Setting all cell universes to zero for CAD.
Setting all cell universes to zero for CAD.

johnnyliu27/openmc,mit-crpg/openmc,johnnyliu27/openmc,johnnyliu27/openmc,shikhar413/openmc,liangjg/openmc,mit-crpg/openmc,amandalund/openmc,wbinventor/openmc,shikhar413/openmc,liangjg/openmc,smharper/openmc,johnnyliu27/openmc,amandalund/openmc,smharper/openmc,liangjg/openmc,shikhar413/openmc,walshjon/openmc,walshjon/openmc,wbinventor/openmc,walshjon/openmc,amandalund/openmc,mit-crpg/openmc,paulromano/openmc,paulromano/openmc,liangjg/openmc,amandalund/openmc,wbinventor/openmc,smharper/openmc,shikhar413/openmc,walshjon/openmc,mit-crpg/openmc,paulromano/openmc,paulromano/openmc,wbinventor/openmc,smharper/openmc