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/sup 238/Pu fuel form processes. Quarterly report, July-September 1982

Description: Fracture tendency of pellets after final heat treatment or vacuum outgassing during production has been reviewed. A statistical analysis of fracture tendency has revealed a cyclical trend. The period of the cycle on average is about every 50 pellets. Phosphorus is considered detrimental to the impact behavior of iridium. Tests show that phosphorus is easily picked up by PuO/sub 2/ through a variety of pathways and is difficult to remove by heating techniques such as are possible in the PuFF Facility. High-temperature impact ductility of CVS welds may be related to grain structure in the weld centerline. Heating at 1500/sup 0/C causes finely structured thorium-bearing patches on grain surfaces in welds to agglomerate into particles. Heating at 2000/sup 0/C appears to heal grain boundary cavities and pores. High-temperature creep has been identified as another mechanism for producing grain boundary cavities that cause weld-quench cracking. 17 figures, 11 tables.
Date: December 1, 1982
Partner: UNT Libraries Government Documents Department

/sup 238/Pu fuel form processes. Bimonthly report, November-December 1979

Description: Progress in the Savannah River Laboratory's /sup 238/Pu Fuel Form Program is summarized. Full-scale fabrication tests continued in the Plutonium Experimental Facility (PEF) with the successful fabrication of seven additional GPHS pellets. Three pellets (GPHS Pellets 14, 15, and 16) were fabricated at off-centerline conditions to help define process limits for production of GPHS fuel pellets in the Plutonium Fuel Fabrication (PuFF) Facility. Two additional limit-test pellets (GPHS Pellets 12 and 13) previously hot pressed underwent final heat treatment. Two pellets (GPHS Pellets 17 and 18) were fabricated at centerline conditions as part of the effort to have Savannah River Laboratory (SRL) GPHS pellets impact tested at LASL. All seven pellets remained integral and demonstrated excellent dimensional stability during final heat treatment. However, the quality of those pellets fabricated at centerline conditions was superior to those that were fabricated as part of the limit tests.
Date: November 1, 1980
Partner: UNT Libraries Government Documents Department

/sup 238/Pu fuel form processes. Quarterly report, January-March 1980

Description: Progress in the general purpose heat source GPHS process demonstration program is reported. Fuel-Scale fabrication tests continued in the Plutonium Experimental Facility (PEF) with the successful fabrication of five additional GPHS pellets (GPHS Pellets 19 to 23). Characterization of GPHS Pellets 17 and 19 to 23 has been completed. Integral pellets of generally good quality continued to be produced in recent fabrication tests at SRL; however, pellets showed more cracks than did centerline pellets. GPHS Pellets 18, 20, and 22, which were fabricated under SRL centerline conditions, were packaged and shipped to LANSL for impact testing. Pre-test inspection at LANSL revealed that all pellets retained the integrity and dimensional stability observed at Savannah River. Direct-strike precipitation of Pu(III) oxalate would eliminate a number of powder-conditioning steps and, therefore, appears to be a safer and simpler method of producing feed for direct fabrication of /sup 238/PuO/sub 2/ fuel forms, according to recent SRL experiments. Powder characterization studies suggested that a mixture of sintered and unsintered rosettes made by direct-strike Pu(III) oxalate precipitation might be successfully substituted for the shards currently being used for fabrication of GPHS fuel forms.
Date: March 1, 1981
Partner: UNT Libraries Government Documents Department

Review of potential host rocks for radioactive waste disposal in the southeast United States-Southern Piedmont subregion

Description: A literature study was conducted on the geology of the Southern Piedmont province in the states of Maryland, Virginia, North Carolina, South Carolina, and Georgia. The purpose was to identify geologic areas potentially suitable for containment of a repository for the long-term isolation of solidified radioactive waste. The crystalline rocks of the Southern Piedmont province range in age from Precambrian to Paleozoic, and are predominantly slates, phyllites, argillites, schists, metavolcanics, gneisses, gabbros, and granites. These rock units were classified as either favorable, potentially favorable, or unfavorable as potential study areas based on an evaluation of the geologic, hydrologic, and geotechnical characteristics. No socio-economic factors were considered. Rocks subjected to multiple periods of deformation and metamorphism, or described as highly fractured, or of limited areal extent were generally ranked as unfavorable. Potentially favorable rocks are primarily the high-grade metamorphic gneisses and granites. Sixteen areas were classified as being favorable for additional study. These areas are primarily large igneous granite plutons as follows: the Petersburg granite in Virginia; the Rolesville-Castallia, Churchland, and Landis plutons in North Carolina; the Liberty Hill, Winnsboro, and Ogden plutons in South Carolina; and the Siloam, Elberton, and six unnamed granite plutons in Georgia.
Date: October 1, 1980
Partner: UNT Libraries Government Documents Department

