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AN EVALUATION OF DATA ON NUCLEAR CARBIDES

Description: Data on the properties, constitution, compatibility, radiation behavior, fabrication, preparation, storage, and handling of uranium, thorium, and plutonium carbides are reviewed. 187 references. (C.J.G.)
Date: May 31, 1960
Creator: Rough, F.A. & Chubb, W. eds.
Partner: UNT Libraries Government Documents Department

THE THERMAL EXPANSION OF PuC AND UC-PuC SOLID SOLUTION

Description: For additional details see report LA-2788. Thermal expansion characteristics for arc melted plutonium-carbon alloys containing 41.1, 43.2, 44.8, 45.4, 45.8 at.% carbon and for U/sub 0.87/Pu/sub 0.13/C have been determined between room temperature and 900 deg C. The average coefflcients of linear thermal expansion for a singie phase alloy conthining 45.8 at.% carbon and for single phase U/sub 0.87/Pu/sub 0.13/C are presented as well as results pertaining to the plutonium-carbon phase diagram. A mechanism has been suggested to explain the unusual contraction that was observed in the dilatometric curves for the alloys that contained 43.2, 44.9, and 45.4 at.% carbon. (auth)
Date: March 12, 1963
Creator: Ogard, A. E.; Land, C. C. & Leary, J. A.
Partner: UNT Libraries Government Documents Department

CARBIDE FUEL DEVELOPMENT. Progress Report, April 1, 1962 to June 30, 1962

Description: All of the UC-PuC powder required for the natural U irradiation specimens, and some of the powder required for the enriched U irradiation specimens was synthesized. All of the natural uranium UC-PuC pellets required were fabrlcated by pressing and sintering, and are being ground to size. The average density of the (U/sub 0.8/Pu/sub 0.2/)C/sub 0.95/ pellets was 12.54 g/cm/ sup 3/ (92.4% of theoretical) and of the (U/sub 0.08/Pu/sub 0.2/)C/sub 0.95/ plus 0.1 wt% Ni pellets was 13.15 g/cm/sup 3 (96.8% of theoretical). Cored pellets were fabricated by pressing and sintering, and the holes are being reamed to size to provide a place for an accurately located central thermocouple. The initial clad irradiation specimens were assembled, and the assembly of the first irradiation capsule was started. The test reactor choice was narrowed to ETR and GETR. The GETR is recommended for at least four of the six capsules. (auth)
Date: August 10, 1962
Creator: Strasser, A. & Taylor, K.
Partner: UNT Libraries Government Documents Department

CARBIDE FUEL DEVELOPMENT. Progress Report, January 1, 1962 to March 31, 1962

Description: Reproducibly high density UC-PuC pellets containing minor amounts of (U,Pu)/sub 2/C/sub 3/ were made with nickel sintering aid. Average densities of 95% and maximum densities of 96.6% of theoretical were obtained. High density, singlephase UC-PuC pellets were made by sintering at high temperatures. Densities of 94% of theoretical appear to be attainable. Improved identification of microstructural constituents was made by means of metallography, x-ray diffraction, and microprobe analysis. Development of specialized chemical analysis techniques continued. The post-irradiation examination of the UC specimens was completed. Mass spectrometer analysis showed that 0.4% of the fission gases was released. Metallographic examination of the UC did not reveal any channges in structure. Metallographic examination of the metal specimen parts that were in contact with UC was completed. No evidence for interaction with niobium and slight evidence for interaction with stainless steel was found. The latter was not deleterious. Perturbation factors were calculated for the UC- PuC experiments. Negotiations continued, in order to select the most suitable test reactor. (auth)
Date: May 28, 1962
Creator: Strasser, A. & Taylor, K.
Partner: UNT Libraries Government Documents Department

CARBIDE FUEL DEVELOPMENT. Progress Report, September 15, 1961 to December 31, 1961

Description: Single phase, solid solution, UC-PuC powder was synthesized reproducibly from a mixture of the oxides and carbon. A simple method of monitoring the reaction was developed. UC-PuC-0.1 wt% Ni pellets of 93% theoretical density were made reproducibly, with some samples as high as 95% of theoretical denstty. The pellets contain minor amounts of (U,Pu)/sub 2/C/sub 3/ most of the time. Efforts to make reproducible 95%, single-phase material are under way. Microprobe analysis of UC-0.1 wt% Ni specimens was completed. A second phase apparently promoted by the nickel was shown to be probably U/sub 2/C/sub 3/. Essentially all the nickel was found in solution in the matrix UC. The postirradiation examination of the UC specimens completed to date showed that the UC pellets had the same appearance after irradiation as before irradiation. Their dimensional changes were very slight (1.4% volume increase). Fission gas release was low and within the sensitivity of the initial measurement (3.5% max). The average specimen burnup was 18,500 MW-d/tonne at an average maximum fuel temperature of 760 deg C (1400 deg F). The plutonium facilities continued satisfactory operation at zero contamination level. (auth)
Date: February 1, 1962
Creator: Strasser, A. & Taylor, K.
Partner: UNT Libraries Government Documents Department

Experience related to the safety of advanced LMFBR fuel elements

Description: Experiments and experience relative to the safety of advanced fuel elements for the liquid metal fast breeder reactor are reviewed. The design and operating parameters and some of the unique features of advanced fuel elements are discussed breifly. Transient and steady state overpower operation and loss of sodium bond tests and experience are discussed in detail. Areas where information is lacking are also mentioned. (auth)
Date: July 1, 1975
Creator: Kerrisk, J.F.
Partner: UNT Libraries Government Documents Department

Micro Ion Source Program NA22 Plutonium Detection Portfolio Final Report

Description: The purpose of the micro ion source program was to enhance the performance of thermal ionization mass spectrometry (TIMS) for various actinides and fission products. The proposal hypothesized that when ions are created at the ion optic center of the mass spectrometer, ion transmission is significantly increased and the resulting ion beam is more sharply focused. Computer modeling demonstrated this logic. In order to prove this hypothesis it was first necessary to understand the chemistry and physics governing the particular ion production process that concentrates the emission of ions into a small area. This has been achieved for uranium and technetium, as was shown in the original proposal and the improvement of both the beam transmission and sharpness of focus were proven. Significantly improved analytical methods have been developed for these two elements based upon this research. The iodine portion of the proposal turned out to be impractical due to volatility of iodine and its compounds. We knew this was a possibility prior to research and we proceeded anyway but did not succeed. Plutonium is a potential option, but is not quite up to the performance level of resin beads. Now, we more clearly understand the chemical and physical issues for plutonium, but have not yet translated this knowledge into improved analytical processes. The problems are that plutonium is considerably more difficult to convert to the required intermediate species, plutonium carbide, and the chemical method we developed that works with uranium functions only moderately well with plutonium. We are of the opinion that, with this knowledge, similar progress can be made with plutonium.
Date: September 1, 2010
Creator: Delmore, James E.
Partner: UNT Libraries Government Documents Department