Additional cell/universe/… in existing geometry to obtain h

[Nico TuD]

Hello every one, I am interested in group constants of an azimuthal reflector element. This reflector element is completely filled with material (water, core barrel, water in downcomer). In the end, I want to specify one reflector node in a deterministic reactor-code model which represents this azimuthal reflector zone. For a better understand look at attached figure, dotted line represents the reflector note in the deterministic reactor-code, solid line represents the reflector element in my serpent model.
Is it possible to define additional cell/universe/… independently from already defined and filled space regions to obtain homogenized group constants for this region? Is there any way to do this in Serpent or is there any better way to obtain this information of this reflector element? Have great thanks for any advises and help.

Figure with reflector element

Reflektor_1.png (4.08 KiB) Viewed 476 times

[Jaakko Leppänen]

You can do this quite easily by re-defining your universes. The procedure is as follows:

1) re-define your root universe 0 into something like u0
2) define two additional universes u1 and u2 in such way that they are completely filled with u0
3) define universe 0 in such way that you have two zones, one filled with universe u1 and the other with u2.

This allows you to pick any arbitrary part of the geometry for your group constant generation. The geometry remains the same, but there is an additional level that defines the part which is used for group constant generation and the part that is not. In this case u1 could be a rectangular prism where you want the group constants to be calculated and u2 everything else.