6. Core Parameters

This document lists all of the Core Parameters that are provided by the ARMI Framework and included plugins.

Core Parameters from Framework

Name	Description	Units
detailedNucKeys	Nuclide vector keys, used to map densities in b.p.detailedNDens and a.p.detailedNDens	ZZZAAA (ZZZ atomic number, AAA mass number, + 100 * m for metastable states
orientation	Triple representing rotations counterclockwise around each spatial axis. For example, a hex assembly rotated by 1/6th has orientation (0,0,60.0)	degrees
currentPercentExpanded
maxAssemNum	maximum assembly number	None
numMoves	numMoves
crMostValuablePrimaryRodLocation	Core assembly location for the most valuable primary control rod.	None
crMostValuableSecondaryRodLocation	Core assembly location for the most valuable secondary control rod.	None
crWorthRequiredPrimary	Worth requirement for the primary control rods in the reactor core to achieve safe shutdown.	pcm
crWorthRequiredSecondary	Worth requirement for the secondary control rods in the reactor core to achieve safe shutdown.	pcm
crTransientOverpowerWorth	Reactivity worth introduced by removal of the highest worth primary control rod from the core, starting from its critical position	pcm
axialMesh	Global axial mesh of the reactor core from bottom to top.	cm
referenceBlockAxialMesh	The axial block boundaries that assemblies should conform to in a uniform mesh case.	cm
breedingRatio2	Ratio of fissile Burned and discharged to fissile discharged	N/A
critSearchSlope	Critical keff search slope	None
directPertKeff	K-eff is computed for the perturbed case with a direct calculation	None
distortionReactivity	The reactivity effect of the current distortions	pcm
doublingTime	The time it takes to produce enough spent fuel to fuel a daughter reactor	EFPY
fissileMass	Fissile mass of the reactor	g
heavyMetalMass	Heavy Metal mass of the reactor	g
innerMatrixIndex	The item index of the inner matrix in an optimization case	None
keffUnc	Uncontrolled k-effective for the reactor core (with control rods fully removed)..	None
lastKeff	Previously calculated Keff for potential keff convergence	None
loadPadDpaAvg	The highest average dpa in any load pad	dpa
loadPadDpaPeak	The peak dpa in any load pad	dpa
maxcladFCCI
maxCladulof	Max Clading Temperature in Unprotected Loss of Flow (ULOF) transient	°C
maxCladulohs	Max Clading Temperature in Unprotected Loss of Heat Sink (ULOHS) transient	°C
maxCladutop	Max Clading Temperature in Unprotected Transient Overpower (UTOP) transient	°C
maxCladptop	Max Clading Temperature in protected Transient Overpower (PTOP) transient	°C
maxCladlockrotor	Max Clading Temperature in lock rotor transient	°C
maxCladplohs	Max Clading Temperature in protected loss of heat sink (PLOHS) transient	°C
maxCladplof	Max Clading Temperature in protected loss of flow (PLOF) transient	°C
maxCladplof2pump	Max Clading Temperature in protected loss of 2 primary pumps (PLOF2pump) transient	°C
maxCladoscillation	Max Clading Temperature in oscillation-driven transient	°C
maxFueloscillation	Max Fuel Temperature in oscillation-driven transient	°C
maxCladpowerdefect	Max Clading Temperature in powerdefect transient	°C
maxFuelpowerdefect	Max Fuel Temperature in powerdefect transient	°C
maxCladsteadystate	Max Clading Temperature in steady state transient	°C
maxDPA	Maximum DPA based on pin-level max if it exists, block level max otherwise	dpa
maxFuelulof	maxFuelulof	°C
maxFuelulohs	maxFuelulohs	°C
maxFuelutop	maxFuelutop	°C
