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Nuclear Superheat Meeting: September 1959

Description: From introduction: The Commission's underlying objective of this program is to conduct sufficient engineering and development work to determine the most feasible and economical methods of producing nuclear super-heated steam from a boiling water reactor.
Date: November 3, 1959
Partner: UNT Libraries Government Documents Department

Nuclear Superheat Meeting: October 1960

Description: From introduction: This report discusses AEC-sponsored nuclear superheat meetings whose primary purpose is to keep the AEC contractors engaged in nuclear superheat projects abreast of the overall AEC superheat program and to provide a means for the exchange of current technical information.
Date: November 10, 1960
Creator: Mravca, Andrew E.
Partner: UNT Libraries Government Documents Department

Hanford Graphite Superheat Reactor (HGSR) Design Study and Evaluation

Description: Report containing the results of a preliminary study of a design concept for a graphite-moderated pressure tube reactor. Topics include reactor design, operating procedures, subsystems, hazards analysis, and economic potential. Appendices begin on page 174.
Date: January 1964
Creator: Hanford Atomic Products Operation. N-Reactor Project Section.
Partner: UNT Libraries Government Documents Department


Description: The thermodynamic properties for the saturated and superheated phases of sodium are presented in tabular form and as a Mollier diagram. The density, thermal conductivity, viscosity, specific heat, and surface tension of the metal are given by tables and charts. The methods used in determlning the properties are discussed. (auth)
Date: October 1, 1960
Creator: Dunning, E.L.
Partner: UNT Libraries Government Documents Department


Description: The design and construction of the Boiling Nuclear Superheater (BONUS) Power Station at Punta Higuera on the seacoast at the westernmost tip of Puerto Rico are described. The reactor has an output of 17.5 Mw(e). This report will serve as a source of information for personnel engaged in management, evaluation, and training. (N.W.R.)
Date: May 1, 1962
Partner: UNT Libraries Government Documents Department

SUPERHEATING WATER-BOILER. Reactor Design and Feasibility Study

Description: A preliminary design is presented for a boilingwater reactor with integral nuclear superheater, which produces steam at 1200 psia, 950 deg F. The design uses stainless steel, UO/sub 2/, and water for materials and stays generally withln the limits of existing reactor technology. The design output is 129,445 lbs of steam per hour at the stated conditions, which corresponds to 17,500 shaft horsepower in a naval steam plant and to 47.25 Mw of heat. This is thought of as a ship propulsion reactor, and its capacity, arrangement, shielding, and control system are appropriate to that application. The feaslbility, size, and weight were studieds also the biologied shielding and mechanical design were studied in relation to plant size and weight. Water treatment, mechanical design of control rod drives, and the steam plant are not considered. The reactor core is cylindrical and divided radially into three regions: a central superheater, an annular boiler, and a surrounding reflector. Moderators are BeO in the superheater and water in the boiler and reflector. Superheater fuel elements consist of three concentric tubes of type 347 stainless steel containing UO/sub 2/ particles in a stainless steel matrix. The boiler elements are of convenional plate type. (M.H.R.)
Date: August 1, 1957
Creator: Marbury, F.; Alden, J.W.; Bedford, R.E.; Bilenas, J.A.; Coppersmith, W.C.; DeVincentis, J. et al.
Partner: UNT Libraries Government Documents Department


Description: An analytical expression is presented which permits the prediction of the maximum nucleate heat flux in pool boiling of saturated or subcooled liquids. The numerical values of the empirical constants which appear in the Kutateladze and Borishanskii criteria for the burnout'' heat flux are derived from the theory. An analytical expression for the empirical function which appears in the correlation of Griffith is also derived. The hitherto unexplored features of transition boiling, i.e., the hydrodynamic instability, the well defined geometrical configuration and the frequency dependence are described, supported by experimental evidence, and used as the basis for the analytical work. The peak heat flux in transition boiling is shown to be limited by the combined effects of Taylor and Helmholtz instabilitiess whereas the minimum transitional heat flux is limited by the effect of Taylor instability ony. The analysis leads to the conclusion that because of the statistical nature of the ddsturbances and the bandwidth'' of the unstable wavelengths which govern the process, an inherent uncertainty exists in determining the exact value of the heat flux at burnout.'' The width of this uncertainty range is plus or minus 14%. The often noted poor reproducibility of experimental data on burnout'' can be inferred, therefore, from the analysis. The reason analytical attacks upon the burnout'' problem, based upon considerations of bubble agitation and other nucleate boiling characteristics, have not been successful is discussed. The literature has shown conclusively that the surface conddtions play the dominant role in determining the superheat accompanying a given heat flux. The analysis reveals, in addition, that even if the nucleating characteristics of the surface were known the problem could still not be solved from these considerations because the mechanism of the instability occurs in the fluid away from the surface. The extension of the analysis to flow systems ...
Date: January 1, 1958
Creator: Zuber, N. & Tribus, M.
Partner: UNT Libraries Government Documents Department


Description: Research on a welding process for closing the ends of pathfinder fuel elements is reported. Optimum parameters for certain variables (amperage, weld travel, preheat, etc.) affecting weld quality were determined, and two modified end cap designs were investigated and found to reduce weld sensitivity to certain variables. Use of chills on the fuel tube greatly improved weld puddie geometry and microstructure. Optimum weld parameters for rods containing UO/sub 2/ fuel were experimentally established. (D.C.W.)
Date: July 30, 1963
Creator: Boschke, R.A. & Wiggins, R.J.
Partner: UNT Libraries Government Documents Department

