In the memorandum entitled "Stored Energy in BNL Reactor Graphite", dated February 25, 1953, there is described an experiment conducted by Gurinsky's group to determine the energy per gram of irradiated graphite released in a 200°C anneal. Similar experiments were subsequently conducted by W. Kosiba, differing from the original in two particulars: a) Instead of two graphite samples, one normal, and one irradiated, Kosiba used only an irradiated sample which he heated first to release the stored energy, and then again after the energy was released. In this way, he obtained time against temperature curves for both normal and irradiated graphite from the same sample. (These curves are graphed for each run in Figs. 1 thru 5.) b) The vycor tubing used in the original experiment was not used by Kosiba. Five runs of this experiment were selected, Runs 4P, 13, 36, and 40 at furnace temperatures of 200°C, and Run 45 at a furnace temperature of 400°C.

The purpose of this report is to describe a method of obtaining deuterons from the 184-inch cyclotron of higher energy than can be achieved from direct acceleration.

Progress report on programs in target research and in accelerator research.

Recent studies on the separation of cobalt and nickel and on the behavior of iron in hydrochloric acid on Dowex-1 resin in relation to the selective adsorption of chloride complexes of these elements have suggested the use of resin for the separation of iron and cobalt.

A calculation method has been developed in order to correlate continuous-flow extraction results in mixer-settlers with rate data for batch experiments. This correlation utilizes dynamic extraction coefficients (E's) that are calculated from the rate data and the equilibrium extraction coefficients. The dynamic coefficients may then be used in stage-by-stage calculations, or their average values used in equations derived herein from the overall performance of center-fed columns.

An improved continuous ether extractor is described. The modifications include a means of safely disposing of the active raffinate and a means of positivity checking the raffinate for completeness of uranium extraction. The results obtained on synthetic samples and on dissolver solutions are given. This work was undertaken because of a need for the determination of uranium in dissolver solutions with an accuracy of 0.1 per cent. After a review of available methods it was decided that a gravimetric determination would meet the requirements of precision and accuracy.

The ZPR-I is a facility to study low power critical assemblies using enriched uranium as fuel, having a light water moderator and an essentially infinite water reflector on all sides. The fuel is held in elements 43" long with a 1" square cross section. Any of these elements may be placed in or removed from any position in the reactor tank. Thus, any desired core configuration may be easily obtained.

This technical report describes work done on the electrolytic refining of natural uranium in fused salt baths composed of various eutectics of alkali metal chlorides in which were dissolved UF, or UCl3.

This report deals with the (1.1) physical properties of graphite, (1.2) effects of pile irradiation on the properties of graphite, (1.3) effect of irradiation on "ceramic" materials, (1.4) exposure and dosage for radiation damage experiments, (1.5) apparatus for the measurement of the thermal conductivity of solids, (1.6) effects of radiation on ice -- the thermoluminescence of ice, (1.7) investigation of color centers and other optical properties of single crystals. (2.1) radiation chemistry of liquids, (3.1) radiochemical investigation of the spontaneous fission of Cm242, (3.2) radiochemical service, (3.3) on the one-body model of alpha, (4.1) spectrographic analysis, (4.2) chemical analysis, (5.1) the 60-inch cyclotron.

The annealing or heat treatment of uranium in any medium other than a good vacuum or purified helium atmosphere, will lower the room temperature properties of ultimate strength, hardness and elongation. In general, the elongation of vacuum annealed uranium exceeds considerably the elongation of air or salt annealed uranium. Any annealing medium which permits contact of the uranium metal with atmospheric gases tends to produce low elongation and ductility and a lowering of the ultimate strength. The above is true for uranium in any solid form, whether it is rolled sheet, cast bars or plates, rolled rod, or extruded shapes. Annealing in the molten salt bath (65% potassium carbonate and 35% lithium carbonate), which is used by Los Alamos and other laboratories concerned with the fabrication of uranium, produces the lowest elongation or ductility and ultimate strength when compared to similar properties of metal annealed in the other media examined. Mass spectrometer analyses of the dissolved gases present in high ductility and low ductility uranium indicate that dissolved hydrogen is probably the chief cause of low physical properties.

Removal of particles from air is discussed in terms of three classes of filtering media--air-sampling, respirator, and air-cleaning. Plots of efficiency versus filtering velocity are presented. The pressure drop characteristics of the filters are discussed in terms of initial pressure drops of the clean filters, variations in pressure drop of the individual filters, and comparison of loading rates.

Several improvements have been made in the gamma scintillation counter (GSC). The Model V gamma scintillation counter uses a canned thallium activated sodium iodide crystal as a detector. Although the electronic components remain unchanged, a modification of the sample support has been made to improve reproducibility of geometry. To assure comparable results between various counters, they must be operated at the same energy threshold and counting yield. Methods have been developed to assure operation at a preferred energy threshold of 0.1 Mev and an arbitrarily fixed counting yield of 3.36% for Cs-Ba-137. Partial pulse height discrimination against U 237 is also accomplished.

