How to run OpenMC without the production of delayed neutrons

User Support
1

Hello everyone:

I want to calculate the beta_eff by the two separated MC simulations, with and without the production of delayed neutrons. However, I have no idea about how to run the simulation without the production of delayed neutrons.
I found the variable “emission_mode” in the class “openmc.data.Product” in user’s docs. Is it the control switch for the production of delayed neutrons?

Thanks in advance for your replies!

Best Regards,
Shyne

2

Dear Shyne,
You can find the diff patch for doing these calculations.

https://gist.github.com/paulromano/2b9d2d4a80dc53625f209a4bdf0801f5

with regards
Ajay

3

Dear Ajay,
Thanks for your replay.And it took me some time to modify the source following your suggestion and recompile the code.
But the modifed code got the identical results of keff with the original one at the same random seed. The test case is the simple case “Modeling a Pin-Cell” in user’s docs(https://openmc.readthedocs.io/en/latest/examples/pincell.html).

It seems the modifed code still runs with the production of delayed neutrons? Or I misunderstood the function of the diff patch?

Best Regards,
Shyne

在 2019年1月10日星期四 UTC+8下午5:43:29，Ajay Rawat写道：

4

Hi Shyne,

It looks like there was one line missing in that diff, namely a change in nuclide_header.F90. I’ve just updated the diff at the link that Ajay sent. Have a look at it again and give it a try.

Best regards,
Paul

5

Dear Paul,

is there may an updated version of this patch which works with the current OpenMCversion?

Thanks already a lot.

Best
Christopher

6

Yes, someone by the name of Christopher just submitted a pull request to make this a proper feature :smile:

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