Question about how to use JEFF3.2 in Openmc

User Support
1

Dear Prof.Paul Romano

I have download JEFF3.2 Nuclear data from NEA home website.
Including JEFF32-ACE-293K to 1800K and Thermal Scattering Law data.
But there is no xsdir file provide in the web site.
How can I using Opemmc with JEFF3.2 ACE format nuclear data library?

Best Wishes
Yours
NiuOBA

2

I’ve attached an example I generated for 293.6 K data. The process that I used is as follows:

  • Untar the data
  • Combine all the .dir files into a single xsdir file: cat *.dir > xsdir
  • Add two lines to the beginning of xsdir
  • atomic weight ratios
  • directory- Convert to cross_sections.xml: openmc-xsdir-to-xml xsdir cross_sections.xml
    The other temperatures would work the same way. I’d suggest putting data for each temperature in its own directory so there are no filename clashes. Unfortunately, there are no .dir files provided for the S(a,b) tables, so the cross_sections.xml generated doesn’t include them.

Best,
Paul

cross_sections.xml (60.2 KB)

3

Dear Pro.Paul Romano:

Thanks for your quickly replay.
I do as your advise in last email, it really works, this helps me a lot.

I try to rename all the *.ACE to a distinct file (for example: Ac225.ACE(293K) to Ac225-293.ACE)
and put all the JEFF *.ACE files into one directory, so that I can use different temperature nuclear data in material card, as you told me in last email.
The *.dir file also changed by bash script accordingly. it works!

Thanks for your help!

But I carefully read the cross_section.xml file and find some error alike:

  1. AM242 material has some clash with AM242m, not only in my cross_section.xml file, but also in the file you send me.
  2. Cu63 and Cu64 has some error in the key words “path”, should I change “filename” into “Cu63-293.ACE” or “Cu65-293.ACE”?
  3. 293K and 300K has some clash, because they have the same likely name *.03c, and I change 293K file into *.02c, it that ok?

Another question is I download the TSL data ( for CH2, H2O, HZr, Graphite, D2O, Be, BeO, Mg, H in CaH2, Ca in CaH2) form the JEFF home web site.
and I also put all the *.ACE and *.dir file in the same directory as forward, and join them in to a xsdir file, then change it into cross_section.xml.
Does these data can be consider as S(a,b) modification nuclear data in thermal spectrum?

Thanks for your help in advance.

Best Wishes
Yours
NiuOBA

4

It looks like all the metastable nuclides have the same problem (alias doesn’t indicate that the nuclide is metastable). I’ve attached an updated version with that issue fixed. If you’re generating it yourself, just search for any metastable nuclides and add an ‘m’ in the alias, e.g. Am-242m.03c.

For the 293.6K and 300K name clash, you would actually have to change not only the 03c identifier in the .dir file but you would actually need to change it in the ACE file as well (it appears on the very first line). Not difficult, but you’d probably want to automate that (using sed, for example).

If the xsdir file you’re converting has TSL data in it, openmc-xsdir-to-xml should be able to handle it ok too. Let me know if you run into problems though.

Best,
Paul

cross_sections.xml (60.2 KB)