3. Settings Report

This document lists all 145 settings in ARMI.

They are all accessible to developers through the armi.settings.caseSettings.Settings object, which is typically stored in a variable named cs. Interfaces have access to a simulation’s settings through self.cs.

ARMI Settings

Name	Description	Default	Options
Tin	The inlet temperature of the reactor in C	360.0
Tout	The outlet temperature of the reactor in C	510.0
acceptableBlockAreaError	The limit of error between a block’s cross- sectional area and the reference block used during the assembly area consistency check	1e-05
aclpDoseLimit	Dose limit in dpa used to position the above-core load pad(if one exists)	80.0
assemFlagsToSkipAxialExpa nsion	Assemblies that match a flag on this list will not be axially expanded.	[]
assemblyRotationAlgorithm	The algorithm to use to rotate the detail assemblies while shuffling		['', 'buRe ducingAsse mblyRotati on', 'simp leAssembly Rotation']
assemblyRotationStationar y	Whether or not to rotate assemblies that are not shuffled.This can only be True if ‘rotation’ is true.	False
availabilityFactor	Availability factor of the plant. This is the fraction of the time that the plant is operating. If variable, use availabilityFactors setting.	1.0
availabilityFactors	List of availability factor of each cycle as a fraction (fraction of time plant is not in an outage). R is repeat. For example [0.5, 1.0, ‘9R’] is 1 50% followed by 10 100%. Empty list is constant duration set by availabilityFactor.	[]
axialExpansion	Perform axial fuel expansion. This will adjust fuel block lengths.	False
axialMeshRefinementFactor	Multiplicative factor on the Global Flux number of mesh per block. Used for axial mesh refinement.	1
bcCoefficient	Value for the parameter A of the generalized boundary condition.	0.0
beta	Individual precursor group delayed neutron fractions	None
bondRemoval	Toggles fuel performance bond removal. This will remove thermal bond from the fuel.	False
boundaries	External Neutronic Boundary Conditions. Reflective does not include axial.	Extrapolat ed	['Extrapol ated', 'Re flective', 'Infinite' , 'ZeroSur faceFlux', 'ZeroInwar dCurrent', 'Generaliz ed']
branchVerbosity	Verbosity of the non- primary MPI nodes	error	['debug', 'extra', 'info', 'i mportant', 'prompt', 'warning', 'error']
buGroups	The range of burnups where cross-sections will be the same for a given cross section type (units of %FIMA)	[10, 20, 30]
burnChainFileName	Path to YAML file that has the depletion chain defined in it	burn- chain.yaml
burnSteps	Number of depletion substeps, n, in one cycle. Note: There will be n+1 time nodes and the burnup step time will be computed as cycle length/n when the simple cycles input format is used.	4
burnupPeakingFactor	The peak/avg factor for burnup and DPA. If it is not set the current flux peaking is used (this is typically conservatively high).	0.0
circularRingMode	Toggle between circular ring definitions to hexagonal ring definitions	False
circularRingOrder	Order by which locations are sorted in circular rings for equilibrium shuffling	angle	['angle', 'distance' , 'distanc eSmart']
circularRingPitch	The relative pitch to be used to define a single circular ring in circular shuffling	1.0
claddingStrain	Evaluate cladding strain.	False
claddingWastage	Evaluate cladding wastage.	False
clearXS	Delete all cross section libraries before regenerating them.	False
comment	A comment describing this case
copyFilesFrom	A list of files that need to be copied at the start of a run.	[]
copyFilesTo	A list of directories to copy provided files into at the start of a run.This list can be of length zero (copy to working dir), 1 (copy all files to the same place), or it must be the same length as copyFilesFrom	[]
coverage	Turn on coverage report generation which tracks all the lines of code that execute during a run	False