Acoustic emission from hydrogen saturated Type 304L stainless steel

Description: Acoustic emission is attributed to energy release within a material body by localized plastic deformation or failure processes. The elastic stress waves may come from slip band formation, mechanical twinning, martensite transformation, or crack propagation. Each of these processes has slightly different acoustic characteristics allowing for easy identification. Acoustic emission was monitored during tensile tests of Type 304L austenitic stainless steel to explore the applicability of the technique to hydrogen-assisted fracture.
Date: January 1, 1978
Creator: Caskey, G.R. Jr.
Partner: UNT Libraries Government Documents Department

Experimental joule-heated ceramic melter for converting radioactive waste to glass

Description: A small electric melter was developed to implement studies for converting radioactive waste to glass at the Savannah River Laboratory (SRL). The ceramic-lined, joule-heated melter has been in operation for ten months. During this period, simulated, high-level-waste, calcined materials and frit were processed at rates of 2 to 15 g/min. The melt chamber is 7.6-cm wide, 22.9-cm long and 7.6-cm deep. The total power consumption is 3.5 KVA when the glass processing temperature is 1150/sup 0/C. A similar unit will be in operation in FY-1979 in the SRL high-level cells.
Date: January 1, 1978
Creator: Chismar, P.H.
Partner: UNT Libraries Government Documents Department

Exposure and temperature dependence of elongated blister formation in complex radiation environments

Description: Blistering of platinum alloy surfaces by /sup 252/Cf alpha particle and fission fragment radiations occurred at relatively low concentrations of implanted helium during exposures at room temperature as well as at 1000/sup 0/C. Distinctive configurations of the blisters resulting from transport of atoms displaced by the fission fragments persisted during the high temperature exposures. Post-exposure heating of specimens exposed at room-temperature produced no additional blistering until temperatures of 1300/sup 0/C were reached. Post-exposure heating of 1000/sup 0/C blistered specimens produced only thermal etching effects. The low helium concentrations required for blistering and the distinctive blister configurations produced by /sup 252/Cf exposures suggest a unique mode of surface distortion resulting from the large number and highly localized distributions of atom displacements generated by /sup 252/Cf fission fragments. Such conditions may not be duplicated in the He-ion and fast neutron radiation environments of fusion reactors.
Date: January 1, 1981
Creator: McDonell, W.R.
Partner: UNT Libraries Government Documents Department

Geology and mineral resources of the Florence, Beaufort, Rocky Mount, and Norfolk 1/sup 0/ x 2/sup 0/ NTMS quadrangles. National Uranium Resource Evaluation program

Description: This document provides geologic and mineral resources data for previously-issued Savannah River Laboratory hydrogeochemical and stream sediment reports of the Beaufort, Florence, Norfolk, and Rocky Mount 1/sup 0/ x 2/sup 0/ National Topographic Map Series quadrangles in the southeastern United States. This report is issued in draft form, without detailed technical and copy editing. This was done to make the report available to the public before the end of the National Uranium Resource Evaluation program.
Date: August 1, 1982
Creator: Harris, W.B.
Partner: UNT Libraries Government Documents Department

Design bases for U. S. Department of Energy storage basin

Description: Bases were developed for the conceptual design of a water basin to store 5000 MT of irradiated light water reactor fuel. The basin, which could be operational by 1983, is designed to receive over 2000 MT per year of spent fuel and to provide interim storage of US and some foreign fuel in support of U.S. policy of receiving and taking title to spent fuel rather than reprocessing this fuel. The bases for various design decisions are discussed.
Date: January 1, 1978
Creator: King, F.D.
Partner: UNT Libraries Government Documents Department

Evaluation of a gamma monitor for survey of waste for shallow land burial

Description: During an 8-month evaluation of the Gamma Waste Monitor, 54 reactor-area scrap casks and 8 shipments from the separations areas containing fission product activities were measured. It was concluded that a more accurate and detailed record of radionuclide burials can be obtained by using this monitor than by present methods of estimation. The monitor will significantly improve records and will provide a more reliable data base for evaluating long-term effects on the environment. Although the monitor can directly detect only gamma-emitting radionuclides, a method is proposed in this report for estimating the total radionuclide distribution by association with radionuclides that are detected. The monitor cannot assay transuranic waste and tritium. In many cases where the radionuclide emits two gamma rays of different energy, corrections for attenuation at other photon energies can be empirically derived from the spectrum. Complete details are included in the Appendix for operating the facility. Experimental data gathered during the evaluation period are contained in the body of this report.
Date: December 1, 1978
Creator: Hoy, J.E.
Partner: UNT Libraries Government Documents Department

