Making reflector region in just one cell


I want to make a reflector (green) and fuel region (yellow) just like this with left side is in radial axis and right side is in axial axis. I used 3 different cell to make the reflector region so it could cover the top, bottom, ans sorrounding. how do I make it in just one cell so i don’t have to apply tally to multiple cell ?

If this is your entire geometry I would just not use a cell filter on your tally, but if you have other features you can package both into a universe and then package that universe back into a cell again.

Hi Azlan, you can also merge all region in your cell’s region definition, i.e. region = (region_1) | (region_2) | (region_3) | …