    data_file = power.csv
  []

  [axial_power_factor]
    type = PiecewiseBilinear
    data_file = powerfactors.csv
    axis = 1
  []
[]

[Kernels]
  [heat]
    type = HeatConduction
    variable = temp
  []
[]

[AuxKernels]
  [fissionrate]
    type = FissionRateAuxLWR
    variable = fission_rate
    rod_ave_lin_pow = power
    axial_power_profile = axial_power_factor
    pellet_diameter = 1.1283791671 #fake pellet diameter to give a value of 1 for Power/area
    pellet_inner_diameter = 0
    energy_per_fission = 1 #J/fission
  []
[]

[BCs]
  [bottom_temp]
    type = DirichletBC
    variable = temp
    boundary = 3
    value = 1373.15
  []

  [top_temp]
    type = DirichletBC
    variable = temp
    boundary = 5
    value = 1373.15
  []
[]

[Materials]
  [thermal]
    type = HeatConductionMaterial
    block = 1
    thermal_conductivity = 1.e4
    specific_heat = 1.
  []
[]

[Executioner]
  type = Transient

  solve_type = 'PJFNK'

  petsc_options = '-snes_ksp_ew '
  petsc_options_iname = '-ksp_gmres_restart -pc_type -pc_hypre_type'
  petsc_options_value = '70 hypre boomeramg'
  l_max_its = 60
  nl_rel_tol = 1e-8
  nl_abs_tol = 1e-10
  l_tol = 1e-5
  start_time = 0.0
  dt = 0.25
  num_steps = 21
[]

[Outputs]
  exodus = true
[]

(include/auxkernels/FissionRateMOX.h)

/*************************************************/
/*           DO NOT MODIFY THIS HEADER           */
/*                                               */
/*                     BISON                     */
/*                                               */
/*    (c) 2015 Battelle Energy Alliance, LLC     */
/*            ALL RIGHTS RESERVED                */
/*                                               */
/*   Prepared by Battelle Energy Alliance, LLC   */
/*     Under Contract No. DE-AC07-05ID14517      */
/*     With the U. S. Department of Energy       */
/*                                               */
/*     See COPYRIGHT for full restrictions       */
/*************************************************/

#pragma once

#include "FissionRateAuxLWR.h"

class FissionRateMOX : public FissionRateAuxLWR
{
public:
  static InputParameters validParams();
  FissionRateMOX(const InputParameters & parameters);

  virtual ~FissionRateMOX() {}

protected:
  virtual void initialSetup() override;
  virtual Real computeValue() override;

  const bool _has_porosity;
  const VariableValue & _porosity;
  const Real _initial_porosity;
};

Description
Example Input Syntax
Input Parameters
Input Files
Child Objects