A model is proposed which depicts the sources of elutriatable fines in the fluidized bed calcination process as being in two major groups, spray drying mechanisms and attrition mechanisms. Based on this model, equations are derived which express the rate of change of the concentration of a chemical tracer material in the elutriated fines, following introduction of the tracer into the feed and following its removal from the feed. This system has been simulated on an analog computer, and by matching the computer simulation to results from an actual calciner run, the rates of generation of fines by each of the two groups of mechanisms has been determined; the same technique results in an estimate of the amount of these fines remaining in the fluidized bed. Agreement between postulated results and results of actual experimental tests lends credence to the usefulness of this analytical technique. (auth)

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The development of instruments for controlling reactor operation is reported. A shim-scram actuator was designed incorporating an electromagnetic dnlve for shim and scram, a shim speed limiting device, and a force feedback position indicator. A three-channel trip circuit and a two-out-of-three logic circuit using controlled switches in place of transistors was designed, built, and tested. A capacitance-type temperature sensor was operated in an inert atmosphere at temperatures up to 3782 deg F. Models of a gridded and a compensated a-c ionization chamber were tested in both thermal neutron and gamma environments. The compensated a-c ionization chamber demonstrated better than 98% gamma compensation at a thermalneutron flux of 5 x 10/sup -11/ nv and 1 Mw reactor power. Unpowered charged-fragment neutron detectors using boron-10 or uranium-235 as the emitter coating were demonstrated to respond linearly to changes of thermalneutron flux. Potentials, developed within the detecting circuit, possibly due to contact potentials, are suspected to be the cause of detector output-current instability as a function of time. Fission counter operation at 816 deg C was demonstrated to be feasible, but operation was not entirely satisfactory. Adequate reactor power range neutron sensing to 535 deg C is feasible using uncompensated d-c ionization chambers. …

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This monthly technical report details activities of the Reactor Physics Research and Engineering staff of the N-Reactor Department for the month of February 1964.

Isostatic-pressing techniques using reversible gels as the pressing medium were studied for improving the uniformity in density and structure of UC-- ZrC bodies. Control of powder-size fraction was studied as a means for controlling the pore distribution. Control of the carbon content by thermal treatment in a mixture of H/sub 2/ and hydrocarbon was also studied. Near stoichiometric 30 UC--70 ZrC powder was prepared by gas-metal reaction. Assembly of an apparatus for study of the thermochemical vapor-deposition of tungsten is near completion. The vaporization and fission product release rates of a hot- pressed high-density 30 UC -70 ZrC sample were measured from 1800 to 2000 deg C. A low-pressure gas adsorption apparatus was set up for measuring the true surface area of UC-ZrC samples. The cell used for the study of fission product diffusion through tungsten was fabricated. Samples are being prepared for fuel-clad compatibility and refractory-metal interdiffusion studies. Diffusion-emission studies were made on a rhenium-clad UC sample at 1800 deg C. The molybdenum pedestal of the loading device of a high-temperature mechanical testing furnace was modified. Thermionic emission microscopy showed that areas of high work function can co-exist with betteremitting UO/sub 2/ dispersions on the surface of a W-UO/sub …

The Hanford reactors contain a very large inventory of fission products and it is very important that this inventory be contained. In recognition of this, rather stringent reactor cooling requirements have been established for the Hanford reactors. This includes the requirement of three independent cooling systems, including the system for full level operation. The second and last-ditch systems both are usable only after a reactor scram and take-over automatically from the flywheel decay of the process pumps. In 1962, two projects were completed that affected the last-ditch cooling adequacy of the K reactors, One project increased the reactor pumping capacity and, therefore, its power level; and the other considerably modified the emergency cooling systems. Since this time, three tests have been conducted to determine this last-ditch cooing adequacy. In order to provide a uniform approach to this adequacy determination, the method employed by Reactor Engineering is presented herein. The report presents a method for determining the maximum reactor power level for which measured last-ditch flows will provide adequate emergency cooling, A number of pertinent charts are included, A method is also presented for determining the last-ditch flow that should be measured during a test for any desired level of normal …

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Reference (2) requested that we review the possibilities that classified information might be revealed by isotopic composition of fission products, and suggest methods of making any such compositions. These questions have been reviewed thoroughly by Hanford Laboratories experts; their analysis confirms earlier conclusions (Reference 1). Based on current classification guides, isotopic compositions of cesium, promethium, and probably other rate earths could reveal secret information. Unless classification rules are changed, we see no way to declassify these fission products except by blending them with unclassified products from other sources.

