armi.reactor.blocks module

Defines blocks, which are axial chunks of assemblies. They contain most of the state variables, including power, flux, and homogenized number densities.

Assemblies are made of blocks.

Blocks are made of components.

class armi.reactor.blocks.Block(name: str, height: float = 1.0)

Bases: Composite

A homogenized axial slab of material.

Blocks are stacked together to form assemblies.

Builds a new ARMI block.

namestr

The name of this block

heightfloat, optional

The height of the block in cm. Defaults to 1.0 so that getVolume assumes unit height.

uniqID = 0

PITCH_DIMENSION = 'op'

PITCH_COMPONENT_TYPE: ClassVar[Optional[Tuple[Type[Component], ...]]] = None

pDefs = <armi.reactor.parameters.parameterDefinitions.ParameterDefinitionCollection object>

createHomogenizedCopy(pinSpatialLocators=False)

Create a copy of a block.

Notes

Used to implement a copy function for specific block types that can be much faster than a deepcopy by glossing over details that may be unnecessary in certain contexts.

This base class implementation is just a deepcopy of the block, in full detail (not homogenized).

property core

property r

Look through the ancestors of the Block to find a Reactor, and return it.

Notes

Typical hierarchy: Reactor <- Core <- Assembly <- Block A block should only have a reactor through a parent assembly. It may make sense to try to factor out usage of b.r.

Returns:

core.parent – ARMI reactor object that is an ancestor of the block.

Return type:

armi.reactor.reactors.Reactor

Raises:

ValueError – If the parent of the block’s core is not an armi.reactor.reactors.Reactor.

makeName(assemNum, axialIndex)

Generate a standard block from assembly number.

This also sets the block-level assembly-num param.

Once, we used a axial-character suffix to represent the axial index, but this is inherently limited so we switched to a numerical name. The axial suffix needs can be brought in in plugins that require them.

Examples

>>> makeName(120, 5)
'B0120-005'

getSmearDensity(cold=True)

Compute the smear density of pins in this block.

Smear density is the area of the fuel divided by the area of the space available for fuel inside the cladding. Other space filled with solid materials is not considered available. If all the area is fuel, it has 100% smear density. Lower smear density allows more room for swelling.

Warning

This requires circular fuel and circular cladding. Designs that vary from this will be wrong. It may make sense in the future to put this somewhere a bit more design specific.

Notes

This only considers circular objects. If you have a cladding that is not a circle, it will be ignored.

Negative areas can exist for void gaps in the fuel pin. A negative area in a gap represents overlap area between two solid components. To account for this additional space within the pin cladding the abs(negativeArea) is added to the inner cladding area.

Parameters:

cold (bool, optional) – If false, returns the smear density at hot temperatures

Returns:

smearDensity – The smear density as a fraction

Return type:

float

autoCreateSpatialGrids()

Creates a spatialGrid for a Block.

Blocks do not always have a spatialGrid from Blueprints, but, some Blocks can have their spatialGrids inferred based on the multiplicty of their components. This would add the ability to create a spatialGrid for a Block and give its children the corresponding spatialLocators if certain conditions are met.

Raises:

ValueError – If the multiplicities of the block are not only 1 or N or if generated ringNumber leads to more positions than necessary.

getMgFlux(adjoint=False, average=False, volume=None, gamma=False)

Returns the multigroup neutron flux in [n/cm^2/s].

The first entry is the first energy group (fastest neutrons). Each additional group is the next energy group, as set in the ISOTXS library.

It is stored integrated over volume on self.p.mgFlux

Parameters:

• adjoint (bool, optional) – Return adjoint flux instead of real

• average (bool, optional) – If true, will return average flux between latest and previous. Doesn’t work for pin detailed yet

• volume (float, optional) – If average=True, the volume-integrated flux is divided by volume before being returned. The user may specify a volume here, or the function will obtain the block volume directly.

• gamma (bool, optional) – Whether to return the neutron flux or the gamma flux.

Returns:

flux

Return type:

multigroup neutron flux in [n/cm^2/s]

setPinMgFluxes(fluxes, adjoint=False, gamma=False)

Store the pin-detailed multi-group neutron flux.

