CHEMICAL ENGINEERING DIVISION SUMMARY REPORT FOR JULY, AUGUST, SEPTEMBER 1958

Technical Report · Mon Dec 01 00:00:00 EST 1958

DOI:https://doi.org/10.2172/4297184· OSTI ID:4297184

8 2 5 6 7 6 1 1 B 3 7 3 7 reprocessing scheme which may be applicable to most power reactor fuels is described. The irradiated fuel is dissolved in an appropriate aqueous solution which is then calcined to a mixture of dry oxide. Fluorination of the mixture ultimately produces the hexafiuorides of U and Pu, which are volatilized. This process will be called the ADF (aqueous dissolution and fluorination) process. The fluorination rates of UF/sub 4/ and PuF/sub 4/ were investigated. Since oxides, as well as fluorides, are involved in this scheme, fluorination rate studies were conducted on UO/sub 2/. The thermal decomposition of PuF/sub 6/ was investigated at 300 deg C by several methods that showed the reaction products to be fluorine and PuF/ sub 4/. A brief study was made on the rate of fluorine consumption by Ni vessels at temperatures from 300 to 600 deg C. Development work has continued on thc fused flouride process for the recovery of enriched U from Zr-matrix fuel alloys. Studies of alternate methods of contacting in the fused salt fluorination step are under way. In one scheme, dropwise fluorination is carried out by spraying molten salt into a fluorine atmosphere. Another scheme involves the use of a frozen salt wall to serve as container of the fused salt during fluorination. Further corrosion data are reported on the behavior of Ni and Ni alloys in fluorinated NaF --ZrF/sub 4/ systems at 600 deg C. Liquid Metal-Fuel Reprocessing. Laboratory work to demonstrate the practicality of the fused fluoride volatility process for the LMFR fuel is being continued. The rapid extraction of U from Bi, very low in Mg concentration, was quantitatively demonstrated. Extraction of Ce from Bi, low in Mg concentration, by the molten fluoride salt has also been accomplished. The partial extraction of U and radioactive Ru from Bi with Zn was demonstrated. Bismuth pentafluoride was prepared by the direct reaction of fluorine with Bi. Fluidization Studies. Development work on the process for the recovery of U from low U-high Zr alloys (ADF process) was continued. As a part of a study to correlate U removal during fluorination with species of ZrF/ sub 4/ formed at various temperatures, identification of fluid-bed dryer products was attempted. Fluorinations in the 21/2-in-diam.. fluid-bed unit succeeded in removing about 99% of the U in four hours at 600 deg C and 12 hours at 500 deg C from materials prepared in a fluid-bed dryer at 300 deg C. Laboratory fluorination studies showed metal additives to U--Zr feed solutions had no inhibiting effect on U volatilization. In the fluid-bed waste calcination process currently under investigation, liquid radioactive wastes are spray injected into a heated fluidized bed of solid particles. A study of the factors influencing particle growth in a fluid-bed Calciner was started. Reactor Chemistry. The study of factors influencing pyrophoricity and oxidation of the reactor materials U, Zr, Th, and Pu has continued. In the U burning-curve tests, variation of the O/sub 2/ flow rate has shown a negligible effect. An ignition test has been developed in which Zr foil specimens were electrically heated to a high temperature in very short times. The oxidation of 60 binary Zr alloys was completed. A short-term study of Mg ignition has shown disagreements with the results of earlier experimenters. The experimental program to determine rates of reaction of molten reactor fuel and cladding metals with water is continuing. The relative values of the neutron-capture cross section of U for monoenergetic neutrons in the energy range 0.36 to 1.50 Mev have been determined. Chemical- Metallurgical Processing. Melt refining, liquid metal extraction, and intermetallic crystallization are now being examined as direct-cycle pyrometallurgical methods of processing

• Research Organization: Argonne National Lab., Lemont, Ill.
• DOE Contract Number: W-31-109-ENG-38
• NSA Number: NSA-13-005332
• OSTI ID: 4297184
• Report Number(s): ANL-5924
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-59
• Country of Publication: United States
• Language: English

Related Subjects

CHEMISTRY
AIR
ALLOYS
BISMUTH
BISMUTH FLUORIDES
BLANKETS
BURNUP
CADMIUM
CADMIUM ALLOYS
CALCINATION
CANNING
CAPTURE
CARBON
CERIUM
CESIUM 137
CESIUM 138
COMBUSTION
CONCENTRATION
CORROSION
COUNTERS
CROSS SECTIONS
CRYSTALLIZATION
DIAGRAMS
ELECTRICITY
ENERGY RANGE
ENRICHMENT- - EVAPORATION
EVAPORATION
FISSION PRODUCTS
FLUIDIZATION
FLUORIDES
FLUORINATION
FLUORINE
FOILS
FUEL CANS
FUEL ELEMENTS
FUELS
FUSED SALTS
GAS FLOW
HEATING
HIGH TEMPERATURE
IMPURITIES
INTERMETALLIC COMPOUNDS
IRRADIATION
JACKETS
LANTHANUM FLUORIDES
LEACHING
LIQUID METAL FUEL
LIQUID METALS
LIQUIDS
LMFR
MAGNESIUM
MELTING
METALLURGY
METALS