crp/OpenMC
1
0
Fork 0
mirror of https://github.com/openmc-dev/openmc.git synced 2026-07-28 06:05:58 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions 5

Initial enrichment option in Element.expand

Browse source 
-> Implementation supports only wt% enrichment
-> Multiple unnecessary conversions from at% to wt% can happen
-> Can produce -ve fractions if enrichment > 100
This commit is contained in:
Mikolaj Adam Kowalski 2020-02-02 20:54:41 +01:00
parent 8fc788d0b2
commit 77c147dd3d
1 changed files with 50 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

52
openmc/element.py
View file

@ -187,8 +187,56 @@ class Element(str):
# Modify mole fractions if enrichment provided
# New treatment for arbitrary element
elif enrichment is not None and enrichment_target is None:
raise ValueError()
# Interpret required enrichment as weight %
elif enrichment is not None and enrichment_target is not None:
# Check if the target nuclide is present in the mixture
if enrichment_target not in abundances.keys():
msg = 'Could not find the the target nuclide {0} in natural '\
'isotopic composition of element {1}. Following ' \
'isotopes are available: {2} '\
.format(enrichment_target, self, list(abundances.keys()))
raise ValueError(msg)
# Check if is a single isotope mixture
if len(abundances) == 1:
msg = 'Element {0} consist of single isotope. Thus it cannot '\
'be enriched.'.format(self)
raise ValueError(msg)
# Convert the atomic abundances to weight fractions
# Compute the element atomic mass
element_am = 0.0
for nuclide in abundances.keys():
element_am += atomic_mass(nuclide) * abundances[nuclide]
# Convert the molar fractions to mass fractions
for nuclide in abundances.keys():
abundances[nuclide] *= atomic_mass(nuclide) / element_am
# Normalize the mass fractions to one
sum_abundances = sum(abundances.values())
for nuclide in abundances.keys():
abundances[nuclide] /= sum_abundances
# Get fraction of non-enriched isotopes in nat. composition
non_enriched = 1.0 - abundances[enrichment_target]
tail_fraction = 1.0 - enrichment / 100.0
# Enrich the mixture
for nuclide, fraction in abundances.items():
abundances[nuclide] = tail_fraction * fraction / non_enriched
abundances[enrichment_target] = enrichment / 100.0
# Convert back to atomic fractions
# Convert the mass fractions to mole fractions
for nuclide in abundances.keys():
abundances[nuclide] /= atomic_mass(nuclide)
# Normalize the mole fractions to one
sum_abundances = sum(abundances.values())
for nuclide in abundances.keys():
abundances[nuclide] /= sum_abundances
# Compute the ratio of the nuclide atomic masses to the element
# atomic mass