# Error in assembly depletion calculation **URL:** \ **Category:** User Support\ **Created:** [February 22, 2020, 4:44am UTC](https://openmc.discourse.group/t/error-in-assembly-depletion-calculation/555 "2020-02-22T04:44:32Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![fsabab](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/fsabab/32/1374_2.png) [@fsabab](https://openmc.discourse.group/u/fsabab)\ **Post date:** [February 22, 2020, 4:44am UTC](https://openmc.discourse.group/t/error-in-assembly-depletion-calculation/555/1 "2020-02-22T04:44:32Z")
When I try to run assembly depletion calculation, the simulation stops after 1st statepoint geneation. I am attaching my python script below. Any help would be really helpful. Thanks [pwr-17.py](https://openmc.discourse.group/uploads/short-url/xGnU9d2hcLDGGjUiPyA9yaVWnPv.py) (9.56 KB) ![Screenshot from 2020-02-20 12-34-54.png](https://global.discourse-cdn.com/free1/uploads/openmc/original/1X/9050224fab07224e3ff4c298731b8c792a555f20.png) ---
**Author:** ![Pranto](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/pranto/32/489_2.png) [@Pranto](https://openmc.discourse.group/u/Pranto)\ **Post date:** [February 22, 2020, 6:20am UTC](https://openmc.discourse.group/t/error-in-assembly-depletion-calculation/555/2 "2020-02-22T06:20:51Z")
U should assign which material should be depleted. in your python script… add fuel.depletable = True Best regards Pranto ---
**Author:** ![fsabab](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/fsabab/32/1374_2.png) [@fsabab](https://openmc.discourse.group/u/fsabab)\ **Post date:** [February 22, 2020, 7:12am UTC](https://openmc.discourse.group/t/error-in-assembly-depletion-calculation/555/3 "2020-02-22T07:12:55Z")
I did what you told. But same error resulted. Any idea how to fix it? ![Screenshot from 2020-02-22 13-10-22.png](https://global.discourse-cdn.com/free1/uploads/openmc/original/1X/a04381b9175bbef4ddacba385a79cf876c64889d.png) ---
**Author:** ![Andrew\_Johnson](https://avatars.discourse-cdn.com/v4/letter/a/e9c0ed/32.png) [@Andrew\_Johnson](https://openmc.discourse.group/u/Andrew_Johnson)\ **Post date:** [February 24, 2020, 11:49pm UTC](https://openmc.discourse.group/t/error-in-assembly-depletion-calculation/555/4 "2020-02-24T23:49:12Z")
Hi Farshid, The main error that you see, about no energy being reported, happens when the depletion routine obtains zero energy production from tallies. This seems a bit strange, because much of your model looks good. From a first glance at least. For some reason, your simulation only performs one active batch and complains about not being able to compute the uncertainties. Looking at some of the other outputs, your k-eff values are reported as nan (not a number) as well. I also see you are using triggers, which I haven’t personally used before. Can you run the simulation with out these triggers and report back? Regards, Andrew ---
**Author:** ![Augusto\_Hernandez\_So](https://avatars.discourse-cdn.com/v4/letter/a/eb8c5e/32.png) [@Augusto\_Hernandez\_So](https://openmc.discourse.group/u/Augusto_Hernandez_So)\ **Post date:** [June 17, 2020, 8:07am UTC](https://openmc.discourse.group/t/error-in-assembly-depletion-calculation/555/5 "2020-06-17T08:07:41Z")
Hi Andrew, I don’t know if actually Farshid replied back to your inquiry; I actually also got the same problem than him while trying to deplete in an assembly. Nevertheless, I did what you suggested to Farshid and actually it worked. So by getting rid of the tally triggers under settings, it actually worked. Thanks. ---
**Author:** ![Pranto](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/pranto/32/489_2.png) [@Pranto](https://openmc.discourse.group/u/Pranto)\ **Post date:** [June 17, 2020, 11:18am UTC](https://openmc.discourse.group/t/error-in-assembly-depletion-calculation/555/6 "2020-06-17T11:18:01Z")
Hi Augusto, There’s a small problem in Farshid’s input file. [Tally trigger for which score?] Add the following line trigger = openmc.Trigger(trigger\_type=‘std\_dev’, threshold=5e-5) trigger.scores = [‘flux’, ‘fission’] Hope it helps