The [g][i] indexing is transposed to be a list of lists, one for each pin. This makes it simple to do depletion for each pin, etc.

Parameters:

• fluxes (2-D list of floats) – The block-level pin multigroup fluxes. fluxes[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.

• adjoint (bool, optional) – Whether to set real or adjoint data.

• gamma (bool, optional) – Whether to set gamma or neutron data.

• Outputs –

• ------- –

• self.p.pinMgFluxes (2-D array of floats) – 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.

getMicroSuffix()

Returns the microscopic library suffix (e.g. ‘AB’) for this block.

DIF3D and MC2 are limited to 6 character nuclide labels. ARMI by convention uses the first 4 for nuclide name (e.g. U235, PU39, etc.) and then uses the 5th character for cross-section type and the 6th for burnup group. This allows a variety of XS sets to be built modeling substantially different blocks.

Notes

The single-letter use for xsType and buGroup limit users to 26 groups of each. ARMI will allow 2-letter xsType designations if and only if the buGroups setting has length 1 (i.e. no burnup groups are defined). This is useful for high-fidelity XS modeling of V&V models such as the ZPPRs.

getHeight()

Return the block height.

setHeight(modifiedHeight, conserveMass=False, adjustList=None)

Set a new height of the block.

Parameters:

• modifiedHeight (float) – The height of the block in cm

• conserveMass (bool, optional) – Conserve mass of nuclides in adjustList.

• adjustList (list, optional) – Nuclides that will be conserved in conserving mass in the block. It is recommended to pass a list of all nuclides in the block.

Notes

There is a coupling between block heights, the parent assembly axial mesh, and the ztop/zbottom/z params of the sibling blocks. When you set a height, all those things are invalidated. Thus, this method has to go through and update them via parent.calculateZCoords. This could be inefficient though it has not been identified as a bottleneck. Possible improvements include deriving z/ztop/zbottom on the fly and invalidating the parent mesh with some kind of flag, signaling it to recompute itself on demand. Developers can get around some of the O(N^2) scaling of this by setting p.height directly but they must know to update the dependent objects after they do that. Use with care.

See also

armi.reactor.reactors.Core.updateAxialMesh

May need to be called after this.

armi.reactor.assemblies.Assembly.calculateZCoords

Recalculates z-coords, automatically called by this.

getWettedPerimeter()

getFlowAreaPerPin()

Return the flowing coolant area of the block in cm^2, normalized to the number of pins in the block.

NumPins looks for max number of fuel, clad, control, etc.

See also

armi.reactor.blocks.Block.getNumPins

figures out numPins

getHydraulicDiameter()

adjustUEnrich(newEnrich)

Adjust U-235/U-238 mass ratio to a mass enrichment.

Parameters:

newEnrich (float) – New U-235 enrichment in mass fraction

Notes

completeInitialLoading must be run because adjusting the enrichment actually changes the mass slightly and you can get negative burnups, which you do not want.

getLocation()

Return a string representation of the location.

coords(rotationDegreesCCW=0.0)

Returns the coordinates of the block.

setBuLimitInfo()

Sets burnup limit based on igniter, feed, etc.

getMaxArea()

getMaxVolume()

The maximum volume of this object if it were totally full.

Returns:

vol – volume in cm^3.

Return type:

float

getArea(cold=False)

Return the area of a block for a full core or a 1/3 core model.

Area is consistent with the area in the model, so if you have a central assembly in a 1/3 symmetric model, this will return 1/3 of the total area of the physical assembly. This way, if you take the sum of the areas in the core (or count the atoms in the core, etc.), you will have the proper number after multiplying by the model symmetry.

Parameters:

cold (bool) – flag to indicate that cold (as input) dimensions are required

Notes

This might not work for a 1/6 core model (due to symmetry line issues).

Returns:

area

Return type:

float (cm^2)

See also

armi.reactor.blocks.Block.getMaxArea

return the full area of the physical assembly disregarding model symmetry

getVolume()

Return the volume of a block.

