armi.physics.fuelPerformance.utils module

Fuel performance utilities.

armi.physics.fuelPerformance.utils.enforceBondRemovalFraction(block, bondRemovedFrac)

Update the distribution of coolant in this block to agree with a fraction

This pulls coolant material out of the bond component and adds it to the other coolant-containing components while conserving mass.

Useful after db load with sodium bond. See armi.bookkeeping.db.database.updateFromDB

\(N_{hom} = \sum_{i} a_i N_i\)

We want \(f = \frac{a_{bond} N_{bond}}{N_{hom}}\) So we can solve this for \(N_{bond}\) and reduce the other number densities accordingly.

Should work for coolants with more than 1 nuclide (e.g. H2O, Pb-Bi, NaK,…)

Parameters

bondRemovedFrac (float) – Fraction of the bond that has been removed.

See also

armi.reactor.assemblies.Assembly.applyBondRemovalFractions()

does this in the original case

armi.physics.fuelPerformance.utils.applyFuelDisplacement(block, displacementInCm)

Expands the fuel radius in a pin by a number of cm.

Assumes there’s thermal bond in it to displace. This adjusts the dimension of the fuel while conserving its mass.

The bond mass is not conserved; it is assumed to be pushed up into the plenum but the modeling of this is not done yet by this method.

Warning

A 0.5% buffer is included to avoid overlaps. This should be analyzed in detail as a methodology before using in any particular analysis.

\[n V = n\prime V\prime n\prime = \frac{V}{V\prime} n\]

armi.physics.fuelPerformance.utils.gasConductivityCorrection(tempInC: float, porosity: float, morphology: int = 2)

Calculate the correction to conductivity for a porous, gas-filled solid

Parameters

• tempInC – temperature in celcius

• porosity – fraction of open/total volume

• optional (morphology,) – correlation to use regarding pore morphology (default 2 is irregular porosity for conservatism)

Returns

chi – correction to conductivity due to porosity (should be multiplied)

Return type

float

Notes

Morphology is treated different by different models:

0, no porosity correction 1, bauer equation, spherical porosity 2, bauer equation, irregular porosity 3, bauer equation, mixed morphology, above 660, spherical. Below 660, irregular 4, maxwell-eucken equation, beta=1.5

Source1In-Pile Measurement of the Thermal Conductivity of Irradiated Metallic Fuel, T.H. Bauer J.W. Holland.

Nuclear Technology, Vol. 110, 1995. Pages 407-421

Source2The Porosity Dependence of the Thermal Conductivity for Nuclear Fuels, G. Ondracek B. Schulz.

Journal of Nuclear Materials, Vol. 46, 1973. Pages 253-258