Approximately 285 ribbed aluminum process tubes will have been installed in the central zone of each K reactor on completion of the zirconium tube replacement program. This report recommends the use of mixer fuel elements in the ribbed tube and discusses the basis for the recommendation. The recommendation is complicated by the fact that two tube designs having different dimensions will be used and the optimum mixer location for the two tube designs is different also.

The initial 30-Mw SRE Core III loading will contain a total of 33 fuel elements. Of these, the central 7 fuel elements are test elements and the remaining 26 are driver elements; 4 of the 7 test elements are designated as standard test elements. These elements are identical to the driver elements with the exception of the active fuel length. The remaining 3 test elements are designated as special test elements and incorporate fuel rods of smaller diameter and increased enrichment to obtain higher burnup rates, greater specific power, and higher fuel temperatures. Geometry design data for the various elements considered in the analysis was obtained from Dwg. No. 650 deg F, the mixed-mean coolant outlet temperature for the core at 1200 deg F ( plus or minus 15 deg F), the maximum average temperature on the cladding at 1275 deg F, and the maximum fuel temperature in the range of 2000 to 2100 deg F. The thermal performance of the fuel elements was analyzed with the SORTD code and the Heating code. The results of the analysis are presented in tabular form. Axial temperature profiles are also presented for representative fuel elements. The core outlet coolant mixed-mean temperature was …

The stability of the circulating beam in a radiofrequency system with large beam loading is investigated. The results are applied to the 3-Bev electron-positron storage ring under design at the Cambridge Electron Accelerator. It is found that for this type of system, in which there are no large transients, it should be possible to use most of the radiofrequency power to supply the radiation losses of the circulating beam and only dissipate a small fraction of the power in the r-f cavities. (auth)

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The feasibility of fabricating aluminum clad, low-density ({approximately} 65 per cent theoretical density) thoria elements using thoria produced-by a modified Sol Gel process, low frequency-low energy vibration for compaction, and the TIG welding process for closure welding has been demonstrated by Hanford Laboratories (HL). They have also assembled thoria fuel elements for the initial irradiation to produce 1 to 2 kgs. of U-233. At this time, it is expected that Hanford will be asked to produce about 25 kg. of ``clean`` U-233 and that authorization to proceed with this program could be expected sometime between now and late fall of CY 1964. The requirements in terms of equipment and manpower, and the time schedules to produce this quantity of U-233 have been published and it was indicated, based on best estimates made at the time, that finished thoria fuel elements could be produced 7 months after authorization of the program, and the full 60 tons of fuel elements completed 9 months after authorization. Approximately $125,000--150.000 of capital equipment in Production Fuels were estimated as being required to produce the quantity of fuel elements required, including prototypes used in engineering development. This report reassesses the Production Fuels Section capability to meet …

The computer program FATT for calculating the transient temperature distribution in the EGCR core is described. The program, in FORTRAN for the IBM 7090, provides an arbitrary choice of axial increments for the reactor core. The heat transfer coefficients are made temperature-dependent. Provisions are available for plotiing the results from the program on the Calcomp plotter. The equations and some typical results are included, and the finlte difference method of solution is described. (auth)

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The deviation from the expected coolant flow distribution within the SNAP 2 reactor is due to the filling and draining of the unfed'' peripheral flow channels. An analysis of the cross-flow in a simulated SNAP 2 model omitting the unfed'' peripheral channels was made. The results of this investigation are presented herein. (auth)

This report, for January 1964 from the Chemical Processing Department at HAPO, discusses the following: Production operation; Purex and Redox operation; Financial operations; facilities engineering; research; and employee relations. Weapons manufacturing operation; and safety and security.

Differential cross sections for elastic {pi}-p scattering have been measured at eight energies for positive pions and seven energies for negative pions. Energies ranged from 310 to 650 MeV. These measurements were made at the 3-BeV proton synchrotron at Saclay, France. A beam of pions from an internal BeO target was directed into a liquid hydrogen target. Fifty-one scintillation counters and a matrix-coincidence system were used to measure simultaneously elastic events at 21 angles and charged inelastic events at 78 {pi}-p angle pairs. Events were detected by a coincidence of pulses indicating the presence of an incident pion, scattered pion, and recoil proton and the results were stored in the memory of a pulse-height analyzer. Various corrections were applied to the data and a least-squares fit was made to the results at each energy. The form of the fitting function was a power series in the cosine of the center-of-mass angle of the scattered pion. Integration under the fitted curves gave values for the total elastic cross section. The importance of certain angular-momentum states, particularly the D{sub 13} state near 600 MeV, is discussed. Several possible explanations are given of the enhancement in the {pi}{sup -}-p cross sections near 600 …

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