Geometry problem

[wahidluthfi]

Hi Umarov,
from your notebook, I found various cell overlaps in your input, so I changed some regions defined for your cells. this is the modified notebook
wwr-smxW.ipynb (483.1 KB)

besides, you also forgot to declare the universe for the outer region of the defined lattice. I add a universe filled with Be for lattice outer

assembly.outer = openmc.Universe(cells=[openmc.Cell(fill=beril)]) # region outside lattice filled with beryllium

here are the calculation results from your settings

I also noticed that your fuel assembly geometry differs from the old model you asked for before, please check

Research reactor assembly

VVR_SM_Box_1.ipynb (14.9 KB) [image] Hi dear experts. I am trying to create a model of research reactor assembly as shown in figure. I also uploaded my code. I am recieving an error below while corresponding cells that assign materials to these regions. : [image] I guess its becouse the way i assigned the regions. Please, give advise how to resolve the coming error. Thank you !