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SNAP I POWER CONVERSION SYSTEM BEARINGS DEVELOPMENT. Period covered: February 1, 1957 to June 30, 1959

Description: Development of bearings for use in the SNAP I power conversion system is described. Liquid mercury, lubricated hydrosphere bearings were selected. Design and performance data are given along with conclusions. (J.R.D.)
Date: June 20, 1960
Creator: Meredith, R.; Ono, G.Y. & Reemsnyder, D.C.
Partner: UNT Libraries Government Documents Department


Description: Materials Science and Technology has evaluated materials compatibility for the SNAP (Systems for Nuclear Auxiliary Power) fuel for containment within a 9975 packaging assembly for a shipping period of one year. The evaluation included consideration for potential for water within the convenience can, corrosion from water, galvanic corrosion, tape degradation, and thermal expansion risk. Based on a review of existing literature and assumed conditions, corrosion and/or degradation of the 304 stainless steel (SS) Primary Containment Vessel (PCV) and the 304 stainless steel convenience cans containing the SNAP fuel is not significant to cause failure during the 1 year time shipping period in the 9975 packaging assembly. However, storage beyond the 1 year shipping period has not been validated.
Date: November 14, 2006
Creator: Vormelker, P
Partner: UNT Libraries Government Documents Department

Experimental Criticality Benchmarks for SNAP 10A/2 Reactor Cores

Description: This report describes computational benchmark models for nuclear criticality derived from descriptions of the Systems for Nuclear Auxiliary Power (SNAP) Critical Assembly (SCA)-4B experimental criticality program conducted by Atomics International during the early 1960's. The selected experimental configurations consist of fueled SNAP 10A/2-type reactor cores subject to varied conditions of water immersion and reflection under experimental control to measure neutron multiplication. SNAP 10A/2-type reactor cores are compact volumes fueled and moderated with the hydride of highly enriched uranium-zirconium alloy. Specifications for the materials and geometry needed to describe a given experimental configuration for a model using MCNP5 are provided. The material and geometry specifications are adequate to permit user development of input for alternative nuclear safety codes, such as KENO. A total of 73 distinct experimental configurations are described.
Date: December 19, 2005
Creator: Krass, A.W.
Partner: UNT Libraries Government Documents Department


Description: Events in nuclear technology in 1961 are reviewed. The SL-1 incident, operation of the Yankee plant, restarting of the Dresden plant, contributions to the state of water reactor technology, transitions to private industry, dry criticality in EBR-II, startup of Los Alamos Molten Plutonium Reactor Experiment (LAMPRE), successful Tory tests, performance of SNAP reactor tests, and use of radioisotope-powered electric source in Transit IV A are discussed. (M.C.G.)
Date: November 1, 1961
Creator: Crewe, A.; Lawreski, S. & Spinrad, B.I.
Partner: UNT Libraries Government Documents Department


Description: A parametric investigation was made of a series of lowmolecular-weight, high-hydrogen-content compounds as propellants for nuclear-powered rockets. The chemical compounds include H/sub 2/, NH/sub 3/, H/sub 2/0, LiH, CH/sub 4/, and CH/ sub 3/OH. A two-part computational program was carried out for each compound; the results for methane are presented in both tabular and graphic form. The results of the first part of the program are presented in static form, that is, by the conventional Mollier diagram, in which specific enthalpy is plotted against specific entropy, with cross plots of temperature, pressure, and molecular weight. The results of the second part of the program are presented in dynamic form by a series of diagrams in which specific impulse is plotted against pressure, with cross plots of chamber temperature, exhaust temperature, and rocket-nozzle area. It was assumed that the propellant gas, starting with a nonzero chamber velocity, maintained instantaneous chemical equilibrium composition as it expanded isentropically through a de LavaI nozzle. (auth)
Date: August 1, 1961
Creator: Krieger, F.J.
Partner: UNT Libraries Government Documents Department


