mirror of
https://github.com/openmc-dev/openmc.git
synced 2026-07-24 12:05:32 -04:00
773757246b
- update references in docstrings and docpages - minor adjustments to related docs in deplete module files - retain backwards compatiblity by exporint Operator alias
266 lines
7.5 KiB
ReStructuredText
266 lines
7.5 KiB
ReStructuredText
.. _pythonapi_deplete:
|
|
|
|
.. module:: openmc.deplete
|
|
|
|
----------------------------------
|
|
:mod:`openmc.deplete` -- Depletion
|
|
----------------------------------
|
|
|
|
Primary API
|
|
-----------
|
|
|
|
The two primary requirements to perform depletion with :mod:`openmc.deplete`
|
|
are:
|
|
|
|
1) A reaction rate operator
|
|
2) A time-integration scheme
|
|
|
|
The former is responsible for obtaining transmuation reaction rates. The latter
|
|
is responsible for projecting reaction rates and compositions forward in
|
|
calendar time across some step size :math:`\Delta t`, and obtaining new
|
|
compositions given a power or power density. The :class:`CoupledOperator` class
|
|
is provided to obtain reaction rates via tallies through OpenMC's transport
|
|
solver, and the :class:`IndependentOperator` class is provided to obtain
|
|
reaction rates from cross-section data. Several classes are provided that
|
|
implement different time-integration algorithms for depletion calculations,
|
|
which are described in detail in Colin Josey's thesis, `Development and
|
|
analysis of high order neutron transport-depletion coupling algorithms
|
|
<http://hdl.handle.net/1721.1/113721>`_.
|
|
|
|
.. autosummary::
|
|
:toctree: generated
|
|
:nosignatures:
|
|
:template: myintegrator.rst
|
|
|
|
PredictorIntegrator
|
|
CECMIntegrator
|
|
CELIIntegrator
|
|
CF4Integrator
|
|
EPCRK4Integrator
|
|
LEQIIntegrator
|
|
SICELIIntegrator
|
|
SILEQIIntegrator
|
|
|
|
Each of these classes expects a "reaction rate operator" to be passed. Operators
|
|
provided by OpenMC are available using the following classes:
|
|
|
|
.. autosummary::
|
|
:toctree: generated
|
|
:nosignatures:
|
|
:template: mycallable.rst
|
|
|
|
CoupledOperator
|
|
IndependentOperator
|
|
|
|
The :class:`CoupledOperator` and :class:`IndependentOperator` classes must also
|
|
have some knowledge of how nuclides transmute and decay. This is handled by the
|
|
:class:`Chain`.
|
|
|
|
Minimal Example
|
|
---------------
|
|
|
|
A minimal example for performing depletion would be:
|
|
|
|
.. code::
|
|
|
|
>>> import openmc
|
|
>>> import openmc.deplete
|
|
>>> geometry = openmc.Geometry.from_xml()
|
|
>>> settings = openmc.Settings.from_xml()
|
|
>>> model = openmc.model.Model(geometry, settings)
|
|
|
|
# Representation of a depletion chain
|
|
>>> chain_file = "chain_casl.xml"
|
|
>>> operator = openmc.deplete.CoupledOperator(
|
|
... model, chain_file)
|
|
|
|
# Set up 5 time steps of one day each
|
|
>>> dt = [24 * 60 * 60] * 5
|
|
>>> power = 1e6 # constant power of 1 MW
|
|
|
|
# Deplete using mid-point predictor-corrector
|
|
>>> cecm = openmc.deplete.CECMIntegrator(
|
|
... operator, dt, power)
|
|
>>> cecm.integrate()
|
|
|
|
Internal Classes and Functions
|
|
------------------------------
|
|
|
|
When running in parallel using `mpi4py
|
|
<https://mpi4py.readthedocs.io/en/stable/>`_, the MPI intercommunicator used can
|
|
be changed by modifying the following module variable. If it is not explicitly
|
|
modified, it defaults to ``mpi4py.MPI.COMM_WORLD``.
|
|
|
|
.. data:: comm
|
|
|
|
MPI intercommunicator used to call OpenMC library
|
|
|
|
:type: mpi4py.MPI.Comm
|
|
|
|
During a depletion calculation, the depletion chain, reaction rates, and number
|
|
densities are managed through a series of internal classes that are not normally
|
|
visible to a user. However, should you find yourself wondering about these
|
|
classes (e.g., if you want to know what decay modes or reactions are present in
|
|
a depletion chain), they are documented here. The following classes store data
|
|
for a depletion chain:
|
|
|
|
.. autosummary::
|
|
:toctree: generated
|
|
:nosignatures:
|
|
:template: myclass.rst
|
|
|
|
Chain
|
|
DecayTuple
|
|
Nuclide
|
|
ReactionTuple
|
|
FissionYieldDistribution
|
|
FissionYield
|
|
|
|
The :class:`Chain` class uses information from the following module variable:
|
|
|
|
.. data:: chain.REACTIONS
|
|
|
|
Dictionary that maps transmutation reaction names to information needed when
|
|
a chain is being generated: MT values, the change in atomic/mass numbers
|
|
resulting from the reaction, and what secondaries are produced.
