8. Block Parameters

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

Block Parameters from Framework

Name

Description

Units

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

pinLocation

Location of fuel pins

None

detailedNDens

High-fidelity number density vector with up to thousands of nuclides. Used in high-fi depletion runs where low-fi depletion may also be occurring. This param keeps the hi-fi and low-fi depletion values from interfering. See core.p.detailedNucKeys for keys.

atoms/bn-cm

burnupMWdPerKg

Burnup in MWd/kg of initial heavy metal

MWd/kg

fissileFraction

Ratio of fissile mass to heavy metal mass at block-level

None

molesHmBOL

Total number of atoms of heavy metal at BOL assuming a full assembly

mole

massHmBOL

Mass of heavy metal at BOL

grams

molesHmBOLByPin

Total number of atoms of heavy metal at BOL

mole

molesHmNow

Total number of atoms of heavy metal

mole

newDPA

Dose in DPA accrued during the current time step

dpa

percentBu

Percentage of the initial heavy metal atoms that have been fissioned

%FIMA

percentBuByPin

Percent burnup of the initial heavy metal atoms that have been fissioned for each pin

%FIMA

percentBuMax

Maximum percentage in a single pin of the initial heavy metal atoms that have been fissioned

%FIMA

percentBuMaxPinLocation

Peak burnup pin location

int

percentBuMin

Minimum percentage of the initial heavy metal atoms that have been fissioned

%FIMA

residence

Duration that a block has been in the core at full power.

EFP days

depletionMatrix

Full BurnMatrix objects containing transmutation and decay info about this block.

N/A

cycleAverageBurnMatrix

Integrated burn matrix mapping this block from its BOC to EOC number densities.

N/A

bu

?

buGroup

The burnup group letter of this block

N/A

buGroupNum

An integer representation of the burnup group, linked to buGroup.

N/A

buRate

Current rate of burnup accumulation. Useful for estimating times when burnup limits may be exceeded.

%FIMA/day

detailedDpa

displacements per atom

dpa

detailedDpaPeak

displacements per atom with peaking factor

dpa

detailedDpaRate

Current time derivative of average detailed DPA

dpa/s

displacementX

Assembly displacement in the x direction

m

displacementY

Assembly displacement in the y direction

m

powerRx

?

W/cm$^3$

dpaRx

?

dpa/s

heliumInB4C

?

He/s/cm$^3$

timeToLimit

Time unit block violates its burnup limit.

days

zbottom

Axial position of the bottom of this block

cm

ztop

Axial position of the top of this block

cm

baseBu

?

?

basePBu

?

?

hydDiam

?

?

nHMAtBOL

Ndens of heavy metal at BOL

atoms/bn-cm.

z

Center axial dimension of this block

cm

pinPeakingStdDev

Standard deviation of the pin peaking factors for the block

None

topIndex

the axial block index within its parent assembly (0 is bottom block)

eqRegion

Equilibrium shuffling region. Corresponds to how many full cycles fuel here has gone through.

eqCascade

Cascade number in repetitive equilibrium shuffling fuel management.

id

?

?

height

the block height

cm

xsType

The xs group letter of this block

N/A

xsTypeNum

An integer representation of the cross section type, linked to xsType.

N/A

type

string name of the input block

N/A

regName

Set by Assembly in writeNIP30 once the region has been placed

?

VoideddopplerWorth

Distributed Voided Doppler constant.

dk/kk’ K**(n-1)

dopplerWorth

Distributed Doppler constant.

