From 36f229eb01de0a8cb7d482d9a9b7a2f2c615f3f5 Mon Sep 17 00:00:00 2001 From: Paul Romano Date: Thu, 29 Jun 2023 04:06:35 -0500 Subject: [PATCH] Remove initial dilute nuclides in MicroXS (#2579) --- openmc/deplete/microxs.py | 125 ++++++------------ tests/regression_tests/microxs/test.py | 9 +- .../microxs/test_reference.csv | 24 ++-- 3 files changed, 57 insertions(+), 101 deletions(-) diff --git a/openmc/deplete/microxs.py b/openmc/deplete/microxs.py index 535f06a2c8d..050389cc26d 100644 --- a/openmc/deplete/microxs.py +++ b/openmc/deplete/microxs.py @@ -5,14 +5,13 @@ """ import tempfile -from copy import deepcopy from pandas import DataFrame, read_csv, Series import numpy as np from openmc.checkvalue import check_type, check_value, check_iterable_type from openmc.exceptions import DataError -from openmc import StatePoint, Materials +from openmc import StatePoint import openmc from .chain import Chain, REACTIONS from .coupled_operator import _find_cross_sections, _get_nuclides_with_data @@ -31,9 +30,10 @@ class MicroXS(DataFrame): @classmethod def from_model(cls, model, - reaction_domain, + domain, + nuclides=None, + reactions=None, chain_file=None, - dilute_initial=1.0e3, energy_bounds=(0, 20e6), run_kwargs=None): """Generate a one-group cross-section dataframe using OpenMC. @@ -44,17 +44,19 @@ def from_model(cls, ---------- model : openmc.Model OpenMC model object. Must contain geometry, materials, and settings. - reaction_domain : openmc.Material or openmc.Cell or openmc.Universe or openmc.RegularMesh + domain : openmc.Material or openmc.Cell or openmc.Universe Domain in which to tally reaction rates. + nuclides : list of str + Nuclides to get cross sections for. If not specified, all burnable + nuclides from the depletion chain file are used. + reactions : list of str + Reactions to get cross sections for. If not specified, all neutron + reactions listed in the depletion chain file are used. chain_file : str, optional Path to the depletion chain XML file that will be used in depletion simulation. Used to determine cross sections for materials not present in the inital composition. Defaults to ``openmc.config['chain_file']``. - dilute_initial : float, optional - Initial atom density [atoms/cm^3] to add for nuclides that - are zero in initial condition to ensure they exist in the cross - section data. Only done for nuclides with reaction rates. energy_bound : 2-tuple of float, optional Bounds for the energy group. run_kwargs : dict, optional @@ -66,29 +68,40 @@ def from_model(cls, Cross section data in [b] """ - # Set up the reaction tallies + # Save any original tallies on the model original_tallies = model.tallies - original_materials = deepcopy(model.materials) - xs = {} - reactions, burnable_nucs, diluted_materials = cls._add_dilute_nuclides( - chain_file, model, dilute_initial) - model.materials = diluted_materials + # Determine what reactions and nuclides are available in chain + if chain_file is None: + chain_file = openmc.config.get('chain_file') + if chain_file is None: + raise DataError( + "No depletion chain specified and could not find depletion " + "chain in openmc.config['chain_file']" + ) + chain = Chain.from_xml(chain_file) + if reactions is None: + reactions = chain.reactions + if not nuclides: + cross_sections = _find_cross_sections(model) + nuclides_with_data = _get_nuclides_with_data(cross_sections) + nuclides = [nuc.name for nuc in chain.nuclides + if nuc.name in nuclides_with_data] + + # Set up the reaction rate and flux tallies energy_filter = openmc.EnergyFilter(energy_bounds) - if isinstance(reaction_domain, openmc.Material): - domain_filter = openmc.MaterialFilter([reaction_domain]) - elif isinstance(reaction_domain, openmc.Cell): - domain_filter = openmc.CellFilter([reaction_domain]) - elif isinstance(reaction_domain, openmc.Universe): - domain_filter = openmc.UniverseFilter([reaction_domain]) + if isinstance(domain, openmc.Material): + domain_filter = openmc.MaterialFilter([domain]) + elif isinstance(domain, openmc.Cell): + domain_filter = openmc.CellFilter([domain]) + elif isinstance(domain, openmc.Universe): + domain_filter = openmc.UniverseFilter([domain]) else: - raise ValueError(f"Unsupported domain type: {type(reaction_domain)}") + raise ValueError(f"Unsupported domain type: {type(domain)}") - # TODO: Right now, we use all nuclides from the material but it probably - # should be based on the burnable nuclides rr_tally = openmc.Tally(name='MicroXS RR') rr_tally.filters = [domain_filter, energy_filter] - rr_tally.nuclides = reaction_domain.get_nuclides() + rr_tally.nuclides = nuclides rr_tally.multiply_density = False rr_tally.scores = reactions @@ -126,68 +139,8 @@ def from_model(cls, # Revert to the original tallies and materials model.tallies = original_tallies - model.materials = original_materials - - return cls(series) - - @classmethod - def _add_dilute_nuclides(cls, chain_file, model, dilute_initial): - """ - Add nuclides not present in burnable materials that have neutron data - and are present in the depletion chain to those materials. This allows - us to tally those specific nuclides for reactions to create one-group - cross sections. - - Parameters - ---------- - chain_file : str - Path to the depletion chain XML file that will be used in depletion - simulation. Used to determine cross sections for materials not - present in the inital composition. - model : openmc.Model - Model object - dilute_initial : float - Initial atom density [atoms/cm^3] to add for nuclides that - are zero in initial condition to ensure they exist in the cross - section data. Only done for nuclides with reaction rates. - Returns - ------- - reactions : list of str - List of reaction names - diluted_materials : openmc.Materials - :class:`openmc.Materials` object with nuclides added to burnable - materials. - """ - if chain_file is None: - chain_file = openmc.config.get('chain_file') - if chain_file is None: - raise DataError( - "No depletion chain specified and could not find depletion " - "chain in openmc.config['chain_file']" - ) - chain = Chain.from_xml(chain_file) - reactions = chain.reactions - cross_sections = _find_cross_sections(model) - nuclides_with_data = _get_nuclides_with_data(cross_sections) - burnable_nucs = [nuc.name for nuc in chain.nuclides - if nuc.name in nuclides_with_data] - diluted_materials = Materials() - for material in model.materials: - if material.depletable: - nuc_densities = material.get_nuclide_atom_densities() - dilute_density = 1.0e-24 * dilute_initial - material.set_density('sum') - for nuc, density in nuc_densities.items(): - material.remove_nuclide(nuc) - material.add_nuclide(nuc, density) - for burn_nuc in burnable_nucs: - if burn_nuc not in nuc_densities: - material.add_nuclide(burn_nuc, - dilute_density) - diluted_materials.append(material) - - return reactions, burnable_nucs, diluted_materials + return cls(series).rename_axis('nuclide') @classmethod def from_array(cls, nuclides, reactions, data): diff --git a/tests/regression_tests/microxs/test.py b/tests/regression_tests/microxs/test.py index f92f61479b9..3d67ee8a38d 100644 --- a/tests/regression_tests/microxs/test.py +++ b/tests/regression_tests/microxs/test.py @@ -40,14 +40,17 @@ def model(): settings = openmc.Settings() settings.particles = 1000 - settings.inactive = 10 - settings.batches = 50 + settings.inactive = 5 + settings.batches = 10 return openmc.Model(geometry, materials, settings) def test_from_model(model): - test_xs = MicroXS.from_model(model, model.materials[0], CHAIN_FILE) + fuel = model.materials[0] + nuclides = ['U234', 'U235', 'U238', 'U236', 'O16', 'O17', 'I135', 'Xe135', + 'Xe136', 'Cs135', 'Gd157', 'Gd156'] + test_xs = MicroXS.from_model(model, fuel, nuclides, chain_file=CHAIN_FILE) if config['update']: test_xs.to_csv('test_reference.csv') diff --git a/tests/regression_tests/microxs/test_reference.csv b/tests/regression_tests/microxs/test_reference.csv index 1804551eb5f..0fc41862d66 100644 --- a/tests/regression_tests/microxs/test_reference.csv +++ b/tests/regression_tests/microxs/test_reference.csv @@ -1,13 +1,13 @@ nuclide,"(n,gamma)",fission -U234,20.548033586079335,0.4951725071956495 -U235,10.593745111766133,48.86980740247932 -U238,0.8607296097035912,0.10623994948321437 -U236,8.697176401063281,0.32148140073986475 -O16,7.503456435273737e-05,0.0 -O17,0.0004107265933745623,0.0 -I135,6.896228129273278,0.0 -Xe135,229100.9245987756,0.0 -Xe136,0.02336047367105298,0.0 -Cs135,2.055822714073886,0.0 -Gd157,12927.465334134899,0.0 -Gd156,3.500756543915523,0.0 +U234,21.418670317831197,0.5014588470882195 +U235,10.343944102483244,47.46718472611891 +U238,0.8741166723597251,0.10829568455139126 +U236,9.083486784689326,0.3325287927011428 +O16,7.548646353912453e-05,0.0 +O17,0.0004018486221310307,0.0 +I135,6.6912565089429235,0.0 +Xe135,223998.64185667288,0.0 +Xe136,0.022934362666193576,0.0 +Cs135,2.28453952223533,0.0 +Gd157,12582.079620036275,0.0 +Gd156,2.9421127515332417,0.0