coverageConfigFile	User-defined coverage configuration file
crossSectionControl	Data structure defining how cross sections are created	<XSSetting s with XS IDs dict_k eys([])>
cycleLength	Duration of one single cycle in days. If availabilityFactor is below 1, the reactor will be at power less than this. If variable, use cycleLengths setting.	365.242199
cycleLengths	List of durations of each cycle in days. The at- power duration will be affected by availabilityFactor. R is repeat. For example [100, 150, ‘9R’] is 1 100 day cycle followed by 10 150 day cycles. Empty list is constant duration set by cycleLength.	[]
cycles	YAML dict defining the cycle history of the case. Options at each cycle include: name, cumulative days, step days, availability factor, cycle length, burn steps, and power fractions. If specified, do not use any of the case settings cycleLength(s), availabilityFactor(s), powerFractions, or burnSteps. Must also specify nCycles and power.	[]
cyclesSkipTightCouplingIn teraction	List of cycle numbers skip tight coupling interaction for. Will still update component temps, etc during these cycles, will just not iterate a second (or more) time.	[]
db	Write the state information to a database at every timestep	True
debugMem	Turn on memory debugging options to help find problems with the code	False
debugMemSize	Show size of objects during memory debugging	False
decayConstants	Individual precursor group delayed neutron decay constants	None
defaultSnapshots	Generate snapshots at BOL, MOL, and EOL.	False
deferredInterfaceNames	Interfaces to delay the normal operations of for special circumstance problem avoidance	[]
deferredInterfacesCycle	The supplied list of interface names in deferredInterfaceNames will begin normal operations on this cycle number	0
detailAllAssems	All assemblies will have ‘detailed’ treatment. Note: This option is interpreted differently by different modules.	False
detailAssemLocationsBOL	Assembly locations for assemblies that will have ‘detailed’ treatment. This option will track assemblies in the core at BOL. Note: This option is interpreted differently by different modules.	[]
detailAssemNums	Assembly numbers(IDs) for assemblies that will have ‘detailed’ treatment. This option will track assemblies that not in the core at BOL. Note: This option is interpreted differently by different modules.	[]
detailedAxialExpansion	Allow each assembly to expand independently of the others. Results in non-uniform axial mesh. Neutronics kernel must be able to handle.	False
disableBlockTypeExclusion InXsGeneration	Control which blocks get merged together by the XSGM. If set to None or True then all block types in the XS ID will be considered. If set to False then a default of [‘fuel’] will be used. Can also be set to an exact list of strings for types to consider.	False
doTH	Activate thermal hydraulics calculations.	False
dpaPerFluence	A quick and dirty conversion that is used to get dpaPeak	4.01568627 451e-22
dpaXsSet	The cross sections to use when computing displacements per atom.	dpa_EBRII_ HT9	['', 'dpa_ EBRII_INC6 00', 'dpa_ EBRII_INCX 750', 'dpa _EBRII_HT9 ', 'dpa_EB RII_PE16', 'dpa_EBRII _INC625']
dumpSnapshot	List of snapshots to perform detailed reactor analysis, such as reactivity coefficient generation.	[]
eigenProb	Is this a eigenvalue problem or a fixed source problem?	True
epsEig	Convergence criteria for calculating the eigenvalue in the global flux solver	1e-07
epsFSAvg	Convergence criteria for average fission source	1e-05
epsFSPoint	Convergence criteria for point fission source	1e-05
eqDirect	Does the equilibrium search with repetitive shuffing but with direct shuffling rather than the fast way	False
existingFixedSource	Specify an exiting fixed source input file.		['', 'FIXSRC', 'VARSRC']
explicitRepeatShuffles	Path to file that contains a detailed shuffling history that is to be repeated exactly.
