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Physics Design of the Mixed Spectrum Critical Assembly

Description: Summary: The Mixed Spectrum Superheater (MSSR) is an integral superheater reactor in which boiling occurs in an annular Boiling Water Reactor section and steam in superheated in an unmoderated fast section in the center. A Mixed Spectrum Critical Assembly (MSCA) to be operated at the Vallecitos Atomic Laboratory has been designed to mock up a 75-150 MWe prototype MSSR. The principal experimental measurements aimed at proving the feasibility of the MSSR concept include power distribution, Doppler effect, flooding effects, distribution of reactivity, control rod worths, and the effect of the control system on the power distribution.
Date: August 1963
Creator: Reynolds, A. B.
Partner: UNT Libraries Government Documents Department

The Measurement of Fission Gas Pressure in Operating Fuel Elements: Post-Irradiation Examination

Description: Summary: Two UO2-filled stainless steel clad fuel rods in which fission gas pressure was measured during irradiation have been subjected to post irradiation examination. Results of free gas analysis and metallographic examination are in general agreement with observed pressures reported previously. Calculated fuel surface temperatures based on extent of fuel recrystallization indicate that in a one-half inch diameter fuel rod with 0.014 inch diametral clearance operated at a maximum heat flux of 531,000 Btu/hr-ft, gap conductance increased with increasing heat flux. An analysis of void configuration indicates that pressure is more sensitive to as-fabricated void volume and changes in this volume resulting from fuel expansion than to fuel central temperature. The decreases in effective void volume with increasing fuel temperatures becomes more significant as initial void volume decreases, and excessive fission gas pressures may be developed in fuel rods operated at high fuel temperatures unless adequate expansion volume is provided in fabrication.
Date: September 20, 1963
Creator: Reynolds, M. B.
Partner: UNT Libraries Government Documents Department

High Power Density Development Project: Potter Meter Calibration and Instrumented Fuel Bundle Pressure Drop

Description: Summary: Technical report describing the testing of eight Potter Meters, for metering inlet flow and measuring exit steam qualities in the Consumers Big Rock Point Instrumented Fuel Assemblies, were individually calibrated for flow and pressure drop up to 500 gpm in the low temperature (130 F) fluid flow facility. The flow calibration comparison made with an ASME orifice installation, agreed to within + - 1 percent among seven of the meters, and meter Serial No. 8 was 2.8 percent lower than the others. Pressure drop among the meters was within about 5 percent. Locked rotor pressure drop data was obtained on one meter. A fully instrumented fuel bundle was tested in the low temperature facility and pressure drop data obtained for the tieplates and meters, spacers, and channel rods. A mock-up of the exit end of the instrumented fuel bundles, composed of 1 foot of fuel rods, tieplate, and Potter Meter was tested in the High Pressure Heat Transfer Facility. Data was obtained for single- and two-phase calibration of total flow and exit steam quality in an instrumented bundle. Each meter was operated, for a minimum of 6-8 hours after bearing modifications necessitated by seizure of the rotors, in the High Pressure Facility under conditions of 1000 psi and qualities of about 5-6 percent to verify operation and obtain some run-in time before reactor installation. A total of 655 hours of test and run-in time was made on all eight meters.
Date: July 26, 1963
Creator: Polomik, E. E. & Swan, C. L.
Partner: UNT Libraries Government Documents Department

Nuclear Superheat Quarterly Project Report: Sixteenth Quarter, May-July 1963

Description: From introduction: "This is the sixteenth in a series of quarterly reports which cover the progress and results from the conceptual designs, economic evaluations and research and development work performed by the General Electric Company as part of Contract AT(01-3)-189, Project Agreement No. 13."
Date: August 15, 1963
Creator: Flock, W. L.
Partner: UNT Libraries Government Documents Department