dk/kk’ * K^(n-1)

distortWorth

Distortion reactivity distribution

pcm/cm^3

fuelWorth

Reactivity worth of fuel material per unit mass

dk/kk’-kg

fuelWorthDollarsPerKg

Reactivity worth of fuel material per unit mass

$/kg

fuelWorthPT

Fuel reactivity

pcm/%/cm^3

structWorthPT

Structure reactivity

pcm/%/cm^3

radExpWorthPT

Radial swelling reactivity

pcm/%/cm^3

coolWorthPT

Coolant reactivity

pcm/%/cm^3

coolFlowingWorthPT

Flowing coolant reactivity

pcm/%/cm^3

axExpWorthPT

Axial swelling reactivity

pcm/%/cm^3

coolantWorth

Reactivity worth of coolant material per unit mass

dk/kk’-kg

coolantWorthDollarsPerKg

Reactivity worth of coolant material per unit mass

$/kg

cladWorth

Reactivity worth of clad material per unit mass

dk/kk’-kg

cladWorthDollarsPerKg

Reactivity worth of clad material per unit mass

$/kg

structureWorth

Reactivity worth of structure material per unit mass

dk/kk’-kg

structureWorthDollarsPerKg

Reactivity worth of structure material (non-clad and non-wire wrap material) per unit mass

$/kg

rxAxialCentsPerK

Axial temperature reactivity coefficient

cents/K

rxAxialCentsPerPow

Axial power reactivity coefficient

cents/K

rxCoolantCentsPerK

Coolant temperature reactivity coefficient

cents/K

rxCoolantCentsPerPow

Coolant power reactivity coefficient

cents/K

rxDopplerCentsPerK

Doppler temperature reactivity coefficient

cents/K

rxDopplerCentsPerPow

Doppler power reactivity coefficient

cents/K

rxFuelCentsPerK

Fuel temperature reactivity coefficient

cents/K

rxFuelCentsPerPow

Fuel power reactivity coefficient

cents/K

rxNetCentsPerK

Net temperature reactivity coefficient

cents/K

rxNetCentsPerPow

Net power reactivity coefficient

cents/K

rxNetPosNeg

Net temperature reactivity coefficient: positive or negative

cents/K

rxNetPosNegPow

Net power reactivity coefficient: positive or negative

cents/K

rxRadialCentsPerK

Radial temperature reactivity coefficient

cents/K

rxRadialCentsPerPow

Radial power reactivity coefficient

cents/K

rxStructCentsPerK

Structure temperature reactivity coefficient

cents/K

rxStructCentsPerPow

Structure power reactivity coefficient

cents/K

rxVoidedDopplerCentsPerK

Voided Doppler temperature reactivity coefficient

cents/K

rxVoidedDopplerCentsPerPow

Voided Doppler power reactivity coefficient

cents/K

virdentGr

Radial surface leakage reactivity

pcm/%/cm^3

virdentGz

Axial surface leakage reactivity

pcm/%/cm^3

virdentLr

Radial volume leakage reactivity

pcm/%/cm^3

virdentLz

Axial volume leakage reactivity

pcm/%/cm^3

assemPeakStd

Spectral reactivity

pcm/%/cm^3

virdentS

Spectral reactivity

pcm/%/cm^3

rxFuelDensityCoeffPerMass

Fuel Density Coefficient

dk/kk’-kg

rxFuelDopplerConstant

Fuel Doppler Constant

dk/kk’ K**(n-1)

rxFuelVoidedDopplerConstant

Fuel Voided-Coolant Constant

dk/kk’ K**(n-1)

rxFuelTemperatureCoeffPerMass

Fuel Temperature Coefficient

dk/kk’-kg

rxFuelVoidedTemperatureCoeffPerMass

Fuel Voided-Coolant Temperature Coefficient

dk/kk’-kg

rxCladDensityCoeffPerMass

Clad Density Coefficient

dk/kk’-kg

rxCladDopplerConstant

Clad Doppler Constant

dk/kk’ K**(n-1)

rxCladTemperatureCoeffPerMass

Clad Temperature Coefficient

dk/kk’-kg

rxStructureDensityCoeffPerMass

Structure Density Coefficient

dk/kk’-kg

rxStructureDopplerConstant

Structure Doppler Constant

dk/kk’ K**(n-1)

