Fix existing unit tests for thermal scattering
Fix existing unit tests for thermal scattering

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