Multirod (Four Rod) Critical Heat Flux at 1000 PSIA

Description: Technical report describing the four-rod heat flux experiments that are a part of a continuing program of study of the critical heat flux, or burnout phenomenon in order that water cooled reactors can be designed with a maximum of safety and efficiency. During heat transfer with boiling, there is a particular heat flux, for a given set of flow conditions and geometry, above which the nucleate boiling process begins to break down. This breakdown of the nucleate boiling process is known as burnout, critical heat flux, departure from nucleate boiling (DNB), and boiling crisis. The present method at General Electric of avoiding the critical heat flux conditions in the reactor is to limit the heat flux, for a given set of flow conditions, to a fraction of the critical heat flux at the same conditions in the single-rod test section of Janssen and Kervinen. Because the critical heat flux of a heater rod facing an unheated wall is lower than that of a heater rod facing another heater rod, the critical heat flux conditions of the single-rod test section, will be a conservative estimate of the critical heat flux conditions in a multirod reactor. The main purpose of these experiments is to establish a set of critical heat flux conditions for a multirod geometry, which verify that the present critical heat flux design limits are satisfactory for use in a multirod reactor, and to establish a basis for future increase of these design limits. The location of the "burnout patch", or the area which experienced the temperature excursion was always located at the top of the heater tubes, facing the channel, in the corner. Comparison of single-rod data with the four-rod data shows a tendency for the critical heat flux data obtained in the four-rod test section to be equal …
Date: September 1963
Creator: Hench, John E.
Partner: UNT Libraries Government Documents Department

Maritime Loop Irradiation Program for Savannah I Fuel Post-Irradiation Examination of SI5BM Fuel Assembly

Description: Abstract: A stainless steel clad 9-rod assembly fabricated by The Babcock & Wilcox Company was irradiated in a boiling water loop of the General Electric Test Reactor. A post-irradiation examination revealed no significant dimensional changes on the fuel rods. the results of mass spectrometric analysis made of the pelletized UO2 fuel indicated a maximum burnup of 11,500 MWD/tonne was attained by Rod B-4 during the exposure.An x-ray diffraction examination of an unirradiated fuel sample revealed the presence of UN2 and U2N3 phases. Metallographic examination of the irradiated microstructures revealed similar second-phase particles.
Date: November 7, 1963
Creator: Mathay, P. W.
Partner: UNT Libraries Government Documents Department

Fuel Failure Examinations and Analyses in the High Power Density Program

Description: Summary: The High Power Density Project includes a comprehensive fuel development program which has the objective of developing and demonstrating the performance of a nuclear reactor core having a high power density, long fuel life, and low fabrication cost. The fuel program is made up of two principal tasks. Task 1A consists of irradiation tests in the VBWR of Type 304 stainless steel clad, UO2 pellet type fuel rods fabricated by current commercial processes. Task 1B consists of the investigation of lower cost fabrication processes and the irradiation testing of fuel elements fabricated by these processes. Both tasks include the investigation of the feasibility and use of thin-wall stainless steel cladding as a means of improving the neutron economy and fuel cycle costs of stainless steel clad fuel. Irradiation of the Task 1A fuel assemblies in the VBWR was initiated in September, 1960. Subsequently, Task 1B fuel assemblies were inserted in the VBWR as various fabrication processes and design concepts were investigated. Fuel cladding failures have occurred in fuel rods in both Task 1A and 1B. As of this date, cladding failures have occurred in twenty-two rods of approximately 700 fuel rods which have been irradiated. Twenty of the failures occurred in cold worked tubing and two in tubing procured commercially as annealed materials.
Date: September 16, 1963
Creator: Arlt, W. H. & Vandenberg, S. R.
Partner: UNT Libraries Government Documents Department

Two-Phase Pressure Losses Quarterly Progress Report: Sixth Quarter, May 12, 1963 - August 12, 1963

Description: Technical report describing that the pressure drops along 3/4-inch, 1-inch, and 1-1/4 inch straight pipes and across three contraction-expansion inserts in a 1-inch pipe have been measured under both single- and two-phase flow conditions. Pressure was varied from 600 to 1400 psia, flow from 0.25 x 10(6) to 1.66 x 10(6) lb/hr ft, and quality from zero to 90 percent. The single-phase pipe friction factor agrees with the Moody value for smooth pipe. The two-phase friction for horizontal flow shows no size effect in the range of pipe sizes from 3/4 inch to 1-1/4 inch. The values lie below the Martinelli curve at the lower qualities (x<0.6), but at high qualities tend to be above the Martinelli curve. The single-phase loss coefficient for the three contraction-expansion inserts show very little Reynolds number effect in the range of channel Reynolds numbers from 3 x 10(4) to 5 x 10(5). The two-phase data for insert number 1 has not yet been reduced. The two-phase loss for insert numbers 2 and 3 lies generally below the loss prediction based on a homogeneous flow model. The two-phase loss for insert number 2 shows excellent agreement with the corresponding loss for the S-1 insert in the 1/2- by 1-3/4-inch rectangular channel reported earlier. The two-phase loss for insert number 3 agrees fairly well with the loss for the S-5 insert.
Date: September 1, 1963
Creator: Janssen, E. (Engineer) & Kervinen, J. A.
Partner: UNT Libraries Government Documents Department