|
|
|
|
:type: dict
|
|
|
|
The following classes are used during a depletion simulation and store auxiliary
|
|
data, such as number densities and reaction rates for each material.
|
|
|
|
.. autosummary::
|
|
:toctree: generated
|
|
:nosignatures:
|
|
:template: myclass.rst
|
|
|
|
AtomNumber
|
|
MicroXS
|
|
OperatorResult
|
|
ReactionRates
|
|
Results
|
|
StepResult
|
|
|
|
The following class and functions are used to solve the depletion equations,
|
|
with :func:`cram.CRAM48` being the default.
|
|
|
|
.. autosummary::
|
|
:toctree: generated
|
|
:nosignatures:
|
|
:template: myintegrator.rst
|
|
|
|
cram.IPFCramSolver
|
|
|
|
.. autosummary::
|
|
:toctree: generated
|
|
:nosignatures:
|
|
:template: myfunction.rst
|
|
|
|
cram.CRAM16
|
|
cram.CRAM48
|
|
pool.deplete
|
|
|
|
.. data:: pool.USE_MULTIPROCESSING
|
|
|
|
Boolean switch to enable or disable the use of :mod:`multiprocessing`
|
|
when solving the Bateman equations. The default is to use
|
|
:mod:`multiprocessing`, but can cause the simulation to hang in
|
|
some computing environments, namely due to MPI and networking
|
|
restrictions. Disabling this option will result in only a single
|
|
CPU core being used for depletion.
|
|
|
|
:type: bool
|
|
|
|
.. data:: pool.NUM_PROCESSES
|
|
|
|
Number of worker processes used for depletion calculations, which rely on the
|
|
:class:`multiprocessing.pool.Pool` class. If set to ``None`` (default), the
|
|
number returned by :func:`os.cpu_count` is used.
|
|
|
|
The following classes are used to help the :class:`openmc.deplete.CoupledOperator`
|
|
compute quantities like effective fission yields, reaction rates, and
|
|
total system energy.
|
|
|
|
.. autosummary::
|
|
:toctree: generated
|
|
:nosignatures:
|
|
:template: myclass.rst
|
|
|
|
helpers.AveragedFissionYieldHelper
|
|
helpers.ChainFissionHelper
|
|
helpers.ConstantFissionYieldHelper
|
|
helpers.DirectReactionRateHelper
|
|
helpers.EnergyScoreHelper
|
|
helpers.FissionYieldCutoffHelper
|
|
helpers.FluxCollapseHelper
|
|
|
|
The :class:`openmc.deplete.IndependentOperator` uses inner class subclassed from
|
|
those listed to perform similar calculations.
|
|
|
|
Intermediate Classes
|
|
--------------------
|
|
|
|
Specific implementations of abstract base classes may utilize some of
|
|
the same methods and data structures. These methods and data are stored
|
|
in intermediate classes.
|
|
|
|
Methods common to tally-based implementation of :class:`FissionYieldHelper`
|
|
are stored in :class:`helpers.TalliedFissionYieldHelper`
|
|
|
|
.. autosummary::
|
|
:toctree: generated
|
|
:nosignatures:
|
|
:template: myclass.rst
|
|
|
|
helpers.TalliedFissionYieldHelper
|
|
|
|
Methods common to OpenMC-specific implementations of :class:`TransportOperator`
|
|
are stored in :class:`openmc_operator.OpenMCOperator`
|
|
|
|
.. autosummary::
|
|
:toctree: generated
|
|
:nosignatures:
|
|
:template: mycallable.rst
|
|
|
|
openmc_operator.OpenMCOperator
|
|
|
|
|
|
Abstract Base Classes
|
|
---------------------
|
|
|
|
A good starting point for extending capabilities in :mod:`openmc.deplete` is
|
|
to examine the following abstract base classes. Custom classes can
|
|
inherit from :class:`abc.TransportOperator` to implement alternative
|
|
schemes for collecting reaction rates and other data from a transport code
|
|
prior to depleting materials
|
|
|
|
.. autosummary::
|
|
:toctree: generated
|
|
:nosignatures:
|
|
:template: mycallable.rst
|
|
|
|
abc.TransportOperator
|
|
|
|
The following classes are abstract classes used to pass information from
|
|
OpenMC simulations back on to the :class:`abc.TransportOperator`
|
|
|
|
.. autosummary::
|
|
:toctree: generated
|
|
:nosignatures:
|
|
:template: myclass.rst
|
|
|
|
abc.NormalizationHelper
|
|
abc.FissionYieldHelper
|
|
abc.ReactionRateHelper
|
|
|
|
Custom integrators or depletion solvers can be developed by subclassing from
|
|
the following abstract base classes:
|
|
|
|
.. autosummary::
|
|
:toctree: generated
|
|
:nosignatures:
|
|
:template: myintegrator.rst
|
|
|
|
abc.Integrator
|
|
abc.SIIntegrator
|
|
abc.DepSystemSolver
|