The effect of helium from tritium decay on the gas-solid equilibrium constant for La-Ni-Al tritides

Description: Change in the equilibrium vapor pressure over LaNi/sub 4.25/ Al/sub 0.75/ tritide with helium in-growth has been observed for helium concentrations up to 10,000 appm. The change is a decrease in pressure from about 500 torr to 90 torr at 80/degree/C. This decrease is believed to be associated with a crystal lattice expansion due to helium, and is similar to the plateau pressure decrease as function of aluminum concentration for the family of LaNi/sub 5-x/Al/sub x/ alloys with O < x < 1. Subsequent tritium cycling recovers the plateau pressure. These data suggest that helium has very short range diffusion for the time of these observations. 18 refs., 4 figs., 2 tabs.
Date: January 1, 1988
Creator: Walters, R.T.
Partner: UNT Libraries Government Documents Department

Environmental Transport Division. 1980 report

Description: Aquatic, atmospheric, and terrestrial studies and instrumentation developments are described in a series of articles. More details about specific studies are given in publications listed at the end of the report.
Date: March 1, 1981
Creator: Adams, S.E.; Fliermans, C.B.; Garrett, A.J. & Halverson, J.E.
Partner: UNT Libraries Government Documents Department

Ensuring the validity of calculated subcritical limits

Description: The care taken at the Savannah River Laboratory and Plant to ensure the validity of calculated subcritical limits is described. Close attention is given to ANSI N16.1-1975, ''Validation of Calculational Methods for Nuclear Criticality Safety.'' The computer codes used for criticality safety computations, which are listed and are briefly described, have been placed in the SRL JOSHUA system to facilitate calculation and to reduce input errors. A driver module, KOKO, simplifies and standardizes input and links the codes together in various ways. For any criticality safety evaluation, correlations of the calculational methods are made with experiment to establish bias. Occasionally subcritical experiments are performed expressly to provide benchmarks. Calculated subcritical limits contain an adequate but not excessive margin to allow for uncertainty in the bias. The final step in any criticality safety evaluation is the writing of a report describing the calculations and justifying the margin.
Date: January 1, 1977
Creator: Clark, H.K.
Partner: UNT Libraries Government Documents Department

Reprocessing of nuclear fuels at the Savannah River Plant

Description: For more than 30 years, the Savannah River Plant (SRP) has been a major supplier of nuclear materials such as plutonium-239 and tritium-3 for nuclear and thermonuclear weapons, plutonium-238 for space exploration, and isotopes of americium, curium, and californium for use in the nuclear research community. SRP is a complete nuclear park, providing most of the processes in the nuclear fuel cycle. Key processes involve fabrication and cladding of the nuclear fuel, target, and control assemblies; rework of heavy water for use as reactor moderator; reactor loading, operation, and unloading; chemical recovery of the reactor transmutation products and spent fuels; and management of the gaseous, liquid, and solid nuclear and chemical wastes; plus a host of support operations. The site's history and the key processes from fabrication of reactor fuels and targets to finishing of virgin plutonium for use in the nuclear weapons complex are reviewed. Emphasis has been given to the chemistry of the recovery and purification of weapons grade plutonium from irradiated reactor targets.
Date: October 4, 1986
Creator: Gray, L.W.
Partner: UNT Libraries Government Documents Department

Reprocessing RERTR silicide fuels

Description: The Reduced Enrichment Research and Test Reactor Program is one element of the United States Government's nonproliferation effort. High-density, low-enrichment, aluminum-clad uranium silicide fuels may be substituted for the highly enriched aluminum-clad alloy fuels now in use. Savannah River Laboratory has performed studies which demonstrate reprocessability of spent RERTR silicide fuels at Savannah River Plant. Results of dissolution and feed preparation tests and solvent extraction processing demonstrations with both unirradiated and irradiated uranium silicide fuels are presented.
Date: May 1, 1983
Creator: Rodrigues, G.C. & Gouge, A.P.
Partner: UNT Libraries Government Documents Department

