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

HCFcoretype

Switch to apply different sets of hot channel factors based on design being analyzed

TWRC

Tin

The inlet temperature of the reactor in C

360.0

Tout

The outlet temperature of the reactor in C

510.0

acceptableBlockAreaError

This is the limit of error in between the 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

assemPowSummary

Print out a summary of how much power is in each assembly type at every timenode.

assemblyRotationAlgorithm

The algorithm to use to rotate the detail assemblies while shuffling

assemblyRotationStationar y

Whether or not to rotate assemblies that are not shuffled.This can only be True if ‘rotation’ is true.

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

This is a flag to let armi add additional mesh points if the dif3d mesh is too irregular

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% CF followed by 10 100 CF. Empty list is constant duration set by ‘availabilityFactor’.

axialExpansion

Perform axial fuel expansion. This will adjust fuel block lengths.

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 DIF3D generalized boundary condition.

beta

Set individual precursor group delayed neutron fractions.

bondRemoval

Toggles fuel performance bond removal. This will remove thermal bond from the fuel.

boundaries

External Neutronic Boundary Conditions. Reflective does not include axial.

Extrapolated

branchVerbosity

Verbosity of the non- master MPI nodes

error

buGroups

The range of burnups where cross-sections will be the same for a given assembly type

[10, 20, 30, 100]

burnChainFileName

Path to YAML file that has the depletion chain defined in it

/home/runner/work/armi/ar mi/armi/resources/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.

4

burnupPeakingFactor

None

circularRingMode

Toggle between circular ring definitions to hexagonal ring definitions

circularRingOrder

Order by which locations are sorted in circular rings for equilibrium shuffling

angle

circularRingPitch

The relative pitch to be used to define a single circular ring in circular shuffling.

1.0

claddingStrain

Evaluate cladding strain.

claddingWastage

Evaluate cladding wastage.

clearXS

Delete all cross section libraries before regenerating them.

comment

A comment describing this case.

conditionalModuleName

This is file name – directory not included – of the python module that contains a conditional function to determine the end of burn cycles

copyFilesFrom

None

copyFilesTo

None

coverage

Turn on coverage report generation which tracks all the lines of code that execute during a run

createAssemblyTypeZones

Let ARMI create zones based on fuel type automatically

crossSectionControl

Data structure defining how cross sections are created

customFuelManagementIndex

An index that determines which of various options is used in management. Useful for optimization sweeps.

cycleLength

Duration of one single cycle in days. If availability factor 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 the availability factor. 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’.

db

Write the state information to a database at every timestep.

True

dbStorageAfterCycle

Only store cycles after this cycle in the DB (to save storage space)

debug

None

debugDB

debugDB

debugMem

Turn on memory debugging options to help find problems with the code

debugMemSize

Show size of objects during memory debugging

decayConstants

Set individual precursor group delayed neutron decay constants.

defaultSnapshots

Generate snapshots at BOL, MOL, and EOL.

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.

detailAllAssems

All assemblies will have ‘detailed’ treatment. Note: This option is interpreted differently by different modules.

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.

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

doOrificedTH

Perform orificed thermal hydraulics (requires bounds file from a previous case).

doTH

Activate thermal hydraulics calculations using the physics module defined in thKernel

dpaPerFluence

A quick and dirty conversion that is used to get dpaPeak by multiplying the factor and fastFluencePeak

4.01568627451e-22

dpaXsSet

The cross sections to use when computing displacements per atom.

dpa_EBRII_HT9

dumpSnapshot

List of snapshots to dump detailed reactor analysis data. Can be used to perform follow-on analysis (i.e., 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.

existingFixedSource

Specify an exiting fixed source input file.

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.

fluxRecon

Perform detailed flux and power reconstruction

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

The fission product model to use in this ARMI run

infinitelyDilute

freshFeedType

None

feed 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.

