Sanderson & Porter have carried out a series of studies over the last four years which indicate that the pebble-bed reactor way be an attractive way to obtain low-cost power. At the request of the Atomic Energy Commission, two design studies have been carried out on this concept at the Oak Ridge National Laboratory. The first of these a preliminary design of a 10-Mw(t) reactor experiment, the PRRE, was initiated September 10, and a report on the study was issued November 1960. The second phase of the work, a conceptual design study of a 330-Mw (e) central station, was initiated November 1, and is the subject of this report.

The objectives of this study have been to examine the problems of the pebble-bed reactor concept and to conceive a design of a facility for investigating the feasibility of this type of reactor. The design must provide for adequate leaktightness of the contaminated-gas system and adequate maintenance of contaminated components, the most vital feasibility questions of the concept.

The fire involved approximately 30 liters of isopropyl alcohol as a result of the ignition of about 16-18 liters of isopropyl alcohol and a slurry of thoria and ammonium nitrate in a 20-liter glass carboy. This material was undergoing a volume reduction by boiling in a floor-type metal hood with Plexiglas sides and 3 sliding door on the front of ordinary glass. The alcohol vapor was vents directly into the hood (Fig1.)

At the present time, plants in the 100-500Mv size range are more numerous and carry the greatest portion (over 50%) of the total steam-electric plant load in the U.S. utilities industry. The contribution of plants of over 1,000-Mv capacity is increasing more rapidly than any other size clarification and at present represents about 10% of the total capacity. By 1962 the TVA will have six plants with capacities of over 1,000-Mv. The largest steam-electric plant in the U.S. is the TVA plant at Kingston, Tenn., with a nameplate capacity of 1,440-Mv. Turbine-generator units are also following a trend of ever-increasing size. In present construction, the 150-200 Mv size range for units is the most common and represents the greatest contribution to capacity. Two units of 500-Mv nameplate rating each, the largest in the U.S., are on order by the TVA, and an 800 Mv unit is contemplated.

The system Dovex 21K and aqueous uranyl sulfate solutions were studied in the solution compositions range: 0-0.005 mol/liter uranyl sulfate, 0.15 mil/liter total sulfate, 0.02 mol/liter H2SO4 (pH 2).It is shown that UO3SO4 and/or UO2(SO4)2-/2 are sorbed on the resin to form R2UO2(SO4)2. It is surmized that these same species are also involved at high uranyl concentrations and pH 2 it is suggested that U2O5SO4, U2O5(SO4)2-/2, and R2U2O3SO4 species may be involved.

Available knowledge of precision limits in S.S. accountability measurements and/or calculations by reactor and chemical processing groups is surveyed and summarizes. Experience in comparisons of reactor (production and research) calculations versus chemical plant accountability measurements is also reported. A general tentative conclusion is that available precisions (+/- 0.54 to +/- 0.78% ) in chemical plant measurements is also reported. A general tentative conclusion is that available precisions (+/- 1.0 to +/- 11.0%) possible by calculations (nuclear and/or engineering) of power reactor systems; however, with operation and empirical experience (e.g. less than +/-1.0%

After two batches (~ 340 kg) of fluoride salt from the ARE were reprocessed, pilot plant operations were terminated because of a leak through which an estimated 780 g of uranium (as UF6) escaped. Of the 21 kg of highly enriched uranium in the feed, 93.12% was collected as UF6 product, 0.13% represented measured losses, and 3.72% was unaccounted for (leak). An additional 3.03% was reclaimed from NaF beds and equipment washes. The product met both chemical purity and activity specifications for product level UF6. Decontamination from fission products was essentially complete. A gross gamma D.F. was apparently limited by the low activity of the feed salt.

Results of four experiemental runs in the Fluorox fluidized bed reactor system are reported. The engineering feasibility of UF6 production from UF4 by use of dry air of O2, 2UF4 + O2 = UF6 + UO2F2, in an Inconel fluidized bed reactor at 800-850°C was demonstrated in two experimental tests in which greater than 90% of the theoretical amount of UF6 was collected or measured. Two runs made with crude UF4 (produced from unpurified mill concentrate) as the feed material, showed that UF6 could be produced at 700-725°C but corrosion on Inconel was prohibitive.

