Fix metastable nuclides listed for NNDC cross sections - #305
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It looks like quite a few tests need updating for at least the Am-242m issue? |
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You're absolutely right; I forgot that a bunch of tests have Am-242m in them. I'll update the test results tonight. |
…orrectly, Am-242m was actually pointing to Am-242. Many other nuclides affected by the missing level cross section issue.
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I've actually fixed two issues with this pull request. The first is the aforementioned issue with cross_sections_nndc.xml not listing Americium isotopes correctly. The second issue is that when OpenMC was reading cross sections and building an absorption cross section and a total cross section, it discarded any reaction with MT > 117. However, in some cases, an ACE file might list individual level reactions for (n,p), (n,d), (n,t), (n,3He) and (n,alpha) in MT=600+ but not list the redundant total reaction in MT=103-107. In such a case, absorption due to these reactions would be ignored. I've now updated the logic to check for reactions with MT=600+ and make sure they get included if the redundant total is absent in the ACE file. In ENDF/B-VII.1, this issue affects:
I've updated the test results, so this pull request is now ready for review. |
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Some metastable nuclides aren't picking up the metastable tag, though that information is of no consequence, currently, in the code. It's in multiple, but not all spots.
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It looks like this fix was only picked up for the room temperature data. 72c, 73c, 74c still show Co-59 for the metastable form of Co-58. And the same issue is there for other nuclides.
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Do we maybe just want to remove the option of >300 K NNDC data since it was corrupted by the bug in PURR?
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Nice to have these fixes and those MT > 117 reactions in there now. On behalf of @paulromano I'd like to thank @paulromano. All tests passed. |
Fix metastable nuclides listed for NNDC cross sections
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Thanks @walshjon! |
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I found today that the pre-supplied cross_sections_nndc.xml file that is used by data/get_nndc_data.py had some errors for metastable nuclides. Namely, it looks like the convention for the NNDC-supplied ACE files is that metastable nuclides have zaids that ends in 9. For example, both Am-242m and Am-244m have the designator 95249.71c. In the process of creating cross_sections_nndc.xml, these metastable nuclides were not properly recognized. In addition, Am-242 was incorrectly listed as Am-242m.
To be clear and succinct -- what was incorrect in cross_sections_nndc.xml is the aliases. This pull request corrects the aliases used in cross_sections_nndc.xml for metastable nuclides and Am-242. In addition, while checking the other pre-supplied cross_sections.xml files, a few errors in the cross_sections_serpent.xml file were spotted and corrected.