maxFuelptop	Max Clading Temperature in protected Transient Overpower (PTOP) transient	°C
maxFuellockrotor	Max Clading Temperature in lock rotor transient	°C
maxFuelplohs	Max Clading Temperature in protected loss of heat sink (PLOHS) transient	°C
maxFuelplof	Max Clading Temperature in protected loss of flow (PLOF) transient	°C
maxFuelplof2pump	Max Clading Temperature in protected loss of 2 primary pumps (PLOF2pump) transient	°C
maxGridDpa	Grid plate max dpa	dpa
maxProcessMemoryInMB	Maximum memory used by an ARMI process	MB
maxTH2SigmaCladIDT	Max 2-sigma temperature of the inner-diameter of the cladding	°C
maxTranPCT	Max Peak Clading Temperature of transients	°C
minProcessMemoryInMB	Minimum memory used by an ARMI process	MB
minutesSinceStart	Run time since the beginning of the calculation	min
outsideFuelRing	The ring with the fraction of flux that best meets the target	int
outsideFuelRingFluxFr	Ratio of the flux in a ring to the total reactor fuel flux	None
peakGridDpaAt60Years	Grid plate peak dpa after 60 years irradiation	dpa
totalIntrinsicSource	Full core intrinsic neutron source from spontaneous fissions before a decay period	neutrons/s
totalIntrinsicSourceDecayed	Full core intrinsic source from spontaneous fissions after a decay period	neutrons/s
assemblyPumpHead	Pressure drop for the max power assembly in zone	Pa
CoreAvgTOut	Core average outlet temperature	°C
CoreMdot	Mass flow rate of full core	kg/s
outletTempIdeal	Average outlet tempeture loop through all assemblies after doing TH	°C
SCMaxDilationPressure	The maximum dilation pressure in the core	Pa
SCorificeEfficiency	Ratio of total flow rate for the optimized orificing scheme to total flow rate for an ideal orificing scheme	None
SCovercoolingRatio	Ratio of the max flow rate to the average flow rate	None
THmaxDeltaPPump	The maximum pumping pressure rise required to pump the given mass flow rate through the rod bundle	Pa
THmaxDilationPressure	THmaxDilationPressure
THoutletTempIdeal	Average outlet temperature loop through all assemblies after doing TH	°C
vesselTemp	vessel temperature	°C
LMDT	Log mean temperature difference in heat exchanger	°C
peakTemperature	peak temperature anywhere in the reactor	°C
power	Thermal power of the reactor core. Corresponds to the nuclear power generated in the core.	W
powerDecay	Decay power from decaying radionuclides	W
medAbsCore	?	?
medFluxCore	?	?
medSrcCore	?	?
pkFlux	?	?
maxdetailedDpaPeak	Highest peak dpa of any block in the problem	dpa
maxFlux	Max neutron flux in the core	n/cm^2/s
adjWeightedFisSrc	Volume-integrated adjoint flux weighted fission source	1/cm^2/s^2
maxDetailedDpaThisCycle	Max increase in dpa this cycle (only defined at EOC)	dpa
dpaFullWidthHalfMax	Full width at half max of the detailedDpa distribution	cm
elevationOfACLP3Cycles	minimum axial location of the ACLP for 3 cycles at peak dose	cm
elevationOfACLP7Cycles	minimum axial location of the ACLP for 7 cycles at peak dose	cm
maxpercentBu	Max percent burnup on any block in the problem	%FIMA
rxSwing	Reactivity swing	pcm
maxBuF	Maximum burnup seen in any feed assemblies	%
maxBuI	Maximum burnup seen in any igniter assemblies	%
keff	Global multiplication factor	None
peakKeff	Maximum keff in the simulation	None
fastFluxFrAvg	Fast flux fraction average	None
leakageFracTotal	Total leakage fraction	None
leakageFracPlanar	Leakage fraction in planar	None
leakageFracAxial	Leakage fraction in axial direction	None
maxpdens	Maximum avg. volumetric power density of all blocks	W/cm^3
maxPD	Maximum areal power density of all assemblies	MW/m^2
