Eutectic Penetration Thickness FCCI AuxKernel

Calculates eutectic penetration thickness based on boundary temperature.

Description

The EutecticThicknessFCCI AuxKernel is used to calculate the eutectic penetration thickness when the temperature is above the eutectic melting point for Fuel-Clad Chemical Interaction of metal fuels with the cladding. The boundary temperature is required. The rate of penetration is added to the variable tracking the penetration thickness for each time step. The penetration thickness may only grow or remain the same.

For metal fuel, a Fuel-Clad Chemical Interaction eutectic may form and melt when the temperature is above the eutectic melting temperature. The formation and melt front then move through the cladding, which thins the clad weakening it. This usually occurs during shorter transients, such as TOP events. In Bison, the penetration thickness of this eutectic melt is tracked similar to the approach used in Karahan and Buongiorno (2010). However, instead of using a diffusion coefficient, which can already be accomplished in Bison, this module relates temperature to penetration rate taken from Bauer et al. (1987) as (1) where is the eutectic penetration rate reported in micrometers per second and is the temperature in Kelvin. Between 1353.15 K and 1506.15 K, the penetration rate becomes (2) which accounts for the melting of the protective UFe layer. The eutectic only penetrates if the temperature is above the melting point usually taken as 988.15 K. Bison converts the rate to meters per second and provides a unit factor which multiplies this rate. The units or scaling may be adjusted using this unit factor. The rate is multiplied by the time step size and added to the current penetration thickness.

Example Input Syntax

[./fcci_eutectic]
boundary = right
execute_on = timestep_end
type = EutecticThicknessFCCI
temperature = temp
variable = thickness
[../]
(test/tests/fcci_ht9/fcci_eutectic.i)

Input Parameters

• variableThe name of the variable that this object applies to

C++ Type:AuxVariableName

Description:The name of the variable that this object applies to

• temperatureCoupled temperature of the boundary

C++ Type:std::vector

Description:Coupled temperature of the boundary

Required Parameters

• execute_onLINEARThe list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, FINAL, CUSTOM.

Default:LINEAR

C++ Type:ExecFlagEnum

Description:The list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, FINAL, CUSTOM.

• boundaryThe list of boundary IDs from the mesh where this boundary condition applies

C++ Type:std::vector

Description:The list of boundary IDs from the mesh where this boundary condition applies

• eutectic_melt988.15Temperature at which the eutectic will melt

Default:988.15

C++ Type:double

Description:Temperature at which the eutectic will melt

• blockThe list of block ids (SubdomainID) that this object will be applied

C++ Type:std::vector

Description:The list of block ids (SubdomainID) that this object will be applied

• unit_factor1Multiply to convert correlation from meters/sec

Default:1

C++ Type:double

Description:Multiply to convert correlation from meters/sec

Optional Parameters

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

C++ Type:std::vector

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

• enableTrueSet the enabled status of the MooseObject.

Default:True

C++ Type:bool

Description:Set the enabled status of the MooseObject.

• seed0The seed for the master random number generator

Default:0

C++ Type:unsigned int

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

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.