skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: CERAMICS RESEARCH

Abstract

Analysis of x-ray diffraction data of a 48.2 at.% C--Pu alloy indicated the possible growing-in of the zeta phase while standing at room temperature for a period of 400 days. Electrical resistivity measurements of two PuC compositions (37.2 and 39.1 at.% C) showed a nonisothermal reaction between 500 and 550 deg C. PuN decomposed during arc melting under one atmosphere of nitrogen to form PuN dendrites in a matrix of alpha plutonium. A combustion, gravimetric method for determining carbon in plutonium carbides was reduced to routine practice in glove boxes with a precision near 1% for samples weighing between 200 to 1000 mg and with carbon contents between 1 to 5 wt%. PuN and UN were found to form solid solutions in all proportions. X-ray powder pattern studies indicated that the region between PuO/sub 1.0/ and PuO/sub 1.6/ in the Pu-- O phase diagram is a two-phase field of PuO and BETA Pu/sub 2/O/sub 3/. The synthesis of plutonium suboxides by carbon reduction of PuO/sub 2/ was studied. An increase in the lattice parameters of several oxide and carbide compounds of plutonium was observed during the course of standing at room temperature. The rates of expansion ranged from 0.085 xmore » 10/sup -3/ to 1.16 x 10/sup -3/ ( DELTA a/a/sub o/) per 100 days. Arc melting of PuO/sub 2/ pellets in argon, followed by air oxidation at 800 deg C produced >99% TD material with an O/Pu ratio of 2.00. PuO/ sub 2/-- MgO mixtures appeared to form a simple binary eutectic system. A method was developed for preparation of UOS by electrodeposition from a molten salt solution. The UOS decomposed above its melting point (1900 plus or minus 50 deg C) into two other phases. Significant changes in the microhardness and lattice dimensions of US occurred after a low neutron exposure. Crystallite growth in UO/sub 2/-50 wt% W cermets was studied in the electron microscope by cine micrography. UO/sub 2/--W cermets were replicated with an alpha sensitive emulsion. The autoradiographs were examined by transmission electron microscopy. Rapid oxidation of UN in a UN--50 wt% W cermet was observed during controlled reaction in the electron microscope. Thin sections of UO/sub 2/ crystals were prepared for electron microscopy. UO/sub 2/ single crystals and UO/sub 2/ cermets for basic studies were prepared. A 50 pound lot of high purity arc-fused UO/sub 2/ was prepared, characterized and sent to Savannah River Laboratory for testing in the HWCTR. The monometric measurement of evolved H/sub 2/, produced by reaction of HCl with uranium, was used to analyze for free uranium metal in UO/ sub 2/. Radial flow thermal conductivity measurements of UO/sub 2/ single crystals relative to polycrystals are in progress. Preliminary results indicated a substantial increase in single crystal conductivity above 1600 deg C that may result from radiant transfer. Metallic inclusions of uranium, which may significantly affect the physical properties of UO/sub 2/, are formed in UO/sub 2/ fuel elements irradiated with central temperatures high enough to produce extensive columnar grain growth. Improved autoradiographs of irradiated UO/sub 2/ fuel rods show that only a portion of the columnar grain region is depleted of fission products and that a high concentration of fission products is located just outside the depleted band. A lightly irradiated sample of polycrystalline UO/sub 2/ retained 83 at.% of the total fission products and 95% of total radioactivity during explosive melting. UO/sub 2/ microcores, useful in fundamental studies, were extracted from several types of UO/sub 2/ by use of ultrasonic drilling techniques. A computer program in FORTRAN language for use in calculating the interplanar spacings of crystals from their line positions on x-ray powder pattern films was written and made operational. Additional evidence supported the hypothesis that the radial limit of melting in irradiated ceramic fuels corres nu onds to the radial limit of subgrain structure. The heat transfer rate through molten UO/sub 2/ was estimated to be 0.05 watts/ cm C. (auth)« less

Publication Date:
Research Org.:
General Electric Co. Hanford Atomic Products Operation, Richland, Wash.
OSTI Identifier:
4640431
Report Number(s):
HW-76301(Paper 1)
NSA Number:
NSA-17-036196
Resource Type:
Technical Report
Resource Relation:
Other Information: Orig. Receipt Date: 31-DEC-63
Country of Publication:
Country unknown/Code not available
Language:
English
Subject:
METALS, CERAMICS, AND OTHER MATERIALS; AIR; ALLOTROPY; ARGON; CARBON; CERAMICS; CERMETS; CHEMICAL REACTIONS; COMBUSTION; CONFIGURATION; CONTROL; CRYSTALS; DECOMPOSITION; DIFFRACTION; ELECTRIC ARCS; ELECTRIC CONDUCTIVITY; ELECTRODEPOSITION; ELECTRON MICROSCOPY; EUTECTICS; EXPANSION; FILMS; FISSION PRODUCTS; FUSED SALTS; GLOVEBOXES; GRAIN SIZE; HARDNESS; HEAT TRANSFER; HIGH TEMPERATURE; HYDROCHLORIC ACID; HYDROGEN; LATTICES; MAGNESIUM OXIDES; MEASURED VALUES; MELTING; MELTING POINTS; MICROSCOPY; MONOCRYSTALS; NEUTRON BEAMS; NITROGEN; OXIDATION; PELLETS; PHASE DIAGRAMS; PHOTOGRAPHY; PLUTONIUM; PLUTONIUM CARBIDES; PLUTONIUM NITRIDES; PLUTONIUM OXIDES; PLUTONIUM-ALPHA; POWDERS; PREPARA