jumpRing	Radial ring number where bred-up fuel assemblies shuffle jump from the low power to the high power region.	None
axial	Axial expansion coefficient	cents/K
doppler	Doppler coefficient	cents/K
dopplerConst	Doppler constant	cents * K^(n-1)
fuelDensity	Fuel temperature coefficient	cents/K
coolantDensity	Coolant temperature coefficient	cents/K
totalCoolantDensity	Coolant temperature coefficient weighted to include bond and interstitial effects	cents/K
cladDensity	Clad temperature coefficient	cents/K
structureDensity	Structure temperature coefficient	cents/K
Voideddoppler	Voided Doppler coefficient	cents/K
VoideddopplerConst	Voided Doppler constant	cents * K^(n-1)
voidWorth	Coolant void worth	$
voidedKeff	Voided keff	None
radialHT9	Radial expansion coefficient when driven by thermal expansion of HT9.	cents/K
radialSS316	Radial expansion coefficient when driven by thermal expansion of SS316.	cents/K
beta	Effective delayed neutron fraction	None
betaComponents	Group-wise delayed neutron fractions.	None
betaDecayConstants	Group-wise precursor decay constants	1/s
promptNeutronGenerationTime	Prompt neutron generation time	s
promptNeutronLifetime	Prompt neutron lifetime	s
rxFuelAxialExpansionCoeffPerTemp	Fuel Axial Expansion Coefficient	dk/kk’-K
rxGridPlateRadialExpansionCoeffPerTemp	Grid Plate Radial Expansion Coefficient	dk/kk’-K
rxAclpRadialExpansionCoeffPerTemp	ACLP Radial Expansion Coefficient	dk/kk’-K
rxControlRodDrivelineExpansionCoeffPerTemp	control rod driveline expansion coefficient	dk/kk’-K
rxCoreWideCoolantVoidWorth	Core-Wide Coolant Void Worth	dk/kk’
rxSpatiallyDependentCoolantVoidWorth	Spatially-Dependent Coolant Void Worth	dk/kk’
rxFuelDensityCoeffPerTemp	Fuel Density Coefficient	dk/kk’-K
rxFuelDopplerCoeffPerTemp	Fuel Doppler Coefficient	dk/kk’-K
rxFuelDopplerConstant	Fuel Doppler Constant	dk/kk’ K**(n-1)
rxFuelVoidedDopplerCoeffPerTemp	Fuel Voided-Coolant Doppler Coefficient	dk/kk’-K
rxFuelVoidedDopplerConstant	Fuel Voided-Coolant Doppler Constant	dk/kk’ K**(n-1)
rxFuelTemperatureCoeffPerTemp	Fuel Temperature Coefficient	dk/kk’-K
rxFuelVoidedTemperatureCoeffPerTemp	Fuel Voided-Coolant Temperature Coefficient	dk/kk’-K
rxCladDensityCoeffPerTemp	Clad Density Coefficient	dk/kk’-K
rxCladDopplerCoeffPerTemp	Clad Doppler Coefficient	dk/kk’-K
rxCladDopplerConstant	Clad Doppler Constant	dk/kk’ K**(n-1)
rxCladTemperatureCoeffPerTemp	Clad Temperature Coefficient	dk/kk’-K
rxStructureDensityCoeffPerTemp	Structure Density Coefficient	dk/kk’-K
rxStructureDopplerCoeffPerTemp	Structure Doppler Coefficient	dk/kk’-K
rxStructureDopplerConstant	Structure Doppler Constant	dk/kk’ K**(n-1)
rxStructureTemperatureCoeffPerTemp	Structure Temperature Coefficient	dk/kk’-K
rxCoolantDensityCoeffPerTemp	Coolant Density Coefficient	dk/kk’-K
rxCoolantTemperatureCoeffPerTemp	Coolant Temperature Coefficient	dk/kk’-K
boecKeff	BOEC Keff	None
cyclics	The number of cyclic mode equilibrium-cycle iterations that have occurred so far	int
maxCyclicNErr	Maximum relative number density error	None
breedingRatio	Breeding ratio of the reactor	N/A
ConvRatioCore	?	?
absPerFisCore	?	?
axialExpansionPercent	Percent of axial growth of fuel blocks	%
corePow	?	?
coupledIteration	?	?
fisFrac	?	?
fisRateCore	?	?
maxcladWastage	Maximum clad wastage in any block in the core	microns
maxdilationTotal	?	?
maxresidence	?	?

Core Parameters from NeutronicsPlugin

Name	Description	Units
eigenvalues	All available lambda-eigenvalues of reactor.	None
kInf	k-infinity	None
refKeff	Reference unperturbed keff	None