Neutronic Modeling of the Whole Core Gas-Cooled Microreactor (GCMR)

Contacts: Ahmed Abdelhameed (aabdelhameed.at.anl.gov), Yinbin Miao (ymiao.at.anl.gov), Nicolas Stauff (nstauff.at.anl.gov)

GCMR Core Description

The GCMR model, developed at ANL, serves as a modeling experiment to explore design options considered by microreactor vendors, encompassing features like control drums, hydride metal, and TRISO fuel. This horizontal gas-cooled microreactor system boasts a thermal power of 20 MW and an approximate lifespan of 9.5 years. Its power conversion cycle utilizes a Brayton cycle, circulating high-temperature (650°C-850°C) and high-pressure (7 MPa) helium coolant. Surrounding the core are BeO radial and axial neutron reflectors, with twelve control drums positioned in the reflector encircling the core. These control rods, containing 96%-enriched B4C, are inserted into holes within the middle core assemblies. Displayed in Figure 1 and Figure 2 are radial and axial views of the core, which is relatively compact, measuring 2.42 m in diameter and 2.40 m in length.

Figure 1: Radial View of the GCMR core

Figure 2: Axial view of the GCMR core

The core comprises three types of fuel assemblies: Assembly A in the inner region, Assembly B in the middle, and Assembly C in the outer core region. Each fuel assembly incorporates TRISO fuel blocks containing 19.75 wt% of LEU fuel and Yttrium hydride moderator pins encased in FeCrAl envelopes. Additionally, burnable poison blocks, composed of Gd2O3 particles with a 25% packing fraction distributed axially, and Helium coolant channels are integrated. Assembly A's detailed design is provided in Figure 3, while Figure 4 illustrates the design differences among the three assemblies. Assemblies B and C are nearly identical, except for the presence of a central shutdown rod location in assembly B. Each of assemblies B and C is equipped with 6 burnable poison rods, 6 moderator pins, and 48 fuel rods. In contrast, Assembly A contains 12 burnable poison rods and 42 fuel rods. The key design parameters of the GCMR core comprise of:

Figure 3: GCMR assembly of Type A

Figure 4: Design of the three types of fuel assemblies in the core

Parameter (unit)	Value
Reactor Power (MWth)	20.0
Core diameter (cm)	242.0
Core height (cm)	240.0
Active height (cm)	200.0
Different radial core zones	3
Number of control drums	12
Lattice pitch (cm)	20.8
Pin pitch (cm)	2.0
TRISO fuel compact radius (cm)	0.85
Moderator compact radius (cm)	0.75
Cr coating thickness (cm)	0.007
FeCrAl envelope thickness (cm)	0.05
Burnable poison compact radius (cm)	0.25
Coolant compact radius (cm)	0.6
Control compact radius (cm)	0.95
Fuel	TRISO, 40% packing fraction
Coolant	He
Moderator (Coating, Envelope)	YH1.8 (Cr, FeCrAl)
Burnable poison absorber	Gd2O3 particles, 25% packing fraction
Control rod	B4C (96% B-10 enrichment)

Mesh

MOOSE's Reactor Module (Shemon et al., 2023) was used to create the mesh structure for the entire core of the GC-MR reactor. This tool was particularly useful in addressing intricate modeling prerequisites for the microreactor core such as fuel assemblies exhibiting different designs, distinct axial loading configurations of the burnable absorbers within the core, and modeling intricacies of control drum designs. The transition of the mesh from a 2D to a 3D structure, along with the incorporation of distinct axial regions, was made notably straightforward by employing the AdvancedExtruderGenerator. The tool's adaptability became especially useful when altering the mesh element size to examine the trade-off between accuracy and computational cost through coarser mesh. Figure 5 illustrates a depiction of the 3-D GCMR, detailing both the axial and radial discretization.

Figure 5: Detailed 3-D GCMR core mesh

#####################################################################################################
# Whole-core mesh for a Gas-cooled Microreactor
# If using or referring to this model, please cite as explained in
# https://mooseframework.inl.gov/virtual_test_bed/citing.html
#####################################################################################################

[Mesh]
  [YH_pin]
    type = PolygonConcentricCircleMeshGenerator
    num_sides = 6
    num_sectors_per_side = '2 2 2 2 2 2'
    background_intervals = 1
    background_block_ids = '10'
    polygon_size = 1
    polygon_size_style ='apothem'
    ring_radii = '0.693 0.7 0.75'
    ring_intervals = '2 1 1'
    ring_block_ids = '101 100 102 103'
  []

  [Coolant_hole]
    type = PolygonConcentricCircleMeshGenerator
    num_sides = 6
    num_sectors_per_side = '2 2 2 2 2 2'
    background_intervals = 1
    background_block_ids = '10'
    polygon_size = 1
    polygon_size_style ='apothem'
    ring_radii = '0.6'
    ring_intervals = '2'
    ring_block_ids = '201 200'
  []

  [Control_hole]
    type = PolygonConcentricCircleMeshGenerator
    num_sides = 6
    num_sectors_per_side = '2 2 2 2 2 2'
    background_intervals = 1
    background_block_ids = '10'
    polygon_size = 1
    polygon_size_style ='apothem'
    ring_radii = '0.95'
    ring_intervals = '2'
    ring_block_ids = '301 300'
  []

  [TRISO_fuel_in]
    type = PolygonConcentricCircleMeshGenerator
    num_sides = 6
    num_sectors_per_side = '2 2 2 2 2 2'
    background_intervals = 1
    background_block_ids = '10'
    polygon_size = 1
    polygon_size_style ='apothem'
    ring_radii = '0.85'
    ring_intervals = '2'
    ring_block_ids = '401 400'
  []

  [TRISO_fuel_mid]
    type = PolygonConcentricCircleMeshGenerator
    num_sides = 6
    num_sectors_per_side = '2 2 2 2 2 2'
    background_intervals = 1
    background_block_ids = '10'
    polygon_size = 1
    polygon_size_style ='apothem'
    ring_radii = '0.85'
    ring_intervals = '2'
    ring_block_ids = '4001 4000'
  []

  [TRISO_fuel_out]
    type = PolygonConcentricCircleMeshGenerator
    num_sides = 6
    num_sectors_per_side = '2 2 2 2 2 2'
    background_intervals = 1
    background_block_ids = '10'
    polygon_size = 1
    polygon_size_style ='apothem'
    ring_radii = '0.85'
    ring_intervals = '2'
    ring_block_ids = '40001 40000'
  []

  [Poison_LBP0]
    type = PolygonConcentricCircleMeshGenerator
    num_sides = 6
    num_sectors_per_side = '2 2 2 2 2 2'
    background_intervals = 1
    background_block_ids = '10'
    polygon_size = 1
    polygon_size_style ='apothem'
    ring_radii = '0.25'
    ring_intervals = '2'
    ring_block_ids = '501 500'
  []

  [Poison_LBP1]
    type = PolygonConcentricCircleMeshGenerator
    num_sides = 6
    num_sectors_per_side = '2 2 2 2 2 2'
    background_intervals = 1
    background_block_ids = '10'
    polygon_size = 1
    polygon_size_style ='apothem'
    ring_radii = '0.25'
    ring_intervals = '2'
    ring_block_ids = '5001 5000'
  []

  [centralFA]
    type = PatternedHexMeshGenerator
    inputs = 'YH_pin Coolant_hole  TRISO_fuel_in Poison_LBP0'
    #           0          1            2           3
    hexagon_size = 10.4
    pattern =
                      '3  1  2  2  1  3;
                    1  0  2  1  2  0  1;
                  2  2  1  2  2  1  2  2;
                2  1  2  3  1  3  2  1  2;
              1  2  2  1  2  2  1  2  2  1;
             3  0  1  3  2  1  2  3  1  0  3;
               1  2  2  1  2  2  1  2  2  1;
                2  1  2  3  1  3  2  1  2;
                 2  2  1  2  2  1  2  2;
                  1  0  2  1  2  0  1;
                    3  1  2  2  1  3'

  background_block_id = 10
  background_intervals = 1
  []

  [Innercore]
    type = PatternedHexMeshGenerator
    inputs = 'YH_pin Coolant_hole  TRISO_fuel_in Poison_LBP0'
    #           0          1            2           3
    hexagon_size = 10.4
    pattern =
                      '3  1  2  2  1  3;
                    1  0  2  1  2  0  1;
                  2  2  1  2  2  1  2  2;
                2  1  2  3  1  3  2  1  2;
              1  2  2  1  2  2  1  2  2  1;
            3  0  1  3  2  1  2  3  1  0  3;
              1  2  2  1  2  2  1  2  2  1;
               2  1  2  3  1  3  2  1  2;
                2  2  1  2  2  1  2  2;
                 1  0  2  1  2  0  1;
                  3  1  2  2  1  3'

  background_block_id = 10
  background_intervals = 1
  []

  [dummy]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    num_sectors_per_side= '2 2 2 2 2 2'
    hexagon_size = 10.4
    background_intervals = 1
    background_block_ids = '700'
  []

  [Outercore]
    type = PatternedHexMeshGenerator
    inputs = 'YH_pin Coolant_hole  Control_hole  Poison_LBP1   TRISO_fuel_mid'
    #           0          1            2             3            4
    hexagon_size = 10.4
    pattern =
                      '4  1  4  4  1  4;
                    1  0  4  1  4  0   1;
                  4  4  1  4  4  1  4   4;
                4  1  4  3  1  3  4  1   4;
              1  4  4  1  4  4  1  4  4   1;
             4  0  1  3  4  2  4  3  1  0  4;
              1  4  4  1  4  4  1  4  4  1;
               4  1  4  3  1  3  4  1  4;
                4  4  1  4  4  1  4  4;
                 1  0  4  1  4  0  1;
                  4  1  4  4  1  4'

    background_block_id = 10
    background_intervals = 1
  []

  [Outercore2]
    type = PatternedHexMeshGenerator
    inputs = 'YH_pin Coolant_hole  Control_hole  Poison_LBP1   TRISO_fuel_mid'
    #           0          1            2             3             4
    hexagon_size = 10.4
    pattern =
                      '4  1  4  4  1  4;
                    1  0  4  1  4  0  1;
                  4  4  1  4  4  1  4  4;
                4  1  4  3  1  3  4  1  4;
              1  4  4  1  4  4  1  4  4  1;
             4  0  1  3  4  2  4  3  1  0  4;
              1  4  4  1  4  4  1  4  4  1;
               4  1  4  3  1  3  4  1  4;
                4  4  1  4  4  1  4  4;
                 1  0  4  1  4  0  1;
                  4  1  4  4  1  4'

    background_block_id = 10
    background_intervals = 1
  []

  [Innercore2]
    type = PatternedHexMeshGenerator
    inputs = 'YH_pin Coolant_hole  Poison_LBP1   TRISO_fuel_out'
    #           0          1            2             3
    hexagon_size = 10.4
    pattern =
                      '3  1  3  3  1  3;
                    1  0  3  1  3  0   1;
                  3  3  1  3  3  1  3   3;
                3  1  3  2  1  2  3  1   3;
              1  3  3  1  3  3  1  3  3   1;
             3  0  1  2  3  1  3  2  1  0  3;
              1  3  3  1  3  3  1  3  3  1;
               3  1  3  2  1  2  3  1  3;
                3  3  1  3  3  1  3  3;
                 1  0  3  1  3  0  1;
                  3  1  3  3  1  3'

    background_block_id = 10
    background_intervals = 1
  []

  [cd0_12]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2 Innercore2'
    sides_to_adapt = '3 4'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_12]
    type = AzimuthalBlockSplitGenerator
    input = cd0_12
    start_angle = 45
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_6]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2 Innercore2'
    sides_to_adapt = '0 1'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_6]
    type = AzimuthalBlockSplitGenerator
    input = cd0_6
    start_angle = 225
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_9]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2 Innercore2 Innercore2'
    sides_to_adapt = '0 5 4'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_9]
    type = AzimuthalBlockSplitGenerator
    input = cd0_9
    start_angle = 135
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_3]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2 Innercore2 Innercore2'
    sides_to_adapt = '1 2 3'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_3]
    type = AzimuthalBlockSplitGenerator
    input = cd0_3
    start_angle = 315
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_1]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2 Innercore2 Innercore2'
    sides_to_adapt = '2 3 4'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_1]
    type = AzimuthalBlockSplitGenerator
    input = cd0_1
    start_angle = 15
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_2]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2  Innercore2'
    sides_to_adapt = '2 3'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_2]
    type = AzimuthalBlockSplitGenerator
    input = cd0_2
    start_angle = 345
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_4]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2 Innercore2 '
    sides_to_adapt = '1 2'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_4]
    type = AzimuthalBlockSplitGenerator
    input = cd0_4
    start_angle = 285
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_5]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to =  'Innercore2 Innercore2 Innercore2'
    sides_to_adapt = '0 1 2'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []
  [cd_5]
    type = AzimuthalBlockSplitGenerator
    input = cd0_5
    start_angle = 255
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []
  [cd0_7]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = ' Innercore2 Innercore2 Innercore2'
    sides_to_adapt = '0 1 5'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_7]
    type = AzimuthalBlockSplitGenerator
    input = cd0_7
    start_angle = 195
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_8]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2 Innercore2 '
    sides_to_adapt = '0 5'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_8]
    type = AzimuthalBlockSplitGenerator
    input = cd0_8
    start_angle = 165
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_10]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2 Innercore2 '
    sides_to_adapt = ' 4 5'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_10]
    type = AzimuthalBlockSplitGenerator
    input = cd0_10
    start_angle = 105
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []
  [cd0_11]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Outercore  Outercore Outercore'
    sides_to_adapt = '3 4 5'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_11]
    type = AzimuthalBlockSplitGenerator
    input = cd0_11
    start_angle = 75
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