Citation Formats

. CERAMICS RESEARCH. Country unknown/Code not available: N. p., 1963. Web.
. CERAMICS RESEARCH. Country unknown/Code not available.
. Thu . "CERAMICS RESEARCH". Country unknown/Code not available.
@article{osti_4640431,
title = {CERAMICS RESEARCH},
author = {},
abstractNote = {Analysis of x-ray diffraction data of a 48.2 at.% C--Pu alloy indicated the possible growing-in of the zeta phase while standing at room temperature for a period of 400 days. Electrical resistivity measurements of two PuC compositions (37.2 and 39.1 at.% C) showed a nonisothermal reaction between 500 and 550 deg C. PuN decomposed during arc melting under one atmosphere of nitrogen to form PuN dendrites in a matrix of alpha plutonium. A combustion, gravimetric method for determining carbon in plutonium carbides was reduced to routine practice in glove boxes with a precision near 1% for samples weighing between 200 to 1000 mg and with carbon contents between 1 to 5 wt%. PuN and UN were found to form solid solutions in all proportions. X-ray powder pattern studies indicated that the region between PuO/sub 1.0/ and PuO/sub 1.6/ in the Pu-- O phase diagram is a two-phase field of PuO and BETA Pu/sub 2/O/sub 3/. The synthesis of plutonium suboxides by carbon reduction of PuO/sub 2/ was studied. An increase in the lattice parameters of several oxide and carbide compounds of plutonium was observed during the course of standing at room temperature. The rates of expansion ranged from 0.085 x 10/sup -3/ to 1.16 x 10/sup -3/ ( DELTA a/a/sub o/) per 100 days. Arc melting of PuO/sub 2/ pellets in argon, followed by air oxidation at 800 deg C produced >99% TD material with an O/Pu ratio of 2.00. PuO/ sub 2/-- MgO mixtures appeared to form a simple binary eutectic system. A method was developed for preparation of UOS by electrodeposition from a molten salt solution. The UOS decomposed above its melting point (1900 plus or minus 50 deg C) into two other phases. Significant changes in the microhardness and lattice dimensions of US occurred after a low neutron exposure. Crystallite growth in UO/sub 2/-50 wt% W cermets was studied in the electron microscope by cine micrography. UO/sub 2/--W cermets were replicated with an alpha sensitive emulsion. The autoradiographs were examined by transmission electron microscopy. Rapid oxidation of UN in a UN--50 wt% W cermet was observed during controlled reaction in the electron microscope. Thin sections of UO/sub 2/ crystals were prepared for electron microscopy. UO/sub 2/ single crystals and UO/sub 2/ cermets for basic studies were prepared. A 50 pound lot of high purity arc-fused UO/sub 2/ was prepared, characterized and sent to Savannah River Laboratory for testing in the HWCTR. The monometric measurement of evolved H/sub 2/, produced by reaction of HCl with uranium, was used to analyze for free uranium metal in UO/ sub 2/. Radial flow thermal conductivity measurements of UO/sub 2/ single crystals relative to polycrystals are in progress. Preliminary results indicated a substantial increase in single crystal conductivity above 1600 deg C that may result from radiant transfer. Metallic inclusions of uranium, which may significantly affect the physical properties of UO/sub 2/, are formed in UO/sub 2/ fuel elements irradiated with central temperatures high enough to produce extensive columnar grain growth. Improved autoradiographs of irradiated UO/sub 2/ fuel rods show that only a portion of the columnar grain region is depleted of fission products and that a high concentration of fission products is located just outside the depleted band. A lightly irradiated sample of polycrystalline UO/sub 2/ retained 83 at.% of the total fission products and 95% of total radioactivity during explosive melting. UO/sub 2/ microcores, useful in fundamental studies, were extracted from several types of UO/sub 2/ by use of ultrasonic drilling techniques. A computer program in FORTRAN language for use in calculating the interplanar spacings of crystals from their line positions on x-ray powder pattern films was written and made operational. Additional evidence supported the hypothesis that the radial limit of melting in irradiated ceramic fuels corres nu onds to the radial limit of subgrain structure. The heat transfer rate through molten UO/sub 2/ was estimated to be 0.05 watts/ cm C. (auth)},
doi = {},
journal = {},
number = ,
volume = ,
place = {Country unknown/Code not available},
year = {1963},
month = {10}
}

Technical Report:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that may hold this item. Keep in mind that many technical reports are not cataloged in WorldCat.

Save / Share: