T h i s r e p o r t was p r e p a r e d a s a n a c c o u n t o f w o r k s p o n s o r e d by t h e U n i t e d S t a t e s G o v e r n m e n t . N e i t h e r t h e U n i t e d S t a t e s n o r t h e U n i t e d S t a t e s A t o m i cE n e r g y C o m m i s s i o n , n o r a n y o f t h e i r e m p l o y e e s , n o r a n y o f t h e i r c o n t r a c t o r s , s u b c o n t r a c t o r s , o r t h e i r e m p l o y e e s , makes a n y w a r r a n t y , e x p r e s s or i m p l i e d , o r assumes a n y l e g a 7 I i a b i I i t y o r r e s p o n s i b i I i t y f o r t h e a c c u r a c y , c o m p l e t en e s s o r u s e f u l n e s s o f a n y i n f o r m a t i o n , a p p a r a t u s , p r o d u c t o r p r o z e s s d i sc l o s e d , o r r e p r e s e n t s t h a t i t s u s e w o u l d n o t i n f r i n g e p r i v a t e l y owned r i g h t s .
DISCLAIMER
€I. S. Cole
N O T I C EThis report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the United States Atomic Energy Commission, cor a n j of their empioyees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product or process disclosed, or represents that its use would not infringe privately owned rights.
ALLIED CHEMICAL CORPORATION IDAHO CHEMICAL PROGRAMS-OPERATIONS OFFICE
ABSTRACTThis report represents a literature survey, plus some experimental work, on the corrosion of austenitic stainless steel alloys due to HN03-HF mixtures. Most of the available data were obtained during the processing of spent nuclear fuel elements where solutions containing nitrates and fluorides are frequently encountered. Austenitic stainless steels have been extensively used in nitrate-fluoride solution service in these plants. It has been shown that their service may be improved by: (1) proper annealing; (2) stabilizing with columbium (niobium) or titanium; ( 3 ) complexing the solutions the stainless steels will contain with aluminum, zirconium, or thorium; (4) utilizing stainless steels which have a low carbon content; ( 5 ) maintaining the uncomplexed hydrofluoric acid in the solution at as low a value as practicable; and (6) utilizing neutron absorbing elements in the alloys at concentrations as low as possible for service as fixed nuclear poisons. Other protective measures such as reduced contact time, temperature, concentration, and fluoride-to-nitrate ratio can be employed to minimize corrosion. n ..