fgRemoval	Toggles fuel performance fission gas removal. This will remove fission gas from the fuel.	False
fissionGasYieldFraction	The fraction of gaseous atoms produced per fission event, assuming a fission product yield of 2.0	0.25
fluxRecon	Perform detailed flux and power reconstruction	False
forceDbParams	A list of parameter names that should always be written to the database, regardless of their Parameter Definition’s typical saveToDB status. This is only honored if the DatabaseInterface is used.	[]
fpModel	This setting is used to determine how fission products are treated in an analysis. By choosing noFissionProducts, no fission products will be added. By selecting, infinitelyDilute, lumped fission products will be initialized to a very small number on the blocks/components that require them. By choosing MO99, the fission products will be represented only by Mo-99. This is a simplistic assumption that is commonly used by fast reactor analyses in scoping calculations and is not necessarily a great assumption for depletion evaluations. Finally, by choosing explicitFissionProducts the fission products will be added explicitly to the blocks/components that are depletable. This is useful for detailed tracking of fission products.	infinitely Dilute	['noFissio nProducts' , 'infinit elyDilute' , 'MO99', 'explicitF issionProd ucts']
fpModelLibrary	This setting should be used when fpModel is set to explicitFissionPr oducts. It is used in conjunction with any nuclideFlags defined in the blueprints to configure all the nuclides that are modeled within the core. Selecting any library option will add all nuclides from the selected library to the model so that analysts do not need to change their inputs when modifying the fission product treatment for calculations.		['', 'MC2-3']
freshFeedType	The type of fresh fuel added to the core, used in certain pre-defined fuel shuffling logic sequences.	feed fuel	['feed fuel', 'igniter fuel', 'inner driver fuel']
fuelHandlerName	The name of the FuelHandler class in the shuffle logic module to activate
fuelPerformanceEngine	Fuel performance engine that determines fission gas removal, bond removal, axial growth, wastage, and cladding strain.		['']
genReports	Employ the use of the reporting utility for ARMI, generating HTML and ASCII summaries of the run	True
genXS	Generate multigroup cross sections for the selected particle type(s) using the specified lattice physics kernel (see Lattice Physics tab). When not set, the XS library will be auto- loaded from an existing ISOTXS in the working directory, but fail if there is no ISOTXS.		['', 'Neutron', 'Neutron and Gamma']
globalFluxActive	Calculate the global flux at each timestep for the selected particle type(s) using the specified neutronics kernel.	Neutron	['', 'Neutron', 'Neutron and Gamma']
gridPlateDpaXsSet	The cross sections to use for grid plate blocks DPA when computing displacements per atom.	dpa_EBRII_ HT9	['', 'dpa_ EBRII_INC6 00', 'dpa_ EBRII_INCX 750', 'dpa _EBRII_HT9 ', 'dpa_EB RII_PE16', 'dpa_EBRII _INC625']
groupStructure	Energy group structure to use in neutronics simulations	ANL33	['ANL9', 'ANL33', 'ANL70', 'ANL116', 'ANL230', 'ANL703', 'ANL1041', 'ANL2082', 'ARMI33', 'ARMI45', '348']
growToFullCoreAfterLoad	Grows from 1/3 to full core after loading a 1/3 symmetric snapshot. Note: This is needed when a full core model is needed and the database was produced using a third core model.	False
independentVariables	List of (independentVarName, value) tuples to inform optimization post- processing	[]
initializeBurnChain	This setting is paired with the burnChainFileName setting. When enabled, this will initialize the burn-chain on initializing the case and is required for running depletion calculations where the transmutations and decays are controlled by the framework. If an external software, such as ORIGEN, contains data for the burn-chain already embedded then this may be disabled.	True
inners	XY and Axial partial current sweep inner iterations. 0 lets the neutronics code pick a default.	0
inputHeightsConsideredHot	This is a flag to determine if block heights, as provided in blueprints, are at hot dimensions. If false, block heights are at cold/as-built dimensions and will be thermally expanded as appropriate.	True
jumpRingNum	The number of hex rings jumped when distributing the feed assemblies in the alternating concentric rings or checkerboard shuffle patterns (convergent / divergent shuffling).	8
latticePhysicsFrequency	Define the frequency at which cross sections are updated with new lattice physics interactions.	BOC	['never', 'BOL', 'BOC', 'ev eryNode', 'firstCoup ledIterati on', 'all']
levelsPerCascade	The number of moves made per cascade when performing convergent or divergent shuffle patterns.	14
lfpCompositionFilePath	Path to the file that contains lumped fission product composition definitions (e.g. equilibrium yields). This is unused when the explicitFissionProducts or MO99 modeling options are selected.	referenceF issionProd ucts.dat
loadFromDBEveryNode	Every node loaded from reference database	False
loadPadElevation	The elevation of the bottom of the above-core load pad (ACLP) in cm from the bottom of the upper grid plate. Used for calculating the load pad dose	0.0
loadPadLength	The length of the load pad. Used to compute average and peak dose.	0.0
loadStyle	Description of how the ARMI case will be initialized	fromInput	['fromInpu t', 'fromDB']
loadingFile	The blueprints/loading input file path containing component dimensions, materials, etc.
