OpenMC/scripts/example_geometry.py
2018-02-13 15:08:05 -06:00

357 lines
12 KiB
Python

"""An example file showing how to make a geometry.
This particular example creates a 3x3 geometry, with 8 regular pins and one
Gd-157 2 wt-percent enriched. All pins are segmented.
"""
from collections import OrderedDict
import math
import numpy as np
import openmc
from openmc.deplete import density_to_mat
def generate_initial_number_density():
""" Generates initial number density.
These results were from a CASMO5 run in which the gadolinium pin was
loaded with 2 wt percent of Gd-157.
"""
# Concentration to be used for all fuel pins
fuel_dict = OrderedDict()
fuel_dict['U235'] = 1.05692e21
fuel_dict['U234'] = 1.00506e19
fuel_dict['U238'] = 2.21371e22
fuel_dict['O16'] = 4.62954e22
fuel_dict['O17'] = 1.127684e20
fuel_dict['I135'] = 1.0e10
fuel_dict['Xe135'] = 1.0e10
fuel_dict['Xe136'] = 1.0e10
fuel_dict['Cs135'] = 1.0e10
fuel_dict['Gd156'] = 1.0e10
fuel_dict['Gd157'] = 1.0e10
# fuel_dict['O18'] = 9.51352e19 # Does not exist in ENDF71, merged into 17
# Concentration to be used for the gadolinium fuel pin
fuel_gd_dict = OrderedDict()
fuel_gd_dict['U235'] = 1.03579e21
fuel_gd_dict['U238'] = 2.16943e22
fuel_gd_dict['Gd156'] = 3.95517E+10
fuel_gd_dict['Gd157'] = 1.08156e20
fuel_gd_dict['O16'] = 4.64035e22
fuel_dict['I135'] = 1.0e10
fuel_dict['Xe136'] = 1.0e10
fuel_dict['Xe135'] = 1.0e10
fuel_dict['Cs135'] = 1.0e10
# There are a whole bunch of 1e-10 stuff here.
# Concentration to be used for cladding
clad_dict = OrderedDict()
