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Progress made in the development of the Experimental Beryllium Oxide Reactor (EBOR) is reported. The objective of the EBOR program is to develop a gas-cooled, beryllium oxide-moderated reactor which can be used in conjunction with a closed-cycle gas turbine or a steam cycle for a small land-based or a maritime power plant. Progress is reported on reactor development, reactor physics, and materials development. (N.W.R.)

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The large aqueous pilot plant facilities at ORNL were cleaned and are being put in standby condition. Experience was gained during the year as anion exchange was used to recover more than one kg of plutonium left in the exploded evaporator system. This experience is being applied to a new recovery program just beginning in cell 1 of Building 4507. (auth)

Hydraulic tests were made on the Hallam Prototype Free-Surface Sodium Pump to determine the net positive suction head (NPSH) required at various sodium flow rates. Pump performance data were also collected. The results indicate that an NPSH of 22 ft sodium is required at the design flow rate of 7200 gpm at approximates 1000 deg F, agreeing with computed values, and that the pump is designed with a safety margin of slightly over l0%. (D.L.C.)

S>The compatibility of type 304L stainless steel in intimate contact with graphite is being studied as a function of temperature and contact pressure. This study is an outgrowth of materials compatibility problems in present and advanced gas-cooled reactors, where structural members in direct contact with graphite provide the possibility of both carburization and self-welding. Initial studies were concerned with surface reactions in the absence of gaseous contaminants under a vacuum of 10/sup -6/ mm Hg at 540 to 705 deg C. Stainless steel specimens are pretreated to provide three surface conditions: H/sub 2/- fired, preoxidized, and Cu-plated. Surface contact pressures ranged from 0 to 10,000 psi. Test results are presented which establish the lower temperature limit for significant diffusion between graphite and stainless steel at approximately 60O deg C. Above this temperature, diffusion between untreated or H2-fired stainless steel surfaces was found to effect complete bonding of the two materials at contact pressures as low as 500 psi. Bonding was effectively prevented by the presence of either an oxide film or a Cu plate at temperatures up to 700 deg C. Where bonding occurred, diffusion rates measured for C in stainless steel were comparable with those reported for stainless steel …

The specification contains information concerning the material, process, and product requirements to be met by the fabricator. (J.R.D.)

Run 25 was the final period of power operational of the HRT. The reactor was operated for periods of 62, 8, 52, and 80 hours at 5 Mw with no outward indication of fuel and core and blanket average temperatures of 270 and 230 deg C, respectively. The uranium concentration in the was 1.7 to 2.0 g U/kg D/sub 2/O. Longer periods of operation were prevented by mechanical difficulties, notably with the fuel feed pump. While the reactor was subcritical after the last of the above runs, the upper patch in the core tank wall became dislodged, allowing greater core-to-blanket mixing. The resultant blanket uranium concentration was 2.9 g U/kg D/sub 2/O. The reactor was subsequently operated at April 28, 1961. The experiment was operated at high temperature for a total of 10,866 hours. The system was critical for a total of 8,841 hours and produced 16,295 Mwhours of power. The fuel, heavy water, and some corrosion specimens were recovered, and the reactor was stored in an assembled state. (auth)

A seven- to twenty-fold volume reduction can be obtained from fluidized bed calcination of aqueous aluminum nitrate wastes, depending on the operating conditions employed and their effect on the intra-panticle porosity and absolute density of the calcined alumina. Among the calcining variables, only the bed temperature and the fuel aluminum concentration had a significant effect on the intra-particle porosity of alumina generated during studies conducted primarily in a two-foot-square fluidized bed calciner. A quantitative correlation of the effect of these variables is presented. Alumina with an intra-particle porosity as low as five per cent can be generated by employing a suitable combination of low bed temperature and dilute aluminum feed concentration. Feed sodium concentration and product alpha alumina content were found to have minor effect on intra-particle porosity. Results also show that an inverse relationship exists between the nitrate content of the calcine and the calcination temperature. (auth)

A spectrographic method using d-c arc excitation in a controlled atmosphere was developed to analyze for seven impurity elements in radioactive hafnium samples. Analysis requires as little as 35 mg of hafnium oxide. (auth)

An addition is presented for the IBM-7090 program MURGATROYD to produce a rough graph of reactor power versus time. A sample of output is included for the case given as an example. (J.R.D.)

The effect of modifying the dislocation structure by room-temperature prestraining on the subsequent yielding behavior at 77 deg K is being studied. Results on tantalum single crystals indicated that a considerable decrease in the early yield stress for a given strain is effected by prestraining at room temperature. Twinning was observed in the tantalum at 77 deg K and normal rates of strain. It is shown that the potential barrler to dislocation motion in crystalline solids can be measured in relatively pure bcc transition metals such as Nb, Ta, Mo, and W. Work is being carried out to extend the method of differential calorimetry to measurements of stored-energy-release spectra in deformed bcc metals. Measurements for copper are discussed. (M.C.G.)

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Calculations are presented which show that the reactivity effect of flooding and unflooding the fast superheating section of the Mixed Spectrum Superheater can be made small by the addition of epithermal poisons to the superheater. The reactivity effects of flooding superheater sections ranging in size from 1.25 to 3.5 ft cubes and containing U/sup 23/5/sup >/oxide or Pu/sup 239/ oxide fuel and various amounts o f the epithermal poison europium were calculated. Reactivity changes during several postulated flooding processes are given. Methods for deterthination of fissile and fertile material and poison cross sections in the resonance- region are discussed. (auth)

Tests were carried out on the self-actuated reactor relief valves and the self-actuated pressurizer steam relief valves in order to insure their reliable operation. The valves operated properly, and the final set pressures were all within the specified limits. (D.L.C.)

A simple mathematical model was developed to describe the steady-state release rate of gaseous fission products from porous ceramic fuels in low- permeability containers. The resulting equations are used to analyze experimental release rate results obtained from a UC/sub 2/-fueled graphite fuel body enclosed in a low-permeability impregnated graphite container. The relative release rates of the fission-product species Kr/sup 85m/, Kr/sup 88/, and Xe/sup 133/ were predicted with reasonable success. Absolute-rate predictions were not possible due to lack of information on true permeability and porosity profiles in the graphite container. (auth)

The results of a limited analysis of the extended SM-2 critical experiments are given. A review of the analytical models is presented to ascertain the accuracy of the reactivity calculations for the reference SMi-2 Core I. A new reference B-l0 loading was derived based on analysis and experimental measurements. Calculations of power distributions and burnup behavior of the reference core are presented and comparisons to available measured data made. (auth)

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