8. Block Parameters
This document lists all of the Block Parameters that are provided by the ARMI
Framework. See armi.reactor.parameters for use.
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 |
|
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 |
|
molesHmBOLByPin |
Total number of atoms of heavy metal at BOL |
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 (integer) |
|
residence |
Duration that a block has been in the core multiplied by the fraction of full power generated in that time. |
days |
molesHmNow |
Total number of atoms of heavy metal |
mole |
molesHmBOL |
Total number of atoms of heavy metal at BOL. |
mole |
massHmBOL |
Mass of heavy metal at BOL |
g |
initialB10ComponentVol |
cc’s of un-irradiated, cold B10 containing component (includes full volume of any components with B10) |
cm^3 |
depletionMatrix |
Full BurnMatrix objects containing transmutation and decay info about this block. |
|
cycleAverageBurnMatrix |
Integrated burn matrix mapping this block from its BOC to EOC number densities. |
|
envGroup |
The environment group letter of this block |
|
envGroupNum |
An integer representation of the environment group (burnup/temperature/etc.). linked to envGroup. |
|
buRate |
Current rate of burnup accumulation. Useful for estimating times when burnup limits may be exceeded. |
%FIMA/days |
buRatePeak |
Current rate of burnup accumulation at peak location |
%FIMA/days |
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 |
heliumInB4C |
Alpha particle production rate in B4C control and shield material. |
He/s/cm^3 |
powerRx |
Power density of the reactor |
W/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 |
nHMAtBOL |
Ndens of heavy metal at BOL |
atoms/(bn*cm) |
z |
Center axial dimension of this block |
cm |
axialExpTargetComponent |
The name of the target component used for axial expansion and contraction of solid components. |
|
topIndex |
(‘the axial block index within its parent assembly (0 is bottom block). This index withregard to the mesh of the reference assembly so it does not increase by 1 for each block.It is used to keep the mesh of the assemblies uniform with axial expansion.See setBlockMesh, makeAxialSnapList’,) |
|
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 |
Inner diameter of the Block. |
|
height |
the block height |
cm |
xsType |
The xs group letter of this block |
|
xsTypeNum |
An integer representation of the cross section type, linked to xsType. |
|
type |
string name of the input block |
|
rxFuelDensityCoeffPerMass |
Fuel density coefficient |
Δk/k/k’/kg |
rxFuelTemperatureCoeffPerMass |
Fuel temperature coefficient |
Δk/k/k’/kg |
rxFuelVoidedTemperatureCoeffPerMass |
Fuel voided-coolant temperature coefficient |
Δk/k/k’/kg |
rxCladDensityCoeffPerMass |
Clad density coefficient |
Δk/k/k’/kg |
rxCladTemperatureCoeffPerMass |
Clad temperature coefficient |
Δk/k/k’/kg |
rxStructureDensityCoeffPerMass |
Structure density coefficient |
Δk/k/k’/kg |
rxStructureTemperatureCoeffPerMass |
Structure temperature coefficient |
Δk/k/k’/kg |
rxCoolantDensityCoeffPerMass |
Coolant density coefficient |
Δk/k/k’/kg |
rxCoolantTemperatureCoeffPerMass |
Coolant temperature coefficient |
Δk/k/k’/kg |
rxFuelDensityCoeffPerTemp |
Fuel density coefficient |
Δk/k/k’/K |
rxFuelDopplerCoeffPerTemp |
Fuel Doppler coefficient |
Δk/k/k’/K |
rxFuelVoidedDopplerCoeffPerTemp |
Fuel voided-coolant Doppler coefficient |
Δk/k/k’/K |
rxFuelDopplerConstant |
Fuel Doppler constant |
Δk/k/k’*K^(n-1) |
rxFuelVoidedDopplerConstant |
Fuel voided-coolant Doppler constant |
Δk/k/k’*K^(n-1) |
rxStructureDopplerConstant |
Structure Doppler constant |
Δk/k/k’*K^(n-1) |
rxCladDopplerConstant |
Clad 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 |
rxCladTemperatureCoeffPerTemp |
Clad temperature coefficient |
Δk/k/k’/K |
rxStructureDensityCoeffPerTemp |
Structure density coefficient |
Δk/k/k’/K |
rxStructureDopplerCoeffPerTemp |
Structure Doppler coefficient |
Δk/k/k’/K |
rxStructureTemperatureCoeffPerTemp |
Structure temperature coefficient |
Δk/k/k’/K |
rxCoolantDensityCoeffPerTemp |
Coolant density coefficient |
Δk/k/k’/K |
rxCoolantTemperatureCoeffPerTemp |
Coolant temperature coefficient |
Δk/k/k’/K |
avgFuelTemp |
Average fuel temperature. |
°C |
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. |
|
axExtenNodeHeight |
Axial extension node height |
m |
blockBeta |
Beta in each block |
|
blockF |
Adjoint-weighted fission source in each block |
1/cm^5/s^2 |
breedRatio |
Breeding ratio |
|
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 |
|
crWastage |
Combines ACCI and clad corrosion for control blocks |
µm |
cyclicNErr |
Relative error of the block number density |
|
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 |
|
mreg |
SASSYS/DIF3D-K radial region index assignment |
|
nPins |
Number of pins |
|
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 |
puFrac |
Current Pu number density relative to HM at BOL |
|
smearDensity |
Smear density of fuel pins in this block. Defined as the ratio of fuel area to total space inside cladding. |
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. |
|
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 |