Free convection in a partially submerged fluid loop

Description: Several natural convection loop systems are studied in order to determine the operational characteristics for a multiple loop container which is used to cool failed nuclear reactor assemblies. Both analytical and experimental studies were undertaken to examine flow in both circular and rectangular flow loops. It was found that when a circular loop is heated at the bottom and cooled at the top, recirculation cells form at all input power fluxes. At fluxes between 0.1 W/cm/sup 2/ and 0.7 W/cm/sup 2/ the cells caused flow oscillations and reversals. With the circular loop heated from the side, no recirculation cells were observed at the power fluxes up to 1.5 W/cm. Boiling did not occur in the circular loop. For a rectangular loop heated and cooled on its vertical sides, no recirculation cells or flow reversals were seen. At input power fluxes above 1.2 W/cm/sup 2/, periodic boiling in the heated side caused flow oscillations.
Date: January 1, 1982
Creator: Britt, T.E. & Wood, D.C.
Partner: UNT Libraries Government Documents Department

Fracture of Fe--Cr--Mn austenitic steel

Description: Tensile tests of Tenelon (U.S. Steel), a nitrogen-strengthened iron-base alloy containing 18% chromium and 15% manganese, demonsterated that cleavage fracture can occur in some austenitic steels and is promoted by the presence of hydrogen. Tensile failure of Tenelon at 78/sup 0/K occurred with no detectable necking at low strain levels. The fracture surface contained cleavage facets that lay along coherent twin boundaries oriented transversely to the tensile axis. Charging gaseous hydrogen at 679 MPa pressure and 650/sup 0/K had no significant effect on the mechanical behavior or fracture mode at 78/sup 0/K, but raised the ductile-to-brittle transition temperature from less than 200/sup 0/K to about 250/sup 0/K.
Date: January 1, 1979
Creator: Caskey, G. R., Jr.
Partner: UNT Libraries Government Documents Department

Savannah River Plant 200 Area technical manual. Part SP. Processing of Np/sup 237/ and Pu/sup 238/

Description: This manual covers the technology involved in the 200 Area process for the recovery of Np/sup 237/ from certain aqueous waste streams in the separations plants, for the recovery of NP/sup 237/ and Pu/sup 238/ from irradiated NpO/sub 2/-Al slugs and for the fabrication of NpO/sub 2/-Al slugs. The manual contains sections on the fundamental chemistry, the primary recovery of Np by ion exchange, the decontamination of Np by ion exchange, the processing of NpO/sub 2/-Al targets, the separation and purification of Np/sup 237/ and Pu/sup 238/, the finishing of Np, the preparation of NpO/sub 2/, the disposal of spent resin, and the safety aspects of the handling of hydrazine. The section on the fabrication of NpO/sub 2/-Al slugs will be added later. 76 refs., 22 figs.
Date: January 3, 1963
Creator: Hill, A.J. (comp.)
Partner: UNT Libraries Government Documents Department

JOSHUA modular data-based system. [For design and analysis of reactor charges; in FORTRAN IV for IBM computers]

Description: The JOSHUA modular data-based system was developed at Savannah River primarily for the design and analysis of nuclear reactor charges. It is a very large computational system (over 300,000 FORTRAN source statements), and was made possible only by a carefully conceived and executed modular design approach. The JOSHUA modular approach and some of its benefits and shortcomings are described. 4 figures.
Date: January 1, 1978
Creator: Honeck, H.C. & Anderson, M.M.
Partner: UNT Libraries Government Documents Department

Limnological database for Par Pond: 1959 to 1980

Description: A limnological database for Par Pond, a cooling reservoir for hot reactor effluent water at the Savannah River Plant, is described. The data are derived from a combination of research and monitoring efforts on Par Pond since 1959. The approximately 24,000-byte database provides water quality, primary productivity, and flow data from a number of different stations, depths, and times during the 22-year history of the Par Pond impoundment. The data have been organized to permit an interpretation of the effects of twenty years of cooling system operations on the structure and function of an aquatic ecosystem.
Date: March 1, 1981
Creator: Tilly, L.J.
Partner: UNT Libraries Government Documents Department

Reference thorium fuel cycle

Description: The purpose of this report is to define a preliminary thorium fuel cycle to serve as a common basis for beginning development work on October 1, 1977, at participating ERDA laboratories, universities, and commercial facilities. Characteristics of the reference fuel cycle for the Thorium Fuel Cycle Technology (TFCT) program are: fissile uranium will be denatured by mixing with /sup 238/U; chemical processing plant design will be based on the assumption that plants are located in secure areas; plutonium will be recycled within these secure areas; thorium will be recycled with recovered uranium and plutonium; the head end of the chemical processing plant will handle a variety of core and blanket fuel assembly designs for light water reactors and heavy water reactors; the fuel form will be a homogeneous mixture of uranium and thorium oxide powders pressed into pellets; fuel cladding will be Zircaloy; and MgO will be added to the fuel to improve the thorium dissolving characteristics. (LK)
Date: September 1, 1977
Creator: Driggers, F.E.
Partner: UNT Libraries Government Documents Department

