Array error in CSAS6

[David Holler]

Hi all,

I'm using CSAS6 to model the ICSBEP MIX-MET-FAST-006 benchmark, which has >1000 hex / tri assemblies modeled discretely. I'm getting this error when I try to run my input:

  ***** error ***** csas message number cs-231 follows:

the calculation was terminated because array 1 is not properly positioned in region 2 of unit 1.

the array boundary is outside position -1.2750000E+01 9.8640293E+01 1.0800000E+02 on the +y array face.

Here is my global unit card:

global unit 1

zcylinder 1 120 216 0

array 1 1 place 21 21 1 0 0 0

boundary 1

The KENO VI example with a hexagonal array (example problem 20) runs just fine and I modeled my input after that. The viewer doesn't show any errors. My triangular array has dimensions 41 x 41 and pitch of 5.1 cm. Are there limitations in CSAS6 for arrays?

Thank you for your time and please let me know if you have any questions.

[Pavlo Ivanusa]

Are you able to provide your entire input?

[David Holler]

Thanks to Pavlo, this issue was resolved. This global unit card fixed the problem:

global unit 1

rhexprism 1 87 216 0

array 1 1 place 21 21 1 0 0 0

zcylinder 2 100 216 0

media 0 1 2 -1

boundary 2

It seems CSAS6 sometimes needs a boundary shape for an array, separate from the global unit boundary. Thanks again Pavlo.

[David Holler]

I'd like to amend this message - this error appears when an array does not completely fill a shape. When I add empty positions around the perimeter of the array, even if they are cropped by the shape, there is no error.