The Fruition of 4f Discovery, The interplay of basic and applied research

Description: A broad base of knowledge is necessary for the successful solution to applied problems, but on the other hand, developing such practical solutions can open the door to new and exciting adventures in basic research. Several such synergistic events are briefly described. These include the design and development of magnetic refrigerant materials (1) for the liquefaction of H{sub 2} gas, and (2) for near-room temperature cooling and refrigeration; and (3) the design and development of cryocooler regenerator materials. The first led to the discovery of both supercooling and superheating in the same substance (Dy and Er); the second to the discovery of the giant magnetocaloric effect, the colossal magnetostriction, and the giant magnetoresistance in the same substance [Gd{sub 5}(Si{sub x}Ge{sub 1-x}{sub 4})]; and the third the disappearance of three of the four magnetically ordered phases in Er by Pr additions in both high purity Er and commercial grade Er.
Date: September 30, 2004
Creator: K.A. Gschneidner, Jr
Partner: UNT Libraries Government Documents Department


Description: In studies of the fabrication of fuel subassemblies for the supercritical-water reactor, the limited ductility of stainless steel-UO/sub 2/ fuel sheet made the fabrication of corrugated-flat-plate-type subassemblies impractical. A fabricable MTR-type assembly, 5/8 in. square and 30 in. long, was developed. Methods for edge cladding fuel sheet were developed and a brazing alloy, GE-75, was found to be corrosion resistant in supercritical water. (auth)
Date: August 16, 1954
Creator: Keeler, J.R. & Hare, A.W.
Partner: UNT Libraries Government Documents Department

On the hot-spot-controlled critical heat flux mechanism in pool boiling of saturated fluids

Description: In this paper, we further investigate the hypothesis that the critical heat flux (CHF) occurs when some point on the heated surface reaches a high enough temperature that liquid can no longer contact that point, resulting in a gradual but continuous increase in the overall surface temperature. This hypothesis unifies the occurrence of the CHF and the quenching of hot surfaces by relating both to the same concept, i.e., the ability of a liquid to contact a hot surface. We use a two-dimensional transient conduction model to study the boiling phenomenon in the second transition region of saturated pool nucleate boiling on a horizontal surface. The heater surface is assumed to consist of two regions: a dry patch region formed as a result of complete evaporation of the thinner liquid macrolayers and a two-phase macrolayer region formed by numerous vapor stems penetrating relatively thick liquid macrolayers. The constitutive relations used to determine the stem-macrolayer configuration in the two-phase macrolayer region of the boiling surface were reevaluated for Gaertner's clean water and water-nickel/salt solution. 29 refs.
Date: January 1, 1992
Creator: Unal, C.; Sadasivan, P. & Nelson, R.A.
Partner: UNT Libraries Government Documents Department


Description: gram are to test nuclear superheating concepts and to advance the technology of boiling-water-reactor design by performing experiments which will improve the understanding of factors limiting the stability of boiling reactors at high power densities. The reactor vessel is a cylinder with ellipsoidal heads, made of carbon steel clad internally with stainless steel. Each of the three cores is 24 in. high and has an effective diameter of 39 in. (W.D.M.)
Date: February 1, 1960
Creator: 1960, Feb.
Partner: UNT Libraries Government Documents Department

Analysis of potential for jet-impingement erosion from leaking steam generator tubes during severe accidents.

Description: This report summarizes analytical evaluation of crack-opening areas and leak rates of superheated steam through flaws in steam generator tubes and erosion of neighboring tubes due to jet impingement of superheated steam with entrained particles from core debris created during severe accidents. An analytical model for calculating crack-opening area as a function of time and temperature was validated with tests on tubes with machined flaws. A three-dimensional computational fluid dynamics code was used to calculate the jet velocity impinging on neighboring tubes as a function of tube spacing and crack-opening area. Erosion tests were conducted in a high-temperature, high-velocity erosion rig at the University of Cincinnati, using micrometer-sized nickel particles mixed in with high-temperature gas from a burner. The erosion results, together with analytical models, were used to estimate the erosive effects of superheated steam with entrained aerosols from the core during severe accidents.
Date: May 1, 2002
Creator: Majumdar, S.; Diercks, D. R.; Shack, W. J. & Technology, Energy
Partner: UNT Libraries Government Documents Department

Local and bulk melting of Cu at grain boundaries

Description: We investigate gain boundary (GB) melting using molecular dynamics simulations on face-centered-cubic Cu bicrystals with symmetric {l_angle}110{r_angle} tilt grain boundaries. Two representative types of GBs are explored: {Sigma} = 11/(113)/50.48{sup o} (low GB energy) and {Sigma} = 27/(552)/148.41{sup o} (high GB energy). The temperature and temporal evolutions of the Cu bicrystals under stepped heating are characterized in terms of order parameters and diffusion coefficients, as ell as the nucleation and growth of melt. Within the GB region, continuous local melting precedes discontinuous bulk melting, while continuous solid state disordering may precede local melting. Premelting may occur for local melting but not for bulk melting. For {Sigma} = 11/(113)/50.48{sup o}, premelting of the GB region is negligible, and local melting occurs near the thermodynamic melting temperature. The GB region as a whole is superheated by about 13% before its bulk melting. In the case of {Sigma} = 27/(552)/148.41, considerable premelting is observed for local melting, while the bulk melting occurs with negligible superheating. The exact melting behavior of a general GB depends on the GB energy, but is likely bracketed within these two cases.
Date: January 1, 2008
Creator: Luo, Shengnian; Han, Li - Bo; An, Qi; Fu, Rong - Shan & Zheng, Lianqing
Partner: UNT Libraries Government Documents Department