6. Core Parameters

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

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.

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

critSearchSlope

Critical keff search slope

1/days

doublingTime

The time it takes to produce enough spent fuel to fuel a daughter

reactor, in effective number of years at full power.

yr

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

maxcladFCCI

The core wide maximum amount of cladding wastage due to fuel chemical clad interaction calculated at the 0-sigma TH HCF temperatures and using the conservative FCCI model

µm

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

totalIntrinsicSourceDecayed

Full core intrinsic source from spontaneous fissions after 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

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

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

promptNeutronGenerationTime

Prompt neutron generation time

s

promptNeutronLifetime

Prompt neutron lifetime

s

rxFuelAxialExpansionCoeffPerTemp

Fuel Axial Expansion Coefficient

Δk/k/k’/K

rxFuelAxialExpansionCoeffPerPercent

Fuel Axial Expansion Coefficient

Δk/k/k’/%

rxGridPlateRadialExpansionCoeffPerTemp

Grid Plate Radial Expansion Coefficient

Δk/k/k’/K

rxAclpRadialExpansionCoeffPerTemp

ACLP Radial Expansion Coefficient

Δk/k/k’/K

rxControlRodDrivelineExpansionCoeffPerTemp

control rod driveline expansion coefficient

Δk/k/k’/K

rxCoreWideCoolantVoidWorth

Core-Wide Coolant Void Worth

Δk/k/k’

rxSpatiallyDependentCoolantVoidWorth

Spatially-Dependent Coolant Void Worth

Δk/k/k’

rxFuelDensityCoeffPerTemp

Fuel Density Coefficient

Δk/k/k’/K

rxFuelDopplerCoeffPerTemp

Fuel Doppler Coefficient

Δk/k/k’/K

rxFuelDopplerConstant

Fuel Doppler Constant

Δk/k/k’*K^(n-1)

rxFuelVoidedDopplerCoeffPerTemp

Fuel Voided-Coolant Doppler Coefficient

Δk/k/k’/K

rxFuelVoidedDopplerConstant

Fuel Voided-Coolant Doppler Constant

Δk/k/k’*K^(n-1)

rxFuelTemperatureCoeffPerTemp

Fuel Temperature Coefficient

Δk/k/k’/K

rxFuelVoidedTemperatureCoeffPerTemp

Fuel Voided-Coolant Temperature Coefficient

Δk/k/k’/K

rxCladDensityCoeffPerTemp

Clad Density Coefficient

Δk/k/k’/K

rxCladDopplerCoeffPerTemp

Clad Doppler Coefficient

Δk/k/k’/K

rxCladDopplerConstant

Clad Doppler Constant

Δk/k/k’*K^(n-1)

rxCladTemperatureCoeffPerTemp

Clad Temperature Coefficient

Δk/k/k’/K

rxStructureDensityCoeffPerTemp

Structure Density Coefficient

Δk/k/k’/K

rxStructureDopplerCoeffPerTemp

Structure Doppler Coefficient

Δk/k/k’/K

rxStructureDopplerConstant

Structure Doppler Constant

Δk/k/k’*K^(n-1)

rxStructureTemperatureCoeffPerTemp

Structure Temperature Coefficient

Δk/k/k’/K

rxCoolantDensityCoeffPerTemp

Coolant Density Coefficient

Δk/k/k’/K

rxCoolantTemperatureCoeffPerTemp

Coolant Temperature Coefficient

Δk/k/k’/K

boecKeff

BOEC Keff

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

refKeff

Reference unperturbed keff