2. Reprocessing materials

Spent fuel treatment requires the use of nitric acid at varying concentrations and temperatures up to boiling point. The composition of this medium shows a wide variety of elements present, mainly from the spent fuel. Its composition and concentration can change along the processing line.

The choice of materials can vary along this processing line and is conditioned by :

• acid concentration ;

• composition (presence of oxidizing ions or fluorine in particular);

• temperature ;

• exposure conditions in the component (heat flow, renewal, condensate).

A large proportion of the installations are made of hyper-hardened austenitic stainless steels (table