Abnormal behavior of surface filter in current scoring in hexagonal pin cell

User Support
1

Hi,
I would like to score neutron leakage from hexagonal pin cell to compute Keff by use of 6 factors formula. As mesh filter cannot be used in this calculation I used Surface filter to tally the partial currents at each surface of the hexagon. This provide abnormal negative currents at some faces and therefore an overestimated non leakage probability. In the case of infinite medium this probability exceeds unity.

Attached is a python script used to build the model and the produced tallies.out.

Regards,
Tarek

process.py (9.59 KB)

tallies.out (6.42 KB)

2

Hi Tarek,

I think the underlying problem is that right now surface current tallies (with a regular surface filter) don’t work properly when applied to surfaces with reflective boundary conditions. I’ll create an issue to track this and look into getting it fixed for our next release.

Best,
Paul

3

Thanks Paul.