clad_dict['O16'] = 3.07427e20
clad_dict['O17'] = 7.48868e17
clad_dict['Cr50'] = 3.29620e18
clad_dict['Cr52'] = 6.35639e19
clad_dict['Cr53'] = 7.20763e18
clad_dict['Cr54'] = 1.79413e18
clad_dict['Fe54'] = 5.57350e18
clad_dict['Fe56'] = 8.74921e19
clad_dict['Fe57'] = 2.02057e18
clad_dict['Fe58'] = 2.68901e17
clad_dict['Cr50'] = 3.29620e18
clad_dict['Cr52'] = 6.35639e19
clad_dict['Cr53'] = 7.20763e18
clad_dict['Cr54'] = 1.79413e18
clad_dict['Ni58'] = 2.51631e19
clad_dict['Ni60'] = 9.69278e18
clad_dict['Ni61'] = 4.21338e17
clad_dict['Ni62'] = 1.34341e18
clad_dict['Ni64'] = 3.43127e17
clad_dict['Zr90'] = 2.18320e22
clad_dict['Zr91'] = 4.76104e21
clad_dict['Zr92'] = 7.27734e21
clad_dict['Zr94'] = 7.37494e21
clad_dict['Zr96'] = 1.18814e21
clad_dict['Sn112'] = 4.67352e18
clad_dict['Sn114'] = 3.17992e18
clad_dict['Sn115'] = 1.63814e18
clad_dict['Sn116'] = 7.00546e19
clad_dict['Sn117'] = 3.70027e19
clad_dict['Sn118'] = 1.16694e20
clad_dict['Sn119'] = 4.13872e19
clad_dict['Sn120'] = 1.56973e20
clad_dict['Sn122'] = 2.23076e19
clad_dict['Sn124'] = 2.78966e19
# Gap concentration
# Funny enough, the example problem uses air.
gap_dict = OrderedDict()
gap_dict['O16'] = 7.86548e18
gap_dict['O17'] = 2.99548e15
gap_dict['N14'] = 3.38646e19
gap_dict['N15'] = 1.23717e17
# Concentration to be used for coolant
# No boron
cool_dict = OrderedDict()
cool_dict['H1'] = 4.68063e22
cool_dict['O16'] = 2.33427e22
cool_dict['O17'] = 8.89086e18
# Store these dictionaries in the initial conditions dictionary
initial_density = OrderedDict()
initial_density['fuel_gd'] = fuel_gd_dict
initial_density['fuel'] = fuel_dict
initial_density['gap'] = gap_dict
initial_density['clad'] = clad_dict
initial_density['cool'] = cool_dict
# Set up libraries to use
temperature = OrderedDict()
sab = OrderedDict()
# Toggle betweeen MCNP and NNDC data
MCNP = False
if MCNP:
temperature['fuel_gd'] = 900.0
temperature['fuel'] = 900.0
# We approximate temperature of everything as 600K, even though it was
# actually 580K.
temperature['gap'] = 600.0
temperature['clad'] = 600.0
temperature['cool'] = 600.0
else:
temperature['fuel_gd'] = 293.6
temperature['fuel'] = 293.6
temperature['gap'] = 293.6
temperature['clad'] = 293.6
temperature['cool'] = 293.6
sab['cool'] = 'c_H_in_H2O'
# Set up burnable materials
burn = OrderedDict()
burn['fuel_gd'] = True
burn['fuel'] = True
burn['gap'] = False
burn['clad'] = False
burn['cool'] = False
return temperature, sab, initial_density, burn
def segment_pin(n_rings, n_wedges, r_fuel, r_gap, r_clad):
""" Calculates a segmented pin.
Separates a pin with n_rings and n_wedges. All cells have equal volume.
Pin is centered at origin.
"""
# Calculate all the volumes of interest
v_fuel = math.pi * r_fuel**2
v_gap = math.pi * r_gap**2 - v_fuel
v_clad = math.pi * r_clad**2 - v_fuel - v_gap
v_ring = v_fuel / n_rings
v_segment = v_ring / n_wedges
# Compute ring radiuses
r_rings = np.zeros(n_rings)
for i in range(n_rings):
r_rings[i] = math.sqrt(1.0/(math.pi) * v_ring * (i+1))
# Compute thetas
theta = np.linspace(0, 2*math.pi, n_wedges + 1)
# Compute surfaces
fuel_rings = [openmc.ZCylinder(x0=0, y0=0, R=r_rings[i])
for i in range(n_rings)]
fuel_wedges = [openmc.Plane(A=math.cos(theta[i]), B=math.sin(theta[i]))
for i in range(n_wedges)]
gap_ring = openmc.ZCylinder(x0=0, y0=0, R=r_gap)
clad_ring = openmc.ZCylinder(x0=0, y0=0, R=r_clad)
# Create cells
fuel_cells = []
if n_wedges == 1:
for i in range(n_rings):
cell = openmc.Cell(name='fuel')
if i == 0:
cell.region = -fuel_rings[0]
else:
cell.region = +fuel_rings[i-1] & -fuel_rings[i]
fuel_cells.append(cell)
else:
for i in range(n_rings):
for j in range(n_wedges):
cell = openmc.Cell(name='fuel')
if i == 0:
if j != n_wedges-1:
cell.region = (-fuel_rings[0]
& +fuel_wedges[j]
& -fuel_wedges[j+1])
else:
cell.region = (-fuel_rings[0]
& +fuel_wedges[j]
& -fuel_wedges[0])
else:
if j != n_wedges-1:
cell.region = (+fuel_rings[i-1]
& -fuel_rings[i]
& +fuel_wedges[j]
& -fuel_wedges[j+1])
else:
cell.region = (+fuel_rings[i-1]
& -fuel_rings[i]
& +fuel_wedges[j]
& -fuel_wedges[0])
fuel_cells.append(cell)
# Gap ring
gap_cell = openmc.Cell(name='gap')
gap_cell.region = +fuel_rings[-1] & -gap_ring
fuel_cells.append(gap_cell)
# Clad ring
clad_cell = openmc.Cell(name='clad')
clad_cell.region = +gap_ring & -clad_ring
fuel_cells.append(clad_cell)
# Moderator
mod_cell = openmc.Cell(name='cool')
mod_cell.region = +clad_ring
fuel_cells.append(mod_cell)
# Form universe
fuel_u = openmc.Universe()
fuel_u.add_cells(fuel_cells)
return fuel_u, v_segment, v_gap, v_clad
def generate_geometry(n_rings, n_wedges):
""" Generates example geometry.
This function creates the initial geometry, a 9 pin reflective problem.
