I have a 17x17 assembly with 3 kind of fuel definitions and I'm sampling the neutron flux in this different cases. In particular, I have one pin divided axially through the "subz" command (say, pin 1), one pin with Gd inside and with the "subr" division (say pin2) and all the others 287 pins with standard fuel and no divisions (say pin of kind 3).

I have defined 3 detectors in order to sample the neutron flux axially for all the three cases, i.e.:

Code: Select all

```
det pin1
de thermal_grid
dm fuelPIN1
dz -180 180 100
det pin2
de thermal_grid
dm fuelPIN2
dz -180 180 200
det GroupOfPin3
de thermal_grid
dm fuelPIN3
dz -180 180 200
```

As I know, the flux should be indipendent of the dimension of the domain, since the ratio between the number of scores in a volume and a volume itself (i.e. the flux) should be constant as the volume increases.

I'm evaluating the volumes with the -checkvolumes routine.

Do you have any explanation about this change in flux magnitudes?

Is there any relationship between the axial division in "dz" and the flux? since the pin2 has 200 divisions and a lower peak, while pin1 has 100 divisions and a higher one.

Thank you very much