The Division of Spent Fuel Storage and Transportation, Interim Staff Guidance (ISG) – 1, Revision 2, Classifying the Condition of Spent Nuclear Fuel for Interim Storage and Transportation Based on Function (ML071420268), provides guidance on classifying spent nuclear fuel as either (1) damaged, (2) undamaged, or (3) intact, before interim storage or transportation. View ISG-1, Rev. 2 here.