A Program of Two-Phase Flow Investigation Quarterly Report: Second Quarterly Report, July-September, 1963

Description: Task A: Modification and Preparation of Experimental Facility. With the exception of the insulation of modified components, the experimental facility is complete. Insulation will be completed by the end of September. the system has been charged with Refrigerant-22 and preliminary loop performance tests have been completed without the test sections.. Task B: Design and Construction of Test Sections. The stainless steel test section has been prepared complete with end flanges and pressure tap locations. Wall thickness tolerances have been ultrasonically checked. Test section inlet and discharge assemblies are being completed and the whole assembly will be ready for installation by the end of September. Glass sections from the same drawn length which will make up the final test sections have been received for pressure tests. The final coated sections and the associated inlet and discharge fittings will be ready for assembly by the end of September. The above sections were ordered after complete preliminary tests defined the properties required of these test sections. Task C: Design and Construction of Test Stand: The mechanical design and drafting of the structural components and drive system is complete. The electrical control system for the platform orientation has been constructed and two modes of operation have received preliminary checkout on the breadboard circuit. Machining of the supported plates and assemblies and the main structural assembly of the stand are complete. Assembly of the platform and electrical components will be completed by the end of September and final alignment and adjustments will be caries out during October. Task E: Pressure and Temperature Instrumentation for Test Section: The temperature transducers have been ordered and their delivery is scheduled for the third week of September. The bridge circuits have been designed and their fabrication is in process. The preamplifiers and the power supply for the temperature transducers …
Date: September 23, 1963
Creator: Staub, F. W. & Zuber, N.
Partner: UNT Libraries Government Documents Department

Specific Zirconium Alloy Design Program Quarterly Progress Report: Sixth Quarter, July - September, 1963

Description: Summary: Fundamental studies in support of the alloy design work are complete except for the experimental determination of the diffusion of oxygen in alloy-doped non-stoichiometric ZrO2. Over 100 oxidation runs have now been made on samples of ZrO2 doped with 1 mole percent of the oxides of Al, Y, Fe, Cr, and Ni. The first round testing of 31 alloys is now essentially complete. Analysis of the steam corrosion rate and hydriding raw data taken at 300, 400, and 500 degrees C indicates that Zr-Cr and Zr-Cu-Fe alloys show the most promise for development for service in steam over the entire temperature range 300-500 degrees C. Maximum resistance to corrosion hydrogen embrittlement requires high initial ductility and thus low, perhaps less than ~2.5 a/o total alloy content. For any composition, susceptibility to hydrogen embrittlement depends on crystallographic texture of the component; under certain circumstances hydrogen embrittlement may be high anisotropic. The second-round testing of 10 selected Zr-Cr and Zr-Cu base alloys is now about 50% complete. Three alternate fabrication schedules were evaluated; and the preliminary results indicate that the Zr-Cu alloy tested is less sensitive to heat treatment than is the Zr-Cr alloy tested. Raising the final alpha annealing temperature from 565 degrees C to 788 degrees C gives better over-all corrosion and hydrating performance for both the Zr-Cr and Zr-Cu alloy tested. Beryllium additions to Zr-Cr or Zr-Cu do not appear to be advantageous. Nickel additions to Zr-Cu do not give an over-all improvement. Nickel additions to Zr-Cu give about the same improvement over Zr-Cu as did iron additions to the Zr-Cu in the first-round test.
Date: October 1, 1963
Creator: Klepfer, H. H.; Jaech, John L.; Douglass, D. L. (David Leslie), 1931-; Blood, R. E. & Perrine, H. E.
Partner: UNT Libraries Government Documents Department

Program for the Development of Plutonium Recycle for Use in Light Water Moderated Reactors Quarterly Progress Report: July 1 - September 30, 1963

Description: A research program is being conducted to obtain experimental data in the irradiation of plutonium-enriched fuel to confirm a theoretical model for predicting isotopic composition and reactivity changes in plutonium-enriched, light-water-moderated reactors. Quarterly progress: The densitometry procedure (for measurement of alpha autoradiographs of fuel pellets) has been modified to eliminate the need for a second emulsion. The existence of a problem of latent image fading and non-reciprocity of the high-resolution emulsion has been recognized. A tentative procedure has been worked out to correct these emulsion difficulties. the number of polished pellets has been increased to thirteen. The number of hot spots per pellet has not changed appreciably. The largest spot seen is irregular with an estimated volume equivalent to that of a sphere of 35 mil diameter with a PuO2 concentration in the neighborhood of 60%. The VBWR irradiation run now under way is not scheduled to end until October. To the end of the last run the cumulative exposure reached 3703 MWD/T, as logged by VBWR operating personnel. Applying the same scale factor between logged exposure and Ce-Cs analysis of the first fuel sample gives a corrected exposure of 4416 MWD/T. Further debugging of EPITHERMOS, the epithermal extension of the BNL THERMOS code, is in progress. A flux wire exposure is being prepared to map the thermal neutron spectrum in the neighborhood of the test pins in the program fuel element.
Date: October 15, 1963
Creator: Robkin, M. A.
Partner: UNT Libraries Government Documents Department

