# Fixed source depletion

**URL:** <https://openmc.discourse.group/t/fixed-source-depletion/5958>\
**Category:** User Support\
**Created:** [August 20, 2025, 2:08am UTC](https://openmc.discourse.group/t/fixed-source-depletion/5958 "2025-08-20T02:08:01Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![hrash47](https://avatars.discourse-cdn.com/v4/letter/h/77aa72/32.png) [@hrash47](https://openmc.discourse.group/u/hrash47)\
**Post date:** [August 20, 2025, 2:08am UTC](https://openmc.discourse.group/t/fixed-source-depletion/5958/1 "2025-08-20T02:08:01Z")

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Hello everyone,

I’ve recently started studying OpenMC depletion and have been going through the available examples. Most of what I’ve found so far focuses on depletion simulations in eigenvalue mode, but I haven’t come across any examples for fixed-source mode.

Could anyone share a simple example or point me toward resources that demonstrate depletion in fixed-source mode? It would really help me get a better understanding of how to set it up.

Thank you in advance!

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**Author:** ![wahidluthfi](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/wahidluthfi/32/3375_2.png) [@wahidluthfi](https://openmc.discourse.group/u/wahidluthfi)\
**Post date:** [August 20, 2025, 9:18am UTC](https://openmc.discourse.group/t/fixed-source-depletion/5958/2 "2025-08-20T09:18:45Z")

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Hi Hrash47, welcome to the openmc community. I think some tasks from neutronic workshop can help you with fixed source depletion, such as this transmutation isotope build up

> <https://github.com/fusion-energy/neutronics-workshop/blob/main/tasks/task_10_activation_transmutation_depletion/1_example_transmutation_isotope_build_up.ipynb>

Or the shutdown dose rate case scenario

> <https://github.com/fusion-energy/neutronics-workshop/blob/main/tasks/task_11_CSG_shut_down_dose_tallies/1_R2S_cell_shut_down_dose_rate.py>