    [core]
    type = PatternedHexMeshGenerator
    inputs = 'Innercore Innercore2 Outercore dummy cd_1 cd_2 cd_3 cd_4 cd_5 cd_6 cd_7 cd_8 cd_9 cd_10 cd_11 cd_12 Outercore2  centralFA'
    #         0         1          2         3     4    5    6    7    8    9    10   11   12   13    14    15    16         17
    pattern_boundary = none
    generate_core_metadata = true
    #external_boundary_id = 9000
    #external_boundary_name = side

  pattern =
        '3  3  3  15  3  3  3;
        3  14  1  1  1  1  4  3;
      3  1  1   16  16  16  1  1  3;
    13  1  16  2  2  2  2  16  1  5;
   3  1  16  2  0  0  0  2  16  1  3;
  3  1  16   2  0  0  0  0  2  16  1  3;
3  12  1  2  0  0  17  0  0  2  1  6  3;
  3  1  16  2  0  0  0  0  2  16  1  3;
   3  1  16  2   0  0   0   2  16  1  3;
    11  1  16  2   2  2   2  16  1  7;
       3  1  1  16  16  16  1  1  3;
       3    10  1   1  1   1  8  3;
          3   3  3  9  3  3   3'

    rotate_angle = 0
   []

   [del_dummy]
     type = BlockDeletionGenerator
     block = '700 '
     input = core
     new_boundary = 10000
   []

   [ADD_outer_shield]
     type = PeripheralRingMeshGenerator
     input = del_dummy
     peripheral_layer_num = 2
     peripheral_ring_radius = 120.1
     input_mesh_external_boundary = 10000
     peripheral_ring_block_id = 250
     #peripheral_ring_block_name = outer_shield
   []

  [del_1]
     type = PlaneDeletionGenerator
     point = '0 0 0'
     normal = '10 17.32 0'
     input = ADD_outer_shield
     new_boundary = 147
  []

  [del_2]
     type = PlaneDeletionGenerator
     point = '0 0 0'
     normal = '10 -17.32 0'
     input = del_1
     new_boundary = 147
  []

  [extrude]
     type = AdvancedExtruderGenerator
     input = del_2
     heights = '20 40 40 40 40 40 20'
     num_layers ='2 4 4  4  4  4 2'
     subdomain_swaps = '10    1000    500 1000    501  1003   5001  1003  5000  1000  400 1000 401 1003 4000 1000 4001 1003 40000 1000 40001 1003 101 1003 100 1000 102 1000 103 1000 301 1003 300 1000;
                        500   19000  501  19003  5001  19900  5000  19903;
                        500   29000  501  29003  5001  29900  5000  29903;
                        500   39000  501  39003  5001  39900  5000  39903;
                        500   49000  501  49003  5001  49900  5000  49903;
                        500   59000  501  59003  5001  59900  5000  59903;
                        10     1000    500  1000  501      1003   5001  1003  5000  1000  400 1000 401 1003 4000 1000 4001 1003 40000 1000 40001 1003 101 1003 100 1000 102 1000 103 1000 301 1773 300 1777'
      direction = '0 0 1'
      top_boundary = 2000
      bottom_boundary = 3000
  []

  [rename_blocks]
      type = RenameBlockGenerator
      old_block =   ' 10      100        101           102  103     200     201          400     401          4000     4001          40000    40001          300          301                  600         602          603        604          1000              1003            19000  29000  39000  49000  59000  19003  29003  39003  49003  59003  19900  29900  39900  49900  59900  19903  29903  39903  49903  59903  1777 1773  250'
      new_block = 'monolith moderator  moderator_tri Cr   FECRAL  coolant coolant_tri  Fuel_in Fuel_tri_in  Fuel_mid Fuel_tri_mid  Fuel_out Fuel_tri_out   Control_hole Control_hole_tri     CD_Radial1  CD_Radial2   CD_poison  CD_coolant   reflector_quad    reflector_tri   BP0_1  BP0_2  BP0_3  BP0_4  BP0_5  BP0_tr_1  BP0_tr_2  BP0_tr_3  BP0_tr_4  BP0_tr_5  BP1_1  BP1_2  BP1_3  BP1_4  BP1_5  BP1_tr_1  BP1_tr_2  BP1_tr_3  BP1_tr_4  BP1_tr_5 Control_ref Control_ref_tri Rad_ref'
      input = extrude
  []

  [rename_sidesets]
      type = RenameBoundaryGenerator
      input = rename_blocks
      old_boundary = '2000         3000            10000  147 '
      new_boundary = 'top_boundary bottom_boundary side   cut_surf'
  []

  [scale] # unit convert from cm to m
     type = TransformGenerator
     input = rename_sidesets
     transform = SCALE
     vector_value = '1e-2 1e-2 1e-2'
  []
[]

Cross-Section Generation Using Serpent Code

The first step is to generate homogenized multi-group cross-sections using Serpent-2. The specific version used for this work is Serpent 2.1.32**. The generated cross-sections are then converted into an XML-format file for compatibility with Griffin.

%------------------------------------------------------------------------------------------
% ANL GCMR Serpent (Version 2.1.32) Model Input
% If using or referring to this model, please cite as explained in
% https://mooseframework.inl.gov/virtual_test_bed/citing.html
% Contacts: Ahmed Abdelhameed (aabdelhameed.at.anl.gov), Nicolas Stauff (nstauff.at.anl.gov)
% -----------------------------------------------------------------------------------------
set title "ANL GC MicroReactor"

surf inf inf
pbed 700 33 "PART_U900_PF40_R85.inp"
pbed 701 33 "PART_U901_PF40_R85.inp"
pbed 702 33 "PART_U902_PF40_R85.inp"
pbed 754 33 "PART_U954_PF25_R25.inp"
pbed 764 33 "PART_U964_PF25_R25.inp"

% infinite cells defining material universes
cell 51 802 moderator  -inf
cell 52 33  matrix_pin -inf
cell 53 803    matrix  -inf
cell 54 804    coolant -inf
cell 55 805      Refl  -inf
cell 56 806  shell_mod -inf
cell 57 807    coolant -inf
cell 58 809  boron_ctr -inf
cell 59 810         Cr -inf
cell 155 811      Refl -inf

% Fuel region

particle 900
     fuel0     2.1250e-02
     buffer    3.1250e-02
     PyC1      3.5250e-02
     SiC       3.8750e-02
     PyC2      4.2750e-02
matrix_pin
particle 901
     fuel1     2.1250e-02
     buffer    3.1250e-02
     PyC1      3.5250e-02
     SiC       3.8750e-02
     PyC2      4.2750e-02
matrix_pin
particle 902
     fuel2     2.1250e-02
     buffer    3.1250e-02
     PyC1      3.5250e-02
     SiC       3.8750e-02
     PyC2      4.2750e-02
matrix_pin

cell i110  3 fill 700       -1  95l   -95lu1 % fuel compact
cell i111  3 fill 700       -1  95lu1 -95lu2 % fuel compact
cell i112  3 fill 700       -1  95lu2 -95lu3 % fuel compact
cell i113  3 fill 700       -1  95lu3 -95lu4 % fuel compact
cell i114  3 fill 700       -1  95lu4 -95u   % fuel compact
cell i12   3 fill 803        1  95l   -95u
cell i13   3 fill 805                  95u
cell i14   3 fill 805                 -95l

cell m110  5 fill 701       -1  95l   -95lu1 % fuel compact
cell m111  5 fill 701       -1  95lu1 -95lu2 % fuel compact
cell m112  5 fill 701       -1  95lu2 -95lu3 % fuel compact
cell m113  5 fill 701       -1  95lu3 -95lu4 % fuel compact
cell m114  5 fill 701       -1  95lu4 -95u   % fuel compact
cell m12   5 fill 803        1  95l   -95u
cell m13   5 fill 805                  95u
cell m14   5 fill 805                 -95l

cell o110  8 fill 702       -1  95l   -95lu1 % fuel compact
cell o111  8 fill 702       -1  95lu1 -95lu2 % fuel compact
cell o112  8 fill 702       -1  95lu2 -95lu3 % fuel compact
cell o113  8 fill 702       -1  95lu3 -95lu4 % fuel compact
cell o114  8 fill 702       -1  95lu4 -95u % fuel compact
cell o12   8 fill 803        1  95l   -95u
cell o13   8 fill 805                  95u
cell o14   8 fill 805                 -95l

% Coolant channel:

cell 20 6 fill 807       -7
cell 21 6 fill 803        7   95l -95u
cell 22 6 fill 805        7   95u
cell 23 6 fill 805        7       -95l

% Central control pin

cell 29 7 fill 805   -9        -95l
cell 30 7 fill 804   -9    95l -97l
cell 31 7 fill 809   -9    97l
cell 32 7 fill 805    9    95u
cell 33 7 fill 805    9        -95l
cell 34 7 fill 803    9    95l -95u

cell m29 27 fill 805   -9        -95l
cell m30 27 fill 804   -9    95l -97lh
cell m31 27 fill 809   -9    97lh
cell m32 27 fill 805    9    95u
cell m33 27 fill 805    9        -95l
cell m34 27 fill 803    9    95l -95u

particle 952
     Gd_bpI1   0.0100 % kernel at 100 microns
     buffer 0.0118 % graphite at 18 microns
     PyC1   0.0141 % different graphite at 23 microns
matrix_pin

particle 954
     Gd_bpI2   0.0100 % kernel at 100 microns
     buffer 0.0118 % graphite at 18 microns
     PyC1   0.0141 % different graphite at 23 microns
matrix_pin

particle 955
     Gd_bpI3   0.0100 % kernel at 100 microns
     buffer 0.0118 % graphite at 18 microns
     PyC1   0.0141 % different graphite at 23 microns
matrix_pin

particle 961
     Gd_bpO1   0.0100 % kernel at 100 microns
     buffer 0.0118 % graphite at 18 microns
     PyC1   0.0141 % different graphite at 23 microns
matrix_pin

particle 963
     Gd_bpO2   0.0100 % kernel at 100 microns
     buffer 0.0118 % graphite at 18 microns
     PyC1   0.0141 % different graphite at 23 microns
matrix_pin

particle 964
     Gd_bpO3   0.0100 % kernel at 100 microns
     buffer 0.0118 % graphite at 18 microns
     PyC1   0.0141 % different graphite at 23 microns
matrix_pin

particle 965
     Gd_bpO3   0.0100 % kernel at 100 microns
     buffer 0.0118 % graphite at 18 microns
     PyC1   0.0141 % different graphite at 23 microns
matrix_pin

cell i150  2 fill 754       -2  95l   -95lu1 % burnable compact
cell i151  2 fill 754       -2  95lu1 -95lu2 % burnable compact
cell i152  2 fill 754       -2  95lu2 -95lu3 % burnable compact
cell i153  2 fill 754       -2  95lu3 -95lu4 % burnable compact
cell i154  2 fill 754       -2  95lu4 -95u   % burnable compact
cell i16   2 fill 803        2  95l   -95u
cell i17   2 fill 805           95u
cell i18   2 fill 805                 -95l

cell o150  9 fill 764       -2  95l   -95lu1 % burnable compact
cell o151  9 fill 764       -2  95lu1 -95lu2 % burnable compact
cell o152  9 fill 764       -2  95lu2 -95lu3 % burnable compact
cell o153  9 fill 764       -2  95lu3 -95lu4 % burnable compact
cell o154  9 fill 764       -2  95lu4 -95u   % burnable compact
cell o16   9 fill 803        2  95l   -95u
cell o17   9 fill 805            95u
cell o18   9 fill 805                 -95l

% plain graphite region
cell 36  1 fill 803            95l -95u
cell 37  1 fill 805            95u
cell 38  1 fill 805                -95l

