2.4. Settings Report

This document lists all the 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.	[]
assemPowSummary	Print a summary of how much power is in each assembly type at every timenode	False
assemblyRotationAlgorithm	The algorithm to use to rotate the detail assemblies while shuffling		['', 'buReducingAssemblyR otation', 'simpleAssemblyRotation']
assemblyRotationStationar y	Whether or not to rotate assemblies that are not shuffled.This can only be True if ‘rotation’ is true.	False
autoGenerateBlockGrids	Should block blueprints attempt to auto-generate a spatial grid upon construction? This feature makes heavy use of multi-index locations, which are not yet universally supported.	True
automaticVariableMesh	Flag to let ARMI add additional mesh points if the neutronics mesh is too irregular	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	['Extrapolated', 'Reflective', 'Infinite', 'ZeroSurfaceFlux', 'ZeroInwardCurrent', 'Generalized']
branchVerbosity	Verbosity of the non- primary MPI nodes	error	['debug', 'extra', 'info', 'important', 'prompt', 'warning', 'error']
buGroups	The range of burnups where cross-sections will be the same for a given assembly type (units of %FIMA)	[10, 20, 30, 100]
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	None	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', 'distanceSmart']
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	None	[]
copyFilesTo	None	[]
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([])>
customFuelManagementIndex	An index that determines which of various options is used in management. Useful for optimization sweeps.	0
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 list 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
dbStorageAfterCycle	Only store cycles after this cycle in the database (to save storage space)	0
debug	None	False
debugDB	debugDB	False
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	Use all blocks in a cross section group when generating a representative block. When this is disabled only fuel blocks will be considered	False
doOrificedTH	Perform orificed thermal hydraulics (requires bounds file from a previous case)	False
doTH	Activate thermal hydraulics calculations using the physics module defined in thKernel	False
dpaPerFluence	A quick and dirty conversion that is used to get dpaPeak by multiplying the factor and fastFluencePeak	4.01568627 451e-22
dpaXsSet	The cross sections to use when computing displacements per atom.	dpa_EBRII_ HT9	['', 'dpa_EBRII_INC600', 'dpa_EBRII_INCX750', 'dpa_EBRII_HT9', 'dpa_EBRII_PE16', 'dpa_EBRII_INC625']
dumpSnapshot	List of snapshots to perform detailed reactor analysis, such as reactivity coefficient generation.	[]
eigenProb	Whether this is 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	['noFissionProducts', 'infinitelyDilute', 'MO99', 'explicitFissionP roducts']
fpModelLibrary	This setting can used when the fpModel setting is set to explicitFissionProducts and is used to configure all the nuclides that should be modeled within the core. Setting this is equivalent to adding all nuclides in the selected code library (i.e., MC2-3) within the blueprints nuclideFlags to be [xs:true, burn:false]. This option acts as a short-cut so that analysts do not need to change their inputs when modifying the fission product treatment for calculations. This may be extended for other cross section generation codes.		['', 'MC2-3']
freshFeedType	None	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 within then working directory and fail if the ISOTXS does not exist.		['', 'Neutron', 'Neutron and Gamma']
geomFile	Input file containing BOL core map
globalFluxActive	Calculate the global flux at each timestep for the selected particle type(s) using the specified neutronics kernel (see Global Flux tab).	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_INC600', 'dpa_EBRII_INCX750', 'dpa_EBRII_HT9', 'dpa_EBRII_PE16', 'dpa_EBRII_INC625']
groupStructure	Energy group structure to use in neutronics simulations	ANL33	['ANL9', 'ANL33', 'ANL70', 'ANL116', 'ANL230', 'ANL703', 'ANL1041', 'ANL2082', 'ARMI33', 'ARMI45', 'CINDER63', '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	[]
infiniteDiluteCutoff	Do not model nuclides with density less than this cutoff. Used with PARTISN and SERPENT.	1e-10
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	None	8
latticePhysicsFrequency	Define the frequency at which cross sections are updated with new lattice physics interactions.	BOC	['never', 'BOL', 'BOC', 'everyNode', 'firstCoupledIteration', 'all']
levelsPerCascade	None	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	['fromInput', 'fromDB']
loadingFile	The blueprints/loading input file path containing component dimensions, materials, etc.
lowPowerRegionFraction	Description needed	0.05
makeAllBlockLFPsIndepende nt	Flag to make all blocks have independent lumped fission products. Note that this is forced to be True when the explicitF issionProducts 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.	[]
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. It can also be passed to physics plugins.	1e-15
moduleVerbosity	Verbosity of any module- specific loggers that are set	{}
mpiTasksPerNode	Number of independent processes that are allocated to each cluster node. 0 means 1 process per CPU.	0
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
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.	[]
numProcessors	Number of CPUs to request on the cluster	1
numberMeshPerEdge	Number of mesh per block edge for finite- difference planar mesh refinement.	1
operatorLocation	The path to the operator code to execute for this run (for custom behavior)
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
reallySmallRun	Clean up files at the beginning of each cycle (BOC)	False
reloadDBName	Name of the database file to load initial conditions from
removePerCycle	None	3
restartNeutronics	Restart global flux case using outputs from last time as a guess	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', 'Equilibrium', 'Snapshots']
savePhysicsFiles	List of snapshots to dump reactor physics kernel input and output files. Can be used to perform follow-on analysis.	[]
shuffleLogic	Python script written to handle the fuel shuffling for this case. This is user-defined per run as a dynamic input.
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
smallRun	Clean up intermediate files after the run completes (EOL)	False
sortReactor	Deprecation Warning! This setting will be remove by 2024.	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 calulation 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.	False
targetK	Target criticality (k-effective) for cycle length, branch, and equilibrium search	1.005
thKernel	Name of primary T/H solver in this run	False
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( [])>
timelineInclusionCutoff	Timers who are not active for this percent of the run will not be presented in the timeline graphic	0.03
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	Track assemblies for detailed fuel histories. For instance, assemblies are tracked after they come out of a reactor by putting them in a Spent Fuel Pool. This might be necessary for your work, but it certainly increases the memory usage of the program.	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_what .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', 'important', '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', 'FluxWeightedAverage', 'ComponentAverage1DSlab']
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
zeroOutNuclidesNotInDB	If a nuclide was added to the problem after a previous case was run, deactivate this to let it survive in a restart run	True
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.	[]