Direct fabrication of /sup 238/PuO/sub 2/ fuel forms

Description: The current process for the fabrication of /sup 238/PuO/sub 2/ heat sources includes precipitation of small particle plutonium oxalate crystals (4 to 6 ..mu..m diameter), a calcination to PuO/sub 2/, ball milling, cold pressing, granulation (60 to 125 ..mu..m), and granule sintering prior to hot pressing the fuel pellet. A new two-step direct-strike Pu(III) oxalate precipitation method which yields mainly large well-developed rosettes (50 to 100 ..mu..m diameter) has been demonstrated in the laboratory and in the plant. These large rosettes are formed by agglomeration of small (2 to 4 ..mu..m) crystals, and after calcining and sintering, were directly hot pressed into fuel forms, thus eliminating several of the powder conditioning steps. Conditions for direct hot pressing of the large heat-treated rosettes were determined and a full-scale General Purpose Heat Source pellet was fabricated. The pellet had the desired granule-type microstructure to provide dimensional stability at high temperature. 27 figures.
Date: July 1, 1982
Creator: Burney, G.A. & Congdon, J.W.
Partner: UNT Libraries Government Documents Department

Dispersion of radioactive pollutant in a tornadic storm

Description: A three-dimensional numerical model is used to calculate ground-level air concentration and deposition (due to precipitation scavenging) after a hypothetical tornado strike at a plutonium fabrication facility in Pennsylvania. Plutonium particles less than 10 ..mu..m in diameter are assumed to be lifted into the tornadic storm cell by the vortex. The rotational characteristics of the tornadic storm are embedded within the larger mesoscale flow of the storm system. The design-basis translational wind values are based on probabilities associated with existing records of tornado strikes in the vicinity of the plant site. Turbulence exchange coefficients are based on empirical values deduced from experimental data in severe storms and from theoretical assumptions obtained from the literature. The quasi-Lagrangian method of moments is used to model the transport of concentration within a grid cell volume. In all case studies, the effects of updrafts and downdrafts, coupled with scavenging of the particulates by precipitation, account for most of the material being deposited within 20 to 45 km downwind of the plant site. Ground-level isopleths in the x-y plane show that most of the material is deposited behind and slightly to the left of the centerline trajectory of the storm. Approximately 5% of the material is dispersed into the stratosphere and anvil section of the storm.
Date: May 1, 1981
Creator: Pepper, D.W.
Partner: UNT Libraries Government Documents Department

Dispersion model for airborne particulates inside a building

Description: An empirical model has been developed for the spread of airborne radioactive particles after they are released inside a building. The model has been useful in performing safety analyses of actinide materials facilities at the Savannah River Plant (SRP), operated for the US Department of Energy by the Du Pont Company. These facilities employ the multiple-air-zone concept; that is, ventilation air flows from rooms or areas of least radioactive material hazard, through zones of increasing hazard, to a treatment system. A composite of the data for dispersion of airborne activity during 12 actual case incidents at SRP forms the basis for this model. These incidents occurred during approximately 90 plant-years of experience at SRP with the chemical and metallurgical processing of purified neptunium and plutonium after their recovery from irradiated uranium. The model gives ratios of the airborne activity concentrations in rooms and corridors near the site of the release. All data are normalized to the data from the air sampler nearest the release point. The model can be applied in predicting airborne activity concentrations from particulate releases elsewhere, if the facility in question has similar features of floor plan, air velocity, and air flow direction. The multiple-air-zone concept has been applied to many designs of nuclear facilities as a safety feature to limit the spread of airborne activity from a release. The model illustrates the limitations of this concept: it predicts an apparently anomalous behavior of airborne particulates; namely, a small migration against the flow of the ventilation air. The following phenomena are suggested as possible mechanisms for this migration: eddy currents in the air flow; leaks of ventilation air between zones; open doors; movement of personnel during an incident; inadequate flow of ventilation air; and thermal gradients. 2 references, 12 figures, 4 tables.
Date: July 1, 1984
Creator: Perkins, W.C. & Stoddard, D.H.
Partner: UNT Libraries Government Documents Department