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

gridPlateDpaXsSet

The cross sections to use for grid plate blocks DPA when computing displacements per atom.

dpa_EBRII_HT9

groupStructure

Energy group structure to use in neutronics simulations

ANL33

growToFullCoreAfterLoad

Grows from 1/3 to full core after loading from 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

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

jumpRingNum

None

8

levelsPerCascade

None

14

lfpCompositionFilePath

Path to the file that contains lumped fission product composition definitions (e.g. equilibrium yields)

loadFromDBEveryNode

Every node loaded from reference database

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

loadPadLength

The length of the load pad. Used to compute average and peak dose.

loadStyle

Description of how the ARMI case will be initialized

fromInput

loadingFile

Browse for the blueprints/loading input file containing component dimensions, materials, etc.

looseCoupling

Update material densities and dimensions after running thermal- hydraulics. Note: Thermal-hydraulics calculation is needed to perform the loose physics coupling calculation.

lowPowerRegionFraction

Description Needed

0.05

makeAllBlockLFPsIndepende nt

Flag to make all blocks have independent lumped fission products

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.

memPerNode

Memory requested per cluster node

2000

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.

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 (or 12 per node on some clusters). Set between 1-12 to increase RAM and number of cores needed for large problems.

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.

1

neutronicsKernel

The neutronics / depletion solver for global flux solve.

neutronicsType

The type of neutronics solution that is desired.

real

numControlBlocks

Number of blocks with control for a REBUS poison search

6

numCoupledIterations

Number of tight coupled physics iterations to occur at each timestep.

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)

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

plotShuffleArrows

Make plots with arrows showing each move.

plots

Generate additional plots throughout the ARMI analysis

power

Nameplate thermal power of the reactor. Can be varied by setting the powerFraction setting.

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% PF followed by 10 100% PF. Specify zeros to indicate decay-only cycles (i.e. for decay heat analysis). Empty list implies always full rated power.

profile

Turn on the profiler for the submitted case. The profiler results will not include all import times.

reallySmallRun

Clean up files at the beginning of each cycle (BOC)

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

ringZones

Define zones by concentric radial rings. Each zone will get independent reactivity coefficients.

runLatticePhysicsBeforeSh uffling

Forces the Generation of Cross Sections Prior to Shuffling the Fuel Assemblies. Note: This is recommended when performing equilibrium shuffling branching searches.

runType

Type of run that this is, e.g. a normal run through all cycles, a snapshot loaded rx. coefficient run, etc.

Standard

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.

smallRun

Clean up intermediate files after the run completes (EOL)

splitZones

Automatically split defined zones further based on number of blocks and assembly types.

True

startCycle

Cycle number to continue calculation from. Database will load from the time step just before. For snapshots use dumpSnapshot

startNode

Timenode number (0 for BOC, etc.) to continue calulation from. Database will load from the time step just before.

stationaryBlocks

blocks with these indices (int values) will not move in moves.

summarizeAssemDesign

Printout a summary of the assembly design details at BOL

True

syncDbAfterWrite

Copy the output DB from the fast scratch space to the shared network drive after each write.

targetK

Target criticality (k-effective) for cycle length, branch, and equilibrium search

1.005

thKernel

Name of primary T/H solver in this run

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.

trace

Activate Python trace module to print out each line as its executed

trackAssems

track assemblies for detailed fuel histories. Disable in case you get memory errors.

True

useInputTemperaturesOnDBL oad

when loading from a database, first set all component temperatures to the input temperatures. Required when a coupled TH case is being derived from a case without any coupled TH.

verbosity

How verbose the output will be

info

xsBlockRepresentation

The type of averaging to perform when creating cross sections for a group of blocks

FluxWeightedAverage

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

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

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

zoneFlowSummary

print flow and power edits for peak and average assemblies

True

zoningStrategy

Channel Grouping Options for Safety;everyFA: every FA is its own channel, byRingZone: based on ringzones, byFuelType: based on fuel type, Manual: you must specify ‘zoneDefinitions’ setting

byRingZone