armi.materials.mox module

Mixed-oxide (MOX) ceramic fuel.

A definitive source for these properties is 1.

1

Thermophysical Properties of MOX and UO2 Fuels Including the Effects of Irradiation. S.G. Popov, et.al. Oak Ridge National Laboratory. ORNL/TM-2000/351 https://rsicc.ornl.gov/fmdp/tm2000-351.pdf

class armi.materials.mox.MOX

Bases: armi.materials.uraniumOxide.UraniumOxide

MOX fuel.

Some parameters (density, thermal conductivity, etc) are inherited from UraniumOxide. These parameters are sufficiently equivalent to pure UO2 in the literature to leave them unchanged.

Specific MOX mixtures may be defined in blueprints under custom isotopics.

name = 'MOX'

theoreticalDensityFrac = 1.0

Thermal conductivity values taken from: Thermal conductivity of uranium dioxide by nonequilibrium molecular dynamics simulation. S. Motoyama. Physical Review B, Volume 60, Number 1, July 1999

enrichedNuclide = 'U235'

Name of enriched nuclide to be interpreted by enrichment modification methods

applyInputParams(U235_wt_frac=None, TD_frac=None, mass_frac_PU02=None, *args, **kwargs)

Apply optional class 1/class 2 custom enrichment input.

Notes

This is often overridden to insert customized material modification parameters but then this parent should always be called at the end in case users want to use this style of custom input.

This is only applied to materials considered fuel so we don’t apply these kinds of parameters to coolants and structural material, which are often not parameterized with any kind of enrichment.

getMassFracPuO2()

setMassFracPuO2(massFracPuO2)

getMolFracPuO2()

setDefaultMassFracs()

UO2 + PuO2 mixture mass fractions.

Pu238: 238.0495599 g/mol Pu239: 239.0521634 g/mol Pu240: 240.0538135 g/mol Pu241: 241.0568515 g/mol Pu242: 242.0587426 g/mol Am241: 241.0568291 g/mol U-235: 235.0439299 g/mol U-238: 238.0507882 g/mol Oxygen: 15.9994 g/mol

JOYO MOX mass fraction calculation: Pu mixture: 0.1% Pu238 + 76.82% Pu239 + 19.23% Pu240 + 2.66% Pu241 + 0.55% Pu242 + 0.64% Am241 Pu atomic mass: 239.326469 g/mol

U mixture: 22.99% U-235 + 77.01% U-238 U atomic mass: 237.359511 g/mol

UPu mixture: 17.7% Pu mixture + 82.3% U mixture UPu atomic mass: 237.70766 g/mol

2 moles of oxygen/1 mole of UPu

grams of UPu = 237.70766 g/mol* 1 mol = 237.70766 g grams of oxygen= 15.9994 g/mol * 2 mol = 31.9988 g

total= 269.70646 g.

Mass fraction UPu : 237.70766/269.70646 = 0.881357 Mass fraction Pu mixture: 0.177*237.70766/269.70646 = 0.156000 Mass fraction U mixture: 0.823*237.70766/269.70646 = 0.725356

Mass fraction Pu238: 0.001*42.074256/269.70646 = 0.000156 Mass fraction Pu239: 0.7682*42.074256/269.70646 = 0.119839 Mass fraction Pu240: 0.1923*42.074256/269.70646 = 0.029999 Mass fraction Pu241: 0.0266*42.074256/269.70646 = 0.004150 Mass fraction Pu242: 0.0055*42.074256/269.70646 = 0.000858 Mass fraction Am241: 0.0064*42.074256/269.70646 = 0.000998 Mass fraction U-235: 0.2299*195.633404/269.70646 = 0.166759 Mass fraction U-238: 0.7701*195.633404/269.70646 = 0.558597 Mass fraction O: 31.9988/269.70646 = 0.118643

meltingPoint()

Melting point in K - ORNL/TM-2000/351

Melting point is a function of PuO2 mol fraction. The liquidus Tl and solidus Ts temperatures in K are given by: Tl(y) = 3120.0 - 388.1*y - 30.4*y^2 Ts(y) = 3120.0 - 655.3*y + 336.4*y^2 - 99.9*y^3 where y is the mole fraction of PuO2 This function returns the solidus temperature. Does not take into account changes in the melting temp due to burnup.

paramCollectionType

alias of armi.reactor.parameters.parameterCollections.FuelMaterialParameterCollection