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Interaction of noble-metal fission products with pyrolytic silicon carbide

Description: Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain layers of pyrolytic carbon and silicon carbide, which act as a miniature pressure vessel and form the primary fission product barrier. Of the many fission products formed during irradiation, the noble metals are of particular interest because they interact significantly with the SiC layer and their concentrations are somewhat higher in the low-enriched uranium fuels currently under consideration. To study fission product-… more
Date: January 1, 1982
Creator: Lauf, R. J. & Braski, D. N.
Partner: UNT Libraries Government Documents Department
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Development of an extended-burnup Mark B design. First semi-annual progress report, July-December 1978. Report BAW-1532-1. [PWR]

Description: The primary objective of this program is to develop and demonstrate an improved PWR fuel assembly design capable of batch average burnups of 45,000-50,000 MWd/mtU. To accomplish this, a number of technical areas must be investigated to verify acceptable extended-burnup fuel performance. This report is the first semi-annual progress report for the program, and it describes work performed during the July-December 1978 time period. Efforts during this period included the definition of a preliminar… more
Date: October 1, 1979
Partner: UNT Libraries Government Documents Department
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Hot cell studies of tritium removal from and dissolution of an irradiated thoria fuel

Description: Tritium removal and dissolution studies on an irradiated thoria-based fuel were conducted in the High Level Caves at the Savannah River Laboratory (SRL). The objectives of these studies were to define the effects of key process-related parameters on tritium evolution and subsequent dissolution. The test program at SRL determined the effects on tritium removal of particle size, heating temperature, oxidation, and agitation. ThO/sub 2//UO/sub 2/ (95%/5%) fuel from the Elk River Reactor, irradiate… more
Date: January 1, 1980
Creator: Pickett, J.B.
Partner: UNT Libraries Government Documents Department
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Some Scoping Experiments for a Space Reactor

Description: Some scoping experiments were performed to evaluate fuel performance in a lithium heat pipe reactor operating at a nominal 1500K heat pipe temperature. Fuel-coolant and fuel-coolant-clad relationships showed that once a failed heat pipe occurs temperatures can rise high enough so that large concentrations of uranium can be transported by the vapor phase. Upon condensation this uranium would be capable of penetrating heat pipes adjacent to the failed pipe. The potential for propagation of failur… more
Date: July 7, 1983
Creator: Alexander, C. A. & Ogden, J. S.
Partner: UNT Libraries Government Documents Department
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Analysis of the thorium axial blanket experiments in the PROTEUS reactor

Description: An extensive program of reactor physics experiments in GCFR fuel pin lattices has been completed recently at the PROTEUS critical facility located at EIR laboratory in Switzerland. The PROTEUS reactor consists of a central test zone surrounded by a uranium buffer and thermal driver region. The test lattices included a PuO/sub 2//UO/sub 2/ fuel region with internal and axial blankets of UO/sub 2/, ThO/sub 2/, and thorium metal. Detailed analysis of the thorium-bearing lattices has been performed… more
Date: January 1, 1980
Creator: White, J.R.; Ingersoll, D.T. & Schmocker, U.
Partner: UNT Libraries Government Documents Department
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Thermodynamics of the Fuel Fragmentation Gas

Description: In the context of nuclear reactor safety studies, a program is in progress at ORNL whereby fuel-fragmentation situations are mocked up by the application of high-current capacitor discharges through solid UO/sub 2/ samples. The goal of the present work is to predict such quantities as the number of gas and liquid fragments and their energy distributions. The point of view adopted is that upon fragmentation, a cloud of UO/sub 2/ vapor is formed containing ''primeval'' liquid fragments which act … more
Date: January 1, 1977
Creator: Perez, R. B. & Alsmiller, R. G., Jr.
Partner: UNT Libraries Government Documents Department
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End of life fission product distributions in F-1 experiment fuel rods

Description: Fission product migration and end-of-life distributions were examined in the F-1 (X094) series of sealed, mixed-oxide fuel rods irradiated in the fast flux of EBR-II. Cesium, rubidium, iodine, and strontium data obtained from axial gamma scanning, mass spectrometry, and radiochemical analyses are presented. The results show significant migration of cesium, probably as both a volatile species and as the noble gas precursor. Cesium metal species leaving the fuel region accumulate predominately at… more
Date: May 1, 1980
Creator: Goodin, D. T.; Langer, S. & Bell, W. E.
Partner: UNT Libraries Government Documents Department
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Examination of fast reactor fuels, FBR analytical quality assurance standards and methods, and analytical methods development: Irradiation tests. Progress report, July 1--September 30, 1977. [PuO/sub 2/; UO/sub 2/]

