Pulverization of UO

Determines whether or not the fuel has pulverized into small fragments during a Loss of Coolant Accident.

Description

Figure 1: Empirical threshold for fuel pulverization.

The UO2Pulverization material computes whether or not the UO2 fuel has disintegrated into small fragments. The empirical threshold that determines whether or not pulverization occurs is illustrated in the figure below. It is observed that a minimum local burnup of 71 MWd/kgU is required for pulverization. At this burnup the temperature threshold is 1193.15 K. The threshold decreases linearly with increasing burnup to a value of 913.15 K at a burnup of 94 MWd/kgU, after which it is constant. It should be noted that despite the temperature threshold being exceeded, pulverization will be prevented if the pellet-to-cladding contact pressure at a particular axial location is greater than 50 MPa. Reproduced from Jernkvist and Massih (2015) and Turnbull et al. (2015).

Example Input Syntax

[./uo2pulverization]
  type = UO2Pulverization
  block = fuel
  layered_average_contact_pressure = layered_average_contact_pressure
  temperature = temperature
[../]
(test/tests/axial_relocation/uo2_pulverization.i)

Input Parameters

  • layered_average_contact_pressureCoupled layer averaged contact pressure

    C++ Type:std::vector

    Description:Coupled layer averaged contact pressure

  • temperatureCoupled temperature

    C++ Type:std::vector

    Description:Coupled temperature

Required Parameters

  • computeTrueWhen false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the Material via MaterialPropertyInterface::getMaterial(). Non-computed Materials are not sorted for dependencies.

    Default:True

    C++ Type:bool

    Description:When false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the Material via MaterialPropertyInterface::getMaterial(). Non-computed Materials are not sorted for dependencies.

  • 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

  • burnup_functionBurnup function

    C++ Type:FunctionName

    Description:Burnup function

  • burnupCoupled Burnup

    C++ Type:std::vector

    Description:Coupled Burnup

  • 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

Optional Parameters

  • enableTrueSet the enabled status of the MooseObject.

    Default:True

    C++ Type:bool

    Description:Set the enabled status of the MooseObject.

  • 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.

  • 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.

  • seed0The seed for the master random number generator

    Default:0

    C++ Type:unsigned int

    Description:The seed for the master random number generator

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

    Default:True

    C++ Type:bool

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

  • 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 computeSubdomainProperties() 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

    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 computeSubdomainProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped

Advanced Parameters

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

    C++ Type:std::vector

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

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

    Default:none

    C++ Type:std::vector

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

Outputs Parameters

Input Files

References

  1. L. O. Jernkvist and A. Massih. Model for axial relocation of fragmented and pulverized fuel pellets in distending fuel rods and its effects on fuel rod heat load. Technical Report SSM-2015:37, Str\r al säkerhets myndigheten, 2015.[BibTeX]
  2. J. A. Turnbull, S. K. Yagnik, M. Hirai, D. M. Staicu, and C. T. Walker. An assessment of the fuel pulverization threshold during loca-type temperature transients. Nuclear Science and Engineering, 179:477–485, 2015.[BibTeX]