Hi all. I’m wondering how to go about finding radiation levels at a time after irradiation. I have a high flux fast neutron source in a concrete room, which is on for a time, then switched off. I’d like to know what kind of radiation levels can be expected, say, an hour after the source has been sw…

I would say this feature is still a research area and not quite ready for general usage. You might find a few papers scattered around the internet where people report that they have added shut down dose rate simulations to their own local / private branches of OpenMC. However you will be glad to h…

Thanks for your reply, that’s really cool to hear. I’ll take a look :slight_smile:

Hi, been thinking more about this and I could achieve the same result by finding the amount of radioactive material produced in each cell. For example, I could find the amount of Re/Os produced in the WC reflector and use this to estimate the radiation levels. With that in mind, does openmc allow o…

Hi, sorry to bring this up again - I’ve tried running the shutdown dose rate code you linked in the neutronics workshop docker container. It’s having trouble reading the chain file. I added the following: import os os.system(‘download_nndc_chain’) openmc.config[‘chain_file’] = ‘chain-nndc-b7.1.x…

sorry about this, the error message is just saving it can’t find the chain file which is needed for depletion simulations you could have a go at downloading a chain file with that same filename using this command executed in a notebook cell !pip install openmc_data !download_nndc_chain -r b7.1

Sorry to bring this up again, but I’m still having the same problem. I’ve tried the following: [Screenshot 2023-04-11 at 10.56.42] but still get the error: OSError: Error reading file ‘chain-nndc-b8.0.xml’: failed to load external entity “chain-nndc-b8.0.xml” I’ve tried using 7.1 and 8.0 but t…

@srichr221 Can you check the directory where you’re running from and see if the chain-nndc-b8.0.xml file does indeed exist? If so, I would take a look at it and see if it looks like a normal XML file. I believe the error indicates that something is wrong with the file. If you attach it to this post,…

Thanks for your reply. I made the following change and it’s able to read the chain file and run: Untitled1.py (15.0 KB) However it’s now running into another issue: [Screenshot 2023-04-11 at 13.31.27] And I’m not entirely sure what it means. Again this is running in the neutronics workshop doc…

Hi @srichr221 That message means the code is trying to set the source strength to None which is not allowed. Just to mention that example is not merged in because it is very early stages and as you can see not ready for wider use. This workflow is in activate development and I hope there will be …

What do you reckon is my best alternative? I need to essentially find out the Activation of a blanket module mock-up to inform the safety procedures of my experiment (ie, if and when handling is possible after irradiation). I could tally the radionuclides produced by just doing a depletion simulati…

Radiation levels post irradiation

User Support

Shimwell June 13, 2023, 12:31pm 13

Just posting here to link two threads as I think they are very similar and I’ve just posted an example on the other thread

Topic		Replies	Views
Shutdown dose rate calculations User Support	23	2128	July 18, 2023
Capabilities of OpenMC User Support	18	1919	February 16, 2022
Neutron activation and decay in openmc User Support	0	342	September 1, 2023
Decay Chains simulation and dose calculations User Support	7	987	March 22, 2022
Conversion of tallies from detector into dose rate User Support	2	176	June 17, 2025

Radiation levels post irradiation

Related topics