rxStructureTemperatureCoeffPerMass

Structure Temperature Coefficient

dk/kk’-kg

rxCoolantDensityCoeffPerMass

Coolant Density Coefficient

dk/kk’-kg

rxCoolantTemperatureCoeffPerMass

Coolant Temperature Coefficient

dk/kk’-kg

rxFuelDensityCoeffPerTemp

Fuel Density Coefficient

dk/kk’-K

rxFuelDopplerCoeffPerTemp

Fuel Doppler Coefficient

dk/kk’-K

rxFuelVoidedDopplerCoeffPerTemp

Fuel Voided-Coolant Doppler Coefficient

dk/kk’-K

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

rxCladTemperatureCoeffPerTemp

Clad Temperature Coefficient

dk/kk’-K

rxStructureDensityCoeffPerTemp

Structure Density Coefficient

dk/kk’-K

rxStructureDopplerCoeffPerTemp

Structure Doppler Coefficient

dk/kk’-K

rxStructureTemperatureCoeffPerTemp

Structure Temperature Coefficient

dk/kk’-K

rxCoolantDensityCoeffPerTemp

Coolant Density Coefficient

dk/kk’-K

rxCoolantTemperatureCoeffPerTemp

Coolant Temperature Coefficient

dk/kk’-K

VirDenTerr

VirDenT error

%

assemNum

Index that refers, nominally, to the assemNum parameter of the containing Assembly object. This is stored on the Block to aid in visualizing shuffle patterns and the like, and should not be used within the code. These are not guaranteed to be consistent with the containing Assembly, so they should not be used as a reliable means to reconstruct the model.

None

avgFuelTemp

?

?

avgTempRef

?

?

axExtenNodeHeight

Axial extension node height

meter

blockBeta

Beta in each block

unitless

blockF

Adjoint-weighted fission source in each block

1/cm^5/s^2

bondBOL

?

?

breedRatio

Breeding ratio

None

fissileDestroyed

Fissile atoms destroyed in last depletion step (not net!)

atoms/bn-cm

fissileBefore

Fissile atoms at beginning of last depletion step (could be substep!)

atoms/bn-cm

fissileAfter

Fissile atoms at end of last depletion step (could be substep!)

atoms/bn-cm

buLimit

Burnup limit

%FIMA

cladACCI

The amount of cladding wastage due to absorber chemical clad interaction

µm

convRatio

Conversion ratio

None

coolRemFrac

Fractional sodium density change for each block

?

crWastage

Combines ACCI and clad corrosion for control blocks

µm

cyclicNErr

Relative error of the block number density

None

deltaTclad

Change in fuel temperature due to 1% rise in power.

1/cm^5/s^2

deltaTduct

Change in fuel temperature due to 1% rise in power.

1/cm^5/s^2

deltaTfuel

Change in fuel temperature due to 1% rise in power.

1/cm^5/s^2

dilationElasticPM

Combined elastic membrane and bending components of duct dilation

mm

dilationElasticT

Thermal expansion component of duct dilation

mm

dilationElasticTRefueling

Thermal expansion component of duct dilation at refueling temperature (180C)

mm

dilationCreepIrrad

Irradiation creep component of duct dilation

mm

dilationSwellingSF

Stress-free void swelling component of duct dilation

mm

blockAxialSwellingSF

Axial stress-free void swelling of block

mm

dilationSwellingSE

Stress-enhanced swelling component of duct dilation

mm

dilationCreepTh1

Primary thermal creep component of duct dilation

mm

dilationCreepTh2

Secondary thermal creep component of duct dilation

mm

dilationTotal

Total duct dilation

mm

dilationRefueling

Amount of duct dilation at refueling temperature (180C)

mm

displacementMAG

?

