5. Core Parameters

This document lists all of the Core Parameters that are provided by the ARMI Framework. See armi.reactor.parameters for use.

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
maxAssemNum	Maximum assembly number
numMoves	numMoves
crMostValuablePrimaryRodLocation	Core assembly location for the most valuable primary control rod.
crMostValuableSecondaryRodLocation	Core assembly location for the most valuable secondary control rod.
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
critSearchSlope	Critical keff search slope	1/days
fissileMass	Fissile mass of the reactor	g
heavyMetalMass	Heavy Metal mass of the reactor	g
keffUnc	Uncontrolled k-effective for the reactor core (with control rods fully removed).
lastKeff	Previously calculated Keff for potential keff convergence
loadPadDpaAvg	The highest average dpa in any load pad	dpa
loadPadDpaPeak	The peak dpa in any load pad	dpa
maxDPA	Maximum DPA based on pin-level max if it exists, block level max otherwise	dpa
maxGridDpa	Grid plate max dpa	dpa
maxProcessMemoryInMB	Maximum memory used by an ARMI process	MB
minProcessMemoryInMB	Minimum memory used by an ARMI process	MB
minutesSinceStart	Run time since the beginning of the calculation	min
peakGridDpaAt60Years	Grid plate peak dpa after 60 years irradiation	dpa
totalIntrinsicSource	Full core intrinsic neutron source from spontaneous fissions before a decay period	n/s
THmaxDeltaPPump	The maximum pumping pressure rise required to pump the given mass flow rate through the rod bundle	Pa
THmaxDilationPressure	THmaxDilationPressure	Pa
THoutletTempIdeal	Average outlet temperature loop through all assemblies after doing TH	°C
power	Thermal power of the reactor core. Corresponds to the nuclear power generated in the core.	W
powerDensity	BOL Power density of the reactor core, in units of Watts pergrams of Heavy Metal Mass. After the BOL, the power parameter will be set, and this will entirely overridden by that.	W/g
powerDecay	Decay power from decaying radionuclides	W
medAbsCore	Median energy of neutrons absorbed in the core	eV
medFluxCore	Median energy of neutrons in the core	eV
medSrcCore	Median energy of source neutrons in the core?	eV
pkFlux	Peak flux in the core	n/cm^2/s
maxdetailedDpaPeak	Highest peak dpa of any block in the problem	dpa
maxFlux	Max neutron flux in the core	n/cm^2/s
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
peakKeff	Maximum keff in the simulation
fastFluxFrAvg	Fast flux fraction average
leakageFracTotal	Total leakage fraction
leakageFracPlanar	Leakage fraction in planar
leakageFracAxial	Leakage fraction in axial direction
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.
beta	Effective delayed neutron fraction
betaComponents	Group-wise delayed neutron fractions
betaDecayConstants	Group-wise precursor decay constants	1/s
rxFuelAxialExpansionCoeffPerTemp	Fuel Axial Expansion Coefficient	Δk/k/k’/K
rxGridPlateRadialExpansionCoeffPerTemp	Grid Plate Radial Expansion Coefficient	Δk/k/k’/K
cyclics	The integer number of cyclic mode equilibrium-cycle iterations that have occurred so far
maxCyclicNErr	Maximum relative number density error
breedingRatio	Breeding ratio of the reactor
ConvRatioCore	Conversion ratio of the core
absPerFisCore	absorptions per fission in core
axialExpansionPercent	Percent of axial growth of fuel blocks	%
coupledIteration	Pre-defined number of tightly coupled iterations.
fisFrac	Percent of fissions in fertile nuclides
fisRateCore	peak/average fission rate in core

Core Parameters from NeutronicsPlugin

Name	Description	Units
eigenvalues	All available lambda-eigenvalues of reactor.
kInf	k-infinity