The meter, based on the galvanic cell described by Hersh, was developed by the Analytical Chemistry Group of the A.A.E.C. Research Establishment to enable traces of oxygen in gases to be determined. The instrument consists of our main parts; the galvanic cell, the electrolytic cell, the flowrate indicator, and the control unit.

The main difficulties of experiments on the influence of radiation on creep is metals are discussed. Some typical apparatuses for investigation by using natural sources, reactors, cyclotrons, etc., are described. These methods have resulted in relatively inaccurate measurements up to now. Therefore, the published results do not allow any statement of laws, but only tendencies. There is a surprising influence of charged particles on creep rate in spite of their low depth of penetration. The discussion of the results leads to the conclusion, that the temperature of the specimen, the stresses and the density of beam are very important. Two requirements are put forward if such researches are to be of technical importance and not only of theoretical interest.

The complex formation reaction between beryllium and aluminon was investigated for different values of pH. It was established that at pH between 4 and 5 a complex is formed containing the constituents in the ratio 1 : 1 . At a pH between 7 and 8 a complex is formed having a beryllium-aluminon ratio of 3 : 1. At pH 6 both complexes are formed . It is shown that the complexes can be distinguished optically and in other aspects. The colorimetric determination of beryllium with aluminon is made at pH 5. At this pH value the results obtained for the determination of beryllium are satisfactory and of sufficient reproducibility.

Selenenoyl-2-acetone is much more suitable for the extraction of thorium from aqueous solutions than acetylacetone, which is extensively used for this purpose. The stability constants of thorium selenenoyl-2-acetoneates and the distribution coefficient of the extracted complex in the CHCl3-H2O system have a higher value than those of the acetylacetonates of this element.

EDTA is an eluant with many possibilities for analytical chemistry. The authors present the results obtained in the separation of carrier-free radioisotopes; separation of Ba, Sr, Y, La; preparation of 228(Ra) from thorium; separation of Ca, Sr, Ba, and Ra. All the results were obtained with Dowex 50.

Ceramic fuel element specimens consisting of a uranium oxide-thorium oxide solid solution dispersed in beryllium oxide were fabricated by hot pressing in graphite dies. Details of fabrication techniques are given. Tests for overall composition, homogeneity and size and shape of fuel grains made during and at the completion of the work indicate that the specimens are in general agreement with initial specifications.

This technical report describes two atmospheric pressure rigs with associated equipment designed for investigating heat transfer and friction characteristics of different type of "roughened" surfaces to develop suitable surfaces for an H.T.G.C.R. fuel element. Operating details are given together with techniques used to measure heat transfer and friction on a surface assembly incorporating selected "roughened" surfaces. Methods for calculating Stanton numbers, friction factors, and Reynolds numbers for such an assembly are included.

It has been shown by studying the possibilities for determining the constants in stepwise complex formation by the interaction of hydrolyzed metal ions and ligands, that in a vast number of cases the direct measurements of metal ion and ligand activities ae necessary. Complete formulae for calculation are given and the conditions which allow some simplifications are established.

Pressure drop and heat transfer in annular tubes have been measured. The surface of the inner tube was artificially roughened. The investigation covered a range of Reynolds numbers from 200 to 100,000. The maximum heat flux, directed from the inner tube to the fluid, was about 316 W/cm2 or 2.7 x 10(6) kcal/m(2) h. The heat transfer medium was water. The hydraulic diameter of the annular tube served as characteristic length in the dimensionless Reynolds and Nusselt number. The results of all experiments are presented in graphic form. Heat transfer and pressure drop increase with the degree of roughness and depend on the type and arrangement of the roughness elements chosen.

The possibilities of producing graphite impermeable to gases and liquids, and suitable for nuclear applications, are discussed. The physical properties of such graphites depend on the different sealing processes and starting materials developed especially for the purpose. In the development of reactor grade graphite, described in a previous article, Germany was well behind other countries. As far as the making of impermeable graphite is concerned, however, advanced processes for and experience in the manufacture of impermeable materials for the chemical industry were available here before the publication of other research in this field. Liquid -- and gas -- impregnation methods are discussed mainly. The problems of sealing and the degree of impermeability that can be obtained are shown using different measuring techniques. Finally, a description is given of "pyrographite", a newly rediscovered old graphite material.