Returns:

volume – Block or component volume in cm^3

Return type:

float

getSymmetryFactor()

Return a scaling factor due to symmetry on the area of the block or its components.

Takes into account assemblies that are bisected or trisected by symmetry lines

In 1/3 symmetric cases, the central assembly is 1/3 a full area. If edge assemblies are included in a model, the symmetry factor along both edges for overhanging assemblies should be 2.0. However, ARMI runs in most scenarios with those assemblies on the 120-edge removed, so the symmetry factor should generally be just 1.0.

See also

armi.reactor.converters.geometryConverter.EdgeAssemblyChanger.scaleParamsRelatedToSymmetry

isOnWhichSymmetryLine()

Block symmetry lines are determined by the reactor, not the parent.

adjustDensity(frac, adjustList, returnMass=False)

adjusts the total density of each nuclide in adjustList by frac.

Parameters:

• frac (float) – The fraction of the current density that will remain after this operation

• adjustList (list) – List of nuclide names that will be adjusted.

• returnMass (bool) – If true, will return mass difference.

Returns:

mass – Mass difference in grams. If you subtract mass, mass will be negative. If returnMass is False (default), this will always be zero.

Return type:

float

completeInitialLoading(bolBlock=None)

Does some BOL bookkeeping to track things like BOL HM density for burnup tracking.

This should run after this block is loaded up at BOC (called from Reactor.initialLoading).

The original purpose of this was to get the moles HM at BOC for the moles Pu/moles HM at BOL calculation.

This also must be called after modifying something like the smear density or zr fraction in an optimization case. In ECPT cases, a BOL block must be passed or else the burnup will try to get based on a pre-burned value.

Parameters:

bolBlock (Block, optional) – A BOL-state block of this block type, required for perturbed equilibrium cases. Must have the same enrichment as this block!

Returns:

hmDens – The heavy metal number density of this block.

Return type:

float

See also

Reactor.importGeom, depletion._updateBlockParametersAfterDepletion

setB10VolParam(heightHot)

Set the b.p.initialB10ComponentVol param according to the volume of boron-10 containing components.

Parameters:

heightHot (Boolean) – True if self.height() is cold height

replaceBlockWithBlock(bReplacement)

Replace the current block with the replacementBlock.

Typically used in the insertion of control rods.

static plotFlux(core, fName=None, bList=None, peak=False, adjoint=False, bList2=[])

add(c)

removeAll(recomputeAreaFractions=True)

remove(c, recomputeAreaFractions=True)

getComponentsThatAreLinkedTo(comp, dim)

Determine which dimensions of which components are linked to a specific dimension of a particular component.

Useful for breaking fuel components up into individuals and making sure anything that was linked to the fuel mult (like the cladding mult) stays correct.

Parameters:

• comp (Component) – The component that the results are linked to

• dim (str) – The name of the dimension that the results are linked to

Returns:

linkedComps – A list of (components,dimName) that are linked to this component, dim.

Return type:

list

getComponentsInLinkedOrder(componentList=None)

Return a list of the components in order of their linked-dimension dependencies.

Parameters:

components (list, optional) – A list of components to consider. If None, this block’s components will be used.

Notes

This means that components other components are linked to come first.

getSortedComponentsInsideOfComponent(component)

Returns a list of components inside of the given component sorted from innermost to outermost.

Parameters:

component (object) – Component to look inside of.

Notes

If you just want sorted components in this block, use sorted(self). This will never include any DerivedShape objects. Since they have a derived area they don’t have a well-defined dimension. For now we just ignore them. If they are desired in the future some knowledge of their dimension will be required while they are being derived.

getNumPins()

Return the number of pins in this block.

mergeWithBlock(otherBlock, fraction)

Turns this block into a mixture of this block and some other block.

Parameters:

• otherBlock (Block) – The block to mix this block with. The other block will not be modified.

• fraction (float) – Fraction of the other block to mix in with this block. If 0.1 is passed in, this block will become 90% what it originally was and 10% what the other block is.

Notes

This merges on a high level (using number densities). Components will not be merged.

