armi.physics.neutronics.fissionProductModel.lumpedFissionProduct module¶

The lumped fission product (LFP) module deals with representing LFPs and loading them from files.

These are generally managed by the FissionProductModel

class armi.physics.neutronics.fissionProductModel.lumpedFissionProduct.LumpedFissionProduct(name=None)[source]¶

Bases: object

Lumped fission product.

The yields are in number fraction and they sum to 2.0 in general so a fission of an actinide results in one LFP, which represents 2 real FPs.

This object is a data structure and works a lot like a dictionary in terms of accessing and modifying the data.

The yields are indexed by nuclideBase – in self.yld the yield fraction is indexed by nuclideBases of the individual fission product isotopes

Examples

>>> fpd = FissionProductDefinitionFile(stream)
>>> lfp = fpd.createSingleLFPFromFile('LFP39')
>>> lfp[<nuclidebase for EU151>]
2.9773e-05

See also

armi.reactor.blocks.Block.getLumpedFissionProductCollection: how you should access these.

Make a LFP

Parameters: name (str, optional) – A name for the LFP. Will be overwritten if you load from file. Provide only if you are spinning your own custom LFPs.

duplicate()[source]¶: Make a copy of this w/o using deepcopy

keys()[source]¶

values()[source]¶

items()[source]¶: make sure gas fraction gets applied

setGasRemovedFrac(removedFrac)[source]¶: Set the fraction of total fission gas that is removed from this LFP.

getGasRemovedFrac()[source]¶

getTotalYield()[source]¶

Get the fractional yield of all nuclides in this lumped fission product

Accounts for any fission gas that may be removed.

Return type: total yield of all fps

getMassFracs()[source]¶

Return a dictionary of mass fractions indexed by nuclide.

Returns: massFracs – mass fractions (floats) of LFP masses
Return type: dict

getNumberFracs()[source]¶

Return a dictionary of number fractions indexed by nuclide.

Returns: numberFracs – number fractions (floats) of fission products indexed by nuclide.
Return type: dict

getMassFrac(nucName=None, nuclideBase=None, useCache=True, storeCache=True)[source]¶

Return the mass fraction of the given nuclide.

Return type: nuclide mass fraction (float)

getMassFracDenom(useCache=True, storeCache=True)[source]¶: See also

armi.physics.neutronics.fissionProductModel.lumpedFissionProduct.LumpedFissionProduct.getMassFrac

getExpandedMass(mass=1.0)[source]¶

returns a dictionary of masses indexed by nuclide base objects

Parameters: mass (float,) – the mass of all the expanded mass of the given LFP.

getGasFraction()[source]¶

get the fraction of gas that is from Xe and Kr gas

Returns: gasFrac – Fraction of LFP that is gaseous
Return type: float

getLanthanideFraction()[source]¶: Return the fraction of fission products that are lanthanides.

printDensities(lfpDens)[source]¶: Print densities of nuclides given a LFP density.

class armi.physics.neutronics.fissionProductModel.lumpedFissionProduct.LumpedFissionProductCollection[source]¶

Bases: dict

A set of lumped fission products

Typically there would be one of these on a block or on a global level.

duplicate()[source]¶

getLumpedFissionProductNames()[source]¶

getAllFissionProductNames()[source]¶

Gets names of all fission products in this collection

TODO: This can use a set, continually updated from the keys() for each lfp, then converted to a list. This will change the order of the fission products, though, so should be done with care

getAllFissionProductNuclideBases()[source]¶: Gets names of all fission products in this collection

getNumberDensities(objectWithParentDensities=None, densFunc=None)[source]¶

Gets all FP number densities in collection

Parameters

objectWithParentDensities (ArmiObject) – object (probably block) that can be called with getNumberDensity(‘LFP35’), etc. to get densities of LFPs.
densFunc (function, optional) – Optional method to extract LFP densities

Returns

fpDensities – keys are fp names, vals are fission product number density in atoms/bn-cm.

Return type

dict

getMassFrac(oldMassFrac=None)[source]¶: returns the mass fraction vector of the collection of lumped fission products

setGasRemovedFrac(removedFrac)[source]¶: Set the fraction of total fission gas that is removed from all LFPs.

getGasRemovedFrac()[source]¶: Get the fraction of total fission gas that is removed from all LFPs.

class armi.physics.neutronics.fissionProductModel.lumpedFissionProduct.SingleLumpedFissionProductCollection[source]¶

Bases: armi.physics.neutronics.fissionProductModel.lumpedFissionProduct.LumpedFissionProductCollection

This is a subclass of LumpedFissionProductCollection to be used when you want to collapse all the fission products into a single lumped fission product

There were numerous checks in places to ensure that a collection of fission products only had 1 lfp and this object consolidates them.

Notes

armi.physics.neutronics.fissionProductModel.lumpedFissionProduct.FissionProductDefinitionFile.createSingleLFPFromFile: is a factory for these

getFirstLfp()[source]¶

getName()[source]¶

updateYieldVector(numberDensities=None, massFrac=None, fpFiltered=False)[source]¶: update the yield values on the single lumped fission product

class armi.physics.neutronics.fissionProductModel.lumpedFissionProduct.FissionProductDefinitionFile(stream)[source]¶

Bases: object

Reads a file that has definitions of one or more LFPs in it to produce LFPs

The format for this file is effectively input lines from a MC2-2 file:

        LFP35 GE73 5  5.9000E-06
        LFP35 GE74 5  1.4000E-05
        LFP35 GE76 5  1.6000E-04
        LFP35 AS75 5  8.9000E-05

and so on

Examples

>>> fpd = FissionProductDefinitionFile(stream)
>>> lfps = fpd.createLFPsFromFile()

The path to this file name is specified by the

fpPat = re.compile('13\\s+([A-Z]+\\d+)[_]{0,1}[0-9]{0,1}\\s+(......)\\s+([+-]?\\d*\\.\\d+[eEdD][+-]\\d+)')¶

createLFPsFromFile()[source]¶

Read the file and create LFPs from the contents

Returns: lfps – List of LumpedFissionProducts contained in the file
Return type: list

createSingleLFPFromFile(name)[source]¶: Read one LFP from the file

createSingleLFPCollectionFromFile(name)[source]¶: Creates a LFPCollection with only one LFP from the file

armi.physics.neutronics.fissionProductModel.lumpedFissionProduct.lumpedFissionProductFactory(cs)[source]¶: Build lumped fission products.

armi.physics.neutronics.fissionProductModel.lumpedFissionProduct.expandFissionProducts(massFrac, lumpedFissionProducts)[source]¶

expands lumped fission products in a massFrac vector

Parameters

massFrac (dict) –
lumpedFissionProducts (LumpedFissionProductCollection (acts like a dict)) – result of <fissionProductInterface>.getGlobalLumpedFissionProducts

Returns

newMassFracs

Return type

dict

armi.physics.neutronics.fissionProductModel.lumpedFissionProduct.collapseFissionProducts(massFracs, lumpedFissionProducts, updateLumpedFissionProduct=False)[source]¶

collapses fission products into a single lumped fission product

Parameters

massFracs (dict) –
dict) (lumpedFissionProducts - LumpedFissionProductCollection (acts like a) – result of <fissionProductInterface>.getGlobalLumpedFissionProducts

Returns

newMassFracs

Return type

dict

Notes

collapsing only works if there is a ‘single lumped fission product collection’ – otherwise its confusing to determine how much of what isotope goes to which lumped fission products

armi.physics.neutronics.fissionProductModel.lumpedFissionProduct.isGas(nuc)[source]¶: True if nuclide is considered a gas.