In 1949 Barad presented two solutions to the general diffusion equation. Basic in both solutions is the assumption that in very stable atmospheres a point source may be replaced by a vertical area of uniform concentration at a short distance downwind. This vertical area is considered to exist at the distance at which the plume finally "levels-off" and assumes a flat ribbon-like appearance. In addition if the distance over which diffusion takes place is limited to one or two miles and if only the stable atmosphere with its narrow range of eddy sizes is considered, the average diffusion co-efficient (K) has a signficance which it does not have in the case of neutral equilibrium.

In obtaining the results reported here a double focusing magnetic type spectrometer was used. Momentum spread was about 1%, and in most cases 2560 counts per point were taken. An end window Geiger tube was used as a detector. The window was of mica with areal density of 1.6 mg/cm2.

Various organizations in the Biophysics Section of the Radiological Sciences Department participated in evaluating local radioactive particle fallout as influenced by the nuclear explosions at the Nevada Proving Grounds during the early part of 1953. Data collected from approximately 50 air monitoring stations operated by the Regional Survey forces were used to determine the trend of radioactive particle concentrations in the atmosphere between March and June. These measurements were supplemented with the findings of associated organizations in the Biophysics Section during and immediately after the peak influx on May 26.

Some data on the temperature effect in pulse columns are reviewed. New data obtained with the "vibrational" stirrer are reported. The effects on both the dispersion and coalescence and the net rate of extraction suggest that improved operation of the RA column and lowered waste losses would be expected at elevated temperatures.

Seven runs were made with the system Penn. Ref. Co. "Supersol" (dispersed) water (continuous) to investigate the effects of pulse frequency, amplitude plate spacing, volume flow ratio, and throughput on backmixing, using the technique of continuous injection of a tracer solution into the packed section. Backmixing was found to be surprisingly insensitive to all the above variables over the range studied with the exception of pulse amplitude and continuous phase flow rate, showing greatest dependence on the later. Backmixing increased with decreasing continuous phase flow rate and increased with pulse amplitude.

The monitoring of thermal and resonance neutron flux in a thermal reactor having high flux over periods of time from 1 to 12 months using think Co foils is considered. Special attention is paid to the many correction factors to be applied to the activation data; neutron temperature, effective cadmium cutoff energy, burnout of Co59 and Co60, and decay of Co60. Results on a homogeneity test of 10 mil, 0.08% Co-A1 alloy foils is given.

A first iteration of the diffusion theory result is executed for the thermal flux distribution in a 7.5" graphite-uranium lattice cell using the integral equation formulation of transport theory.

"Neutron total cross sections for bismuth and uranium have been measured in a good geometry transmission experiment, using a time-of-flight instrumentation. The source of neutrons was the stripped deuteron beam of the 184-inch synchrocyclotron. The results are shown in Fig. 1. Uncertainties are shown in terms of standard deviations, due to counting statistics only, and to energy channel width."

Abstract: "The age-diffusion is adequate to describe the neutron behavior of a very large class of nonthermal reactors (all except those whose dimensions are comparable to the neutron mean free path). Thus, a convenient means of obtaining an accurate solution to this equation is very useful for general reactor calculations. Methods for reducing the age-diffusion equation to a finite set of coupled ordinary differential equations, called multigroup equations, are described. The relative merits of several alternate schemes are discussed. The multigroup equations may be solved by iterative procedures based on an assumed spatial distribution of the fission source neutrons. In practice the initially assumed source shape is accurate enough so that additional iterations are unnecessary. Analytical and numerical methods for solving the multigroup equations with the assumed source are discussed. The adjoint equations are also reduced to multigroup form, and examples of the adjoint function in obtaining improved reactivity values are given."

Abstract: "The determination of trace concentrations of uranium in synthetic materials, ores, soils and water by neutron radioactivation analysis is described. The principles of the activation analysis method as applied to trace uranium determination, the processing of irradiated specimens, and some examples of the results obtained by this method of analysis are discussed in this paper."

From abstract: "The cross section of carbon for the n, y reaction was determined using samples of graphite, barium carbonate and carbon dioxide. The results were consistent only when samples were used which were enriched in C¹³."

Abstract: "A precise potentiometric method for the determination of uranium in essentially pure uranium oxides is described. Ten gram samples of oxides are reduced in a Jones reductor and titrated potentiometrically to U+4, using platinum and tungsten electrodes. A weighed amount of solid Bureau of Standards potassium dichromate is then used to oxidize at least 99 percent of the uranous ion, and the oxidation is completed by titration with 0.01 N potassium dichromate using calomel and platinum electrodes. This method, which is based on a primary chemical standard, has a precision of +/- 0.015% on a single determination at the 95 percent confidence interval."