1. The reaction between beryllium salts and salicylic acid was studied by the spectrophotometric method in the ultra violet portion of the spectrum. The optimum pH value for this process was found to be 9.0 to 9.5. 2. Two independent methods showed that beryllium and salicylic acid form a compound in the ration 1:2. The instability constant was determined for the a complex of the formula (Be OH Sal2)3- names (4.9 +- 0.6) x 10-18. 3. The stability of the complex and the availability of the reagents makes the reaction investigated a suitable one for analytical applications.

The extraction of beryllium by triisooctylamine is measured over the pH range from 1 to 10, in the presence of malonic, maleic, succinic, phthalic, and salicylic acids. Values are obtained for the stability constants of the various metal-acid complexes by potentiometric titration. The degree of extraction is dependent on the abundance of the anionic complex present in the aqueous phase and this is in turn dependent on the strength of the corresponding acid and the stability of the complex. (auth).

The slowing down spectra of neutrons were obtained for heavy water, light water, and mixtures of heavy water and light water. It was assumed that fission neutrons are produced uniformly throughout an infinite moderator and the only process considered was elastic scattering, spherically symmetric in the center-of-mass system. The (n,2n) reaction with the deuterium nucleus and absorption were assumed negligible. The average transfer cross section, fast diffusion coefficient, the slowing down area, and average velocity ratio were obtained for two-group calculations using the epithermal spectra. (auth).

Pechiney and Brush UOX BeO differ markedly in fabrication behaviour, only Brush UOX being readily sinterable. A comparative study of the two powders has shown few outstanding differences in powder properties. Both are of high purity but contain free and combined moisture to the extent of about 1.5 per cent. Pechiney BeO has a larger mean crystallite size (0.2 — 0.3μ) than Brush UOX (0.1 — 0.15μ) and a larger range of crystallite size, and both contain a small proportion of crystallites of size 1μ. and larger. The tap density of UOX is much lower than that of Pechiney, and its surface area is higher by a factor of two, UOX BeO can be hot—pressed or cold—pressed and sintered to high densities at temperatures of 1400º and 1500ºC respectively, which are approximately 300ºC lower than those required for Pechiney. Grain size of fabricated material increases with fabrication temperature in both grades, and at the same temperatures is larger for UOX than Pechiney. However, at comparable densities grain sizes are also comparable for the two materials, The bend strength at room temperature of hot—pressed Pechiney BeO reaches a maximum of approximately 30,000 p.s.i. when pressed at 1750ºC. Above this temperature the …

An investigation of the solvent extraction behavior of salicylato- beryllium complexes is reported. A simplified method for calculating the stability constants has been developed. The values obtained are beta /sub 1/ = 4.0 x 10/sup 12/ and beta /sub 2/ = 4 3 x 10/sup 22/ in 0.15 M sodium perchlorate. (auth)

A method is presented for the analysis of transient temperatures in a homogeneous circular cylindrical fuel element in a coolant channel with no axial conduction and no heat loss to the channel wall. In addition, some results were obtained for mean fuel element temperatures in power transients for a simpler model, but accounting for details of the axial coolant temperature distribution in the unsteady state. (auth).

Beryllium is a favoured canning and/or moderating material in the proposed Australian High Temperature Gas Cooled Reactor. With carbon dioxide as the most likely coolant a detailed knowledge of the corrosion of beryllium in this gas is required. Two separate investigations have proceeded simultaneously. First the effect of the following variables was studied; surface preparation of the specimen, temperature (100—725ºC), pressure (0—280 p.s.i.g.), velocity, and impurity content of the gas. The influence of irradiation has not yet been studied. Autoclaves, thermobalances, and dynamic loops were used. The results were statistically analysed and kinetic data obtained. In all cases specimens with etched surfaces yielded approximately 25 — 30 per cent, greater weight gains than specimens with ground or polished surfaces. On extruded material no "breakaway" oxidation was encountered below 650ºC in commercially dry gas (< 20 p.p.m. moisture). The rate of attack was to some extent affected by the pressure of the gas. Breakaway was only observed in one series of specimens at 650ºC. In this particular case the gas pressure was 280 p.s.i.g. However, it seems that surface temperatures of beryllium cans made from extruded material should be maintained below 650ºC in a reactor system using the commercially pure carbon …