% Moderator region:

cell 40  4 fill 802      -3   95l -95u % 0.95 cm pin
cell 41a 4 fill 810    3 -4   95l -95u % 0.05 cm coating
cell 41b 4 fill 806    4 -5   95l -95u % 0.05 cm shell
cell 42  4 fill 803    5      95l -95u
cell 43  4 fill 806      -5   96l -95l % 0.05 cm shell
cell 44  4 fill 806      -5   95u -96u % 0.05 cm shell
cell 45  4 fill 805       5   96l -95l % 0.05 cm shell
cell 46  4 fill 805       5   95u -96u % 0.05 cm shell
cell 47  4 fill 805           96u
cell 48  4 fill 805               -96l

% --- cylinders
surf  1 cyl 0.0 0.0 0.850  0.000000 240
surf  2 cyl 0.0 0.0 0.250  0.000000 240
surf  3 cyl 0.0 0.0 0.693  0.000000 240
surf  4 cyl 0.0 0.0 0.700  0.000000 240
surf  5 cyl 0.0 0.0 0.750  0.000000 240
surf  7 cyl 0.0 0.0 0.600  0.000000 240
surf  9 cyl 0.0 0.0 0.950  0.000000 240

% --- axial dimensions
surf 95l pz  20
surf 95lu1 pz  60.0
surf 95lu2 pz  100.0
surf 95lu3 pz  140.0
surf 95lu4 pz  180.0
surf 95u pz  220
surf 96l pz  19.95
surf 96u pz  220.05
surf 97l pz  220
surf 97lh pz  220

% --- hexprism assembly
surf 30 hexxprism 0.0 0.0 10.4000 0 240

% --- Assembly lattice

lat 26 3  0.0 0.0 13 13   2.000000                 % regular fuel assembly with rods - central
    1 1 1 1 1 1 1 1 1 1 1 1 1
    1 1 1 1 1 1 3 6 3 3 6 3 1
    1 1 1 1 1 6 4 3 6 3 4 6 1
    1 1 1 1 3 3 6 3 3 6 3 3 1
    1 1 1 3 6 3 2 6 2 3 6 3 1
    1 1 6 3 3 6 3 3 6 3 3 6 1
    1 3 4 6 2 3 6 3 2 6 4 3 1
    1 6 3 3 6 3 3 6 3 3 6 1 1
    1 3 6 3 2 6 2 3 6 3 1 1 1
    1 3 3 6 3 3 6 3 3 1 1 1 1
    1 6 4 3 6 3 4 6 1 1 1 1 1
    1 3 6 3 3 6 3 1 1 1 1 1 1
    1 1 1 1 1 1 1 1 1 1 1 1 1

cell 67 19 fill 26  -30
cell 167 19 fill 803  30

lat 13 3  0.0 0.0 13 13   2.000000                 % regular fuel assembly - inner
    1 1 1 1 1 1 1 1 1 1 1 1 1
    1 1 1 1 1 1 2 6 3 3 6 2 1
    1 1 1 1 1 6 4 3 6 3 4 6 1
    1 1 1 1 3 3 6 3 3 6 3 3 1
    1 1 1 3 6 3 2 6 2 3 6 3 1
    1 1 6 3 3 6 3 3 6 3 3 6 1
    1 2 4 6 2 3 6 3 2 6 4 2 1
    1 6 3 3 6 3 3 6 3 3 6 1 1
    1 3 6 3 2 6 2 3 6 3 1 1 1
    1 3 3 6 3 3 6 3 3 1 1 1 1
    1 6 4 3 6 3 4 6 1 1 1 1 1
    1 2 6 3 3 6 2 1 1 1 1 1 1
    1 1 1 1 1 1 1 1 1 1 1 1 1

cell 60 14 fill 13  -30
cell 160 14 fill 803  30

lat 10 3  0.0 0.0 13 13   2.000000                 % regular fuel assembly with rods - middle
    1 1 1 1 1 1 1 1 1 1 1 1 1
    1 1 1 1 1 1 5 6 5 5 6 5 1
    1 1 1 1 1 6 4 5 6 5 4 6 1
    1 1 1 1 5 5 6 5 5 6 5 5 1
    1 1 1 5 6 5 2 6 2 5 6 5 1
    1 1 6 5 5 6 5 5 6 5 5 6 1
    1 5 4 6 2 5 7 5 2 6 4 5 1
    1 6 5 5 6 5 5 6 5 5 6 1 1
    1 5 6 5 2 6 2 5 6 5 1 1 1
    1 5 5 6 5 5 6 5 5 1 1 1 1
    1 6 4 5 6 5 4 6 1 1 1 1 1
    1 5 6 5 5 6 5 1 1 1 1 1 1
    1 1 1 1 1 1 1 1 1 1 1 1 1

cell 61 15 fill 10  -30
cell 161 15 fill 803  30

lat 12 3  0.0 0.0 13 13   2.000000                 % regular fuel assembly with rods - middle core - 2nd type of CR
    1 1 1 1 1 1 1 1 1 1 1 1 1
    1 1 1 1 1 1 5 6 5 5 6 5 1
    1 1 1 1 1 6 4 5 6 5 4 6 1
    1 1 1 1 5 5 6 5 5 6 5 5 1
    1 1 1 5 6 5 2 6 2 5 6 5 1
    1 1 6 5 5 6 5 5 6 5 5 6 1
    1 5 4 6 2 5 27 5 2 6 4 5 1
    1 6 5 5 6 5 5 6 5 5 6 1 1
    1 5 6 5 2 6 2 5 6 5 1 1 1
    1 5 5 6 5 5 6 5 5 1 1 1 1
    1 6 4 5 6 5 4 6 1 1 1 1 1
    1 5 6 5 5 6 5 1 1 1 1 1 1
    1 1 1 1 1 1 1 1 1 1 1 1 1

cell 66 25 fill 12  -30
cell 166 25 fill 803  30

lat 11 3  0.0 0.0 13 13   2.000000                 % regular fuel assembly without rod and burnable poisons - outer core
    1 1 1 1 1 1 1 1 1 1 1 1 1
    1 1 1 1 1 1 8 6 8 8 6 8 1
    1 1 1 1 1 6 4 8 6 8 4 6 1
    1 1 1 1 8 8 6 8 8 6 8 8 1
    1 1 1 8 6 8 2 6 2 8 6 8 1
    1 1 6 8 8 6 8 8 6 8 8 6 1
    1 8 4 6 2 8 6 8 2 6 4 8 1
    1 6 8 8 6 8 8 6 8 8 6 1 1
    1 8 6 8 2 6 2 8 6 8 1 1 1
    1 8 8 6 8 8 6 8 8 1 1 1 1
    1 6 4 8 6 8 4 6 1 1 1 1 1
    1 8 6 8 8 6 8 1 1 1 1 1 1
    1 1 1 1 1 1 1 1 1 1 1 1 1

cell 62 16 fill 11  -30
cell 162 16 fill 803  30

% control drum region (currently plain)
cell 164 17 fill 807 -30
cell 165 17 fill 811  30

% reflector region
cell 63 18 fill 811  -30
cell 163 18 fill 811  30

lat 50  2  0.0 0.0 17 17 20.8
18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18
18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18
18 18 18 18 18 18 18 18 18 18 18 17 18 18 18 18 18
18 18 18 18 18 18 18 18 17 16 16 16 16 17 18 18 18
18 18 18 18 18 18 18 16 16 15 15 15 16 16 18 18 18
18 18 18 18 18 17 16 15 25 25 25 25 15 16 17 18 18
18 18 18 18 18 16 15 25 14 14 14 25 15 16 18 18 18
18 18 18 18 16 15 25 14 14 14 14 25 15 16 18 18 18
18 18 18 17 16 25 14 14 14 14 14 25 16 17 18 18 18
18 18 18 16 15 25 14 14 14 14 25 15 16 18 18 18 18
18 18 18 16 15 25 14 14 14 25 15 16 18 18 18 18 18
18 18 17 16 15 25 25 25 25 15 16 17 18 18 18 18 18
18 18 18 16 16 15 15 15 16 16 18 18 18 18 18 18 18
18 18 18 17 16 16 16 16 17 18 18 18 18 18 18 18 18
18 18 18 18 18 17 18 18 18 18 18 18 18 18 18 18 18
18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18
18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18

surf  11 cyl 0.0 0.0 121   0.0 240

cell 170 0 fill 50 -11

% -----------DRUMS DEFINITTION---------------------------------------------------------------------------------------

 731 732 733 734 735 736 737 738 739 740 741 742
cell 180 0 fill       731 -731
cell 181 0 fill       732 -732
cell 182 0 fill       733 -733
cell 183 0 fill       734 -734
cell 184 0 fill       735 -735
cell 185 0 fill       736 -736
cell 186 0 fill       737 -737
cell 187 0 fill       738 -738
cell 188 0 fill       739 -739
cell 189 0 fill       740 -740
cell 190 0 fill       741 -741
cell 191 0 fill       742 -742

surf 731 cyl 104.0000   0.00 10.0000   0.00 240.00
surf 831 cyl 104.0000   0.00 9.0000   0.00 240.00
surf 771 plane 1.0000   0.00 0.0 110.36
surf 871 plane 1.0000  -0.00 0.0  97.64
cell 801  731 fill 811   -731   -771
cell 802  731 fill 809    831  -731  771
cell 803  731 fill 811   -831   771
surf 732 cyl 52.0000  90.07 10.0000   0.00 240.00
surf 832 cyl 52.0000  90.07 9.0000   0.00 240.00
surf 772 plane 1.0000   1.73 0.0 220.73
surf 872 plane 1.0000   1.73 0.0 195.27
cell 806  732 fill 811   -732   -772
cell 807  732 fill 809    832  -732  772
cell 808  732 fill 811   -832   772
surf 733 cyl -52.0000  90.07 10.0000   0.00 240.00
surf 833 cyl -52.0000  90.07 9.0000   0.00 240.00
surf 773 plane 1.0000  -1.73 0.0 -220.73
surf 873 plane 1.0000  -1.73 0.0 -195.27
cell 811  733 fill 811   -733   773
cell 812  733 fill 809    833  -733  -773
cell 813  733 fill 811   -833   -773
surf 734 cyl -104.0000   0.00 10.0000   0.00 240.00
surf 834 cyl -104.0000   0.00 9.0000   0.00 240.00
surf 774 plane 1.0000  -0.00 0.0 -110.36
surf 874 plane 1.0000   0.00 0.0 -97.64
cell 816  734 fill 811   -734   774
cell 817  734 fill 809    834  -734  -774
cell 818  734 fill 811   -834   -774
surf 735 cyl -52.0000 -90.07 10.0000   0.00 240.00
surf 835 cyl -52.0000 -90.07 9.0000   0.00 240.00
surf 775 plane 1.0000   1.73 0.0 -220.73
surf 875 plane 1.0000   1.73 0.0 -195.27
cell 821  735 fill 811   -735   775
cell 822  735 fill 809    835  -735  -775
cell 823  735 fill 811   -835   -775
surf 736 cyl 52.0000 -90.07 10.0000   0.00 240.00
surf 836 cyl 52.0000 -90.07 9.0000   0.00 240.00
surf 776 plane 1.0000  -1.73 0.0 220.73
surf 876 plane 1.0000  -1.73 0.0 195.27
cell 826  736 fill 811   -736   -776
cell 827  736 fill 809    836  -736  776
cell 828  736 fill 811   -836   776
surf 737 cyl 93.6000  54.04 10.0000   0.00 240.00
surf 837 cyl 93.6000  54.04 9.0000   0.00 240.00
surf 777 plane 1.0000   0.58 0.0 132.15
surf 877 plane 1.0000   0.58 0.0 117.45
cell 831  737 fill 811   -737   -777
cell 832  737 fill 809    837  -737  777
cell 833  737 fill 811   -837   777
surf 738 cyl 0.0000 108.08 10.0000   0.00 240.00
surf 838 cyl 0.0000 108.08 9.0000   0.00 240.00
surf 778 plane 0.0000   1.00 0.0 114.44
surf 878 plane 1.0000 895647891448936.75 0.0 91101729311334400.00
cell 836  738 fill 811   -738   -778
cell 837  738 fill 809    838  -738  778
cell 838  738 fill 811   -838   778
surf 739 cyl -93.6000  54.04 10.0000   0.00 240.00
surf 839 cyl -93.6000  54.04 9.0000   0.00 240.00
surf 779 plane 1.0000  -0.58 0.0 -132.15
surf 879 plane 1.0000  -0.58 0.0 -117.45
cell 841  739 fill 811   -739   779
cell 842  739 fill 809    839  -739  -779
cell 843  739 fill 811   -839   -779
surf 740 cyl -93.6000 -54.04 10.0000   0.00 240.00
surf 840 cyl -93.6000 -54.04 9.0000   0.00 240.00
surf 780 plane 1.0000   0.58 0.0 -132.15
surf 880 plane 1.0000   0.58 0.0 -117.45
cell 846  740 fill 811   -740   780
cell 847  740 fill 809    840  -740  -780
cell 848  740 fill 811   -840   -780
surf 741 cyl -0.0000 -108.08 10.0000   0.00 240.00
surf 841 cyl -0.0000 -108.08 9.0000   0.00 240.00
surf 781 plane 1.0000 895647891448936.75 0.0 -102501465868115968.00
surf 881 plane 1.0000 895647891448936.38 0.0 -91101729311334368.00
cell 851  741 fill 811   -741   781
cell 852  741 fill 809    841  -741  -781
cell 853  741 fill 811   -841   -781
surf 742 cyl 93.6000 -54.04 10.0000   0.00 240.00
surf 842 cyl 93.6000 -54.04 9.0000   0.00 240.00
surf 782 plane 1.0000  -0.58 0.0 132.15
surf 882 plane 1.0000  -0.58 0.0 117.45
cell 856  742 fill 811   -742   -782
cell 857  742 fill 809    842  -742  782
cell 858  742 fill 811   -842   782

cell 171 0 outside  11

set ures 1

% -----------------------------------------------------------------------------------
% Material data:

% materials

mat fuel0   -10.7440 burn 1  tmp 725.0   rgb 200 0 0
  92235.01c    6.8794e-02
  92238.01c    2.7604e-01
 6012.01c    1.3793e-01
  8016.01c    5.1724e-01

mat fuel1   -10.7440 burn 1  tmp 725.0   rgb 230 0 0
  92235.01c    6.8794e-02
  92238.01c    2.7604e-01
 6012.01c    1.3793e-01
  8016.01c    5.1724e-01

mat fuel2   -10.7440 burn 1  tmp 725.0   rgb 255 0 0
  92235.01c    6.8794e-02
  92238.01c    2.7604e-01
 6012.01c    1.3793e-01
  8016.01c    5.1724e-01

mat Gd_bpI1 -7.0395  burn 1  tmp 725.0  rgb 0 0 200
 64152.01c   2.43139E-05
 64154.01c   2.61576E-04
 64155.01c   1.76435E-03
 64156.01c   2.42465E-03
 64157.01c   1.84189E-03
 64158.01c   2.90497E-03
 64160.01c   2.52445E-03
 8016.01c   3.52386E-02

mat Gd_bpI2 -7.0395 burn 1  tmp 725.0  rgb 0 0 250
 64152.01c   2.43139E-05
 64154.01c   2.61576E-04
 64155.01c   1.76435E-03
 64156.01c   2.42465E-03
 64157.01c   1.84189E-03
 64158.01c   2.90497E-03
 64160.01c   2.52445E-03
 8016.01c   3.52386E-02

mat Gd_bpI3 -7.0395 burn 1  tmp 725.0  rgb 0 0 200
64152.01c   2.43139E-05
64154.01c   2.61576E-04
64155.01c   1.76435E-03
64156.01c   2.42465E-03
64157.01c   1.84189E-03
64158.01c   2.90497E-03
64160.01c   2.52445E-03
8016.01c   3.52386E-02

mat Gd_bpO1 -7.0395 burn 1  tmp 725.0  rgb 0 0 250
64152.01c   2.43139E-05
64154.01c   2.61576E-04
64155.01c   1.76435E-03
64156.01c   2.42465E-03
64157.01c   1.84189E-03
64158.01c   2.90497E-03
64160.01c   2.52445E-03
8016.01c   3.52386E-02

mat Gd_bpO2 -7.0395 burn 1  tmp 725.0  rgb 0 0 200
64152.01c   2.43139E-05
64154.01c   2.61576E-04
64155.01c   1.76435E-03
64156.01c   2.42465E-03
64157.01c   1.84189E-03
64158.01c   2.90497E-03
64160.01c   2.52445E-03
8016.01c   3.52386E-02

mat Gd_bpO3 -7.0395 burn 1  tmp 725.0  rgb 0 0 250
64152.01c   2.43139E-05
64154.01c   2.61576E-04
64155.01c   1.76435E-03
64156.01c   2.42465E-03
64157.01c   1.84189E-03
64158.01c   2.90497E-03
64160.01c   2.52445E-03
8016.01c   3.52386E-02

mat boron_ctr -2.4700 tmp 725.0  rgb 0 0 250 % highly enriched B4C
 5010.01c 0.768
 5011.01c 0.032
 6012.01c 0.20

mat coolant    -3.6500e-03  tmp 725.0 rgb 0 0 100
 2004.01c  1.0

mat shell_mod  -7.0550  tmp 725.0   rgb 33 233 133  % density at 900K - FeCrAl
24050.01c  8.6800E-03
24052.01c  1.6762E-01
24053.01c  1.8980E-02
24054.01c  4.7200E-03
26054.01c  4.3790E-02
26056.01c  6.9249E-01
26057.01c  1.6610E-02
26058.01c  2.1140E-03
13027.01c  4.5000E-02

% --- Carbon buffer layer:

mat buffer  -1.0400 moder grph 6012 tmp 725.0  rgb 0 200 200
 6012.01c    1.0

% --- Pyrolytic carbon layer:

mat PyC1     -1.8820 moder grph 6012 tmp 725.0   rgb 0 200 200
 6012.01c    1.0

% --- Pyrolytic carbon layer:

mat PyC2     -1.8820 moder grph 6012 tmp 725.0 rgb 0 200 200
 6012.01c    1.0

% --- Silicon carbide layer:

mat SiC     -3.1710  tmp 725.0 rgb 0 100 0
14028.01c    0.4611
14029.01c    0.0234
14030.01c    0.0154
 6012.01c     0.5

mat Nb   -8.4132  tmp 725.0   rgb 100 0 100   % Nobium
41093.01c  -0.99
40090.01c  -5.132E-03
40091.01c  -1.107E-03
40092.01c  -1.674E-03
40094.01c  -1.660E-03
40096.01c  -2.618E-04

mat Cr   -7.1900  tmp 725.0   rgb 100 0 200   % Chromium
24050.01c  -4.345e-2
24052.01c  -83.789e-2
24053.01c  -9.501e-2
24054.01c  -2.365e-2

% --- Graphite matrix:

mat matrix_pin       -1.8060 moder grph 6012  tmp 725.0  rgb 220 220 220
 6012.01c    1

mat matrix       -1.8060 moder grph 6012  tmp 725.0 rgb 200 200 200
 6012.01c  0.9999997
 5010.01c  0.0000003

mat moderator   -4.0850 moder h-yh2 1001 moder y-yh2 39089 tmp 725.0   rgb 73 64 171
39089.01c  0.357142857
1001.01c   0.642857143

mat Refl        -2.7987  moder beo 4009 tmp 725.0   rgb 100 220 200  % GREY
 4009.01c    0.5
 8016.01c    0.5

% -----------------------------------------------------------------------------

therm grph    grph.84t
therm  beo     be-beo.84t
therm h-yh2   h-yh2.84t
therm y-yh2   y-yh2.84t

% Calculation parameters:

% -----------------------------------------------------------------------------

% --- Geometry plot:
plot 3 10000 10000   120.0
plot 2 10000 10000   0.2

% --- Libraries:

% Add your own libraries here
set acelib "sss_endfb8_serpent_yan.xsdir"  % ACE library for cross-sections
set declib "sss_endfb7.dec" % Decay library
set nfylib "sss_endfb7.nfy" % Neutron fission yield library

% --- Boundary conditions:

set bc 1

% --- Power density

set power 20000000.0  % W

% --- Histories:
set pop 10000 300 30

set xenon 1
set gcu 700 701 702 754 764 802 803 804 805 806 807 809 810 811

set nfg  11  8.00000e-08 1.80000e-07 6.25000e-07 1.30000e-06 4.00000e-06
             1.48730e-04 9.11800e-03 1.83000e-01 5.00000e-01 1.35300e+00

% -----------------------------------------------------------------------------

Note on LFS files linked to Serpent Model

Git Large File Storage (LFS) is used for the following files:


PART_U901_PF40_R85
PART_U902_PF40_R85
PART_U903_PF40_R85
PART_U904_PF40_R85

These files define the distribution, and radius of the TRISO and burnable poison particles considering specific packing fraction. Make sure to install git lfs, then fetch and pull these files to be able to run the Serpent inputs.

Griffin Model

Griffin utilizes the cross-sections in the XML-format file in conjunction with the mesh file. The 3D whole-core mesh is constructed using MOOSE's Reactor module, ensuring consistency between geometric representations in the mesh file and Serpent-2. Griffin solves the neutron transport equation using discontinuous finite element (DFEM) with SN transport and CMFD acceleration, employing on-the-fly coarse mesh generation for CMFD.

Note: Efforts were dedicated to simplifying the 3D whole-core GC-MR mesh to reduce computational demands. Special attention was given to avoid too coarse mesh sizes, particularly in critical regions such as the radial reflector and control drum areas, ensuring proper convergence of DFEM-SN with CMFD.

#####################################################################################################
# Griffin steady state Model of whole-core Gas-cooled Microreactor
# DFEM-SN with CMFD acceleration
# If using or referring to this model, please cite as explained in
# https://mooseframework.inl.gov/virtual_test_bed/citing.html
#####################################################################################################

[Mesh]
  [fmg]
    type = FileMeshGenerator
    file = 'mesh/Griffin_mesh_in.e'
  []

  [fmg_id]
    type = SubdomainExtraElementIDGenerator
    input = fmg
    subdomains = '10 100 101 102 103 200 201 400 401 4000 4001 40000 40001 300 301 600 602 603 604 1000 1003 19000 29000 39000 49000 59000 19003 29003 39003 49003 59003 19900 29900 39900 49900 59900 19903 29903 39903 49903 59903 1777 1773 250'
    extra_element_id_names = 'material_id'
    extra_element_ids = '803 802 802 810 806 807 807 700 700 701 701 702 702 807 807 811 811 809 807 805 805 764 764 764 764 764 764 764 764 764 764 754 754 754 754 754 754 754 754 754 754 809 809 811'
  []

  [coarse_mesh]
    type = GeneratedMeshGenerator
    dim = 3
    nx = 20
    ny = 20
    nz = 20
    xmin = -1.21
    xmax = 1.21
    ymin = -1.21
    ymax = 1.21
    zmin = 0.0
    zmax = 2.4
  []

  [assign_coarse_id]
    type = CoarseMeshExtraElementIDGenerator
    input = fmg_id
    coarse_mesh = coarse_mesh
    extra_element_id_name = coarse_element_id
  []
[]

[Executioner]
  type = SweepUpdate
  # Richardson iterations
  richardson_abs_tol = 1e-8
  richardson_rel_tol = 1e-8
  richardson_value = eigenvalue
  richardson_max_its = 1000
  inner_solve_type = GMRes
  max_inner_its = 20
  fixed_point_max_its = 1
  custom_rel_tol = 1e-6
  force_fixed_point_solve = true

  #CMFD  acceletation
  cmfd_acceleration = true
  coarse_element_id = coarse_element_id
  diffusion_eigen_solver_type = newton
  prolongation_type = multiplicative
  max_diffusion_coefficient = 1
[]

[Debug]
  check_boundary_coverage = false
  print_block_volume = false
  show_actions = false
[]

[AuxVariables]
  [Tf]
    initial_condition = 725.0
    order = CONSTANT
    family = MONOMIAL
  []
[]

[TransportSystems]
  particle = neutron
  equation_type = eigenvalue
  G = 11
  VacuumBoundary = 'top_boundary bottom_boundary side'
  ReflectingBoundary = 'cut_surf'

  [SN]
    scheme = DFEM-SN
    family = MONOMIAL
    order = FIRST
    AQtype = Gauss-Chebyshev
    NPolar = 2
    NAzmthl = 3
    NA = 2
    n_delay_groups = 6
    sweep_type = asynchronous_parallel_sweeper
    using_array_variable = true
    collapse_scattering = true
    hide_angular_flux = true
  []
[]

[GlobalParams]
  library_file = '../ISOXML/XS_Griffin.xml'
  library_name = XS_Griffin
  isotopes = 'pseudo'
  densities = 1.0
  is_meter = true
  plus = true
  dbgmat = false
  grid_names = 'Tfuel'
  grid_variables = 'Tf'
[]

[PowerDensity]
  power = 20000000
  power_density_variable = power_density
[]

[Materials]
  [mod]
    type = CoupledFeedbackMatIDNeutronicsMaterial
    block = '10 100 101 102 103 200 201 400 401 4000 4001 40000 40001 300 301 600 602 603 604 1000 1003 19000 29000 39000 49000 59000 19003 29003 39003 49003 59003 19900 29900 39900 49900 59900 19903 29903 39903 49903 59903 1777 1773 250'
  []
[]

[UserObjects]
  [axial_power_inner]
    type = LayeredIntegral
    variable = power_density
    direction = z
    num_layers = 24
    block = '400 401 4000 4001 40000 40001 1000 1003'
  []
[]

[AuxKernels]
  [axial_power_inner]
    type = SpatialUserObjectAux
    variable = axial_power_inner
    execute_on = timestep_end
    user_object = axial_power_inner
  []
[]

[AuxVariables]
  [axial_power_inner]
    order = CONSTANT
    family = MONOMIAL
  []
[]

[VectorPostprocessors]
  [axial_power_inner_elm]
    type = ElementValueSampler
    variable = axial_power_inner
    sort_by = z
    execute_on = timestep_end
  []
[]

[Outputs]
  csv = true
  exodus = true
  perf_graph = true
[]

Run Commands

The mesh file can be generated using the –mesh-only option as such:

mpirun -np <number_of_cores> /path/to/griffin-opt -i mesh_input.i --mesh-only

We can then execute the simulation as follows:

mpirun -np <number_of_cores> /path/to/griffin-opt -i Griffin_steady_state.i

The Griffin code is a component of the blue_crab code package, so griffin-opt can be replaced with the BlueCrab executable : blue_crab-opt.

