INTERIM REPORT ON CORROSION BY ALKALI-METAL FLUORIDES: WORK TO MAY 1, 1953

Technical Report · Mon Jun 01 00:00:00 EDT 1959

DOI:https://doi.org/10.2172/4248030· OSTI ID:4248030

Adamson, G. M.; Crouse, R. S.; Manly, W. D.

4 9 1 3 3 6 3 4 7 9 8 6 5 suitable for us in high-temperature molten-fluoride reactor systems, the corrosion of several metals by various fused fluoride mixtures was studied in thermalconvection leops made from the metal being tested. In these teats the temperaturc drop was fairly large, but the velocity of the liquid was low and not subject to control. The fluoride mixture used in most of the study contained 43.5 mole a KF, lO.9 mole % NaF, 44.5 mole % LiF, and 1.1 mole % UF/sub 4/. and is referred to as ''fluoride 14.'' In a series of screening tests Inconel, or similar high-nickel alloys, was shown to be most promising container material. The data reported are from loops that were operated for only relatively short times, 500 hr. and with impure fluoride mixtures. The lack of purity of the mixtures was an important consideration in the tests reported. With fluoride 14 an average figure for the maxium microscopically visible attack on Ineonel was 0.012 to 0.015 in after 500 hr of circulation The attack was in the form of small voids which did not connect with the surface or with each other. It is shown that for the times used here the attack was caused primarily by the reduction of fuel impurities by chromium metal from the container and by the leaching of sufficient chromium to reach equilibrium concentrations in reactions with the fluorides, primathe depth and type attack varied only slightly when changes were made in the major components of the various fluoride mixtures studied. The only effect definitely established was that, in every case. mixtures containing uranium fluoride caused more attack than did similar mixtures contain no uranium. When the loop was operated at a fluid temperature of 1650 F, the attack was slightly deeper than it was at 1300 F. The addition of zirconium hydride to the fuel almost completely eliminated their attack Alkali metals also acted as inhibitors. It was found that type: 316 stainless steel might be congidered for a container for molten fluoride mixtures that do not include potassium fluoride. With such stainless steels and zirconium fluoride-base mixtures, the maximum depth of attack was about the same as that found with Inconel; however. more material was masstransferred and cold-leg deposits were found. When aljkali-metal-base mixtures were circulated in type 316 stainless steel, plugging occurred in a relatively short time; the plugging was probably caused by the formation of a compound similar to K/sub 2/NaCrF/sub 6/. (auth) l5056 ts have been prepared for each paper. (W.L.H.) l5057 Various light-scattering quantities which may be used for the size determination of suspended colloidal spheres are derived from the Mie theory for the parameters a = 0.2(0.2115.0 and m = 1.05(0.0511.30. They include (1) the tolal turbidity as obtained by transmission measurements, (2) the light scattering and the polarization ratio at 90 deg, and (3) the spectra of the preceding quantities and thc ''wavelength exponents'' characterizing the spectra. In addition, the angular scattering in the forward and backward directions and the dissymmetry are derived, but only for selected m-values. The data are compared with the results obtained from the approximating theories of Rayleigh-Gans and of Debye. Detailed experiments were carried out on the total turbidity, the angular scattering at 90 deg, the ''scattering ratio'' at 90 deg, and the wavelength exponents. The experimental work obtained on monodiperse systems fully verifies the theoretical data. The theoretical data and the experimental methods developed were applied to the determination of size- distribution curves in heter

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• DOE Contract Number: W-7405-ENG-26
• NSA Number: NSA-13-015055
• OSTI ID: 4248030
• Report Number(s): ORNL-2337
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-59
• Country of Publication: United States
• Language: English

Related Subjects

CHEMISTRY
ALKALI METALS
ALUMINUM ALLOYS
CHEMICAL REACTIONS
CHEMICALS
CHROMIUM
CHROMIUM ALLOYS
CONFIGURATION
CORROSION
CORROSION PROTECTION
EQUILIBRIUM
FLUID FLOW
FUSED SALTS
HIGH TEMPERATURE
IMPURITIES
LIQUID FLOW
LITHIUM FLUORIDES
MEASURED VALUES
METALS
MICROSCOPY
MIXING
NICKEL ALLOYS
NIOBIUM ALLOYS
POTASSIUM FLUORIDES
PRECIPITATION
QUANTITY RATIO
REACTION KINETICS
REACTORS
REDUCTION
REPORT
SODIUM FLUORIDES
SOLUTIONS
STAINLESS STEELS
SURFACES
TABLES
TEMPERATURE
TESTING
TITANIUM ALLOYS
URANIUM TETRAFLUORIDE
USES
VELOCITY
VESSELS
ZIRCONIUM FLUORIDES
ZIRCONIUM HYDRIDES