Surface Numbering for Tangent Bounded Cell

[Terry_Price]

Hey Guys,

If I have a geometry like in the attached picture, and I want to determine the surface sense of the bounding surfaces of cell 27, which is bound by the cylinder 101, and the planes 5, and 15, can I just say

surfaces=" -101 5 -15"

or will openMC not recognize the tangential bounding, and I’ll need to make the cylinder like 0.000001 cm smaller than it actually is, and bound it with

surfaces=" -101 5 -15 14 -6"

I know in DRAGON, I have to do the later. Does making such a very small bounding surface cause any issues with openMC?

[paulromano]

It is perfectly fine in OpenMC to have the cylinder exact tangent to those surfaces. If you do find you run into problems though, feel free to shoot another message to the list.

Best,
Paul

[Terry_Price]

Well, I tried it, but I couldn’t get it to form a proper cell if my binding surfaces were only two corner-forming planes and a tangentially affixed cylinder. I had to introduce two new planes to get it to form a cell properly.