Results

Segmentations of the whole-core GC-MR mesh utilized in the analyses, employing DFEM-SN with CMFD and an 11-energy-group structure, are illustrated in Figure 6. The simulation was conducted for 1/6 of the core with reflected boundary conditions on the cut surfaces and vacuum boundaries for the remaining surfaces. The resulting k-eff value for 2 polar angles and 3 azimuthal angles in the SN was determined as 1.051468, reasonably aligning with the k-eff value obtained from the Monte Carlo Serpent-2 code, which is 1.054670 ± 16 pcm. It was determined that an even closer alignment could be achieved with higher numbers of polar and azimuthal angles. Figure 7 presents a comparison between the normalized axial power distribution computed by both Serpent-2 and Griffin for DFEM-SN (n_polar=2,n_azimuthal=3) with CMFD.

Figure 6: 1/6 GCMR core with reflective boundary condition

Figure 7: Normalized axial power distribution computed by both Serpent-2 and Griffin

References

Emily Shemon, Yinbin Miao, Shikhar Kumar, Kun Mo, Yeon Sang Jung, Aaron Oaks, Scott Richards, Guillaume Giudicelli, Logan Harbour, and Roy Stogner. Moose reactor module: an open-source capability for meshing nuclear reactor geometries. Nuclear Science and Engineering, 0(0):1–25, 2023. URL: https://doi.org/10.1080/00295639.2022.2149231, arXiv:https://doi.org/10.1080/00295639.2022.2149231, doi:10.1080/00295639.2022.2149231.

@Article{shemon2023reactor,
    author = "Shemon, Emily and Miao, Yinbin and Kumar, Shikhar and Mo, Kun and Jung, Yeon Sang and Oaks, Aaron and Richards, Scott and Giudicelli, Guillaume and Harbour, Logan and Stogner, Roy",
    title = "MOOSE Reactor Module: An Open-Source Capability for Meshing Nuclear Reactor Geometries",
    journal = "Nuclear Science and Engineering",
    volume = "0",
    number = "0",
    pages = "1-25",
    year = "2023",
    doi = "10.1080/00295639.2022.2149231",
    URL = "https://doi.org/10.1080/00295639.2022.2149231",
    eprint = "https://doi.org/10.1080/00295639.2022.2149231"
}

(microreactors/gcmr/core/MESH/Griffin_mesh.i)

#####################################################################################################
# Whole-core mesh for a Gas-cooled Microreactor
# If using or referring to this model, please cite as explained in
# https://mooseframework.inl.gov/virtual_test_bed/citing.html
#####################################################################################################

[Mesh]
  [YH_pin]
    type = PolygonConcentricCircleMeshGenerator
    num_sides = 6
    num_sectors_per_side = '2 2 2 2 2 2'
    background_intervals = 1
    background_block_ids = '10'
    polygon_size = 1
    polygon_size_style ='apothem'
    ring_radii = '0.693 0.7 0.75'
    ring_intervals = '2 1 1'
    ring_block_ids = '101 100 102 103'
  []

  [Coolant_hole]
    type = PolygonConcentricCircleMeshGenerator
    num_sides = 6
    num_sectors_per_side = '2 2 2 2 2 2'
    background_intervals = 1
    background_block_ids = '10'
    polygon_size = 1
    polygon_size_style ='apothem'
    ring_radii = '0.6'
    ring_intervals = '2'
    ring_block_ids = '201 200'
  []

  [Control_hole]
    type = PolygonConcentricCircleMeshGenerator
    num_sides = 6
    num_sectors_per_side = '2 2 2 2 2 2'
    background_intervals = 1
    background_block_ids = '10'
    polygon_size = 1
    polygon_size_style ='apothem'
    ring_radii = '0.95'
    ring_intervals = '2'
    ring_block_ids = '301 300'
  []

  [TRISO_fuel_in]
    type = PolygonConcentricCircleMeshGenerator
    num_sides = 6
    num_sectors_per_side = '2 2 2 2 2 2'
    background_intervals = 1
    background_block_ids = '10'
    polygon_size = 1
    polygon_size_style ='apothem'
    ring_radii = '0.85'
    ring_intervals = '2'
    ring_block_ids = '401 400'
  []

  [TRISO_fuel_mid]
    type = PolygonConcentricCircleMeshGenerator
    num_sides = 6
    num_sectors_per_side = '2 2 2 2 2 2'
    background_intervals = 1
    background_block_ids = '10'
    polygon_size = 1
    polygon_size_style ='apothem'
    ring_radii = '0.85'
    ring_intervals = '2'
    ring_block_ids = '4001 4000'
  []

  [TRISO_fuel_out]
    type = PolygonConcentricCircleMeshGenerator
    num_sides = 6
    num_sectors_per_side = '2 2 2 2 2 2'
    background_intervals = 1
    background_block_ids = '10'
    polygon_size = 1
    polygon_size_style ='apothem'
    ring_radii = '0.85'
    ring_intervals = '2'
    ring_block_ids = '40001 40000'
  []

  [Poison_LBP0]
    type = PolygonConcentricCircleMeshGenerator
    num_sides = 6
    num_sectors_per_side = '2 2 2 2 2 2'
    background_intervals = 1
    background_block_ids = '10'
    polygon_size = 1
    polygon_size_style ='apothem'
    ring_radii = '0.25'
    ring_intervals = '2'
    ring_block_ids = '501 500'
  []

  [Poison_LBP1]
    type = PolygonConcentricCircleMeshGenerator
    num_sides = 6
    num_sectors_per_side = '2 2 2 2 2 2'
    background_intervals = 1
    background_block_ids = '10'
    polygon_size = 1
    polygon_size_style ='apothem'
    ring_radii = '0.25'
    ring_intervals = '2'
    ring_block_ids = '5001 5000'
  []

  [centralFA]
    type = PatternedHexMeshGenerator
    inputs = 'YH_pin Coolant_hole  TRISO_fuel_in Poison_LBP0'
    #           0          1            2           3
    hexagon_size = 10.4
    pattern =
                      '3  1  2  2  1  3;
                    1  0  2  1  2  0  1;
                  2  2  1  2  2  1  2  2;
                2  1  2  3  1  3  2  1  2;
              1  2  2  1  2  2  1  2  2  1;
             3  0  1  3  2  1  2  3  1  0  3;
               1  2  2  1  2  2  1  2  2  1;
                2  1  2  3  1  3  2  1  2;
                 2  2  1  2  2  1  2  2;
                  1  0  2  1  2  0  1;
                    3  1  2  2  1  3'

  background_block_id = 10
  background_intervals = 1
  []

  [Innercore]
    type = PatternedHexMeshGenerator
    inputs = 'YH_pin Coolant_hole  TRISO_fuel_in Poison_LBP0'
    #           0          1            2           3
    hexagon_size = 10.4
    pattern =
                      '3  1  2  2  1  3;
                    1  0  2  1  2  0  1;
                  2  2  1  2  2  1  2  2;
                2  1  2  3  1  3  2  1  2;
              1  2  2  1  2  2  1  2  2  1;
            3  0  1  3  2  1  2  3  1  0  3;
              1  2  2  1  2  2  1  2  2  1;
               2  1  2  3  1  3  2  1  2;
                2  2  1  2  2  1  2  2;
                 1  0  2  1  2  0  1;
                  3  1  2  2  1  3'


  background_block_id = 10
  background_intervals = 1
  []

  [dummy]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    num_sectors_per_side= '2 2 2 2 2 2'
    hexagon_size = 10.4
    background_intervals = 1
    background_block_ids = '700'
  []

  [Outercore]
    type = PatternedHexMeshGenerator
    inputs = 'YH_pin Coolant_hole  Control_hole  Poison_LBP1   TRISO_fuel_mid'
    #           0          1            2             3            4
    hexagon_size = 10.4
    pattern =
                      '4  1  4  4  1  4;
                    1  0  4  1  4  0   1;
                  4  4  1  4  4  1  4   4;
                4  1  4  3  1  3  4  1   4;
              1  4  4  1  4  4  1  4  4   1;
             4  0  1  3  4  2  4  3  1  0  4;
              1  4  4  1  4  4  1  4  4  1;
               4  1  4  3  1  3  4  1  4;
                4  4  1  4  4  1  4  4;
                 1  0  4  1  4  0  1;
                  4  1  4  4  1  4'

    background_block_id = 10
    background_intervals = 1
  []

  [Outercore2]
    type = PatternedHexMeshGenerator
    inputs = 'YH_pin Coolant_hole  Control_hole  Poison_LBP1   TRISO_fuel_mid'
    #           0          1            2             3             4
    hexagon_size = 10.4
    pattern =
                      '4  1  4  4  1  4;
                    1  0  4  1  4  0  1;
                  4  4  1  4  4  1  4  4;
                4  1  4  3  1  3  4  1  4;
              1  4  4  1  4  4  1  4  4  1;
             4  0  1  3  4  2  4  3  1  0  4;
              1  4  4  1  4  4  1  4  4  1;
               4  1  4  3  1  3  4  1  4;
                4  4  1  4  4  1  4  4;
                 1  0  4  1  4  0  1;
                  4  1  4  4  1  4'

    background_block_id = 10
    background_intervals = 1
  []

  [Innercore2]
    type = PatternedHexMeshGenerator
    inputs = 'YH_pin Coolant_hole  Poison_LBP1   TRISO_fuel_out'
    #           0          1            2             3
    hexagon_size = 10.4
    pattern =
                      '3  1  3  3  1  3;
                    1  0  3  1  3  0   1;
                  3  3  1  3  3  1  3   3;
                3  1  3  2  1  2  3  1   3;
              1  3  3  1  3  3  1  3  3   1;
             3  0  1  2  3  1  3  2  1  0  3;
              1  3  3  1  3  3  1  3  3  1;
               3  1  3  2  1  2  3  1  3;
                3  3  1  3  3  1  3  3;
                 1  0  3  1  3  0  1;
                  3  1  3  3  1  3'

    background_block_id = 10
    background_intervals = 1
  []

  [cd0_12]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2 Innercore2'
    sides_to_adapt = '3 4'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_12]
    type = AzimuthalBlockSplitGenerator
    input = cd0_12
    start_angle = 45
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_6]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2 Innercore2'
    sides_to_adapt = '0 1'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_6]
    type = AzimuthalBlockSplitGenerator
    input = cd0_6
    start_angle = 225
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_9]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2 Innercore2 Innercore2'
    sides_to_adapt = '0 5 4'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_9]
    type = AzimuthalBlockSplitGenerator
    input = cd0_9
    start_angle = 135
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_3]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2 Innercore2 Innercore2'
    sides_to_adapt = '1 2 3'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_3]
    type = AzimuthalBlockSplitGenerator
    input = cd0_3
    start_angle = 315
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_1]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2 Innercore2 Innercore2'
    sides_to_adapt = '2 3 4'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_1]
    type = AzimuthalBlockSplitGenerator
    input = cd0_1
    start_angle = 15
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_2]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2  Innercore2'
    sides_to_adapt = '2 3'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_2]
    type = AzimuthalBlockSplitGenerator
    input = cd0_2
    start_angle = 345
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_4]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2 Innercore2 '
    sides_to_adapt = '1 2'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_4]
    type = AzimuthalBlockSplitGenerator
    input = cd0_4
    start_angle = 285
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_5]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to =  'Innercore2 Innercore2 Innercore2'
    sides_to_adapt = '0 1 2'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []
  [cd_5]
    type = AzimuthalBlockSplitGenerator
    input = cd0_5
    start_angle = 255
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []
  [cd0_7]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = ' Innercore2 Innercore2 Innercore2'
    sides_to_adapt = '0 1 5'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_7]
    type = AzimuthalBlockSplitGenerator
    input = cd0_7
    start_angle = 195
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_8]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2 Innercore2 '
    sides_to_adapt = '0 5'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_8]
    type = AzimuthalBlockSplitGenerator
    input = cd0_8
    start_angle = 165
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

