removed 0 as lower energy group
removed 0 as lower energy group

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