Dose rate from Resnuclei from specific region

I want to score the dose rate from Resnuclei produced after certain cooling time only from a specific region of the geometry. Right now the dose rate is being scored from all the regions of the geometry where there is resnuclei is generated due to the interaction of the neutrons. Please let me know how can I get the dose rate only from the residual nuclei produced in specific region of geometry.

Dear Sujoy,
the ASSIGNMAterial card provides a specific function for exactly this purpose (check the explanation of ASSIGNMA in the manual, especially WHAT(6) and Note 5).
The option provided by WHAT(6) (or Mat(Decay) in Flair) allows you to change the material assignment of specific regions during the transport of radioactive decay products.
In your case, if you want to discard the contribution of a specific region to the residual dose rate, you should set WHAT(6) to VACUUM.


Dear Fabio,
Thank you for your help. I will change the input accordingly and let you know the result.

Dear Fabio,
Thank you once again. It worked.