I’ve got no idea regarding the jupyter kernal crashing, I tried to reproduce the error over here, but everything works fine over here. I guess it is a local install issue which python is famous for
This last screen shot is not the openmc-source-plotter but rather a openmc.plot_geometry call. The error message suggests that the cross section xml file can’t be found.
This question regarding setting the cross-section file has come up a few times before, perhaps this post might help OpenMC cross_section.xml problem - #2 by Pranto
Alternatively, the recently released openmc version 0.13.2 introduces a new config option for setting the variable which 3. Data Configuration — OpenMC Documentation
openmc.config['cross_sections'] = 'path_to_cross_sections.xml'