?

heightBOL

As-fabricated height of this block (as input). Used in fuel performance. Should be constant.

cm

intrinsicSource

Intrinsic neutron source from spontaneous fissions before a decay period

?

intrinsicSourceDecayed

Intrinsic source from spontaneous fissions after a decay period

?

kgFis

Mass of fissile material in block

kg

kgHM

Mass of heavy metal in block

kg

mchan

SASSYS/DIF3D-K (external) channel index assignment

None

mreg

SASSYS/DIF3D-K radial region index assignment

None

nPins

Number of pins

None

newDPAPeak

The peak DPA accumulated in the last burn step

dpa

percentBuPeak

Peak percentage of the initial heavy metal atoms that have been fissioned

%FIMA

powerShapeDelta

Change in power shape when core temperature rises.

W

powerShapePercent

Percent change in power shape when core temperature rises.

%

puFrac

Current Pu number density relative to HM at BOL

None

smearDensity

Smear density of fuel pins in this block. Defined as the ratio of fuel area to total space inside cladding.

?

distortionReactivity

?

?

harmonic

?

?

harmonicAdj

?

?

Block Parameters from NeutronicsPlugin

Name

Description

Units

axMesh

number of neutronics axial mesh points in this block

mgFlux

multigroup volume-integrated flux

n-cm/s

adjMgFlux

multigroup adjoint neutron flux

n-cm/s

lastMgFlux

multigroup volume-integrated flux used for averaging the latest and previous depletion step

n-cm/s

mgFluxGamma

multigroup gamma flux

g-cm/s

mgNeutronVelocity

multigroup neutron velocity

cm/s

extSrc

multigroup external source

g/cm^3/s

mgGammaSrc

multigroup gamma source

g/cm^3/s

gammaSrc

gamma source

g/cm^3/s

mgFluxSK

multigroup volume-integrated flux stored for multiple time steps in spatial kinetics (2-D array)

pinMgFluxes

The block-level pin multigroup fluxes. pinMgFluxes[g][i] represents the flux in group g for pin i. Flux units are the standard n/cm^2/s. The “ARMI pin ordering” is used, which is counter-clockwise from 3 o’clock. See TP1-1.9.31-RPT-0010 for more details.

n/s/cm$^2$

pinMgFluxesAdj

should be a blank 3-D array, but re-defined later (ng x nPins x nAxialSegments)

pinMgFluxesGamma

should be a blank 3-D array, but re-defined later (ng x nPins x nAxialSegments)

g/s/cm$^2$

pinPowers

The block-level pin linear power densities. pinPowers[i] represents the average linear power density of pin i. Power units are Watts/cm (Watts produced per cm of pin length). The “ARMI pin ordering” is used, which is counter-clockwise from 3 o’clock. See TP1-1.9.31-RPT-0010 for more details.

W/cm

pinPowersNeutron

The block-level pin linear power densities from neutron-induced interactions. pinPowersNeutron[i] represents the average linear power density of pin i (from neutron heating). Power units are Watts/cm (Watts produced per cm of pin length).

W/cm

pinPowersGamma

The block-level pin linear power densities from gamma heating. pinPowersGamma[i] represents the average linear power density of pin i (from gamma heating). Power units are Watts/cm (Watts produced per cm of pin length).”,

W/cm

axialPowerProfile

For each reconstructed axial location, a tuple (z,power density) where with axial origin at the bottom of assembly in which the blocks are located.

axialPowerProfileNeutron

axialPowerProfileGamma

axialMgFluxReconCoeff

The coefficients in the axial multigroup flux profile polynomial for this block. The flux profile is usually A*z^4 + B*z^3 + C*z^2 + D*z + E, and so this variable will be the 5 x ng list, so axialMgFluxReconCoeff[g][i] is the ith coefficient for flux group g. Also, this flux profile is normalized (for each group) so that its average is always 1.0 in each block. One must multiply the coefficients of each group by the block-average group flux to obtain the axial group flux profile.

