[en] The uranium product denitrator at the Idaho Chemical Processing Plant has had serious operating problems since 1970, including inadequate contamintion control, fluidized bed caking, frequent bed heater failure, product overflow plugging, and poor feed control. These problems were minimized through selective redesign and upgrade of the process equipment as part of a process upgrade program completed in March 1981. Following startup and testing of the rebuilt product denitrator, 1044 kg of enriched uranium was processed in three weeks while demonstrating greater reliability, ease of operation, and improved contamination control. To maximize personnel safety in the future, the denitrator vessel should be made critically safe by geometry and process instrumentation isolated from the process for semi-remote operation