The performance of a Schultz-type texture goniometer is shown to be adversely affected by a number of experimental errors all of which result in defocusing of the diffracted beam. Those errors result from the tilting of the specimen, from lack of precision in positioning it and from its absorption coefficient. An experimental procedure is outlined which minimized these errors and results in optimum performance of the instrument.

An apparatus for differential thermal analysis of active or toxic materials is described. The technique is superior to thermogravimetric analysis. Analysis of the dehydration of beryllium sulphate shows that the process takes place in three stages. Some applications are given for a modified apparatus for quantitative work.

A set of simultaneous differential equations is established to describe the temperature distribution for coolant flow in three concentric channels separated by walls of finite thermal conductivity and surrounding a cylindrical heat source. The solution of this set of differential equations is dependent on the heat source function Q(z) which must be known or specified. An assumed function Q(z) constant is taken as being a representative case and the resultant solutions are applied to several geometric arrangements. The system of three channel flow reduces to two channel flow when there is zero heat flow across the outer intermediate wall. This condition may arise if the wall is a perfect insulator, or if the flow in the third channel is zero. For the former case the temperature in the third channel is constant over its length, and in the second the stationary coolant assumes the temperature of the coolant in the middle channel. From the set of differential equations established for two channel flow, treatment similar to that used for three channel flow is adopted and the resultant solutions are applied to several geometric arrangements. Brief mention is made of single channel flow. By assuming that the heat sources is zero …

Empirical methods are given for calculating reactivity changes in HIFAR with changes in fuel loading, poison concentration, and temperature variations. The procedures are derived from the analysis of typical operating programs, reinforced by analogue computer analysis of variation of the important fission product poisons Xenon 135 and Samarium 149.

The second partial differentials of the production cost equation are derived in a generalized and non-dimensional form in order to determine the effect on production cost of electricity from a gas-cooled nuclear power plant of departure from optimum operating conditions. Fuel element surface temperatures up to 650 degrees C, production costs up to 1d. (A)/kwh and reactor coolant temperature rises up to half the maximum surface temperature are included. The most significant parameter is the ratio of the reactor coolant temperature rise to maximum surface temperature which causes a maximum increase in production cost of 0.5 per cent, for a +- 5.0 percent change in its value.

Fast neutron irradiation affects the properties of beryllium oxide by causing displacements and by causing nuclear transmutations. This report outlines the overall aims of a programmer to investigate this problem, reviews the information from overseas laboratories, and describes the results obtained to date at Lucas Heights. Results are given of measurements of properties of beryllium oxide fabricated by various methods and irradiated to doses of up to 7 x 10(20) avt (fission neutrons) at temperatures of 75 - 700 degrees C. The properties include macroexamination, dimensions, porosity, lattice parameter and line broadening, mechanical properties, thermal conductivity, metallography, and long wavelength neutron scattering. It is shown that an anisotropic lattice growth occurs which results in crumbling of the material at high doses. Fine-grained (<3 mu) materials withstands crumbling up to much higher doses than coase-grained material. The relationship between macroscopic growth, latttice growth, and the cracking and powdering is discussed in some detail and the results used to show the reasons for apparent discrepancies in data from overseas laboratories. Information relating to the defect structure is discussed and it is suggested that interstitial clusters in the basal planes are probably the cause of the marked anisotropy in the lattice growth. The …

A programme is described for determining the neutron enhancement due to the (n,2n) reaction in a reactor moderated by beryllium. For moderation by pure beryllium the enhancement has been found to be 9.7 per cent.