This is used e.g. for inserting a control block partially to get a very tight criticality control. In this case, a control block would be merged with a duct block. It is also used when a control rod is specified as a certain length but that length does not fit exactly into a full block.

getComponentAreaFrac(typeSpec)

Returns the area fraction of the specified component(s) among all components in the block.

Parameters:

typeSpec (Flags or list of Flags) – Component types to look up

Examples

>>> b.getComponentAreaFrac(Flags.CLAD)
0.15

Returns:

The area fraction of the component.

Return type:

float

verifyBlockDims()

Optional dimension checking.

getDim(typeSpec, dimName)

Search through blocks in this assembly and find the first component of compName. Then, look on that component for dimName.

Parameters:

• typeSpec (Flags or list of Flags) – Component name, e.g. Flags.FUEL, Flags.CLAD, Flags.COOLANT, …

• dimName (str) – Dimension name, e.g. ‘od’, …

Returns:

dimVal – The dimension in cm.

Return type:

float

Examples

>>> getDim(Flags.WIRE,'od')
0.01

getPinCenterFlatToFlat(cold=False)

Return the flat-to-flat distance between the centers of opposing pins in the outermost ring.

getWireWrapCladGap(cold=False)

Return the gap betwen the wire wrap and the clad.

getPlenumPin()

Return the plenum pin if it exists.

isPlenumPin(c)

Return True if the specified component is a plenum pin.

getPitch(returnComp=False)

Return the center-to-center hex pitch of this block.

Parameters:

returnComp (bool, optional) – If true, will return the component that has the maximum pitch as well

Returns:

• pitch (float or None) – Hex pitch in cm, if well-defined. If there is no clear component for determining pitch, returns None

• component (Component or None) – Component that has the max pitch, if returnComp == True. If no component is found to define the pitch, returns None

Notes

The block stores a reference to the component that defines the pitch, making the assumption that while the dimensions can change, the component containing the largest dimension will not. This lets us skip the search for largest component. We still need to ask the largest component for its current dimension in case its temperature changed, or was otherwise modified.

See also

setPitch

sets pitch

hasPinPitch()

Return True if the block has enough information to calculate pin pitch.

getPinPitch(cold=False)

Return sub-block pitch in blocks.

This assumes the spatial grid is defined by unit steps

getDimensions(dimension)

Return dimensional values of the specified dimension.

getLargestComponent(dimension)

Find the component with the largest dimension of the specified type.

Parameters:

dimension (str) – The name of the dimension to find the largest component of.

Returns:

largestComponent – The component with the largest dimension of the specified type.

Return type:

armi.reactor.components.Component

setPitch(val, updateBolParams=False)

Sets outer pitch to some new value.

This sets the settingPitch and actually sets the dimension of the outer hexagon.

During a load (importGeom), the setDimension doesn’t usually do anything except set the setting See Issue 034

But during a actual case modification (e.g. in an optimization sweep, then the dimension has to be set as well.

See also

getPitch

gets the pitch

getMfp(gamma=False)

Calculate the mean free path for neutron or gammas in this block.

\[<\Sigma> = \frac{\sum_E(\phi_e \Sigma_e dE)}{\sum_E (\phi_e dE)} = \frac{\sum_E(\phi_e N \sum_{\text{type}}(\sigma_e) dE}{\sum_E (\phi_e dE))}\]

Block macro is the sum of macros of all nuclides.

phi_g = flux*dE already in multigroup method.

Returns:

mfp, mfpAbs, diffusionLength

Return type:

tuple(float, float float)

setAreaFractionsReport()

getBlocks()

This method returns all the block(s) included in this block its implemented so that methods could iterate over reactors, assemblies or single blocks without checking to see what the type of the reactor-family object is.

updateComponentDims()

This method updates all the dimensions of the components.

Notes

This is VERY useful for defining a ThRZ core out of differentialRadialSegements whose dimensions are connected together some of these dimensions are derivative and can be updated by changing dimensions in a Parameter Component or other linked components

See also

armi.reactor.components.DifferentialRadialSegment.updateDims, armi.reactor.components.Parameters, armi.physics.optimize.OptimizationInterface.modifyCase

breakFuelComponentsIntoIndividuals()

Split block-level components (in fuel blocks) into pin-level components.

