Problem in C-Nat material file,

User Support
1

I am trying to simulate a graphite nuclear reactor, but the program keeps giving me an Error after running Opem-mc.

the Error is :

Reading settings XML file…
Reading cross sections XML file…
Reading geometry XML file…
Reading materials XML file…
ERROR: Cannot expand element: c-Nat
ERROR STOP

can someone help please?!

2

Carbon is a special case in that most (all?) data libraries do not actually have isotopic evaluations, i.e. the evaluation is for natural Carbon. As such, in the input for OpenMC, you either need to specify C-Nat as a nuclide, or C as an element:

or

Both have the same effect.

Best,
Paul