  [cd0_10]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Innercore2 Innercore2 '
    sides_to_adapt = ' 4 5'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_10]
    type = AzimuthalBlockSplitGenerator
    input = cd0_10
    start_angle = 105
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []
  [cd0_11]
    type =HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    meshes_to_adapt_to = 'Outercore  Outercore Outercore'
    sides_to_adapt = '3 4 5'
    num_sectors_per_side= '4 4 4 4 4 4'
    hexagon_size = 10.4
    background_intervals = 2
    background_block_ids = 604
    ring_radii = '9 10'
    ring_intervals = '1 1'
    ring_block_ids = '600 602'
    is_control_drum = true
  []

  [cd_11]
    type = AzimuthalBlockSplitGenerator
    input = cd0_11
    start_angle = 75
    angle_range = 90
    old_blocks = 602
    new_block_ids = 603
  []

    [core]
    type = PatternedHexMeshGenerator
    inputs = 'Innercore Innercore2 Outercore dummy cd_1 cd_2 cd_3 cd_4 cd_5 cd_6 cd_7 cd_8 cd_9 cd_10 cd_11 cd_12 Outercore2  centralFA'
    #         0         1          2         3     4    5    6    7    8    9    10   11   12   13    14    15    16         17
    pattern_boundary = none
    generate_core_metadata = true
    #external_boundary_id = 9000
    #external_boundary_name = side

  pattern =
        '3  3  3  15  3  3  3;
        3  14  1  1  1  1  4  3;
      3  1  1   16  16  16  1  1  3;
    13  1  16  2  2  2  2  16  1  5;
   3  1  16  2  0  0  0  2  16  1  3;
  3  1  16   2  0  0  0  0  2  16  1  3;
3  12  1  2  0  0  17  0  0  2  1  6  3;
  3  1  16  2  0  0  0  0  2  16  1  3;
   3  1  16  2   0  0   0   2  16  1  3;
    11  1  16  2   2  2   2  16  1  7;
       3  1  1  16  16  16  1  1  3;
       3    10  1   1  1   1  8  3;
          3   3  3  9  3  3   3'

    rotate_angle = 0
   []

   [del_dummy]
     type = BlockDeletionGenerator
     block = '700 '
     input = core
     new_boundary = 10000
   []

   [ADD_outer_shield]
     type = PeripheralRingMeshGenerator
     input = del_dummy
     peripheral_layer_num = 2
     peripheral_ring_radius = 120.1
     input_mesh_external_boundary = 10000
     peripheral_ring_block_id = 250
     #peripheral_ring_block_name = outer_shield
   []

  [del_1]
     type = PlaneDeletionGenerator
     point = '0 0 0'
     normal = '10 17.32 0'
     input = ADD_outer_shield
     new_boundary = 147
  []

  [del_2]
     type = PlaneDeletionGenerator
     point = '0 0 0'
     normal = '10 -17.32 0'
     input = del_1
     new_boundary = 147
  []

  [extrude]
     type = AdvancedExtruderGenerator
     input = del_2
     heights = '20 40 40 40 40 40 20'
     num_layers ='2 4 4  4  4  4 2'
     subdomain_swaps = '10    1000    500 1000    501  1003   5001  1003  5000  1000  400 1000 401 1003 4000 1000 4001 1003 40000 1000 40001 1003 101 1003 100 1000 102 1000 103 1000 301 1003 300 1000;
                        500   19000  501  19003  5001  19900  5000  19903;
                        500   29000  501  29003  5001  29900  5000  29903;
                        500   39000  501  39003  5001  39900  5000  39903;
                        500   49000  501  49003  5001  49900  5000  49903;
                        500   59000  501  59003  5001  59900  5000  59903;
                        10     1000    500  1000  501      1003   5001  1003  5000  1000  400 1000 401 1003 4000 1000 4001 1003 40000 1000 40001 1003 101 1003 100 1000 102 1000 103 1000 301 1773 300 1777'
      direction = '0 0 1'
      top_boundary = 2000
      bottom_boundary = 3000
  []

  [rename_blocks]
      type = RenameBlockGenerator
      old_block =   ' 10      100        101           102  103     200     201          400     401          4000     4001          40000    40001          300          301                  600         602          603        604          1000              1003            19000  29000  39000  49000  59000  19003  29003  39003  49003  59003  19900  29900  39900  49900  59900  19903  29903  39903  49903  59903  1777 1773  250'
      new_block = 'monolith moderator  moderator_tri Cr   FECRAL  coolant coolant_tri  Fuel_in Fuel_tri_in  Fuel_mid Fuel_tri_mid  Fuel_out Fuel_tri_out   Control_hole Control_hole_tri     CD_Radial1  CD_Radial2   CD_poison  CD_coolant   reflector_quad    reflector_tri   BP0_1  BP0_2  BP0_3  BP0_4  BP0_5  BP0_tr_1  BP0_tr_2  BP0_tr_3  BP0_tr_4  BP0_tr_5  BP1_1  BP1_2  BP1_3  BP1_4  BP1_5  BP1_tr_1  BP1_tr_2  BP1_tr_3  BP1_tr_4  BP1_tr_5 Control_ref Control_ref_tri Rad_ref'
      input = extrude
  []

  [rename_sidesets]
      type = RenameBoundaryGenerator
      input = rename_blocks
      old_boundary = '2000         3000            10000  147 '
      new_boundary = 'top_boundary bottom_boundary side   cut_surf'
  []

  [scale] # unit convert from cm to m
     type = TransformGenerator
     input = rename_sidesets
     transform = SCALE
     vector_value = '1e-2 1e-2 1e-2'
  []
[]

(microreactors/gcmr/core/Serpent_Model/serpent_input.i)

%------------------------------------------------------------------------------------------
% ANL GCMR Serpent (Version 2.1.32) Model Input
% If using or referring to this model, please cite as explained in
% https://mooseframework.inl.gov/virtual_test_bed/citing.html
% Contacts: Ahmed Abdelhameed (aabdelhameed.at.anl.gov), Nicolas Stauff (nstauff.at.anl.gov)
% -----------------------------------------------------------------------------------------
set title "ANL GC MicroReactor"

surf inf inf
pbed 700 33 "PART_U900_PF40_R85.inp"
pbed 701 33 "PART_U901_PF40_R85.inp"
pbed 702 33 "PART_U902_PF40_R85.inp"
pbed 754 33 "PART_U954_PF25_R25.inp"
pbed 764 33 "PART_U964_PF25_R25.inp"

% infinite cells defining material universes
cell 51 802 moderator  -inf
cell 52 33  matrix_pin -inf
cell 53 803    matrix  -inf
cell 54 804    coolant -inf
cell 55 805      Refl  -inf
cell 56 806  shell_mod -inf
cell 57 807    coolant -inf
cell 58 809  boron_ctr -inf
cell 59 810         Cr -inf
cell 155 811      Refl -inf

% Fuel region

particle 900
     fuel0     2.1250e-02
     buffer    3.1250e-02
     PyC1      3.5250e-02
     SiC       3.8750e-02
     PyC2      4.2750e-02
matrix_pin
particle 901
     fuel1     2.1250e-02
     buffer    3.1250e-02
     PyC1      3.5250e-02
     SiC       3.8750e-02
     PyC2      4.2750e-02
matrix_pin
particle 902
     fuel2     2.1250e-02
     buffer    3.1250e-02
     PyC1      3.5250e-02
     SiC       3.8750e-02
     PyC2      4.2750e-02
matrix_pin

cell i110  3 fill 700       -1  95l   -95lu1 % fuel compact
cell i111  3 fill 700       -1  95lu1 -95lu2 % fuel compact
cell i112  3 fill 700       -1  95lu2 -95lu3 % fuel compact
cell i113  3 fill 700       -1  95lu3 -95lu4 % fuel compact
cell i114  3 fill 700       -1  95lu4 -95u   % fuel compact
cell i12   3 fill 803        1  95l   -95u
cell i13   3 fill 805                  95u
cell i14   3 fill 805                 -95l

cell m110  5 fill 701       -1  95l   -95lu1 % fuel compact
cell m111  5 fill 701       -1  95lu1 -95lu2 % fuel compact
cell m112  5 fill 701       -1  95lu2 -95lu3 % fuel compact
cell m113  5 fill 701       -1  95lu3 -95lu4 % fuel compact
cell m114  5 fill 701       -1  95lu4 -95u   % fuel compact
cell m12   5 fill 803        1  95l   -95u
cell m13   5 fill 805                  95u
cell m14   5 fill 805                 -95l

cell o110  8 fill 702       -1  95l   -95lu1 % fuel compact
cell o111  8 fill 702       -1  95lu1 -95lu2 % fuel compact
cell o112  8 fill 702       -1  95lu2 -95lu3 % fuel compact
cell o113  8 fill 702       -1  95lu3 -95lu4 % fuel compact
cell o114  8 fill 702       -1  95lu4 -95u % fuel compact
cell o12   8 fill 803        1  95l   -95u
cell o13   8 fill 805                  95u
cell o14   8 fill 805                 -95l


% Coolant channel:

cell 20 6 fill 807       -7
cell 21 6 fill 803        7   95l -95u
cell 22 6 fill 805        7   95u
cell 23 6 fill 805        7       -95l

% Central control pin

cell 29 7 fill 805   -9        -95l
cell 30 7 fill 804   -9    95l -97l
cell 31 7 fill 809   -9    97l
cell 32 7 fill 805    9    95u
cell 33 7 fill 805    9        -95l
cell 34 7 fill 803    9    95l -95u


cell m29 27 fill 805   -9        -95l
cell m30 27 fill 804   -9    95l -97lh
cell m31 27 fill 809   -9    97lh
cell m32 27 fill 805    9    95u
cell m33 27 fill 805    9        -95l
cell m34 27 fill 803    9    95l -95u


particle 952
     Gd_bpI1   0.0100 % kernel at 100 microns
     buffer 0.0118 % graphite at 18 microns
     PyC1   0.0141 % different graphite at 23 microns
matrix_pin

particle 954
     Gd_bpI2   0.0100 % kernel at 100 microns
     buffer 0.0118 % graphite at 18 microns
     PyC1   0.0141 % different graphite at 23 microns
matrix_pin

particle 955
     Gd_bpI3   0.0100 % kernel at 100 microns
     buffer 0.0118 % graphite at 18 microns
     PyC1   0.0141 % different graphite at 23 microns
matrix_pin

particle 961
     Gd_bpO1   0.0100 % kernel at 100 microns
     buffer 0.0118 % graphite at 18 microns
     PyC1   0.0141 % different graphite at 23 microns
matrix_pin

particle 963
     Gd_bpO2   0.0100 % kernel at 100 microns
     buffer 0.0118 % graphite at 18 microns
     PyC1   0.0141 % different graphite at 23 microns
matrix_pin

particle 964
     Gd_bpO3   0.0100 % kernel at 100 microns
     buffer 0.0118 % graphite at 18 microns
     PyC1   0.0141 % different graphite at 23 microns
matrix_pin

particle 965
     Gd_bpO3   0.0100 % kernel at 100 microns
     buffer 0.0118 % graphite at 18 microns
     PyC1   0.0141 % different graphite at 23 microns
matrix_pin

cell i150  2 fill 754       -2  95l   -95lu1 % burnable compact
cell i151  2 fill 754       -2  95lu1 -95lu2 % burnable compact
cell i152  2 fill 754       -2  95lu2 -95lu3 % burnable compact
cell i153  2 fill 754       -2  95lu3 -95lu4 % burnable compact
cell i154  2 fill 754       -2  95lu4 -95u   % burnable compact
cell i16   2 fill 803        2  95l   -95u
cell i17   2 fill 805           95u
cell i18   2 fill 805                 -95l

cell o150  9 fill 764       -2  95l   -95lu1 % burnable compact
cell o151  9 fill 764       -2  95lu1 -95lu2 % burnable compact
cell o152  9 fill 764       -2  95lu2 -95lu3 % burnable compact
cell o153  9 fill 764       -2  95lu3 -95lu4 % burnable compact
cell o154  9 fill 764       -2  95lu4 -95u   % burnable compact
cell o16   9 fill 803        2  95l   -95u
cell o17   9 fill 805            95u
cell o18   9 fill 805                 -95l

% plain graphite region
cell 36  1 fill 803            95l -95u
cell 37  1 fill 805            95u
cell 38  1 fill 805                -95l