Description: Information is presented concerning the examination of fast reactor fuels, FBR analytical quality assurance standards, and analytical methods development irradiation tests.
Date: November 1, 1977
Creator: Baker, R.D. (comp.)
Partner: UNT Libraries Government Documents Department
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Light water reactor fuel reprocessing: dissolution studies of voloxidized fuel

Description: Voloxidation is a proposed head-end process to remove tritium from irradiated LWR fuel by roasting the fuel in the presence of oxygen. The process oxidizes UO/sub 2/ to a fine U/sub 3/O/sub 8/ powder with high surface area for dissolution. Small-scale tests with irradiated Robinson, Oconee, and Saxton reactor fuels have been made to determine the dissolution behavior of both voloxidized and nonvoloxidized (UO/sub 2/) fuel. No significant technical problems were encountered in batch-dissolving o… more
Date: January 1, 1977
Creator: Johnson, D. R. & Stone, J. A.
Partner: UNT Libraries Government Documents Department
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Application of ultrasonic thermometry in LMFBR safety research

Description: Ultrasonic thermometry has many potential applications in reactor safety research, where extremely high temperatures and lack of visual access may preclude the use of conventional diagnostics. An application (the in-core molten fuel pool experiment) will be described in which thoriated tungsten ultrasonic thermometers were used to measure temperatures in UO/sub 2/ to incipient melt (2860/sup 0/). Each thermometer included five sensor elements 10 mm long, providing five temperatures within the U… more
Date: January 1, 1977
Creator: Carlson, G. A.; Sullivan, W. H. & Plein, H. G.
Partner: UNT Libraries Government Documents Department
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Nuclear materials research progress reports for 1979

Description: Research is presented concerning iodide stress corrosion cracking of zircaloy, self-diffusion of oxygen in hypostoichiometric urania, surface chemistry of epitaxial silicon deposition by thermal cracking of silane, kinetics of laser pulse vaporization of UO/sub 2/, gas laser model for laser induced evaporation, solubility of hydrogen in uranium dioxide, thermal gradient migration of metallic inclusions in UO/sub 2/, molecular beam studies of atomic hydrogen reduction of oxides, and thermal grad… more
Date: December 1, 1979
Creator: Olander, D.R.
Partner: UNT Libraries Government Documents Department
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Voloxidation studies with UO/sub 2/ reactor fuels

Description: Voloxidation was studied experimentally in small-scale laboratory tests with irradiated UO/sub 2/ reactor fuels. The present study developed new data on the effects on the voloxidation reaction of hull length, oxygen concentration, temperature, agitation, fuel density, and fuel type and burnup. The reaction was studied by measuring weight gains, yields of U/sub 3/O/sub 8/, product densities and particle-size distributions, reaction rates, tritium release, and behavior of other off-gases (/sup 1… more
Date: January 1, 1980
Creator: Stone, J A
Partner: UNT Libraries Government Documents Department
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Helium/solid powder O-ring leakage correlation experiments using a radiotracer

Description: UO/sub 2/ definitely leaked past the O-ring in three of the tests confirming the major results of the previous work. Continuous leakage at these levels may require additional precautions under present regulatory policies. The mechanism and the time and particle size dependence for the leakage are not known, but there is some indication leakage is more likely at low temperatures. It is possible leakage is due to movement of the O-ring during temperature or pressure cycling at the beginning or en… more
Date: January 1, 1984
Creator: Bild, R. W.; Leisher, W. B.; Weissman, S. H. & Seya, M.
Partner: UNT Libraries Government Documents Department
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Voloxidation and dissolution of irradiated plutonium recycle fuels

Description: Voloxidation removed > 99.4% of the tritium in the fuels tested (LWR recycled fuels containing /sup 239/Pu). Voloxidation increased the amount of insoluble residue by roughly a factor of two. Voloxidation increased the amount of plutonium in the insoluble residue by factors of 4 to 5. Voloxidation made the insoluble plutonium much harder to dissolve.
Date: January 1, 1980
Creator: Cadieux, J.R. & Stone, J.A.
Partner: UNT Libraries Government Documents Department
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Tests of a Higgins contactor for the engineering-scale resin loading of uranium

Description: The loading of uranium on weak-acid ion exchange resin is a basic step in the production of fuel particles for high-temperature gas-cooled reactors (HTGRs). In the work reported here, an engineering-scale continuous resin loader (2-in.-ID Higgins contactor) was tested with existing engineering-scale process equipment. The Higgins contactor was first successfully used to convert Na/sup +/-form resin to the H/sup +/-form; then it was evaluated as a uranium loader. Results show that the 2-in.-ID H… more
Date: January 1, 1978
Creator: Spence, R. D. & Haas, P. A.
Partner: UNT Libraries Government Documents Department
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Fuel systems for compact fast space reactors

