It is desirable that a reactor exhibit a self-regulating effect. If this were not true any disturbance to the reactor would result in a continual increase in the magnitude of the disturbance and the reactor would be unstable. In this investigation the reactor is considered to have two reactivity feed-backs: metal temperature and water temperature reactivity effects. These two variables through a metal temperature coefficient and water temperature coefficient determine not only the reactor stability but also determine many operational characteristics.

Document HW-33176, "A Proposed Scope of the 100-K Sulfuric Acid Addition Facilities", presented the justification and bases for a sulfuric acid addition facility at the 183-K headhouses and included a system for adding the acid to the raw water. Since the issue of this document several factors to consider in such a system have been brought to light by experience gained both at K and at other areas. The alternate system presented here eliminates several of the troublesome points in the previously proposed system.

Apparent [Sigma] hyperon decay events in a large emulsion stack of 240 9" x 12" pellicles have been classified into those judged to have occurred at rest and those in flight. Of 36 decay events at rest, 21 secondaries were observed to be protons of about 1675 microns range. Of the events decaying in flight, 23 were decays into protons and 46 were decays into near-minimum secondaries. Attempts have been made to trace the tracks of 35 of the lightly ionizing secondaries; the results of this effort are summarized in a table.

This review lists some of the salient features of semiconductor particle counters and cannot claim to contain an exhaustive listing of all the work in the field. Performance results on the surface-barrier counters as developed at California Institute of Technology are included as typical for this type of counter, though comparable results have been obtained elsewhere.

"A convenient summary is given of useful formulas on the kinematics of high energy electron scattering together with a derivation of the relevant formulas for transforming from the center of mass to the laboratory system such parameters as scattering cross sections. The formulas derived hold for any two- body collision: the approximation (m = 0) employed for the electron scattering calculations is rigorously true for the elastic scattering of photons."

Abstract: "A theoretical criterion is given for the conditions under which the ions from an ion source may be decelerated by a decelerating grid, following the accelerating grid which extracts ions from the emitter, without causing a reduction in the current supplied by the source."

From introduction: "This article constitutes the third of a series of three papers on the "direct" measurements of the meson masses by the "Hp vs. Range" mass ratio method...The study here reported is a logical extension of the pion-proton mass ratio technique."

Abstract: "A torus model of the elementary particles is suggested in which the electron and proton are made stable by gravitational forces derived from the electromagnetic field. It is suggested that the gravitational forces for the unstable particles, presumably the mesons, are not sufficient to keep the torus from expanding in the direction of its large radius. Rest energy zero can be achieved, presumably for photons and neutrons, when the gravitational energy and electromagnetic field energy are equal in magnitude. The manner in which these models can exhibit spin, magnetic moment, wave length, and phase velocity is indicated. The origin of nuclear forces from an electromagnetic basis is indicated."

The feasibility of removing and recovering cesium-137 from various HAPO process solutions by precipitation of Cs2ZnFe(CN)6 has been demonstrated previously. Pilot plant studies of calcination and steam hydrolysis of non-radioactive Cs2ZnFe(CN)6 precipitates by members of the Process Equipment Development Operation are currently in progress. In support of these pilot plant studies, experiments were performed to determine the extent, if any, to which cesium volatilizes during calcination and hydrolysis of Cs2ZnFe(CN)6 precipitates containing cesium-137. Experimental procedures and results are presented in this report.

The following report describes results from a study of three types of cement (Barytes, Brookhaven, and Portland) exposed in the ORNL Reactor for periods of seven and twenty-eight days.

Cost estimates for two types of Th producing plants are offered. One utilizes Th(NO3)4 as raw material, the other uses monazite sand. Final processing schemes and plant designs are not fixed, so the estimates represent maximum costs. Recommendations for research and development of Th producing methods are given.

The basic information about the path of carbon in photosynthesis is reviewed, together with the methods that were used to discover it. This has led to the knowledge of what is required of the photochemical reaction in the form of chemical species. Attention is then directed to the structure of the photochemical apparatus itself insofar as it is viewable by electron microscopy, and some principles of ordered structure are devised for the types of molecules to be found in the chloroplasts. From the combination of these, a structure for the grana lamella is suggested and a mode of function proposed. Experimental test for this mode of function is underway; one method is to examine photoproduced unpaired electrons. This is discussed.

The equilibrium and maximum override values for xenon and samarium poisoning have been computed using the recently issued effective cross sections of C. H. Westcott. Values are given as a function of specific power, neutron temperature, and epithermal flux content.

"This is a selective bibliography of books and periodical articles relating to extrusion die design with special emphasis on extrusion of beryllium. Material on the extrusion process has been included when it contains information that might be of possible help in die designing."

