CHEMICAL ENGINEERING DIVISION SUMMARY REPORT, JANUARY, FEBRUARY, MARCH 1961

Technical Report · Tue Oct 31 00:00:00 EST 1961

DOI:https://doi.org/10.2172/4012788· OSTI ID:4012788

8 7 < 6 ; : : = 8 g developed for recovering fissionable and fertile materials from shortcooled reactor fuels. The second laboratory demonstration of the melt-refining process with highly irradiated EBR- IItype fuel pins was completed. A 392-g charge of U-5% fissium fuel pins irradiated to an estimated burnup of 0.4 total at.% and cooled 28 days was melt refined for three hours at 1400 deg C. Data were not obtained on the behavior of fission products. The effect of N concentration on the nitridation rates of unirradiated U-fissium alloys in Ar-N atmospheres was determined. Experiments on the storage of fuel pins at 350 deg C in Ar atmospheres showed that the presence of 5% N lowered product yields only slightly during subsequent melt-refining operations. Supplementary pouring techniques, such as the use of probes and mashers designed to break crusts over the melts, are moderately effective, but are a less desirable solution to the problem of maintaining high yields than the elimination of contaminants in the Ar atmosphere. A liquid metal process is under development for recovery of the fissionable material contained in melt refining crucible skulls produced in the EBR-II fuel cycle. Information obtained in separate studies of the individual process steps is listed. A systematic study is underway to ascertain the influence of atomic size, metallic valence, and electronic configuration on the coprecipitation of various metallic elements with the Cd-Ce intermetallic phase CeCd/sub 11/. Values for the coprecipitation coefficient lambda , defined by the equation log (tracer in solution/ total tracer) = lambda log (carrier in solution/total carrier), were determined for Na, Li, K, Y, Ba, lambda = 0; La, lambda = 1.49; Th, lambda = 1.08; Pr, lambda = 0.63; Ga, lambda = 0.23; Sm, lambda = 0.17; U, lambda = 0.13; Sr, lambda = 0.10; Eu, lambda = 0.099; Sc, lambda = 0.05; and Zr, lambda = 0.04. In pilot-plant studies the reaction of 304 stainless steel tube sections with Cl was investigated in a 1 1/2-inchdiameter two-zone fluid-bed reactor. An average penetration rate of 4.6 mils/hr was obtained in a 4.7-hour run at 575 deg C using 87% Cl (in N). At 625 deg C, using the same Cl concentration, a 35-mil tube completely reacted in 3.8 hours. The effect of Cl dilution at 625 deg C was noticeable at concentrations below 48 vol.%. The rate of thermal decomposition of PuF/sub 6/ was studied at 140 to 173 deg C by a static method and from 150 to 250 deg C by a flow method. A study of the kinetics of decomposition established the mechanism of the reaction. The rate of the reaction has been formulated as concurrent first- and zero-order reactions with respect to PuF/sub 6/ pres sure in the range between 50 and 1100 mm at 140 to 170 deg C. The reaction of elemental Br with PuF/sub 6/ has been investigated. The stoichiometry of the reaction was established. Primary products of the reaction are PuF/sub 4/ and BrF/sub 5/. The utility of the reaction for the separation of U and PuF/sub 6/ was demonstrated. In studies of fission product behavior, mixtures of UO/sub 2/ - Ru/sup 106/ were reacted with F at 400 and 500 deg C. It was found that at both of these temperatures Ru was volatilized at a rate equal to or faster than that of U volatilization as UF/sub 6/. However, it was found that RuF/sub 5/ decomposed and was deposited on a colder portion of the walls of the fluorination vessel. Two series of in-pile, metal-water experiments were completed. Meltdowns were conducted on stainless steel-urania cermets, U wires, and on ceramic core, metal-clad fuel specimens. Cermets made of 90 wt.% stainless steel with urania showed similar behavior when submerged in water irrespective of whether the sample was in the form of pins or plates; metal temperatures greater than 1500 deg C were attained. The original geometry was changed into one or two large globules together with many fine particles; the more energetic transients also produced some fine (1-mil diameter) powder. Chemical analyses indicated that a separation of the urania from the stainless steel took place during the melting-quenching cycle of the reactor burst. The larger globules were depleted in U

• Research Organization: Argonne National Lab., Ill.
• DOE Contract Number: W-31-109-ENG-38
• NSA Number: NSA-15-025734
• OSTI ID: 4012788
• Report Number(s): ANL-6333
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-61
• Country of Publication: United States
• Language: English

Related Subjects

GENERAL AND MISCELLANEOUS
ARGON
ATOMIC MODELS
BARIUM
BROMINE
BROMINE FLUORIDES
BURNUP
CADMIUM ALLOYS
CARRIERS
CERIUM ALLOYS
CERMETS
CHEMICAL REACTIONS
CHLORINE
CONFIGURATION
COOLING
DECOMPOSITION
DECONTAMINATION
DEFECTS
EBR-2
EFFICIENCY
ENERGY
EQUATIONS
EUROPIUM
FAILURES
FERTILE MATERIALS
FILMS
FISSION PRODUCTS
FISSIONABLE MATERIALS
FLUIDIZATION
FLUORINATION
FLUORINE
FUEL CANS
FUEL ELEMENTS
GALLIUM
GRAIN SIZE
HEAT TREATMENTS
HIGH TEMPERATURE
IMPURITIES
IN PILE LOOPS
INTERMETALLIC COMPOUNDS
LANTHANUM
LIQUID METALS
LITHIUM
MELTING
METALS
NITROGEN
PHASE DIAGRAMS
PLUTONIUM FLUORIDES
POTASSIUM
PRASEODYMIUM
PRECIPITATION
PRE