Dobule checking about coupled neutron-photon calculation for proper normalization to power while depleting

User Support
1

Hello,

I was reading the posts about employing the best models for obtaining, in the best possible way, the energy deposition for the subsequent flux to power normalization during depletion calculations. So far I am not interested in reading (or to get an output tally) of the photon and neutron energy deposition but, moreover, I am so far only interested in the code computing the energy deposition while performing depletion calculations. As I understand it, in order to do this, I just need to activate the following ‘energy-deposition’ attribute, i.e.:

op = openmc.deplete.Operator(geometry, settings, "chain.xml",
    energy_mode="energy-deposition")

Is it the only thing I need to do so the code calculates in the best possible way the normalization factor due to photon and neutron depositions? 
Or, do I also need to add photo_transport to 'true' in the settings? I am running the version from the master branch, but from the forum threads I've seen many pull requests in the last weeks regarding the improvement of such module. Shall I use the latest pull from the development branch instead ? 

Or, do I need to do something else so I can benchmark, for instance, the newest SERPENT photon/neutron energy deposition model? I am actually using the ENDFB71 libraries that were computed by the OpenMC team (I have them since January). I think these libraries are ok in terms of containing the proper KERMA factors for such type of energy deposition calculations; am I right? 
Thank you for your attention! 

Augusto
2

Hi Augusto,

The “energy-deposition” mode is the currently the most accurate way for normalizing reaction rates in depletion, regardless of n or n+p transport. If you want the most accurate, as you indicated, then you will need to activate photon transport via the settings… As for which branch to use, the develop branch is more likely to give you the “best” answers, as there have been some fixes that pertain to your question. #1449 looks the most impactful.

As for benchmarking against Serpent n+p transport+depletion, I believe those libraries should work but I haven’t ran any coupled n+p depletion simulations to confirm that.

Please let us know how this goes! I for one am very interested!

Cheers,

Drew

3

This thread in the user’s group may also be useful: https://groups.google.com/d/msg/openmc-users/4cUVFbv5KTE/yYHhw5o0CAAJ