Piercing Z-Cylinder surface with X-Cylinder surface horizontally.

User Support
1

How does OpenMC handle piercing a Z-Cylinder surface with X-Cylinder or Y-Cylinder surface horizontally? I have a TRIGA reactor design, where the core is surrounded by graphite and lead shield, and the surrounding Z-Cylinder surfaces are usually pierced through to create beam ports. These beam ports are in X or Y direction. How do openmc handle this? Any help is appreciated. Thanks.

2

Sharif,

You would need to divide up your geometry into different cells whose regions are defined as the intersection / union of surface half-spaces. Usually beam ports would be modeled using cones or cylinders. If you need to have an arbitrarily oriented cylinder, you could use a general second-order surface. If you want to understand more about how the geometry system works, I would recommend reading our theory/methodology guide on geometry.

Best regards,
Paul

3

Hello Dr Paul. Can you please share a demo of this surface intersection? It will help me understand better. Thanks.

4

Hello, Dr. Paul, I am trying the below code for a sample case. I have three z-Cylindrical surfaces and cells. I want to put an x-cylindrical cell through the second and third cell. What am I missing here? Please help me resolve this issue.

<?xml version=**'1.0' **encoding=**'utf-8'**?>

<cell id**=“1” material=“4” name=“cell 1” region="-1 6 -5" universe=**“0” />

<cell id**=“2” material=“5” name=“cell 2” region=“1 -2 6 -5 4” universe=**“0” />

<cell id**=“3” material=“6” name=“cell 3” region=“2 -3 -5 6 4” universe=**“0” />

<cell id**=“4” material=“5” name=“cell 4” region=“8 -7 -4” universe=**“0” />

<surface coeffs**=“0 0 10.6682” id=“1” name=“graphite_in” type=**“z-cylinder” />

<surface coeffs**=“0 0 14.1682” id=“2” name=“graphit_out” type=**“z-cylinder” />

<surface boundary**=“vacuum” coeffs=“0 0 15.1682” id=“3” name=“plomb_out” type=**“z-cylinder” />

<surface boundary**=“vacuum” coeffs=“0 0 4.0” id=“4” name=“graphite_beam” type=**“x-cylinder” />

<surface boundary**=“vacuum” coeffs=“30” id=“5” type=**“z-plane” />

<surface boundary**=“vacuum” coeffs="-30" id=“6” type=**“z-plane” />

<surface boundary**=“vacuum” coeffs=“20” id=“7” type=**“x-plane” />

<surface coeffs**=“12” id=“8” type=**“x-plane” />

<?xml version=**'1.0' **encoding=**'utf-8'**?>

<material id**=“4” name=“water”>**

<density units**=“g/cm3” value=**“0.99644” />

<nuclide ao**=“66678664998.0” name=**“H1” />

<nuclide ao**=“33339331998.0” name=**“O16” />

<sab name**=**“c_H_in_H2O” />

<material id**=“5” name=“graphite”>**

<density units**=“g/cm3” value=**“1.65” />

<nuclide ao**=“82729999998.0” name=**“C0” />

<sab name**=**“c_Graphite” />

<material id**=“6” name=“Plomb”>**

<density units**=“g/cm3” value=**“11.3405” />

<nuclide ao**=“32959999998.0” name=**“Pb207” />

Thank you.

5
  1. First try the cylinder part surrounded by a sphere, the boundary condition of the sphere is vacuum, and the vacuum between the sphere and the cylinder
  2. You want to dig a small cylindrical hole in a cylinder of different sizes. You first build a small cylindrical cell and fill it with the material. Then construct cells of different size cylinders in order from the inside to the outside, paying attention to the geometric intersection of small cylindrical cell.
  3. Finally, define the area between the constructed space geometry and the sphere. You should use ‘-sphre & (-zp_down | +zp_up | +zc_outer | +xp_outer | +xc_outer )’
    I don’t know if my thoughts can help you, I wish you good luck.
    在 2019年2月5日星期二 UTC+8上午7:42:25，Sharif Abu Darda写道：