% Moderator region:

cell 40  4 fill 802      -3   95l -95u % 0.95 cm pin
cell 41a 4 fill 810    3 -4   95l -95u % 0.05 cm coating
cell 41b 4 fill 806    4 -5   95l -95u % 0.05 cm shell
cell 42  4 fill 803    5      95l -95u
cell 43  4 fill 806      -5   96l -95l % 0.05 cm shell
cell 44  4 fill 806      -5   95u -96u % 0.05 cm shell
cell 45  4 fill 805       5   96l -95l % 0.05 cm shell
cell 46  4 fill 805       5   95u -96u % 0.05 cm shell
cell 47  4 fill 805           96u
cell 48  4 fill 805               -96l

% --- cylinders
surf  1 cyl 0.0 0.0 0.850  0.000000 240
surf  2 cyl 0.0 0.0 0.250  0.000000 240
surf  3 cyl 0.0 0.0 0.693  0.000000 240
surf  4 cyl 0.0 0.0 0.700  0.000000 240
surf  5 cyl 0.0 0.0 0.750  0.000000 240
surf  7 cyl 0.0 0.0 0.600  0.000000 240
surf  9 cyl 0.0 0.0 0.950  0.000000 240

% --- axial dimensions
surf 95l pz  20
surf 95lu1 pz  60.0
surf 95lu2 pz  100.0
surf 95lu3 pz  140.0
surf 95lu4 pz  180.0
surf 95u pz  220
surf 96l pz  19.95
surf 96u pz  220.05
surf 97l pz  220
surf 97lh pz  220

% --- hexprism assembly
surf 30 hexxprism 0.0 0.0 10.4000 0 240

% --- Assembly lattice

lat 26 3  0.0 0.0 13 13   2.000000                 % regular fuel assembly with rods - central
    1 1 1 1 1 1 1 1 1 1 1 1 1
    1 1 1 1 1 1 3 6 3 3 6 3 1
    1 1 1 1 1 6 4 3 6 3 4 6 1
    1 1 1 1 3 3 6 3 3 6 3 3 1
    1 1 1 3 6 3 2 6 2 3 6 3 1
    1 1 6 3 3 6 3 3 6 3 3 6 1
    1 3 4 6 2 3 6 3 2 6 4 3 1
    1 6 3 3 6 3 3 6 3 3 6 1 1
    1 3 6 3 2 6 2 3 6 3 1 1 1
    1 3 3 6 3 3 6 3 3 1 1 1 1
    1 6 4 3 6 3 4 6 1 1 1 1 1
    1 3 6 3 3 6 3 1 1 1 1 1 1
    1 1 1 1 1 1 1 1 1 1 1 1 1

cell 67 19 fill 26  -30
cell 167 19 fill 803  30

lat 13 3  0.0 0.0 13 13   2.000000                 % regular fuel assembly - inner
    1 1 1 1 1 1 1 1 1 1 1 1 1
    1 1 1 1 1 1 2 6 3 3 6 2 1
    1 1 1 1 1 6 4 3 6 3 4 6 1
    1 1 1 1 3 3 6 3 3 6 3 3 1
    1 1 1 3 6 3 2 6 2 3 6 3 1
    1 1 6 3 3 6 3 3 6 3 3 6 1
    1 2 4 6 2 3 6 3 2 6 4 2 1
    1 6 3 3 6 3 3 6 3 3 6 1 1
    1 3 6 3 2 6 2 3 6 3 1 1 1
    1 3 3 6 3 3 6 3 3 1 1 1 1
    1 6 4 3 6 3 4 6 1 1 1 1 1
    1 2 6 3 3 6 2 1 1 1 1 1 1
    1 1 1 1 1 1 1 1 1 1 1 1 1

cell 60 14 fill 13  -30
cell 160 14 fill 803  30

lat 10 3  0.0 0.0 13 13   2.000000                 % regular fuel assembly with rods - middle
    1 1 1 1 1 1 1 1 1 1 1 1 1
    1 1 1 1 1 1 5 6 5 5 6 5 1
    1 1 1 1 1 6 4 5 6 5 4 6 1
    1 1 1 1 5 5 6 5 5 6 5 5 1
    1 1 1 5 6 5 2 6 2 5 6 5 1
    1 1 6 5 5 6 5 5 6 5 5 6 1
    1 5 4 6 2 5 7 5 2 6 4 5 1
    1 6 5 5 6 5 5 6 5 5 6 1 1
    1 5 6 5 2 6 2 5 6 5 1 1 1
    1 5 5 6 5 5 6 5 5 1 1 1 1
    1 6 4 5 6 5 4 6 1 1 1 1 1
    1 5 6 5 5 6 5 1 1 1 1 1 1
    1 1 1 1 1 1 1 1 1 1 1 1 1

cell 61 15 fill 10  -30
cell 161 15 fill 803  30

lat 12 3  0.0 0.0 13 13   2.000000                 % regular fuel assembly with rods - middle core - 2nd type of CR
    1 1 1 1 1 1 1 1 1 1 1 1 1
    1 1 1 1 1 1 5 6 5 5 6 5 1
    1 1 1 1 1 6 4 5 6 5 4 6 1
    1 1 1 1 5 5 6 5 5 6 5 5 1
    1 1 1 5 6 5 2 6 2 5 6 5 1
    1 1 6 5 5 6 5 5 6 5 5 6 1
    1 5 4 6 2 5 27 5 2 6 4 5 1
    1 6 5 5 6 5 5 6 5 5 6 1 1
    1 5 6 5 2 6 2 5 6 5 1 1 1
    1 5 5 6 5 5 6 5 5 1 1 1 1
    1 6 4 5 6 5 4 6 1 1 1 1 1
    1 5 6 5 5 6 5 1 1 1 1 1 1
    1 1 1 1 1 1 1 1 1 1 1 1 1

cell 66 25 fill 12  -30
cell 166 25 fill 803  30

lat 11 3  0.0 0.0 13 13   2.000000                 % regular fuel assembly without rod and burnable poisons - outer core
    1 1 1 1 1 1 1 1 1 1 1 1 1
    1 1 1 1 1 1 8 6 8 8 6 8 1
    1 1 1 1 1 6 4 8 6 8 4 6 1
    1 1 1 1 8 8 6 8 8 6 8 8 1
    1 1 1 8 6 8 2 6 2 8 6 8 1
    1 1 6 8 8 6 8 8 6 8 8 6 1
    1 8 4 6 2 8 6 8 2 6 4 8 1
    1 6 8 8 6 8 8 6 8 8 6 1 1
    1 8 6 8 2 6 2 8 6 8 1 1 1
    1 8 8 6 8 8 6 8 8 1 1 1 1
    1 6 4 8 6 8 4 6 1 1 1 1 1
    1 8 6 8 8 6 8 1 1 1 1 1 1
    1 1 1 1 1 1 1 1 1 1 1 1 1

cell 62 16 fill 11  -30
cell 162 16 fill 803  30

% control drum region (currently plain)
cell 164 17 fill 807 -30
cell 165 17 fill 811  30


% reflector region
cell 63 18 fill 811  -30
cell 163 18 fill 811  30



lat 50  2  0.0 0.0 17 17 20.8
18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18
18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18
18 18 18 18 18 18 18 18 18 18 18 17 18 18 18 18 18
18 18 18 18 18 18 18 18 17 16 16 16 16 17 18 18 18
18 18 18 18 18 18 18 16 16 15 15 15 16 16 18 18 18
18 18 18 18 18 17 16 15 25 25 25 25 15 16 17 18 18
18 18 18 18 18 16 15 25 14 14 14 25 15 16 18 18 18
18 18 18 18 16 15 25 14 14 14 14 25 15 16 18 18 18
18 18 18 17 16 25 14 14 14 14 14 25 16 17 18 18 18
18 18 18 16 15 25 14 14 14 14 25 15 16 18 18 18 18
18 18 18 16 15 25 14 14 14 25 15 16 18 18 18 18 18
18 18 17 16 15 25 25 25 25 15 16 17 18 18 18 18 18
18 18 18 16 16 15 15 15 16 16 18 18 18 18 18 18 18
18 18 18 17 16 16 16 16 17 18 18 18 18 18 18 18 18
18 18 18 18 18 17 18 18 18 18 18 18 18 18 18 18 18
18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18
18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18


surf  11 cyl 0.0 0.0 121   0.0 240

cell 170 0 fill 50 -11

% -----------DRUMS DEFINITTION---------------------------------------------------------------------------------------

 731 732 733 734 735 736 737 738 739 740 741 742
cell 180 0 fill       731 -731
cell 181 0 fill       732 -732
cell 182 0 fill       733 -733
cell 183 0 fill       734 -734
cell 184 0 fill       735 -735
cell 185 0 fill       736 -736
cell 186 0 fill       737 -737
cell 187 0 fill       738 -738
cell 188 0 fill       739 -739
cell 189 0 fill       740 -740
cell 190 0 fill       741 -741
cell 191 0 fill       742 -742


surf 731 cyl 104.0000   0.00 10.0000   0.00 240.00
surf 831 cyl 104.0000   0.00 9.0000   0.00 240.00
surf 771 plane 1.0000   0.00 0.0 110.36
surf 871 plane 1.0000  -0.00 0.0  97.64
cell 801  731 fill 811   -731   -771
cell 802  731 fill 809    831  -731  771
cell 803  731 fill 811   -831   771
surf 732 cyl 52.0000  90.07 10.0000   0.00 240.00
surf 832 cyl 52.0000  90.07 9.0000   0.00 240.00
surf 772 plane 1.0000   1.73 0.0 220.73
surf 872 plane 1.0000   1.73 0.0 195.27
cell 806  732 fill 811   -732   -772
cell 807  732 fill 809    832  -732  772
cell 808  732 fill 811   -832   772
surf 733 cyl -52.0000  90.07 10.0000   0.00 240.00
surf 833 cyl -52.0000  90.07 9.0000   0.00 240.00
surf 773 plane 1.0000  -1.73 0.0 -220.73
surf 873 plane 1.0000  -1.73 0.0 -195.27
cell 811  733 fill 811   -733   773
cell 812  733 fill 809    833  -733  -773
cell 813  733 fill 811   -833   -773
surf 734 cyl -104.0000   0.00 10.0000   0.00 240.00
surf 834 cyl -104.0000   0.00 9.0000   0.00 240.00
surf 774 plane 1.0000  -0.00 0.0 -110.36
surf 874 plane 1.0000   0.00 0.0 -97.64
cell 816  734 fill 811   -734   774
cell 817  734 fill 809    834  -734  -774
cell 818  734 fill 811   -834   -774
surf 735 cyl -52.0000 -90.07 10.0000   0.00 240.00
surf 835 cyl -52.0000 -90.07 9.0000   0.00 240.00
surf 775 plane 1.0000   1.73 0.0 -220.73
surf 875 plane 1.0000   1.73 0.0 -195.27
cell 821  735 fill 811   -735   775
cell 822  735 fill 809    835  -735  -775
cell 823  735 fill 811   -835   -775
surf 736 cyl 52.0000 -90.07 10.0000   0.00 240.00
surf 836 cyl 52.0000 -90.07 9.0000   0.00 240.00
surf 776 plane 1.0000  -1.73 0.0 220.73
surf 876 plane 1.0000  -1.73 0.0 195.27
cell 826  736 fill 811   -736   -776
cell 827  736 fill 809    836  -736  776
cell 828  736 fill 811   -836   776
surf 737 cyl 93.6000  54.04 10.0000   0.00 240.00
surf 837 cyl 93.6000  54.04 9.0000   0.00 240.00
surf 777 plane 1.0000   0.58 0.0 132.15
surf 877 plane 1.0000   0.58 0.0 117.45
cell 831  737 fill 811   -737   -777
cell 832  737 fill 809    837  -737  777
cell 833  737 fill 811   -837   777
surf 738 cyl 0.0000 108.08 10.0000   0.00 240.00
surf 838 cyl 0.0000 108.08 9.0000   0.00 240.00
surf 778 plane 0.0000   1.00 0.0 114.44
surf 878 plane 1.0000 895647891448936.75 0.0 91101729311334400.00
cell 836  738 fill 811   -738   -778
cell 837  738 fill 809    838  -738  778
cell 838  738 fill 811   -838   778
surf 739 cyl -93.6000  54.04 10.0000   0.00 240.00
surf 839 cyl -93.6000  54.04 9.0000   0.00 240.00
surf 779 plane 1.0000  -0.58 0.0 -132.15
surf 879 plane 1.0000  -0.58 0.0 -117.45
cell 841  739 fill 811   -739   779
cell 842  739 fill 809    839  -739  -779
cell 843  739 fill 811   -839   -779
surf 740 cyl -93.6000 -54.04 10.0000   0.00 240.00
surf 840 cyl -93.6000 -54.04 9.0000   0.00 240.00
surf 780 plane 1.0000   0.58 0.0 -132.15
surf 880 plane 1.0000   0.58 0.0 -117.45
cell 846  740 fill 811   -740   780
cell 847  740 fill 809    840  -740  -780
cell 848  740 fill 811   -840   -780
surf 741 cyl -0.0000 -108.08 10.0000   0.00 240.00
surf 841 cyl -0.0000 -108.08 9.0000   0.00 240.00
surf 781 plane 1.0000 895647891448936.75 0.0 -102501465868115968.00
surf 881 plane 1.0000 895647891448936.38 0.0 -91101729311334368.00
cell 851  741 fill 811   -741   781
cell 852  741 fill 809    841  -741  -781
cell 853  741 fill 811   -841   -781
surf 742 cyl 93.6000 -54.04 10.0000   0.00 240.00
surf 842 cyl 93.6000 -54.04 9.0000   0.00 240.00
surf 782 plane 1.0000  -0.58 0.0 132.15
surf 882 plane 1.0000  -0.58 0.0 117.45
cell 856  742 fill 811   -742   -782
cell 857  742 fill 809    842  -742  782
cell 858  742 fill 811   -842   782

cell 171 0 outside  11

set ures 1

% -----------------------------------------------------------------------------------
% Material data:

