Pranto
October 13, 2020, 10:52am
1
Decay, Neutron fission yield & Neutron reaction sublibrary files are taken from NNDC-ENDF-b7.0 .
AssertionError Traceback (most recent call last)
<ipython-input-9-e1cb954a0bff> in <module>
----> 1 chain = openmc.deplete.Chain.from_endf(decay_files, nfy_files, neutron_files)
2 chain.export_to_xml('chain_endfb70.xml')
~/anaconda3/envs/openmc12/lib/python3.8/site-packages/openmc/deplete/chain.py in from_endf(cls, decay_files, fpy_files, neutron_files, progress)
298 decay_data = {}
299 for f in decay_files:
--> 300 data = openmc.data.Decay(f)
301 # Skip decay data for neutron itself
302 if data.nuclide['atomic_number'] == 0:
~/anaconda3/envs/openmc12/lib/python3.8/site-packages/openmc/data/decay.py in __init__(self, ev_or_filename)
315 ev = ev_or_filename
316 else:
--> 317 ev = Evaluation(ev_or_filename)
318
319 file_obj = StringIO(ev.section[8, 457])
~/anaconda3/envs/openmc12/lib/python3.8/site-packages/openmc/data/endf.py in __init__(self, filename_or_obj)
446 fh.close()
447
--> 448 self._read_header()
449
450 def __repr__(self):
~/anaconda3/envs/openmc12/lib/python3.8/site-packages/openmc/data/endf.py in _read_header(self)
477 self.target['isomeric_state'] = m = items[3]
478 self.info['format'] = items[5]
--> 479 assert self.info['format'] == 6
480
481 # Set correct excited state for Am242_m1, which is wrong in ENDF/B-VII.1
What’s the solution in case of ENDF/B-VII.0?
The ENDF/B-VII.0 decay file is missing a record at the beginning. You can fix it with the following:
with open('dec-ENDF-VII0.endf', 'r') as a, open('dec-ENDF-VII0_fixed.endf', 'w' as b:
b.write(' '*70 + ' 1 0 0\n')
b.write(a.read())
Then, to actually get all the individual evaluations inside the file, run
decay_evals = openmc.data.endf.get_evaluations('dec-ENDF-VII0_fixed.endf')
...
openmc.deplete.Chain.from_endf(decay_evals, ...)
1 Like
Pranto
October 15, 2020, 5:24am
3
@paulromano Still got the same error.
In [10]: decay_evals = openmc.data.endf.get_evaluations('dec-ENDF-VII0_fixed.endf')
---------------------------------------------------------------------------
AssertionError Traceback (most recent call last)
<ipython-input-10-0edcfa40da84> in <module>
----> 1 decay_evals = openmc.data.endf.get_evaluations('dec-ENDF-VII0_fixed.endf')
~/anaconda3/envs/openmc12/lib/python3.8/site-packages/openmc/data/endf.py in get_evaluations(filename)
361 break
362 fh.seek(pos)
--> 363 evaluations.append(Evaluation(fh))
364 return evaluations
365
~/anaconda3/envs/openmc12/lib/python3.8/site-packages/openmc/data/endf.py in __init__(self, filename_or_obj)
446 fh.close()
447
--> 448 self._read_header()
449
450 def __repr__(self):
~/anaconda3/envs/openmc12/lib/python3.8/site-packages/openmc/data/endf.py in _read_header(self)
477 self.target['isomeric_state'] = m = items[3]
478 self.info['format'] = items[5]
--> 479 assert self.info['format'] == 6
480
481 # Set correct excited state for Am242_m1, which is wrong in ENDF/B-VII.1
AssertionError:
Sorry, there was a mistake in my code above for writing a “fixed” file (I was missing a newline character before). I’ve editing the post above so it should be correct now.
1 Like
Pranto
October 15, 2020, 12:09pm
5
This time It creates an empty file.
In [5]: chain = openmc.deplete.Chain.from_endf(decay_files, nfy_files, neutron_files)
...: chain.export_to_xml('chain_endfb70.xml')
Processing neutron sub-library files...
Processing decay sub-library files...
Processing fission product yield sub-library files...
Creating depletion_chain...
In [6]:
I’m not sure what’s happening in your case. When I try to generate a chain using all ENDF/B-VII.0, I run into an error due to a negative uncertainty in one of the decay files. I got around this by making a temporary change in OpenMC:
diff --git a/openmc/data/decay.py b/openmc/data/decay.py
index 3e7d9599c..f669a3ed5 100644
--- a/openmc/data/decay.py
+++ b/openmc/data/decay.py
@@ -429,7 +429,10 @@ class Decay(EqualityMixin):
if len(values) >= 8:
di['total_internal_conversion'] = ufloat(*values[6:8])
if len(values) == 12:
- di['k_shell_conversion'] = ufloat(*values[8:10])
+ try:
+ di['k_shell_conversion'] = ufloat(*values[8:10])
+ except Exception:
+ di['k_shell_conversion'] = None
di['l_shell_conversion'] = ufloat(*values[10:12])
spectrum['discrete'].append(di)
After that, I’m able to successfully generate a chain. Here’s the script I used (modify as needed based on where your files are):
from pathlib import Path
import openmc.deplete
import openmc.data
endf_dir = Path('/opt/data/endf/endf-b-vii.0/')
# Fix missing TPID line in decay file
with open(endf_dir / 'decay' / 'dec-ENDF-VII0.endf', 'r') as original, open('dec_fixed.endf', 'w') as fixed:
fixed.write(' '*70 + ' 1 0 0\n')
fixed.write(original.read())
decay_evals = openmc.data.endf.get_evaluations('dec_fixed.endf')
# Get neutron and fission product yield evaluations
neutron_files = tuple((endf_dir / "neutrons").glob("*endf"))
nfy_files = tuple((endf_dir / "nfy").glob("*endf"))
# Generate chain
chain = openmc.deplete.Chain.from_endf(decay_evals, nfy_files, neutron_files)
chain.export_to_xml('chain_endfb70.xml')
Here’s the resulting chain file:chain_endfb70.xml (1.7 MB)
Pranto
October 15, 2020, 12:59pm
7
In my case, It didn’t happen.
Thanks @paulromano
Pranto
October 20, 2020, 10:44am
8
@paulromano , Could you update generate_endf71_chain_casl.py script because openmc/deplete/chain.py has undergone a number of updates over time e.g _REACTIONS REACTIONS global dictionary?
Thanks for pointing that out @Pranto . I’ve just updated a pull request with changes necessary to get this script working: https://github.com/openmc-dev/data/pull/45