makeAllBlockLFPsIndepende nt	Flag to make all blocks have independent lumped fission products. Note that this is forced to be True when the explicitFissionProducts modeling option is selected or an interface named mcnp is on registered on the operator stack.	False
materialNamespaceOrder	Ordered list of Python namespaces for finding materials by class name. This allows users to choose between different implementations of reactor materials. For example, the framework comes with a basic UZr material, but power users will want to override it with their own UZr subclass. This allows users to specify to get materials out of a plugin rather than from the framework.	[]
mcnpLibraryVersion	This setting controls the nuclides in the problem according to the available nuclides in the selected library. For instance, some MCNP libraries contain elemental nuclides while others do not. Only used when MCNP is selected as neutronicsKernel.	B-VII.1	['ENDF/B- V.0', 'END F/B- VII.0', 'E NDF/B- VII.1', 'E NDF/B- VIII.0']
minMeshSizeRatio	This is the minimum ratio of mesh sizes (dP1/(dP1 + dP2)) allowable – only active if automaticVariableMesh flag is set to True	0.15
minimumFissileFraction	Minimum fissile fraction (fissile number densities / heavy metal number densities).	0.045
minimumNuclideDensity	Density to use for nuclides and fission products at infinite dilution. This is also used as the minimum density considered for computing macroscopic cross sections.	1e-15
moduleVerbosity	Verbosity of any module- specific loggers that are set	{}
nCycles	Number of cycles that will be simulated. Fuel management happens at the beginning of each cycle. Can include active (full- power) cycles as well as post-shutdown decay-heat steps. For restart cases, this value should include both cycles from the restart plus any additional cycles to be run after startCycle.	1
nTasks	Number of parallel tasks to request on the cluster	1
neutronicsKernel	The neutronics / depletion solver for global flux solve.
neutronicsType	The type of neutronics solution that is desired.	real	['real', 'adjoint', 'both']
nonUniformAssemFlags	Assemblies that match a flag group on this list will not have their mesh changed with the reference mesh of the core for uniform mesh cases (non-detailed axial expansion). Another plugin may need to make the mesh uniform if necessary.	[]
numberMeshPerEdge	Number of mesh per block edge for finite- difference planar mesh refinement.	1
outers	XY and Axial partial current sweep max outer iterations.	100
outputCacheLocation	Location where cached calculations are stored and retrieved if exactly the same as the calculation requested. Empty string will not cache.
outputFileExtension	The default extension for plots	jpg	['jpg', 'png', 'svg', 'pdf']
plotShuffleArrows	Make plots with arrows showing each move.	False
plots	Generate additional plots throughout the ARMI analysis	False
power	Nameplate thermal power of the reactor. Can be varied by setting the powerFractions setting.	0.0
powerDensity	Thermal power of the Reactor, per gram of Heavy metal mass. Ignore this setting if the power setting is non- zero.	0.0
powerFractions	List of power fractions at each cycle (fraction of rated thermal power the plant achieves). R is repeat. For example [0.5, 1.0, ‘9R’] is 1 50% followed by 10 100%. Specify zeros to indicate decay-only cycles (i.e. for decay heat analysis). None implies always full rated power.	[]
profile	Turn on the profiler for the submitted case. The profiler results will not include all import times.	False
reloadDBName	Name of the database file to load initial conditions from
removePerCycle	The number of fuel assemblies removed per cycle at equilibrium.	3
restartNeutronics	Restart global flux case using outputs from last time as a guess	False
rmExternalFilesAtBOC	Clean up files at the beginning of each cycle (BOC)	False
rmExternalFilesAtEOL	Clean up intermediate files after the run completes (EOL)	False
runLatticePhysicsBeforeSh uffling	Forces the Generation of Cross Sections Prior to Shuffling the Fuel Assemblies. Note: This is recommended when performing equilibrium shuffling branching searches.	False
runType	Type of run that this is, e.g. a normal run through all cycles, a snapshot- loaded reactivity coefficient run, etc.	Standard	['Standard ', 'Equili brium', 'S napshots']
savePhysicsFiles	List of snapshots to dump reactor physics kernel input and output files. Can be used to perform follow-on analysis.	[]
shuffleLogic	Path to a Python script or dotted module path that handles the fuel shuffling for this case. This is user-defined per run as a dynamic input.