Nuclear and radiation hazards have been investigated for all phases of operation to be carried out in the mechanical decladding of SRE fuel elements. The SRE fuel is 2.8% enriched with a maximum burnup of 1,000 Mvd/ton and minimum cooling of 120 days. Each element contains 9 kg of uranium metal (~2 kg U-235) and is made up from 84 slugs (3/4"D x 6'"), clad with (10 mil wall) stainless steel tubing. It is planned to ship the fuel from Santa Susana, California, to Oak Ridge in the modified PAR loop carriers, with a maximum of 10 elements being shipped in each carrier per trip.

The design of internally cooled electrical coils for the production of high frequency intensity magnetic fields presents many new aspects and combinations of the familiar modes of heat transfer. However, the customary methodology appears to be sufficient for preliminary analysis and understanding of those problems. This methodology comprises the derivation of a qualitative, approximate equation expressing the relative performance of the various parts of a system, followed by an examination of this equation in order to locate the limiting features of the system. These features are then investigated by more powerful methods, which in turn provide guidance for development research in the laboratory.

Volstility Pilot Plant Mark III Fluorinator will be a double-chamber type vessel, each chamber 2-1/2ft. by 16in. o.d. separated by a 5 in. pipe 15 in. long. ASME flanged and dished heads will be used for the chamber tops and conical sections with a 60º apex angle for the chamber bottoms. A new furnace designed to maintain the complete lower chamber (molten salt + freeboard) above melt temperature will eliminate past experiences of salt solidification on the wall, heads, and in or on the internal process lines. External pipe runs will be sutoresistance heated to allow melting and drain back of salt plugs. The upper chamber serves as a gas de-entrainment and solids precipitation device to retain most of the entrained salt and condensable fluorides in the 100-400°C temperature range.

In the use of a reactor as a device to measure neutron cross sections, the pile oscillator is often employed because of its much higher sensitivity compared to that available in static reactivity measurements. The factor limiting the available in static reactivity measurements. The factor limiting the available sensitivity is the generation of random noise, which originates in the statistical nature of the chain reaction. In other words, the nuclear reactions which maintain the chain reaction do not proceed uniformly, but rather at rates which fluctuate in time around some average values. These fluctuations limit the accuracy of measurements in the reactor.

The thickness of an oxide film on phosphor bronze helices was determined by first establishing the oxygen content of the helix "as received" and after cleansing with nitric acid. Based on the assumption that the difference between these two values was the oxygen in the film, and that the film consisted entirely of cupric oxide, the thickness of the film was calculated from the density of cupric oxide, weight of the film, and surface area of film. A value of 1080 A was calculated as the thickness by this method.

The technique of high-frequency titrimetry has been applied to the determination of thorium, uranium, sulfate, and free acid. In Part I of this report, the reproducibility of the method for the titration of standard solutions which contained 50mg of thorium in the absence of interferences is established. The coefficient of variation of the method, under these conditions, was found to be less than one per cent. In Part II, the effect of uranium on the high-frequency titration of thorium, as well as the application of the method to actual samples, is discussed. Uranium in a ratio of 5 to 1 to thorium can be tolerated. When the method is applied to the analysis of representative samples, the coefficient of variation is one per cent.

A study was made of a method for the flame photometric determination of iron. In Part I of this report, the flame emission spectrum of iron, measured by means of a Beckman Model DU spectrophotometer with a flame attachment, is compated to that measured with an ORNL high-sensitivity, recording, single-beam instrument, in order to determine which instrument is best suited for this application. Although it was found that the Beckman product has the higher resolving power over the wavelength region of 360 to 400mu, it does no posses the sensitivity or ease of operation of the ORNL instrument. On this basis, the ORNL flame spectrophotometer is used in subsequent tests. After selecting the best-suited instrument for the flame photometric determination of iron, it was necessary to establish the optimum operating conditions for this particular method. These conditions are described in Part II.