The fuel component will be broken up according to its multiplicity.

Order matters! The first pin component will be located at a particular (x, y), which will be used in the fluxRecon module to determine the interpolated flux.

The fuel will become fuel001 through fuel169 if there are 169 pins.

getIntegratedMgFlux(adjoint=False, gamma=False)

Return the volume integrated multigroup neutron tracklength in [n-cm/s].

The first entry is the first energy group (fastest neutrons). Each additional group is the next energy group, as set in the ISOTXS library.

Parameters:

• adjoint (bool, optional) – Return adjoint flux instead of real

• gamma (bool, optional) – Whether to return the neutron flux or the gamma flux.

Returns:

integratedFlux – multigroup neutron tracklength in [n-cm/s]

Return type:

numpy.array

getLumpedFissionProductCollection()

Get collection of LFP objects. Will work for global or block-level LFP models.

Returns:

lfps – lfpName keys , lfp object values

Return type:

LumpedFissionProduct

See also

armi.physics.neutronics.fissionProductModel.lumpedFissionProduct.LumpedFissionProduct

LFP object

rotate(rad)

Function for rotating a block’s spatially varying variables by a specified angle (radians).

Parameters:

rad (float) – Number (in radians) specifying the angle of counter clockwise rotation.

setAxialExpTargetComp(targetComponent)

Sets the targetComponent for the axial expansion changer.

Parameter

targetComponent: Component object

component specified to be target component for axial expansion changer

See also

armi.reactor.converters.axialExpansionChanger.py

:ExpansionData::_setTargetComponents

getPinCoordinates()

Compute the local centroid coordinates of any pins in this block.

The pins must have a CLAD-flagged component for this to work.

Returns:

localCoordinates – list of (x,y,z) pairs representing each pin in the order they are listed as children

Return type:

list

Notes

This assumes hexagonal pin lattice and needs to be upgraded once more generic geometry options are needed. Only works if pins have clad.

paramCollectionType

alias of BlockParameterCollection

class armi.reactor.blocks.HexBlock(name, height=1.0)

Bases: Block

Defines a HexBlock.

PITCH_COMPONENT_TYPE: ClassVar[Optional[Tuple[Type[Component], ...]]] = (<class 'armi.reactor.components.basicShapes.Hexagon'>,)

coords(rotationDegreesCCW=0.0)

Returns the coordinates of the block.

createHomogenizedCopy(pinSpatialLocators=False)

Create a new homogenized copy of a block that is less expensive than a full deepcopy.

Notes

This can be used to improve performance when a new copy of a reactor needs to be built, but the full detail of the block (including component geometry, material, number density, etc.) is not required for the targeted physics solver being applied to the new reactor model.

The main use case is for the uniform mesh converter (UMC). Frequently, a deterministic neutronics solver will require a uniform mesh reactor, which is produced by the UMC. Many deterministic solvers for fast spectrum reactors will also treat the individual blocks as homogenized mixtures. Since the neutronics solver does not need to know about the geometric and material details of the individual child components within a block, we can save significant effort while building the uniform mesh reactor with the UMC by omitting this detailed data and only providing the necessary level of detail for the uniform mesh reactor: number densities on each block.

can affect cross sections. This temperature variation is captured by the lattice physics module. As long as temperature distribution is correctly captured during cross section generation, it doesn’t need to be transferred to the neutronics solver directly through this copy operation.

Returns:

A homogenized block containing a single Hexagon Component that contains an average temperature and the number densities from the original block.

Return type:

b

See also

armi.reactor.converters.uniformMesh.UniformMeshGeometryConverter.makeAssemWithUniformMesh

getMaxArea()

Compute the max area of this block if it was totally full.

getDuctIP()

Returns the duct IP dimension.

getDuctOP()

Returns the duct OP dimension.

initializePinLocations()

Initialize pin locations.

setPinPowers(powers, powerKeySuffix='')

Updates the pin linear power densities of this block for the current rotation. The linear densities are represented by the linPowByPin parameter.

