POWER REACTOR FUELS REPROCESSING. PROGRESS REPORT ON CORROSION STUDIES

Technical Report · Wed Aug 26 00:00:00 EDT 1959

DOI:https://doi.org/10.2172/4195211· OSTI ID:4195211

Maness, R F

Work is reported on corrosion studies of candidate materials of construction for equipment for the dissolution of Zircaloy cladding in NH/sub 4/F- NH/sub 4/NO/sub 3/ solutions, the total dissolution of suainless steel clad fuels in HNO/sub 3/-HF solutions, and the dissolution of stainless steel cladding in dilute H/sub 2/SO/sub 4/. A single material of construction which could be used for a processing complex which would handle all of the low-enrichment fuels concerned was searched for. In the Zirflex Process (NH/sub 4/F-NH/sub 4/NO/sub 3/ ) the 300 series stainless steels, vacuum-melted Hastelloy-F, Carpenter 20, Nio- nel, Haynes 25, and Incoloy 804 have satisfactory corrosion resistance to solutions involved in the dissolution of Zr or Zircaloy claddings. Satisfactory dissolution rates for 304-L stainless steel cladding are obtained in the Niflex Process (1MHNC/sub 3/-2MHF) solutions. The minimum practical fluoride to stainless steel ratio is about five. Among many materials studied, vacuum-melted HastelloyF offers the best corrosion resistance to HNO/sub 3/-HF solutions encountered during decladding. In the Sulfex Process (H/sub 2/SO/sub 4/) dissolution rates for both annealed 304-L and 347 stainless steel in 3 to 3 M H/ sub 2/SO/sub 4/ are from 5 to 10 mils per hour. Vacuum-melted Hastelloy-F and Ni- o-nel show adequate corrosion resistance to the H/sub 2/SO/sub 4/-stainless steel solutions concerned in H/sub 2/SO/sub 4/ decladding. Ouring U or UO/sub 2/ core dissolution in HNO/sub 3/ following decladding, some sulfate (sulfex decladding) or (fluoride zirflex decladding) will be present due to incomplete rinsing or to the presence of solids (UF/sub 4/). Residual sulfate in the concentration range has no significant effect on the corrosion of 304-L stainless steel or vacuum- melted Hastelloy-F by HNC/sub 3/. Fluoride present will increase the corrosion potential but can be effectively complexed by Al. Corrosion rates of 304-L, vacuum-melted Hastelloy-F, and Ni-o-nel in HNO/sub 3/ solutions are not markedly increased by low concentration (0.1 to 0.3M) of ferric nitrate. However, at higher concentrations ( approximately 1 M) corrosion of an intergranular nature is severe. (W. L. H.)

• Research Organization: General Electric Co. Hanford Atomic Products Operation, Richland, Wash.
• Sponsoring Organization: USDOE
• DOE Contract Number: AT(45-1)-1350
• NSA Number: NSA-14-004385
• OSTI ID: 4195211
• Report Number(s): HW-61662
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-60
• Country of Publication: United States
• Language: English

Related Subjects

CHEMISTRY
ALLOYS
ALUMINUM
AMMONIUM COMPOUNDS
ANNEALING
CANNING
CARPENTER
CHROMIUM ALLOYS
COBALT ALLOYS
COMPLEXES
COPPER ALLOYS
CORROSION
ENRICHMENT
FLUORIDES
FUELS
HASTELLOY
HYDROFLUORIC ACID
IRON NITRATES
MANGANESE ALLOYS
MELTING
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NIFLEX PROCESS
NITRATES
NITRIC ACID
REACTOR CORE
REACTORS
REPROCESSING
SILICIDES
SOLUTIONS
STAINLESS STEELS
SULFATES
SULFEX PROCESS
SULFURIC ACID
TITANIUM ALLOYS
TUNGSTEN ALLOYS
URANIUM
URANIUM DIOXIDE
URANIUM TETRAFLUORIDE
VACUUM
ZIRCALOY
ZIRFLEX PROCESS