axialMgFluxProfileAdj

axialMgFluxProfileNeutron

axialMgFluxProfileNeutronAdj

axialMgFluxProfileGamma

radialMgFluxProfile

radialMgFluxProfileAdj

radialMgFluxProfileNeutron

radialMgFluxProfileNeutronAdj

radialMgFluxProfileGamma

betad

Delayed neutron beta

chi

Energy distribution of fission neutrons

chid

Energy distribution of delayed fission neutrons

linPow

Pin-averaged linear heat generation rate

W/m

linPowByPin

Pin linear power

W/cm

linPowByPinNeutron

Pin linear neutron power

W/cm

linPowByPinGamma

Pin linear gamma power

W/cm

reactionRates

List of reaction rates in specified by setting “reactionsToDB”

Reactions/sec

rateBalance

Numerical balance between particle production and destruction (should be small)

1/cm^3/s

rateExtSrc

Rate of production of neutrons from an external source.

1/cm^3/s

rateFisAbs

Neutron abs. rate in fissile material

1/cm^3/s

rateFisSrc

Fission source rate. This is related to production rate in fissile by a factor of keff

1/cm^3/s

rateLeak

Rate that neutrons leak out of this block.

1/cm^3/s

rateParasAbs

Rate of parasitic absorption (absorption in non-fertile/fissionable material)

1/cm^3/s

rateProdNet

Net production rate of neutrons

1/cm^3/s

rateScatIn

Rate neutrons in-scatter in this block

1/cm^3/s

rateScatOut

Rate that neutrons out-scatter in this block (removal - absorption)

1/cm^3/s

capturePowerFrac

Fraction of the power produced through capture in a block.

None

fastFluence

Fast spectrum fluence

#/cm^2

fastFluencePeak

Fast spectrum fluence with a peaking factor

#/cm^2

fluence

Fluence

#/cm^2

flux

neutron flux

n/cm^2/s

fluxAdj

Adjoint flux

fluxAdjPeak

Adjoint flux

pdens

Average volumetric power density

W/cm$^3$

pdensDecay

Decay power density from decaying radionuclides

W/cm$^3$

arealPd

Power divided by XY area

MW/m^2

arealPdGamma

Areal gamma power density

MW/m^2

fertileBonus

The fertile bonus

None

fisDens

Fission density in a pin (scaled up from homogeneous)

fissions/cm^3/s

fisDensHom

Homogenized fissile density

1/cm^3/s

fluxDeltaFromRef

Relative difference between the current flux and the directly-computed perturbed flux.

None

fluxDirect

Flux is computed with a direct method

n/cm^2/s

fluxGamma

Gamma scalar flux

g/cm^2/s

fluxPeak

Peak neutron flux calculated within the mesh

n/cm^2/s

fluxPertDeltaFromDirect

Relative difference between the perturbed flux and the directly-computed perturbed flux

None

fluxPertDeltaFromDirectfluxRefWeighted

None

fluxPerturbed

Flux is computed by MEPT

1/cm^2/s

fluxRef

Reference flux

1/cm^2/s

kInf

Neutron production rate in this block/neutron absorption rate in this block. Not truly kinf but a reasonable approximation of reactivity.

None

medAbsE

Median neutron absorption energy

eV

medFisE

Median energy of neutron causing fission

eV

medFlxE

Median neutron flux energy

eV

pdensGamma

Average volumetric gamma power density

W/cm^3

pdensNeutron

Average volumetric neutron power density

W/cm^3

ppdens

Peak power density

W/cm^3

ppdensGamma

Peak gamma density

W/cm^3

rateAbs

Total absorption rate in this block (fisson + capture).

1/cm^3/s

rateCap

Parasitic capture rate in this block.

1/cm^3/s

rateFis

Fission rate in this block.

1/cm^3/s

rateProdFis

Production rate of neutrons from fission reactions (nu * fission source / k-eff)

1/cm^3/s

rateProdN2n

Production rate of neutrons from n2n reactions.

1/cm^3/s

powerGenerated

Generated power. Different than b.p.power only when gamma transport is activated.

