HEAD-END PROCESSES FOR DISSOLVING STAINLESS STEEL-UO$sub 2$ DISPERSION TYPE FUEL ELEMENTS. I. CARBIDE AND NITRIDE TREATMENTS. II. ANODIC DISSOLUTION

Technical Report · Wed Jan 01 04:00:00 EST 1958

OSTI ID:4307039

Martin, F S; Waterman, M J

The treatment of 18-8-1 type stainless steel plate with ammonia or methane at about 1000 deg C renders the metal more susceptible to dissolution in nitric acid. Thc rate of penetration (of carbide or nitride) is very slow, and the method does not seem to be very suitable, except for the treatment of very thin plates (~0.025" thickness). Stainless steel and stainless steel-UO/sub 2/ cermets dissolve readily in nitric acid if an anodic potential is applied. High current efficiencies are obtainable with d-c and moderate efficiencies with a-c. A wide range of initial nitric acid concentrations may be used and dissolution may be carried to the point where large quantities of ferric hydroxide are precipitated. Uranium recoveries are > 99.5%. The bulk of the fission product activity is found in solution, but fission product niobium is associated with traces of insoluble residue. The method would be suitable for the dissolution of large pieces of stainless steel (e.g., whole fuel elements) where individual electrical contacts may be made external to the solution; it would not be suitable where large numbers of small pieces have to be held (e.g. in a platinum basket), due to the almost negligible current efficiencies that arc obtained in such cases. (auth)

• Research Organization: United Kingdom Atomic Energy Authority. Research Group. Atomic Energy Research Establishment, Harwell, Berks, England
• NSA Number: NSA-12-010469
• OSTI ID: 4307039
• Report Number(s): AERE-C/R-2454
• Country of Publication: United Kingdom
• Language: English

Related Subjects

AMMONIA-- ANODES-- CARBIDES-- DISPERSIONS-- EFFICIENCY- - ELECTRIC POTENTIAL-- FUEL ELEMENTS-- IRON HYDROXIDES-- METALLURGY-- METHANE-- NITRIC ACID-- NITRIDES-- PLATES-- QUANTITY RATIO-- SEPARATION PROCESSES-- SOLUBILITY-- SOLUTIONS-- STAINLESS STEELS-- TEMPERATURE-- URANIUM DIOXIDE
CHEMISTRY
FISSION PRODUCTS-- NIOBIUM-- PRECIPITATION-- RECOVERY-- RESIDUES-- TRACE AMOUNTS-- URANIUM-- USES