Description: Water testing of the RI-7C3 impeller in the Pt-2 test stand was completed. Still photographs and movies showed that a vortex was present on the leading edge tip of all blades at NPSH values up to 150 ft at all five test flows of 660, 680, 700, 720, and 740 gpm. Sound data showed a possible correlation with the cavitation performance of the impeller. The sound intensity increased until the tip vortices entered the flow channels and then decreased, reaching a minimum just before head loss occurred. As the head fell off, the sound intensity increased to a level as great or greater than the previous maximum. The TP-1 turbopump detail parts required to complete the assembly of the pump in its modified form were completed. The turbopump was assembled with the tested impeller and installed in the PT-4 water pump test stand. The pump was operated at low speed to assure proper seating of the seals and testing started. The PT-6 liquid metal test stand construction drawings were completed. Construction of the test stand was started by disassembling, cleaning, and acid pickling the entire loop piping. Reassembly of the test loop was started. (N.W.R.)
Date: January 15, 1964
Creator: Kulp, R.S. & Altieri, J.V.
Partner: UNT Libraries Government Documents Department


Description: A partial model of the reactor core was used, and demineralized water was circulated at flow rates determined by the Reynolds analogy to the prototype. Black plastic beads were introduced into the flow stream and photographed by using a Milliken camera recording at 500 frames per second. Calculations showed that 79% of the total mass flow was accounted for by this method. The 21% of the mass flow that was not accounted for was presumed to be due to flow in non- channel areas and in two non-orificed channels. Some error could also be attributed to the use of non-spherical beads that created non-uniform velocities in the channels, The visibility through the SNAP 2/10A core section, for the purpose of visual observation and optical recording, was very good. The high speed pictures were clear and sharp. The velocity determination based on the frame by frame analysis of the film did not present any problem. The experiment demonstrated that clear Lucite can be used as the material for visual flow observation in a full-scale SNAP 2/10A model core vessel. (auth)
Date: January 15, 1964
Creator: Thomasson, K.A.
Partner: UNT Libraries Government Documents Department

Space Shielding Materials for Prometheus Application

Description: At the time of Prometheus program restructuring, shield material and design screening efforts had progressed to the point where a down-selection from approximately eighty-eight materials to a set of five ''primary'' materials was in process. The primary materials were beryllium (Be), boron carbide (B{sub 4}C), tungsten (W), lithium hydride (LiH), and water (H{sub 2}O). The primary materials were judged to be sufficient to design a Prometheus shield--excluding structural and insulating materials, that had not been studied in detail. The foremost preconceptual shield concepts included: (1) a Be/B{sub 4}C/W/LiH shield; (2) a Be/B{sub 4}C/W shield; (3) and a Be/B{sub 4}C/H{sub 2}O shield. Since the shield design and materials studies were still preliminary, alternative materials (e.g., {sup nal}B or {sup 10}B metal) were still being screened, but at a low level of effort. Two competing low mass neutron shielding materials are included in the primary materials due to significant materials uncertainties in both. For LiH, irradiation-induced swelling was the key issue, whereas for H{sub 2}O, containment corrosion without active chemistry control was key, Although detailed design studies are required to accurately estimate the mass of shields based on either hydrogenous material, both are expected to be similar in mass, and lower mass than virtually any alternative. Unlike Be, W, and B{sub 4}C, which are not expected to have restrictive temperature limits, shield temperature limits and design accommodations are likely to be needed for either LiH or H{sub 2}O. The NRPCT focused efforts on understanding swelting of LiH, and observed, from approximately fifty prior irradiation tests, that either casting ar thorough out-gassing should reduce swelling. A potential contributor to LiH swelling appears to be LiOH contamination due to exposure to humid air, that can be eliminated by careful processing. To better understand LiH irradiation performance and mitigate the risks in LiH development for ...
Date: January 20, 2006
Creator: Lewis, R.
Partner: UNT Libraries Government Documents Department

The Evaluation of Lithium Hydride for Use in a Space Nuclear Reactor Shield, Including a Historical Perspective