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 |
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 |
THdilationPressure |
Dilation pressure |
Pa |
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 |
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 |
THdeltaPTotal |
Total pressure difference in a block |
Pa |
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 |
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 |
THhotChannel |
Hot channel (highest coolant dT) identifier |
Name |
Description |
Units |
|---|---|---|
fuelCladLocked |
Boolean to indicate if the fuel is locked with the clad. This is used to determine the expansion constraints for the fuel during thermal and/or burn-up expansion of the fuel and cladding materials. |
|
gasReleaseFraction |
Fraction of generated fission gas that no longer exists in the block. |
|
bondRemoved |
Fraction of thermal bond between fuel and clad that has been pushed out. |
|
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 |
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 |
#*cm/s |
mgNeutronVelocity |
multigroup neutron velocity |
cm/s |
extSrc |
multigroup external source |
#/cm^3/s |
mgGammaSrc |
multigroup gamma source |
#/cm^3/s |
gammaSrc |
gamma source |
#/cm^3/s |
mgFluxSK |
multigroup volume-integrated flux stored for multiple time steps in spatial kinetics (2-D array) |
n*cm/s |
pinMgFluxes |
The block-level pin multigroup fluxes. pinMgFluxes[i, g] 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. |
n/cm^2/s |
pinMgFluxesAdj |
should be a blank 3-D array, but re-defined later (nPins x ng x nAxialSegments) |
|
pinMgFluxesGamma |
should be a blank 3-D array, but re-defined later (nPins x ng x nAxialSegments) |
#/cm^2/s |
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. |
W/cm^3 |
axialPowerProfileNeutron |
For each reconstructed axial location, a tuple (z, neutron power density) where with axial origin at the bottom of assembly in which the blocks are located. |
W/cm^3 |
axialPowerProfileGamma |
For each reconstructed axial location, a tuple (z, gamma power density) where with axial origin at the bottom of assembly in which the blocks are located. |
W/cm^3 |
betad |
Delayed neutron beta |
|
chi |
Energy distribution of fission neutrons |
|
chid |
Energy distribution of delayed fission neutrons |
|
linPow |
Pin-averaged linear heat rate, which is calculated by evaluating the block power and dividing by the number of pins. If gamma transport is enabled, then this represents the combined neutron and gamma heating. If gamma transport is disabled then this represents the energy generation in the pin, where gammas are assumed to deposit their energy locally. Note that this value does not implicitly account for axial and radial peaking factors within the block. Use linPowByPin for obtaining the pin linear heat rate with peaking factors included. |
W/m |
linPowByPin |
Pin linear linear heat rate, which is calculated through flux reconstruction and accounts for axial and radial peaking factors. This differs from the linPow parameter, which assumes no axial and radial peaking in the block as this information is unavailable without detailed flux reconstruction. The same application of neutron and gamma heating results applies. |
W/cm |
linPowByPinNeutron |
Pin linear neutron heat rate. This is the neutron heating component of linPowByPin |
W/cm |
linPowByPinGamma |
Pin linear gamma heat rate. This is the gamma heating component of linPowByPin |
W/cm |
reactionRates |
List of reaction rates in specified by setting “reactionsToDB” |
#/s |
pointsEdgeFastFluxFr |
Fraction of flux above 100keV at edges of the block |
|
pointsEdgeDpa |
displacements per atom at edges of the block |
dpa |
pointsEdgeDpaRate |
Current time derivative of the displacement per atoms at edges of the block |
dpa/s |
cornerFastFlux |
Neutron flux above 100keV at hexagon block corners |
n/cm^2/s |
pointsCornerFastFluxFr |
Fraction of flux above 100keV at corners of the block |
|
pointsCornerDpa |
displacements per atom at corners of the block |
dpa |
pointsCornerDpaRate |
Current time derivative of the displacement per atoms at corners of the block |
dpa/s |
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. |
|
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 |
fertileBonus |
The fertile bonus |
|
fisDens |
Fission density in a pin (scaled up from homogeneous) |
fissions/cm^3/s |
fisDensHom |
Homogenized fissile density |
1/cm^3/s |
fluxGamma |
Gamma scalar flux |
#/cm^2/s |
fluxPeak |
Peak neutron flux calculated within the mesh |
n/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. |
|
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 |
rateProdN2n |
Production rate of neutrons from n2n reactions. |
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 |
powerGenerated |
Generated power. Different than b.p.power only when gamma transport is activated. |
W |
power |
Total power |
W |
powerGamma |
Total gamma power |
W |
powerNeutron |
Total neutron power |
W |
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 |
|
pdensGenerated |
Volume-averaged generated power density. Different than b.p.pdens only when gamma transport is activated. |
W/cm^3 |