% materials

mat fuel0   -10.7440 burn 1  tmp 725.0   rgb 200 0 0
  92235.01c    6.8794e-02
  92238.01c    2.7604e-01
 6012.01c    1.3793e-01
  8016.01c    5.1724e-01

mat fuel1   -10.7440 burn 1  tmp 725.0   rgb 230 0 0
  92235.01c    6.8794e-02
  92238.01c    2.7604e-01
 6012.01c    1.3793e-01
  8016.01c    5.1724e-01

mat fuel2   -10.7440 burn 1  tmp 725.0   rgb 255 0 0
  92235.01c    6.8794e-02
  92238.01c    2.7604e-01
 6012.01c    1.3793e-01
  8016.01c    5.1724e-01

mat Gd_bpI1 -7.0395  burn 1  tmp 725.0  rgb 0 0 200
 64152.01c   2.43139E-05
 64154.01c   2.61576E-04
 64155.01c   1.76435E-03
 64156.01c   2.42465E-03
 64157.01c   1.84189E-03
 64158.01c   2.90497E-03
 64160.01c   2.52445E-03
 8016.01c   3.52386E-02

mat Gd_bpI2 -7.0395 burn 1  tmp 725.0  rgb 0 0 250
 64152.01c   2.43139E-05
 64154.01c   2.61576E-04
 64155.01c   1.76435E-03
 64156.01c   2.42465E-03
 64157.01c   1.84189E-03
 64158.01c   2.90497E-03
 64160.01c   2.52445E-03
 8016.01c   3.52386E-02



mat Gd_bpI3 -7.0395 burn 1  tmp 725.0  rgb 0 0 200
64152.01c   2.43139E-05
64154.01c   2.61576E-04
64155.01c   1.76435E-03
64156.01c   2.42465E-03
64157.01c   1.84189E-03
64158.01c   2.90497E-03
64160.01c   2.52445E-03
8016.01c   3.52386E-02

mat Gd_bpO1 -7.0395 burn 1  tmp 725.0  rgb 0 0 250
64152.01c   2.43139E-05
64154.01c   2.61576E-04
64155.01c   1.76435E-03
64156.01c   2.42465E-03
64157.01c   1.84189E-03
64158.01c   2.90497E-03
64160.01c   2.52445E-03
8016.01c   3.52386E-02

mat Gd_bpO2 -7.0395 burn 1  tmp 725.0  rgb 0 0 200
64152.01c   2.43139E-05
64154.01c   2.61576E-04
64155.01c   1.76435E-03
64156.01c   2.42465E-03
64157.01c   1.84189E-03
64158.01c   2.90497E-03
64160.01c   2.52445E-03
8016.01c   3.52386E-02

mat Gd_bpO3 -7.0395 burn 1  tmp 725.0  rgb 0 0 250
64152.01c   2.43139E-05
64154.01c   2.61576E-04
64155.01c   1.76435E-03
64156.01c   2.42465E-03
64157.01c   1.84189E-03
64158.01c   2.90497E-03
64160.01c   2.52445E-03
8016.01c   3.52386E-02

mat boron_ctr -2.4700 tmp 725.0  rgb 0 0 250 % highly enriched B4C
 5010.01c 0.768
 5011.01c 0.032
 6012.01c 0.20

mat coolant    -3.6500e-03  tmp 725.0 rgb 0 0 100
 2004.01c  1.0

mat shell_mod  -7.0550  tmp 725.0   rgb 33 233 133  % density at 900K - FeCrAl
24050.01c  8.6800E-03
24052.01c  1.6762E-01
24053.01c  1.8980E-02
24054.01c  4.7200E-03
26054.01c  4.3790E-02
26056.01c  6.9249E-01
26057.01c  1.6610E-02
26058.01c  2.1140E-03
13027.01c  4.5000E-02

% --- Carbon buffer layer:

mat buffer  -1.0400 moder grph 6012 tmp 725.0  rgb 0 200 200
 6012.01c    1.0

% --- Pyrolytic carbon layer:

mat PyC1     -1.8820 moder grph 6012 tmp 725.0   rgb 0 200 200
 6012.01c    1.0

% --- Pyrolytic carbon layer:

mat PyC2     -1.8820 moder grph 6012 tmp 725.0 rgb 0 200 200
 6012.01c    1.0

% --- Silicon carbide layer:

mat SiC     -3.1710  tmp 725.0 rgb 0 100 0
14028.01c    0.4611
14029.01c    0.0234
14030.01c    0.0154
 6012.01c     0.5

mat Nb   -8.4132  tmp 725.0   rgb 100 0 100   % Nobium
41093.01c  -0.99
40090.01c  -5.132E-03
40091.01c  -1.107E-03
40092.01c  -1.674E-03
40094.01c  -1.660E-03
40096.01c  -2.618E-04

mat Cr   -7.1900  tmp 725.0   rgb 100 0 200   % Chromium
24050.01c  -4.345e-2
24052.01c  -83.789e-2
24053.01c  -9.501e-2
24054.01c  -2.365e-2

% --- Graphite matrix:

mat matrix_pin       -1.8060 moder grph 6012  tmp 725.0  rgb 220 220 220
 6012.01c    1

mat matrix       -1.8060 moder grph 6012  tmp 725.0 rgb 200 200 200
 6012.01c  0.9999997
 5010.01c  0.0000003

mat moderator   -4.0850 moder h-yh2 1001 moder y-yh2 39089 tmp 725.0   rgb 73 64 171
39089.01c  0.357142857
1001.01c   0.642857143

mat Refl        -2.7987  moder beo 4009 tmp 725.0   rgb 100 220 200  % GREY
 4009.01c    0.5
 8016.01c    0.5

% -----------------------------------------------------------------------------

therm grph    grph.84t
therm  beo     be-beo.84t
therm h-yh2   h-yh2.84t
therm y-yh2   y-yh2.84t

% Calculation parameters:

% -----------------------------------------------------------------------------

% --- Geometry plot:
plot 3 10000 10000   120.0
plot 2 10000 10000   0.2

% --- Libraries:

% Add your own libraries here
set acelib "sss_endfb8_serpent_yan.xsdir"  % ACE library for cross-sections
set declib "sss_endfb7.dec" % Decay library
set nfylib "sss_endfb7.nfy" % Neutron fission yield library



% --- Boundary conditions:

set bc 1

% --- Power density

set power 20000000.0  % W

% --- Histories:
set pop 10000 300 30

set xenon 1
set gcu 700 701 702 754 764 802 803 804 805 806 807 809 810 811

set nfg  11  8.00000e-08 1.80000e-07 6.25000e-07 1.30000e-06 4.00000e-06
             1.48730e-04 9.11800e-03 1.83000e-01 5.00000e-01 1.35300e+00

% -----------------------------------------------------------------------------

(microreactors/gcmr/core/Neutronics/Griffin_steady_state.i)

#####################################################################################################
# Griffin steady state Model of whole-core Gas-cooled Microreactor
# DFEM-SN with CMFD acceleration
# If using or referring to this model, please cite as explained in
# https://mooseframework.inl.gov/virtual_test_bed/citing.html
#####################################################################################################

[Mesh]
  [fmg]
    type = FileMeshGenerator
    file = 'mesh/Griffin_mesh_in.e'
  []

  [fmg_id]
    type = SubdomainExtraElementIDGenerator
    input = fmg
    subdomains = '10 100 101 102 103 200 201 400 401 4000 4001 40000 40001 300 301 600 602 603 604 1000 1003 19000 29000 39000 49000 59000 19003 29003 39003 49003 59003 19900 29900 39900 49900 59900 19903 29903 39903 49903 59903 1777 1773 250'
    extra_element_id_names = 'material_id'
    extra_element_ids = '803 802 802 810 806 807 807 700 700 701 701 702 702 807 807 811 811 809 807 805 805 764 764 764 764 764 764 764 764 764 764 754 754 754 754 754 754 754 754 754 754 809 809 811'
  []

  [coarse_mesh]
    type = GeneratedMeshGenerator
    dim = 3
    nx = 20
    ny = 20
    nz = 20
    xmin = -1.21
    xmax = 1.21
    ymin = -1.21
    ymax = 1.21
    zmin = 0.0
    zmax = 2.4
  []

  [assign_coarse_id]
    type = CoarseMeshExtraElementIDGenerator
    input = fmg_id
    coarse_mesh = coarse_mesh
    extra_element_id_name = coarse_element_id
  []
[]

[Executioner]
  type = SweepUpdate
  # Richardson iterations
  richardson_abs_tol = 1e-8
  richardson_rel_tol = 1e-8
  richardson_value = eigenvalue
  richardson_max_its = 1000
  inner_solve_type = GMRes
  max_inner_its = 20
  fixed_point_max_its = 1
  custom_rel_tol = 1e-6
  force_fixed_point_solve = true

  #CMFD  acceletation
  cmfd_acceleration = true
  coarse_element_id = coarse_element_id
  diffusion_eigen_solver_type = newton
  prolongation_type = multiplicative
  max_diffusion_coefficient = 1
[]

[Debug]
  check_boundary_coverage = false
  print_block_volume = false
  show_actions = false
[]

[AuxVariables]
  [Tf]
    initial_condition = 725.0
    order = CONSTANT
    family = MONOMIAL
  []
[]

[TransportSystems]
  particle = neutron
  equation_type = eigenvalue
  G = 11
  VacuumBoundary = 'top_boundary bottom_boundary side'
  ReflectingBoundary = 'cut_surf'

  [SN]
    scheme = DFEM-SN
    family = MONOMIAL
    order = FIRST
    AQtype = Gauss-Chebyshev
    NPolar = 2
    NAzmthl = 3
    NA = 2
    n_delay_groups = 6
    sweep_type = asynchronous_parallel_sweeper
    using_array_variable = true
    collapse_scattering = true
    hide_angular_flux = true
  []
[]

[GlobalParams]
  library_file = '../ISOXML/XS_Griffin.xml'
  library_name = XS_Griffin
  isotopes = 'pseudo'
  densities = 1.0
  is_meter = true
  plus = true
  dbgmat = false
  grid_names = 'Tfuel'
  grid_variables = 'Tf'
[]

[PowerDensity]
  power = 20000000
  power_density_variable = power_density
[]

[Materials]
  [mod]
    type = CoupledFeedbackMatIDNeutronicsMaterial
    block = '10 100 101 102 103 200 201 400 401 4000 4001 40000 40001 300 301 600 602 603 604 1000 1003 19000 29000 39000 49000 59000 19003 29003 39003 49003 59003 19900 29900 39900 49900 59900 19903 29903 39903 49903 59903 1777 1773 250'
  []
[]

[UserObjects]
  [axial_power_inner]
    type = LayeredIntegral
    variable = power_density
    direction = z
    num_layers = 24
    block = '400 401 4000 4001 40000 40001 1000 1003'
  []
[]

[AuxKernels]
  [axial_power_inner]
    type = SpatialUserObjectAux
    variable = axial_power_inner
    execute_on = timestep_end
    user_object = axial_power_inner
  []
[]

[AuxVariables]
  [axial_power_inner]
    order = CONSTANT
    family = MONOMIAL
  []
[]

[VectorPostprocessors]
  [axial_power_inner_elm]
    type = ElementValueSampler
    variable = axial_power_inner
    sort_by = z
    execute_on = timestep_end
  []
[]

[Outputs]
  csv = true
  exodus = true
  perf_graph = true
[]

GCMR Core Description
Mesh
Cross - Section Generation Using Serpent Code
Note on LFS files linked to Serpent Model
Griffin Model
Run Commands
Results
References