W

power

Total power

W

powerDecay

Total decay power

W

powerGamma

Total gamma power

W

powerNeutron

Total neutron power

W

detailedDpaNewCycle

The total DPA accumulated in all burn steps of one cycle

dpa

detailedDpaPeakNewCycle

The total peak DPA accumulated in all burn steps of one cycle

dpa

detailedDpaThisCycle

Displacement per atom accumulated during this cycle. This accumulates over a cycle and resets to zero at BOC.

dpa

detailedDpaPeakRate

Peak DPA rate based on detailedDpaPeak

DPA/s

dpaPeakFromFluence

DPA approximation based on a fluence conversion factor set in the dpaPerFluence setting

dpa

enrichmentBOL

Enrichment during fabrication

mass fraction

fastFlux

Neutron flux above 100keV

1/cm^2/s

fastFluxFr

Fraction of flux above 100keV

cornerFastFlux

Neutron flux above 100keV at hexagon block corners

n/cm^2/s

pointsFastFluxFr

Fraction of flux above 100keV at points within the block

None

pointsDpa

displacements per atom at points within the block

dpa

pointsDpaRate

Current time derivative of the displacement per atoms at points within the block

dpa/s

pdensGenerated

Volume-averaged generated power density. Different than b.p.pdens only when gamma transport is activated.

W/cm^3

Block Parameters from FuelPerformancePlugin

Name

Description

Units

gasReleaseFraction

Fraction of generated fission gas that no longer exists in the block. Should be between 0 and 1, inclusive.

fraction

bondRemoved

Fraction of thermal bond between fuel and clad that has been pushed out. Should be between 0 and 1, inclusive.

fraction

cladWastage

Total cladding wastage from inner and outer surfaces.

µm

totalCladStrain

Total diametral clad strain.

%

axialGrowthPct

Axial growth percentage

%

fpPeakFuelTemp

Fuel performance calculated peak fuel temperature.

C

fpAveFuelTemp

Fuel performance calculated average fuel temperature.

C

gasPorosity

Fraction of fuel volume that is occupied by gas pores

liquidPorosity

Fraction of fuel volume that is occupied by liquid filled pores

fuelRadialDisplacement

Radial fuel displacement from irradiation

cm

Block Parameters from ThermalHydraulicsPlugin

Name

Description

Units

pressureLossCoeffs

Pressure loss coefficients from form losses outside of bundle region of assembly, e.g. losses through pin attachment hardware, expansion in inlet nozzle.

inletLossCoeff

Pressure loss coefficients from form losses to be applied at the block inlet

THaveInletVel

Average fluid velocity taken at the inlet of the block.

m/s

THaveOutletVel

Average fluid velocity taken at the outlet of the block.

m/s

THdeltaPAccel

Acceleration component to the pressure drop.

Pa

THdeltaPFric

Friction component to the pressure drop.

Pa

THdeltaPInlet

Pressure drop at the inlet of the block.

Pa

THdeltaPOutlet

Pressure drop at the outlet of the block.

Pa

THhotChannelCladMidwallT

Midwall (average) clad temperature for the hot channel or hot pin.

°C

THhotChannelHeatTransferCoeff

Film heat transfer coefficient for hot channel in the assembly.

W/m^2/K

THinletDynamicPressure

Dynamic pressure drop component taken at the inlet of the block.

Pa

THmixingLength

Approximation of length for subchannel mixing in subchan model.

THpeakingStdDev

Standard deviation of pin peaking for modeling pin-level power in subchan.

THradialPeakingFactor

Approximation of radial peaking for modeling pin-level power in subchan.