shuffleSequenceFile	Path to a YAML file defining a custom shuffle sequence
skipCycles	Number of cycles to be skipped during the calculation. Note: This is typically used when repeating only a portion of a calculation or repeating a run.	0
sortReactor	If unsorted, ArmiObject IDs will be by the order they were added to the Reactor.	True
startCycle	Cycle number to continue calculation from. Database will load from the time step just before. For snapshots use dumpSnapshot.	0
startNode	Timenode number (0 for BOC, etc.) to continue calculation from. Database will load from the time step just before.	0
stationaryBlockFlags	Blocks with these flags will not move in moves. Used for fuel management.	['GRID_PLA TE']
summarizeAssemDesign	Print a summary of the assembly design details at BOL	True
syncDbAfterWrite	Copy the output database from the fast scratch space to the shared network drive after each write.	True
targetK	Target criticality (k-effective) for cycle length, branch, and equilibrium search	1.005
tempGroups	The range of fuel temperatures where cross- sections will be the same for a given cross section type (units of degrees C)	[]
tightCoupling	Boolean to turn on/off tight coupling	False
tightCouplingMaxNumIters	Maximum number of iterations for tight coupling.	4
tightCouplingSettings	Data structure defining the tight coupling parameters and convergence criteria for each interface.	<TightCoup lingSettin gs with Interface functions dict_keys( [])>
tolerateBurnupChange	Burnup window for computing cross sections. If the prior cross sections were computed within the window, new cross sections will not be generated and the prior calculated cross sections will be used.	0.0
trace	Activate Python trace module to print out each line as it’s executed	False
trackAssems	Retain discharged assemblies in a spent fuel pool so their histories can be analyzed or the assemblies reused. Turning this off removes discharged assemblies to minimize memory and database size. Assemblies explicitly discharged to the spent fuel pool remain regardless, allowing selective tracking.	False
uniformMeshMinimumSize	Minimum mesh size used when generating an axial mesh for the uniform mesh converter. Providing a value for this setting allows fuel and control material boundaries to be enforced better in uniform mesh.	None
userPlugins	YAML list defining the locations of UserPlugin subclasses. You can enter the full ARMI import path: armi.test.test_wha t.MyPlugin, or you can enter the full file path: /path/to/my/pluginz.py:My Plugin	[]
verbosity	How verbose the output will be	info	['debug', 'extra', 'info', 'i mportant', 'prompt', 'warning', 'error']
versions	Versions of ARMI, and any Apps or Plugins that register a version here.	{}
xsBlockRepresentation	The type of averaging to perform when creating cross sections for a group of blocks	Average	['Median', 'Average', 'FluxWeigh tedAverage ', 'Compon entAverage 1DSlab']
xsBucklingConvergence	Convergence criteria for the buckling iteration if it is available in the lattice physics solver	1e-05
xsEigenvalueConvergence	Convergence criteria for the eigenvalue in the lattice physics kernel	1e-05
xsKernel	Method to determine broad group cross sections for assemblies	MC2v3	['', 'MC2v2', 'MC2v3', ' MC2v3- PARTISN', 'SERPENT']
xsScatteringOrder	Scattering order for the lattice physics calculation	3
zoneDefinitions	Manual definitions of zones as lists of assembly locations (e.g. “zoneName: loc1, loc2, loc3”) . Zones are groups of assemblies used by various summary and calculation routines. See also zonesFile for an alternative method of specifying zones.	[]
zonesFile	Input file containing the definition of Zones to be applied to the reactor. See also zoneDefinitions for an alternative method of specifying zones.