8. Assembly Parameters

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

Assembly Parameters from Framework

Name

Description

Units

powerDecay

List of decay heats at each time step specified in decayHeatCalcTimesInSeconds setting.

W

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

arealPd

Power in assembly divided by its XY cross-sectional area. Related to PCT.

MW/m^2

buLimit

buLimit

chargeBu

Max block-average burnup in this assembly when it most recently entered the core. If the assembly was discharged and then re-charged, this value will only reflect the most recent charge.

%FIMA

chargeCycle

Cycle number that this assembly most recently entered the core. If the assembly was discharged and then re-charged, this value will only reflect the most recent charge.

chargeFis

Fissile mass in assembly when it most recently entered the core. If the assembly was discharged and then re-charged, this value will only reflect the most recent charge.

kg

chargeTime

Time at which this assembly most recently entered the core. If the assembly was discharged and then re-charged, this value will only reflect the most recent charge.

yr

multiplicity

The number of physical assemblies that the associated object represents. This is typically 1, but may need to change when the assembly is moved between containers with different types of symmetry. For instance, if an assembly moves from a Core with 1/3rd symmetry into a spent-fuel pool with full symmetry, rather than splitting the assembly into 3, the multiplicity can be set to 3. For now, this is a bit of a hack to make fuel handling work; multiplicity in the 1/3 core should be 3 to begin with, in which case this parameter could be used as the primary means of handling symmetry and fractional domains throughout ARMI. We will probably roll that out once the dust settles on some of this SFP work. For now, the Core stores multiplicity as 1 always, since the powerMultiplier to adjust to full-core quantities.

daysSinceLastMove

daysSinceLastMove

kInf

kInf

maxDpaPeak

maxDpaPeak

dpa

maxPercentBu

maxPercentBu

%

numMoves

numMoves

timeToLimit

timeToLimit

days

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)

notes

A string with notes about the assembly, limited to 1000 characters. This parameter is not meant to store data. Needlessly storing large strings on this parameter for every assembly is potentially unwise from a memory perspective.

crCriticalFraction

The insertion fraction when the control rod assembly is in its critical configuration. Note that the default of -1.0 is a trigger for this value not being set yet.

crCurrentElevation

The current elevation of the bottom of the moveable section of a control rod assembly.

cm

crInsertedElevation

The elevation of the furthest-most insertion point of a control rod assembly. For a control rod assembly inserted from the top, this will be the lower tip of the bottom-most moveable section in the assembly when fully inserted.

cm

crRodLength

length of the control material within the control rod

cm

crWithdrawnElevation

The elevation of the tip of a control rod assembly when it is fully withdrawn. For a control rod assembly inserted from the top, this will be the lower tip of the bottom-most moveable section in the assembly when fully withdrawn.

cm

THdeltaPNoGrav

Total pressure difference minus gravity; it can be thought of as being ‘total pressure loss’

Pa

THdeltaPPump

Pumping pressure rise required to pump the given mass flow rate through the rod bundle

Pa

THdeltaPTotal

Total pressure difference across the assembly

Pa

THcoolantOutletT

The nominal average bulk coolant outlet temperature out of the block.

°C

THmassFlowRate

The nominal assembly flow rate

kg/s

THlocalDTout

Maximum delta-Ts for outlet temperatures of all assemblies

°C

THlocalDToutFuel

Maximum delta-Ts for outlet temperatures of fuel assemblies

°C

THorificeZone

orifice zone for assembly; should be location specific

type

The name of the assembly input on the blueprints input

nozzleType

nozzle type for assembly

THcoolantInletT

Assembly inlet temperature in C (cold temperature)

°C

assemNum

Assembly number

dischargeTime

Time the Assembly was removed from the Reactor.

yr

hotChannelFactors

Definition of set of HCFs to be applied to assembly.

AziMesh

Number of points in the Azimuthal mesh.

RadMesh

Number of points in the Radial mesh.