In-Core Instrumentation Development Program Quarterly Progress Report June - September 1963

Description: Introduction: The objective of Project Agreement 22 is to determine the feasibility of covering the complete reactor neutron flux start range from 10(3) - 5 x 10(13) nv by using in-core chambers. The counting mode of operating will be used at low neutron fluxes and the root mean square voltage fluctuation mode will be used at high neutron flux levels. Experiments have been run utilizing various ion chambers, gases, gas pressures, voltage, and cables to measure sensitivities and range operating in the counting and RMS voltage modes. Theoretical discussions are presented showing how the RMS voltage is related to individual pulse at both amplifier input and output. Noise is also compared at amplifier output so that the optimum bandwidth can be selected. Spectral shifts with changes in applied voltage causing signal variations have been examined and can be eliminated by appropriate selection of amplifier bandwidth. In the counting mode, all experiments have been conducted with unterminated cable. The chamber has been designed with geometry, gas, and pressure to completely stop fission fragments in the gas and hence maximize the charge generated in the chamber. Cables have been selected to minimize capacity. Various gases, pressures, and voltages have been used to determine that an optimum design has been achieved.
Date: October 1963
Creator: DuBridge, R. A.
Partner: UNT Libraries Government Documents Department

Development of Pulsed Neutron Application to Power Reactor Start-Up Procedures. Sixth Quarterly Progress Report, July 1-September 30, 1963

Description: Activities in a program to develop techniques in the use of pulsed neutron sources to measure shutdown parameters related to large thermal power reactors are reported. The development of pulsed neutron source techniques for large power reactors has led to a new theoretical model recently developed by E. Garelis and J.L. Russell, Jr. The theory is presently based on a bare, one-group model with m-delayed precursors and takes all spatial modes into account. Results indicate, however, that the application of this model is much broader. Experiments were designed and carried out to both verify this new theory and to demonstrate the performance of the experimental hardware in a large power reactor.
Date: October 15, 1963
Creator: Garelis, Edward & Meyer, P.
Partner: UNT Libraries Government Documents Department

Development Program for Increased Output in the Garigliano Nuclear Reactor. Quarterly Report No. 4

Description: The United States and the European Atomic Energy Community (Euratom), on May 29, and June 18, 1958, signed an agreement which provides a basis for co-operation in programs for the advancement of the peaceful applications of atomic energy. The work described in this report represents the Joint U.S.-Euratom effort. The over-all development program is designed to obtain the test data and operating experience necessary to eventually realize a 50 percent increase in the output of the Garigliano Nuclear Power Station located at Sessa Aurunca (Campania, Italy). Two tasks are in progress: Task III-F involves the preparation of test specimens of reactor vessel material for irradiation; Task IV consists of the formulation of specification for a complete data logging and computer system.
Date: October 1, 1963
Creator: Sorlie, T.
Partner: UNT Libraries Government Documents Department

Transition Boiling Heat Transfer Program; Third Quarterly Progress Report, July - September 1963

Description: Summary: Initial critical heat flux, transition boiling temperature fluctuation, and film boiling coefficient data have been obtained on a two-rod cluster assembly at 1000 psia and 25 to 90 percent steam qualities. A representation showing the range of critical heat flux data is presented. Typical temperature recordings which indicate transition and film boiling behavior are shown. Fabrication of a new high pressure observational test section is nearly complete. An optical table and illumination system has been build and operationally tested for photographic use on the new observational section.
Date: October 1, 1963
Creator: Quinn, E. P.
Partner: UNT Libraries Government Documents Department

High Power Density Development Project: Fourteenth Quarterly Progress Report, July-September 1963

