Nuclear fuel pellets (uranium oxide) are sintered at high temperature in a reducing atmosphere. Therefore the sintering furnaces need to be lined with high purity alumina refractoies.

High density alumina bricks Alundum®  AH199B or Alfrax®  101 are used for the hot face wall and bubble alumina-based insulating fire bricks Alundum® AN599 are used for the backup lining.