The countercurrent gas-liquid system BF3(g)—anisole·BF3(l) for the concentration of boron isotopes has been studied. The single-storage separation factor varies from 1.039 at 0°C to 1.029 at 30°C. Rate of exchange is rapid, and, with efficient contacting equipment, complete exchange may be obtained in less than 15 sec. A total separation of 1.525 has been realized in laboratory equipment. The critical-product reflux reaction is quite efficient. Only about 55 moles of BF3 remain in each million moles of effluent solvent under laboratory conditions. The vapor pressure of BF3 over the complex rises sharply as the temperature is increased. At 0°C the pressure is 150 mm Hg, and at 40°C the pressure has risen to 1800 mm Hg. From vapor-pressure measurements, an approximate upper limit of ΔH= -12kcal per mole of complex was calculated for the reaction [equation not transcribed]. Qualitative tests indicate good resistance of anisole to decomposition by BF3 under plant conditions. The uncatalyzed exchange of boron between BF3 and BCl3 was found to be too slow to be exploited in a countercurrent system. The single-stage, equilibrium separation factor for the Nitrox system is a function of acid concentration. At 26°C the factor ranges from 1.064 with 1 M acid …

Absolute differential cross sections for the reaction p + p - w+ + d were obtained by detecting meson-deuteron coincidences produced by passing the 340-Mev external proton beam of the Berkeley synchro-cyclotron through a liquid hydrogen target.

An inventory of the contaminated materials accumulated since the initiation of this project in June 1958, revealed a larger variety and quantity of materials that could be burned, than was specified for the initial scope. Therefore, it is desirable to revise the scope to permit handling the majority of these materials with the initially installed equipment.

This procedure is intended to be used as: 1. An instruction and guide for operation of the KER loops. 2. To aid in familiarization and understanding of the general operation of the loops. 3. To prevent lost time due to errors in loop operation. The procedure is not meant to be completely comprehensive in all details of loop operation.

Technical report describing that the use of controlled amounts of carbonate, acting both as complexing agent buffer led to a fairly satisfactory procedure for the determination of Th in Th-U alloys, using cupferron. The alloy, dissolved in NHO2, in the presence of HF, is treated with H2SO4 and the mixture is evaporated in SO2 fumes. The solution is diluted and (NH4)2CO2 is added. Th is precipitated from this solution with cupferron. The precipitate is weighed as ThO2 after ignition. An accuracy of 6% was obtained. A method was developed specifically for the determination of Th in U-Th alloys containing 1 to 10% Th. An ion exchange resin in column is used to separate Th from U, with NH2OH-HCl as complexing agent. The Th is then precipitated, ignited, and weighed in the conventional manner.

Abstract: "Four brazing methods and one other joining process were evaluated for the joining of aluminum spacer fins to flat-plate aluminum-clad fuel elements. None of these methods appear completely suitable for use in a mass-production operation. Furnace brazing and salt-bath brazing were most promising. However, the mechanical problems involved in the application of either process deter their recommendation. Resistance brazing and torch-brazing were proven impractical. The great difference in mass between the two pieces being joined prevents the use of either the resistance or torch method. Pressure bonding is not applicable because of the excessive deformation of parts being joined."

This report reviews aspects of experimental and clinical research performed in the investigation on the pathogenesis and recovery of bone marrow injury caused by total body irradiation.

Abstract: "The effect of variation in fuel element density upon f, p in a D2O cooled and moderated lattice of cylindrical fuel elements is investigated. The CP-3 lattice is chosen as a reference. The effect of a source term in the fuel element is considered. f, p are calculated as functions of "a", the ratio of the modified fuel element density to the original (fuel only) density. Curves showing f(a), p(a) are included. It is concluded that a 1 per cent decrease in the product, f(d), p(a) is not suffered until a=0.3. A 5 per cent decrease in k is estimated at a-0.4. The necessity of introducing the fuel element source term into the calculation after a has been decreased to about 0.6 is brought out."

The Lindemann assumption of direct contact of neighboring atoms at fusion is replaced by the criterion that melting occurs when the root-mean-square amplitude of thermal vibration reaches a critical fraction ρ, presumed the same for all isotropic monatomic solids, of the distance of separation of nearest-neighbor atoms. The Debye-Waller theory of the temperature dependence of the intensity of Bragg reflection of x-rays is used, without further assumptions, to derive a generalized Lindemann law. In contrast to the Lindemann form, all physical quantities involved in this formulation are evaluated at the fusion point, and departure of the average energy of an atomic oscillation from the equipartition value is taken into account by the quantization factor of the Debye-Waller theory. If the Grüneisen constant γm of the solid at fusion is evaluated by its definition from the Debye frequency of the solid, use of the generalized Lindemann law and Clapeyron's equation permits one to express γm in terms of the bulk modulus of the solid at melting and the latent heat and volume change of fusion. By means of Grüneisen's law applied to the solid at fusion, γm can be expressed likewise in terms of the corresponding bulk modulus, thermal expansion, volume, …

The following report analyzes results from studies made while applying chelating agents to ion exchange separations of the elements americium and curium.