Using TENDL Library

User Support
1

Hello folks,

I would like to try the TENDL nuclear data library in my study; I downloaded it from the official website. In my model, which perfectly runs with the official OpenMC library, the fuel temperature is 1110 K, and the temperature of the coolant (liquid salt) and moderator (graphite) is 948 K. For the graphite, with the ENDF/B-VII.1, I use the thermal scattering data ‘c_Graphite’.

Now, running the case with the TENDL library I am having these problems:

  1. Warning and error messages are shown due to the temperature of the fuel, it seems that the data is only available at room temperature.

“WARNING: Cross sections for U235 are only available at one temperature.
Reverting to nearest temperature method.
ERROR: Nuclear data library does not contain cross sections for U235 at or near 1110.000000 K.”

  1. It seems that the thermal scattering data is not included in the TENDL library (or have a different identification) because the comment below is shown. I checked the folder where all the TENDL files are stored and did not find any clue on the thermal scattering.
    “ERROR: Could not find thermal scattering data c_Graphite in cross_sections.xml file.”

Please, any recommendation for solving these issues?

Thanks in advance,
Javier

2

Hi Javier,

The HDF5 files that are distributed on that website were generated directly from the ACE files. The ACE files only contain data at 293.6 K, which is why you’re not seeing any data for higher temperatures. TENDL also does not include any thermal scattering evaluations, so you would need to supplement your library with thermal scattering evaluations from elsewhere (probably ENDF/B-VIII.0 or JEFF-3.3). If you want multi-temperature data, you’ll need to generate it from the ENDF files using the Python API. There are a collection of scripts in our data repository that will give you a few examples of how it can be done, so I would recommend looking at those and then adapting one to your needs.

Best,
Paul

3

Hi Paul,

Thank you for your response. After posting those questions, I saw the “Nuclear Data” notebook and I am trying to generate my data following the steps indicated in the “Generating data from NJOY” section.

Regards,
Javier