Add test for heating by nuclide

tests/unit_tests/test_heating_by_nuclide.py

@@ -0,0 +1,57 @@
+import openmc
+import pytest
+
+from tests.testing_harness import config
+
+
+@pytest.fixture
+def model():
+    # Create simple sphere model
+    model = openmc.Model()
+    mat = openmc.Material()
+    mat.add_nuclide('U235', 1.0)
+    mat.add_nuclide('H1', 1.0)
+    mat.set_density('g/cm3', 5.0)
+    sph = openmc.Sphere(r=10.0, boundary_type='vacuum')
+    cell = openmc.Cell(fill=mat, region=-sph)
+    model.geometry = openmc.Geometry([cell])
+    model.settings.particles = 1000
+    model.settings.inactive = 0
+    model.settings.batches = 5
+    model.settings.photon_transport = True
+
+    # Add two tallies, one with heating by nuclide and one with total heating
+    particle_filter = openmc.ParticleFilter(['neutron', 'photon'])
+    heating_by_nuclide = openmc.Tally()
+    heating_by_nuclide.filters = [particle_filter]
+    heating_by_nuclide.nuclides = ['U235', 'H1']
+    heating_by_nuclide.scores = ['heating']
+
+    heating_total = openmc.Tally()
+    heating_total.filters = [particle_filter]
+    heating_total.scores = ['heating']
+    model.tallies.extend([heating_by_nuclide, heating_total])
+
+    return model
+
+
+def test_heating_by_nuclide(model, run_in_tmpdir):
+    # If running in MPI mode, setup proper keyword arguments for run()
+    kwargs = {'openmc_exec': config['exe']}
+    if config['mpi']:
+        kwargs['mpi_args'] = [config['mpiexec'], '-n', config['mpi_np']]
+    sp_path = model.run(**kwargs)
+
+    # Get tallies from resulting statepoint
+    with openmc.StatePoint(sp_path) as sp:
+        heating_by_nuclide = sp.tallies[model.tallies[0].id]
+        heating_total = sp.tallies[model.tallies[1].id]
+
+    for particle in heating_by_nuclide.filters[0].bins:
+        # Get slice of each tally corresponding to a single particle
+        kwargs = {'filters': [openmc.ParticleFilter], 'filter_bins': [(particle,)]}
+        particle_slice_by_nuclide = heating_by_nuclide.get_values(**kwargs)
+        particle_slice_total = heating_total.get_values(**kwargs)
+
+        # Summing over nuclides should equal total
+        assert particle_slice_by_nuclide.sum() == pytest.approx(particle_slice_total.sum())