A study of the thermodynamic properties of dilute aqueous hydrochloric acid solutions at elevated temperatures by an electromotive force method was undertaken for several reasons. First, a great need for fundamental information at elevated temperatures was evident from the growing number of industries making use of aqueous solutions at elevated temperatures. Second, the use of the hydrogen electrode against the silver-silver chloride electrode in dilute hydrochloric acid solutions promised to give fundamental thermodynamic information on an important electrode system as well as on hydrochloric acid over a wide temperature range.

The 0.045m UO2SO4, 0.036m CuSO4, 0.025 m H2SO4 solution (HRT fuel composition) was chemically stable during 1, 866hr of operation at 280ºC and 1500 psi. The system was pressurized by boiling a 0.4 gpm stream of the fuel in a titanium heat exchanger at 313ºC.

Considerable delay has occurred in getting ratification of the Eurochemic charter by 80% of the participating nations. The French, who were not expected to ratify the charter until an elected government was again established , actually ratified under de Gaulle late in 1958.

In order to make rational predictions of the operating characteristics of uranium anion exchange contactors, an understanding of the mechanism and kinetics of the exchange is necessary. Toward this objective an effort is being made to determine the equilibrium sorption isotherms and rates of sorption of uranium on the anion exchange resin Dovex 21K.

In order to make rational predictions of the operating characteristics of uranium anion exchange contactors, an understanding of the mechanism and kinetics of the exchange is necessary. Toward this objective an effort is being made to determine the equilibrium sorption isotherms and rates of sorption of uranium on the anion exchange resin Dovex 21K.

To better understand the solvent extraction process much effort has been and is being expended at ORNL and elsewhere to measure reaction kinetics of the extraction reactions. To date these efforts have been largely unsuccessful, due to the attempt to apply homogeneous reaction kinetics to two-phase systems. An optical method has been devised for analyzing the concentration profile in the vicinity of a quiescent interface during steady-state diffusion at rather large molecular fluxes. The system under study is the extraction of uranyl ion from water by a TBP solution. Considerable effort has been directed to eliminating leaks in the diffusion cell and testing the optical system/

During the development of in-reactor corrosion experiments three types of bomb designs have been developed for following quantitatively the consumption of oxygen in a bomb which is fabricated from the particular metal under test. The bombs are designed so as to be rocked continuously during their in-reactor exposure, consequently agitating the uranium salt solution contained in the bomb and permitting gentle movement of the solution past metal specimens and other corroding surfaces. The oxygen pressure is produced within the bomb at the beginning of the run either by the withdrawal of gas from an oxygen tank or by the decomposition of hydrogen peroxide added just prior to closure. Temperature measurements are obtained by mans of thermocouples placed in a well within the bomb body or, in the latest design, there will also be thermocouples staked at several points on the outer wall of the bomb. The assembly is inserted in an experimental access hole in the reactor, brought up to a predetermined operating temperature by means of an electric furnace in close contact with the bomb, and allowed to remain for the desired amount of exposure to reactor radiation. Periodic measurements of temperature and pressure are made and the bomb …

Results of previous toroid tests with 28 micro 1600 fired ThO2 spheres are analyzed. Four possible explanations for the essentially zero attack rates are offered and discussed: peculiar motion of toroids or some unknown wall effect; rotational hydrodynamic forces cushioning the particle impact; the bed was not in suspension and not sliding over the walls of the toroid; round particles are not as erosive to oxide film surface as sharp pointed particles.

Calculations indicate that it is impossible, even at high oxygen injection rates, to insure an excess of oxygen in the HRT fuel solution if the bubble letdown rate is more than 1 or 2 liters per minute. If, on the other hand, no bubbles are allowed to form, a reasonable excess oxygen concentration can be maintained with an oxygen injection rate which would not tax the capacity of the off-gas system. The xenon poison will be reduced to less than 2% by liquid letdown alone, and if an iodine absorption bed is installed below the catalytic recombiner, the xenon poison should be less than 1% without any bubble letdown. Therefore, it is recommended that sufficient copper be added to prevent the formation of gas bubbles and that the oxygen injection rate be limited to a value which would permit adequate holdup times in the present charcoal adsorption beds, assuming this quantity is sufficient to meet corrosion requirements.