It is assumed that initializePinLocations() has already been executed for fueled blocks in order to access the pinLocation parameter. The pinLocation parameter is not accessed for non-fueled blocks.

The linPowByPin parameter can be directly assigned to instead of using this method if the multiplicity of the pins in the block is equal to the number of pins in the block.

Parameters:

• powers (list of floats, required) – The block-level pin linear power densities. powers[i] represents the average linear power density of pin i. The units of linear power density is watts/cm (i.e., watts produced per cm of pin length). The “ARMI pin ordering” must be be used, which is counter-clockwise from 3 o’clock.

• powerKeySuffix (str, optional) – Must be either an empty string, NEUTRON, or GAMMA. Defaults to empty string.

Notes

This method can handle assembly rotations by using the pinLocation parameter.

rotate(rad)

Rotates a block’s spatially varying parameters by a specified angle in the counter-clockwise direction.

The parameters must have a ParamLocation of either CORNERS or EDGES and must be a Python list of length 6 in order to be eligible for rotation; all parameters that do not meet these two criteria are not rotated.

The pin indexing, as stored on the pinLocation parameter, is also updated via rotatePins.

Parameters:

rad (float, required) – Angle of counter-clockwise rotation in units of radians. Rotations must be in 60-degree increments (i.e., PI/6, PI/3, PI, 2 * PI/3, 5 * PI/6, and 2 * PI)

See also

rotatePins

rotatePins(rotNum, justCompute=False)

Rotate the pins of a block, which means rotating the indexing of pins. Note that this does not rotate all block quantities, just the pins.

Parameters:

• rotNum (int, required) – An integer from 0 to 5, indicating the number of counterclockwise 60-degree rotations from the CURRENT orientation. Degrees of counter-clockwise rotation = 60*rot

• justCompute (boolean, optional) – If True, rotateIndexLookup will be returned but NOT assigned to the object parameter self.p.pinLocation. If False, rotateIndexLookup will be returned AND assigned to the object variable self.p.pinLocation. Useful for figuring out which rotation is best to minimize burnup, etc.

Returns:

rotateIndexLookup – This is an index lookup (or mapping) between pin ids and pin locations. The pin indexing is 1-D (not ring,pos or GEODST). The “ARMI pin ordering” is used for location, which is counter-clockwise from 1 o’clock. Pin ids are always consecutively ordered starting at 1, while pin locations are not once a rotation has been applied.

Return type:

dict of ints

Notes

Changing (x,y) positions of pins does NOT constitute rotation, because the indexing of pin atom densities must be re-ordered. Re-order indexing of pin-level quantities, NOT (x,y) locations of pins. Otherwise, subchannel input will be in wrong order.

How rotations works is like this. There are pins with unique pin numbers in each block. These pin numbers will not change no matter what happens to a block, so if you have pin 1, you always have pin 1. However, these pins are all in pinLocations, and these are what change with rotations. At BOL, a pin’s pinLocation is equal to its pin number, but after a rotation, this will no longer be so.

So, all params that don’t care about exactly where in space the pin is (such as depletion) can just use the pin number, but anything that needs to know the spatial location (such as fluxRecon, which interpolates the flux spatially, or subchannel codes, which needs to know where the power is) need to map through the pinLocation parameters.

This method rotates the pins by changing the pinLocation parameter.

See also

armi.reactor.blocks.HexBlock.rotate

Rotates the entire block (pins, ducts, and spatial quantities).

Examples

rotateIndexLookup[i_after_rotation-1] = i_before_rotation-1

verifyBlockDims()

Perform some checks on this type of block before it is assembled.

getPinToDuctGap(cold=False)

Returns the distance in cm between the outer most pin and the duct in a block.

Parameters:

cold (boolean) – Determines whether the results should be cold or hot dimensions.

Returns:

pinToDuctGap – Returns the diameteral gap between the outer most pins in a hex pack to the duct inner face to face in cm.