Description: LiH was one of the five primary shield materials the NRPCT intended to develop (along with beryllium, boron carbide, tungsten, and water) for potential Prometheus application. It was also anticipated that {sup 10}B metal would be investigated for feasibility at a low level of effort. LiH historically has been selected as a low mass, neutron absorption material for space shields (Systems for Nuclear Auxiliary Power (SNAP), Topaz, SP-100). Initial NRPCT investigations did not produce convincing evidence that LiH was desirable or feasible for a Prometheus mission due to material property issues (primarily swelling and hydrogen cover gas containment), and related thermal design complexity. Furthermore, if mass limits allowed, an option to avoid use of LiH was being contemplated to lower development costs and associated risks. However, LiH remains theoretically the most efficient neutron shield material per unit mass, and, with sufficient testing and development, could be an optimal material choice for future flights.
Date: December 9, 2005
Creator: Poeth, D.
Partner: UNT Libraries Government Documents Department


Description: This report was prepared to document the physical, chemical and radiological properties of plutonium oxide materials that were processed in the Plutonium Fuel Form Facility (PuFF) in building 235-F at the Savannah River Plant (now known as the Savannah River Site) in the late 1970s and early 1980s. An understanding of these properties is needed to support current project planning for the safe and effective decontamination and deactivation (D&D) of PuFF. The PuFF mission was production of heat sources to power Radioisotope Thermoelectric Generators (RTGs) used in space craft. The specification for the PuO{sub 2} used to fabricate the heat sources required that the isotopic content of the plutonium be 83 {+-} 1% Pu-238 due to its high decay heat of 0.57 W/g. The high specific activity of Pu-238 (17.1 Ci/g) due to alpha decay makes this material very difficult to manage. The production process produced micron-sized particles which proved difficult to contain during operations, creating personnel contamination concerns and resulting in the expenditure of significant resources to decontaminate spaces after loss of material containment. This report examines high {sup 238}Pu-content material properties relevant to the D&D of PuFF. These relevant properties are those that contribute to the mobility of the material. Physical properties which produce or maintain small particle size work to increase particle mobility. Early workers with {sup 238}PuO{sub 2} felt that, unlike most small particles, Pu-238 oxide particles would not naturally agglomerate to form larger, less mobile particles. It was thought that the heat generated by the particles would prevent water molecules from binding to the particle surface. Particles covered with bound water tend to agglomerate more easily. However, it is now understood that the self-heating effect is not sufficient to prevent adsorption of water on particle surfaces and thus would not prevent agglomeration of particles. Operational ...
Date: November 24, 2009
Creator: Duncan, A. & Kane, M.
Partner: UNT Libraries Government Documents Department

Correlation of Liquid Fraction in Two-Phase Flow With Application to Liquid Metals

Description: A generalized correlation for the liquid fraction in twophase flow is presented which is proposed for use with all iluids, including liquid metals. The correlation is based on isothermal, two-phase, two-component liquid fraction data for liquid Hg--N/sub 2/ and water-air. Liquid fraction is shown to be a function of the Martinelli flow modulus and liquid/gas density and viscosity ratios. Good correspondence is indicated between the liquid fraction predicted by this correlation and the Martinelli-Nelson correlation for steam, experimental data for steam, and experimental data for Santowax R. Prediction of liquid fraction by this method is shown for Na, K, Rb, and Hg. Application of the method to boiling Hg, for a range of temperatures and exit qualities, is demonstrated for SNAP systems. (auth)
Date: April 15, 1963
Creator: Baroczy, C. J.
Partner: UNT Libraries Government Documents Department

Solubility study of strontium fuel compounds

Description: Strontium titanate, distrontium titanate, and strontium fluoride have been considered as isotopic fuels in thermoelectric generators for space and terrestrial applications. Evaluation of the radiobiological and radioecological effects of accidental release of /sup 90/Sr on land, in water, and in air requires a knowledge of the dissolution rates of the fuel in fresh water, salt water, and dilute HCl. Results of a study to investigate the behavior of these strontium fuel forms in the different test solutions are presented. (TFD)
Date: June 1, 1966
Creator: Gray, J. H.
Partner: UNT Libraries Government Documents Department