Description: Development of nuclear reactor cores having high power density, long fuel life, and low fabrication costs is the objective of this program sponsored by the AEC. Five tasks are in progress: (1) Task 1A-High Power Density Fuel Development. The number of assemblies has been reduced to seven as a result of the failure of two pellet fuel assemblies. The average burnup of the group operating as of September 1 is 7500 MWD/T. (2) Task 1B-Fuel Fabrication Development. Assembly. Assembly 12S gave positive signals of being a leaker under the multi-type in-core sampler and was declared failed based on the in-core results and visual observation of a cracked rod. Modifications to the instrumented fuel assembly probes were made by removing the failed flow meter rotors to allow continued use of the flux detectors and thermocouples. Flux detectors and thermocouples performed properly after reactor start up. Flux wire tubes were found to be kinked such that their use was prohibited. (3) Task II-Stability, Heat Transfer and Fluid Flow. A series of noise recordings of fluxes, flows, and temperatures has been made at 91 MWt at the Big Rock Point plant. Preliminary analyses of some of the these records were made to obtain noise amplitude as a function of frequency. Thermocouple response tests were performed to verify the temperature measurement obtained during the steady-state noise tests at Big Rock. (4) Task III-Physics Development. Plans for achieving optimum performance from the Big Rock plant are being based on the concept of maintaining a fixed power shape throughout each operating cycle. The desired shape for the present cycle has been computed. Methods of selecting control rod patterns to maintain this shape are being investigated for use in the on-line computer. The computer was put on line during plant startup in August, and is presently performing …
Date: October 1963
Creator: Holladay, R. L.
Partner: UNT Libraries Government Documents Department

A Controlled-Environment Steam Corrosion Facility

Description: Abstract; Technical report describing a low-flow autoclave system developed for out-of-pile corrosion testing of materials in controlled environment steam up to 500 C. The system has been set up in triplicate to provide for the exposure of various zirconium alloys to steam at 300, 400, and 500 C. The oxygen and hydrogen of the steam were controlled at 25 ppm and 3 ppm, respectively, to simulate the gas conditions from radiolytic water decomposition found in a boiling water reactor. The autoclave internals were so designed to result in a temperature variation between specimens under test of less than 2C.
Date: October 1963
Creator: Nelson, W. B.
Partner: UNT Libraries Government Documents Department

Fuel Cycle Program Design and Fabrication of Special Assembly 10-L : Compacted Powder Fuel Rods Clad With 0.127-MM Wall Stainless Steel

Description: Technical report describing sixteen fuel rods clad with thin type 304 stainless steel and filled with vibratory compact powder UO2 that were fabricated and incorporated into a bundle for irradiation testing in the VBWR. The UO2 powders were tested for gas content. N2, CO, and H2 were the principal gases evolved by both type of UO2, but the arc-fused UO2 released about ten times as much gas as the Dyna Pak UO2. The amount of gas released was also a function of particle size and temperature. The gas evolution data were used to design the gas plenum to accommodate the absorbed gases along with the fission gases.
Date: October 1963
Creator: Ogawa, S. Y. & Williamson, N. E.
Partner: UNT Libraries Government Documents Department

Prediction of Two-Phase Critical Flow Rate

Description: Technical report of a proposal of an analytical model to predict two-phase critical flow rate. The model is based upon thermal equilibrium, a "lumped" treatment of the two-phase velocity (each phase is represented by a single mean velocity), and upon the neglect of frictional and hydrostatic pressure losses. A comparison, of the proposed predictions with available test results and previous analyses shows that: (1) The present model agrees very well with the published test data. (2) In contrast to all other analyses, the model requires no assumption about the gas void fraction.
Date: October 1963
Creator: Levy, S.
Partner: UNT Libraries Government Documents Department

Design and Fabrication of Pellet Fuel Rods Clad With Thin Wall Stainless Steel

Description: Summary: Stainless steel clad nuclear fuel cycle costs can be reduced to those associated with Zircaloy clad fuel or potentially lower by reducing the thickness of the clad tube wall until performance penalties offset the savings associated with the reduction in parasitic neutron absorption. To demonstrate the feasibility and investigate performance capabilities of thin clad fuel rods for power reactor application an assembly was fabricated with 0.0127 cm (5 mil) thick stainless steel cladding tubes for irradiation testing in the Vallecitos Boiling Water Reactor (VBWR). The fuel bundle was placed in the VBWR and irradiation was begun in November, 1961. The irradiation is scheduled to continue until the target exposure of 2.74 x 10(20) fissions/cc (10,000 MWD/T of uranium) average burnup is reached. Destructive examinations of fuel rods will be performed at regular intervals throughout life to determine fuel rod performance.
Date: February 1964
Creator: Hoffmann, J. P.
Partner: UNT Libraries Government Documents Department
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