Return type:

float

getRotationNum()

Get index 0 through 5 indicating number of rotations counterclockwise around the z-axis.

setRotationNum(rotNum)

Set orientation based on a number 0 through 5 indicating number of rotations counterclockwise around the z-axis.

getSymmetryFactor()

Return a factor between 1 and N where 1/N is how much cut-off by symmetry lines this mesh cell is.

Reactor-level meshes have symmetry information so we have a reactor for this to work. That’s why it’s not implemented on the grid/locator level.

When edge-assemblies are included on both edges (i.e. MCNP or DIF3D-FD 1/3-symmetric cases), the edge assemblies have symmetry factors of 2.0. Otherwise (DIF3D-nodal) there’s a full assembly on the bottom edge (overhanging) and no assembly at the top edge so the ones at the bottom are considered full (symmetryFactor=1).

If this block is not in any grid at all, then there can be no symmetry so return 1.

autoCreateSpatialGrids()

Given a block without a spatialGrid, create a spatialGrid and give its children the corresponding spatialLocators (if it is a simple block).

In this case, a simple block would be one that has either multiplicity of components equal to 1 or N but no other multiplicities. Also, this should only happen when N fits exactly into a given number of hex rings. Otherwise, do not create a grid for this block.

Notes

If the block meets all the conditions, we gather all components to either be a multiIndexLocation containing all of the pin positions, otherwise, locator is the center (0,0).

Also, this only works on blocks that have ‘flat side up’.

Raises:

ValueError – If the multiplicities of the block are not only 1 or N or if generated ringNumber leads to more positions than necessary.

getPinCenterFlatToFlat(cold=False)

Return the flat-to-flat distance between the centers of opposing pins in the outermost ring.

hasPinPitch()

Return True if the block has enough information to calculate pin pitch.

getPinPitch(cold=False)

Get the pin pitch in cm.

Assumes that the pin pitch is defined entirely by contacting cladding tubes and wire wraps. Grid spacers not yet supported.

Parameters:

cold (boolean) – Determines whether the dimensions should be cold or hot

Returns:

pinPitch – pin pitch in cm

Return type:

float

getWettedPerimeter()

Return the total wetted perimeter of the block in cm.

getFlowArea()

Return the total flowing coolant area of the block in cm^2.

getHydraulicDiameter()

Return the hydraulic diameter in this block in cm.

Hydraulic diameter is 4A/P where A is the flow area and P is the wetted perimeter. In a hex assembly, the wetted perimeter includes the cladding, the wire wrap, and the inside of the duct. The flow area is the inner area of the duct minus the area of the pins and the wire.

paramCollectionType

alias of BlockParameterCollection

class armi.reactor.blocks.CartesianBlock(name: str, height: float = 1.0)

Bases: Block

Builds a new ARMI block.

namestr

The name of this block

heightfloat, optional

The height of the block in cm. Defaults to 1.0 so that getVolume assumes unit height.

PITCH_DIMENSION = 'widthOuter'

PITCH_COMPONENT_TYPE

alias of Rectangle

getMaxArea()

Get area of this block if it were totally full.

setPitch(val, updateBolParams=False)

getSymmetryFactor()

Return a factor between 1 and N where 1/N is how much cut-off by symmetry lines this mesh cell is.

getPinCenterFlatToFlat(cold=False)

Return the flat-to-flat distance between the centers of opposing pins in the outermost ring.

paramCollectionType

alias of BlockParameterCollection

class armi.reactor.blocks.ThRZBlock(name: str, height: float = 1.0)

Bases: Block

Builds a new ARMI block.

namestr

The name of this block

heightfloat, optional

The height of the block in cm. Defaults to 1.0 so that getVolume assumes unit height.

getMaxArea()

Return the area of the Theta-R-Z block if it was totally full.

radialInner()

Return a smallest radius of all the components.

radialOuter()

Return a largest radius of all the components.

thetaInner()

Return a smallest theta of all the components.

thetaOuter()

Return a largest theta of all the components.

axialInner()

Return the lower z-coordinate.

axialOuter()

Return the upper z-coordinate.

verifyBlockDims()

Perform dimension checks related to ThetaRZ blocks.

paramCollectionType

alias of BlockParameterCollection