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]¶

getGaseousYieldFraction()[source]¶: Return the yield fraction of the gaseous nuclides.

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

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

Return the mass fraction of the given nuclide.

Return type: nuclide mass fraction (float)

getMassFracDenom()[source]¶: See also

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

printDensities(lfpDens)[source]¶

Print number densities of nuclides within the lumped fission product.

Parameters: lfpDens (float) – Number density (atom/b-cm) of the lumped fission product

Notes

This multiplies the provided number density for the lumped fission product by the yield of each nuclide.

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

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

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 as follows:

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

and so on

Examples

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

The path to this file is specified by the lfpCompositionFilePath user setting.

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

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

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