One pin, containing gadolinium, is discretized into sectors.
In addition to what one would do with the general OpenMC geometry code, it
is necessary to create a dictionary, volume, that maps a cell ID to a
volume. Further, by naming cells the same as the above materials, the code
can automatically handle the mapping.
Parameters
----------
n_rings : int
Number of rings to generate for the geometry
n_wedges : int
Number of wedges to generate for the geometry
"""
pitch = 1.26197
r_fuel = 0.412275
r_gap = 0.418987
r_clad = 0.476121
n_pin = 3
# This table describes the 'fuel' to actual type mapping
# It's not necessary to do it this way. Just adjust the initial conditions
# below.
mapping = ['fuel', 'fuel', 'fuel',
'fuel', 'fuel_gd', 'fuel',
'fuel', 'fuel', 'fuel']
# Form pin cell
fuel_u, v_segment, v_gap, v_clad = segment_pin(n_rings, n_wedges, r_fuel, r_gap, r_clad)
# Form lattice
all_water_c = openmc.Cell(name='cool')
all_water_u = openmc.Universe(cells=(all_water_c, ))
lattice = openmc.RectLattice()
lattice.pitch = [pitch]*2
lattice.lower_left = [-pitch*n_pin/2, -pitch*n_pin/2]
lattice_array = [[fuel_u for i in range(n_pin)] for j in range(n_pin)]
lattice.universes = lattice_array
lattice.outer = all_water_u
# Bound universe
x_low = openmc.XPlane(x0=-pitch*n_pin/2, boundary_type='reflective')
x_high = openmc.XPlane(x0=pitch*n_pin/2, boundary_type='reflective')
y_low = openmc.YPlane(y0=-pitch*n_pin/2, boundary_type='reflective')
y_high = openmc.YPlane(y0=pitch*n_pin/2, boundary_type='reflective')
z_low = openmc.ZPlane(z0=-10, boundary_type='reflective')
z_high = openmc.ZPlane(z0=10, boundary_type='reflective')
# Compute bounding box
lower_left = [-pitch*n_pin/2, -pitch*n_pin/2, -10]
upper_right = [pitch*n_pin/2, pitch*n_pin/2, 10]
root_c = openmc.Cell(fill=lattice)
root_c.region = (+x_low & -x_high
& +y_low & -y_high
& +z_low & -z_high)
root_u = openmc.Universe(universe_id=0, cells=(root_c, ))
geometry = openmc.Geometry(root_u)
v_cool = pitch**2 - (v_gap + v_clad + n_rings * n_wedges * v_segment)
# Store volumes for later usage
volume = {'fuel': v_segment, 'gap':v_gap, 'clad':v_clad, 'cool':v_cool}
return geometry, volume, mapping, lower_left, upper_right
def generate_problem(n_rings=5, n_wedges=8):
""" Merges geometry and materials.
This function initializes the materials for each cell using the dictionaries
provided by generate_initial_number_density. It is assumed a cell named
'fuel' will have further region differentiation (see mapping).
Parameters
----------
n_rings : int, optional
Number of rings to generate for the geometry
n_wedges : int, optional
Number of wedges to generate for the geometry
"""
# Get materials dictionary, geometry, and volumes
temperature, sab, initial_density, burn = generate_initial_number_density()
geometry, volume, mapping, lower_left, upper_right = generate_geometry(n_rings, n_wedges)
# Apply distribmats, fill geometry
cells = geometry.root_universe.get_all_cells()
for cell_id in cells:
cell = cells[cell_id]
if cell.name == 'fuel':
omc_mats = []
for cell_type in mapping:
omc_mat = density_to_mat(initial_density[cell_type])
if cell_type in sab:
omc_mat.add_s_alpha_beta(sab[cell_type])
omc_mat.temperature = temperature[cell_type]
omc_mat.depletable = burn[cell_type]
omc_mat.volume = volume['fuel']
omc_mats.append(omc_mat)
cell.fill = omc_mats
elif cell.name != '':
omc_mat = density_to_mat(initial_density[cell.name])
if cell.name in sab:
omc_mat.add_s_alpha_beta(sab[cell.name])
omc_mat.temperature = temperature[cell.name]
omc_mat.depletable = burn[cell.name]
omc_mat.volume = volume[cell.name]
cell.fill = omc_mat
return geometry, lower_left, upper_right