Description: About 200 refractory metal clad ceramic fuel pins have been irradiated in thermal reactors under the 1200 K to 1550 K cladding temperature conditions of primary relevance to space reactors. This paper reviews performance with respect to fissile atom density, operating temperatures, fuel swelling, fission gas release, fuel-cladding compatibility, and consequences of failure. It was concluded that UO/sub 2/ and UN fuels show approximately equal performance potential and that UC fuel has lesser po… more
Date: December 1, 1983
Creator: Cox, C.M.; Dutt, D.S. & Karnesky, R.A.
Partner: UNT Libraries Government Documents Department
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Effect of pressure on the transient swelling rate of oxide fuel. [LMFBR]

Description: An analysis of the transient swelling rate of oxide fuel, based on fission-gas bubble conditions calculated with the FRAS3 code, has been developed and implemented in the code. The need for this capability arises in the coupling of the FRAS3 fission-gas analysis code to the FPIN fuel-pin mechanics code. An efficient means of closely coupling the calculations of swelling strains and stresses between the modules is required. The present analysis provides parameters that allow the FPIN calculation… more
Date: April 1, 1982
Creator: Gruber, E.E.
Partner: UNT Libraries Government Documents Department
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Fuel Utilization Improvement in PWRs Using the Denatured /sup 233/U-Th Cycle

Description: A number of changes in PWR core design and/or operating strategy were evaluated to assess the fuel utilization improvement achievable by their implementation in a PWR using thorium-based fuel and operating in a recycle mode. The reference PWR for this study was identical to the B and W Standard Plant except that the fuel pellets were of denatured (/sup 233/U//sup 238/U-Th)O/sub 2/. An initial scoping study identified the three most promising improvement concepts as (1) a very tight lattice, (2)… more
Date: June 1, 1980
Creator: Jones, H. M.; Schwenk, G. A.; Toops, E. C. & Uotinen, V. O.
Partner: UNT Libraries Government Documents Department
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First in-core molten fuel pool experiment. [LMFBR]

Description: If during a LMFBR accident a fuel debris bed is not adequately cooled by overlying sodium and dryout occurs, then the fuel would heat up and melt. Molten fuel pools are of concern due to their potential for ablation of the supporting structure and possible penetration of the reactor vessel. The major goal of the molten fuel pool program has been to develop a versatile experiment in which heat flux and structural ablation could be studied using real materials under typical temperature and heatin… more
Date: January 1, 1977
Creator: Plein, H.G. & Carlson, G.A.
Partner: UNT Libraries Government Documents Department
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Catalysis studies

Description: The New Research Initiatives Program (NRIP) project on catalysis in Los Alamos Scientific Laboratory (LASL) Group CMB-8 has made significant progress towards performing the first basic in situ experimental studies of heterogeneous catalysis on solid compound surfaces in a LEED-Auger system. To further understand the surface crystallography of a possible catalyst compound, LEED-Auger measurements were made on UO/sub 2/(approximately 100) vicinal surfaces. These (approximately 100) vicinal surfac… more
Date: November 1, 1977
Creator: Taylor, T. N. & Ellis, W. P.
Partner: UNT Libraries Government Documents Department
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Leaching studies using PNL 76-68 glass beads and UO/sub 2/ rods with Umtanum basalt and Nugget sandstone

Description: We have performed a 440-day leaching experiment, Bead Leach II, using PNL 76-68 glass beads and simulated uranium fuel rods in the presence of repository host rocks. The experiment was conducted in a single pass continuous-flow apparatus consisting of 72 channels. The experimental conditions were: 25/sup 0/C and 75/sup 0/C, flow rates of 1, 10, and 300 m1/d, and leachant solutions consisting of simulated basalt groundwater, brine, and sodium bicarbonate solution. The two host rocks studied were… more
Date: February 1, 1984
Creator: Bazan, F.; Rego, J.; Failor, R. & Coles, D.
Partner: UNT Libraries Government Documents Department
open access

Analysis of fuel relocation for the NRC/PNL Halden assemblies IFA-431, IFA-432, and IFA-513

Description: The effects of the thermally-induced cracking and subsequent relocation of UO/sub 2/ fuel pellets on the thermal and mechanical behavior of light-water reactor fuel rods during irradiation are quantified in this report. Data from the Nuclear Regulatory Commission/Pacific Northwest Laboratory Halden experiments on instrumented fuel assemblies (IFA) IFA-431, IFA-432, and IFA-513 are analyzed. Beginning-of-life in-reactor measurements of fuel center temperatures, linear heat ratings, and cladding … more
Date: April 1, 1980
Creator: Williford, R. E.; Mohr, C. L.; Lanning, D. D.; Cunningham, M. E.; Rausch, W. N. & Bradley, E. R.
Partner: UNT Libraries Government Documents Department
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