THhotChannelCladODT

Nominal clad outer diameter temperature of the hot pin

°C

THhotChannelCladIDT

Nominal clad inner diameter temperature of the hot pin

°C

THhotChannelFuelODT

Temperature of the fuel outer diameter

°C

THhotChannelFuelCenterlineT

Nominal hot channel fuel centerline temperature

°C

THdeltaPBundle

Pressure difference in a bundle, including contributions from friction, acceleration, and gravity

Pa

TH0SigmaCladODT

0-sigma clad outer diameter temperature of the hot pin

°C

TH2SigmaCladODT

2-sigma clad outer diameter temperature of the hot pin

°C

TH3SigmaCladODT

3-sigma clad outer diameter temperature of the hot pin

°C

TH0SigmaCladIDT

0-sigma clad inner diameter temperature of the hot pin

°C

TH2SigmaCladIDT

2-sigma clad inner diameter temperature of the hot pin

°C

TH3SigmaCladIDT

3-sigma clad inner diameter temperature of the hot pin

°C

TH0SigmaFuelCenterlineT

0-sigma fuel centerline temperature

°C

TH2SigmaFuelCenterlineT

2-sigma fuel centerline temperature

°C

TH3SigmaFuelCenterlineT

3-sigma fuel centerline temperature

°C

THdilationPressure

Dilation pressure

Pa

THmaxLifeTimePower

Maximum power over the lifetime of this block.

W

TH0SigmaOutletT

0-sigma clad outer diameter temperature of the hot pin

°C

TH2SigmaOutletT

2-sigma clad outer diameter temperature of the hot pin

°C

TH3SigmaOutletT

3-sigma clad outer diameter temperature of the hot pin

°C

THTfuelCL

Average temperature of the fuel centerline used for neutronic coupling

°C

THTfuelOD

Average temperature of the fuel outer diameter used for neutronic coupling

°C

THaverageCladODT

Block average of the outer clad temperature.

°C

THaverageCladIDT

Block average of the inner clad temperature

°C

THassemPressDrop

The pressure drop across this block

Pa

THaveCoolantVel

Average of the inlet and outlet coolant velocities

m/s

THaverageCladTemp

The nominal average clad temperature in the block, which should be used for neutronic and TH feedback.

°C

THaverageGapTemp

The nominal average gap temperature in the block, which should be used for neutronic and TH feedback.

°C

THaverageDuctTemp

The nominal average duct temperature in the block, which should be used for neutronic and TH feedback.

°C

THcoolantAverageT

Flow-based average of the inlet and outlet coolant temperatures.

°C

THcoolantInletT

The nominal average bulk coolant inlet temperature into the block.

°C

THcoolantOutletT

Coolant temperature at the outlet of this block

°C

THcoolantStaticT

Volume-based average coolant temperature, recommended for neutronics

°C

THdPfrict

Frictional pressure drop

Pa

THdeltaPFormLoss

Pressure differences due to user input loss coefficeints

Pa

THdeltaPGrav

hydrostatic pressure difference in a block

Pa

THdeltaPNoGrav

Sum of the loss pressure drops due to friction, acceleration, and inlet + outlet

Pa

THdeltaPTotal

Total pressure difference in a block

Pa

THinletCoolantVel

Flow velocity

m/s

THhotChannelOutletT

Nominal hot channel outlet temperature

°C

THlocalDTout

Maximum delta-Ts for outlet temperatures of all assemblies

°C

THlocalDToutFuel

Maximum delta-Ts for outlet temperatures of fuel assemblies

°C

THmassFlowRate

Mass flow rate

kg/s

THmaxCoolantVel

The maximum outlet coolant velocity

m/s

THorificeSetting

A list of orifice settings corresponding to the assembly list

Pa/(kg/s)**2

THorificeZone

A list of orificing zones corresponding to the assembly list

THcornTemp

Best estimate duct temperature [degC] for assembly corners

°C

THedgeTemp

Best estimate duct temperature for assembly edges

°C

THbundleAveTemp

Bundle averaged temperature

°C

THcoldChanTemp

Best estimate cold channel temperature

°C

THcoldChannel

Cold channel (lowest coolant dT) identifier

THcoldPin

Cold pin (lowest PCT) pin identifier

THhotChannel

Hot channel (highest coolant dT) identifier

THhotPin

Hot pin (highest PCT) pin identifier