Apparent excessive concentrations of atmospheric contamination which were reported to be associated with an inert-gas-shielded consumable electrode arc wielding operation were studied to evaluate the potential health hazards. A study was made of the concentrations of metal fume and gaseous products of the operation as well as the spectrum of ultraviolet radiation. Recommendations for necessary controls were made.

Report discussing reaction of hydrogen with uranium in a range of temperatures and pressures. Experimental materials, methods and results are included.

This report covers the progress made on an intensive program to develop and evaluate UO2 as a possible fuel element for the PWR.

A study of the variables involved in regeneration was undertaken to determine means of improving the regeneration efficiency and increasing the useful life of a reactor. Information gained from regeneration studies on a 4-inch-diameter by 8-foot-high column indicates that the present regeneration procedure is optimum as to quantity, concentration, and rate of addition of regenerant solution. It appears feasible to restore a plugged reactor by washing off all the silver nitrate from the packing and recoating by a normal regeneration cycle. Such a procedure could be utilized only if there is sufficient dead space in the bottom of the reactor to hold the wash solution.

Twelve neutron activation analyses for naturally occurring technetium-98 were performed. Positive results were obtained in ten cases. Precautions were taken to avoid interference by molybdenum and technetium-99. the cross section for the reaction [formula] as found to be equal to 4 +- 2 mb for the neutron spectrum of the vertical thimbles of the Argonne CP-5 reactor. The chemical state of molybdenum (VI) in basic solution was studied by an anion-exchange technique. Evidence was obtained for the existence of polymeric species at pH-values up to 14. Preliminary work on the stability of Domax-1 anion exchange resin in perchlorate media indicates rapid deterioration even at 0.2F ClO4-.

A gage employing a narrow "pencil" of beta-rays has been developed to determine the thickness of films used a cyclotron targets. The instrument, pictured in Figure 1, allows an estimate of the evenness of films a few mg/cm thick by reproducibly scanning the sample with a collimated beta-ray beam 3/32 in. in diameter.

It is recommended that self-concentration of Purex wastes should not be started until much more complete knowledge is obtained of the conditions and reactions in these wastes. The presently planned tests in the Semi-Works will be a practical demonstration of the problems but will be of little value on the initial Purex wastes as these tests are being run almost concurrent with the filling of the first Purex storage tank.

This technical report represents a brief survey of work by this project on the effects of ultraviolet radiation (UV) on certain of the photochemical and metabolic properties of rhubarb chard and sugar beet (Beta vulgaris). These plants were selected for this work because for some years they have been used as sources of chloroplasts for Hill reaction studies in this laboratory. Some of this work has appeared as a brief paper.

Introduction: "At the start of the uranium project, it became necessary to design and construct a furnace suitable for melting and casting uranium powder into massive form. Early experiments showed that pressed and sintered compacts of uranium powder were inferior to the cast metal. Since the metal powder is quite phrophoric, such casting would have to be done in an inert atmosphere or in vacuum. Preliminary investigations indicated that the powder could be melted in vacuum induction furnace. Facilities were then engaged in the Department of Metallurgy at the Massachusetts Institute of Technology for developing a vacuum induction furnace to melt and cast uranium on a large scale."

Thus we see that the derivation of elementary age theory is based on replacing the probability of collision governed by the Milne kernel by a Gaussian probability having the same zeroth and second moments. It is apparent that the age theory distribution will fail close to the source and at many free paths from the source.

An evaluation of the relative health hazards of radioisotopes produced in nuclear reactors is reported. The most important hazards were indicated to be I131, the Sr90 - Y90 chain, the Ce144 -Pr144 chain, Sr 89, the Ba140-La40 chain, Y91, the Zr95-Nb95 chain, Pr143, La140 , and Pa233. The most critical body organs affected by air-borne contamination are the thyroid gland, the bone marrow, the lungs, and the gastrointestinal tract. Where possible, continuous daily removal of gaseous and solid fission products from the reactor environment can be shown to permit very significant reductions in the total hazards. Homogeneous reactors, such as the Thermal Breeder Reactor and the Homogeneous Plutonium Producer Reactor, specifically studied in this report, are designed with daily removal cycles and may be considered potentially safer than heterogeneous reactors.

The following report analyzes various experiments made to discover factors that may affect properties of extruded compacts of crystal bar zirconium.

Abstract: The reactor kinetics equations are combined into a single integral equation whose kernel describes the time-dependent characteristics of the reactor including six delayed groups of neutrons. Numerical solutions of the integral equation are given for constant, linear, and ∫sin²kx dx reactivities. An approximate solution of the integral equation is obtained which provides a basis for the formulation and solution of the reactor system control problem using the methods of servomechanisms theory. The reactor frequency response function, a product of the approximate solution, is calculated and plot given.

This report follows experiments on K[infinity], measuring the element for several red sizes, enrichments, and water-to-uranium volume ratios-(1, 2), by making use of the relation k[infinity] = 0M-[2]B-[2] (M-2 = migration area, B = buckling). The purpose of this report is to compare the experimental data for k[infinity] with values calculated from the four-factor formula k[infinity] = [eta][epsilon]pf.

From introduction: "As part of the program for improvement of graphite, the structural characteristics of graphite have been studied to determine the relation between physical and structural changes during irradiation."

Due to laboratory interest in devices capable of production of high current with short rise times in gaseous discharges (plasmas), an experimental machine has been built and tested to obtain data applicable to the design of a high gradient magnetic induction machine. This machine consists of a condenser type energy storage bank air core coupled to a toroid in which the plasma is produced. It has been used to determine circuit parameters and the effect of these parameters on the plasma.

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.

A detailed study of the activation of low-reactivity UO2 particles toward HF by successive oxidation and reduction was carried out. The effect of repeated successive oxidation and reduction on the reactivity of the UO2 source material toward HF was evaluated by hydrofluorination.

As previously reported, zirconium undergoes large dimensional increases after scaling in air in a critical temperature range, 700 degree-1050 degree C. This finding was observed with specimens of a constant thickness (0;062 in.) To study the thickness effect, a number of specimens ranging in thickness from 0.020 to 0.200 in. were scaled in air at a temperature (900 degree C) where the growth is a maximum for a given time. Both cold rolled iodine sheet and forged iodide bar stock were used. to determine the effect of orientation, specimens from the forged bar were obtained such that the scaling surface was either parallel to or perpendicular to the long axis of the bar.

"This report is concerned with a listing of some of the pertinent properties of promising materials which do not form low melting alloys or brittle intermetallic compounds with uranium, and which could be ductile enough to be fabricated in the form of small tubing."

In order to utilize the advantages of the electron microscope for the study of respirable particles, it is desirable to have an instrument capable of sampling from atmospheres having very sparse dispersions of particles at a rate sufficiently high to result in precipitation densities of approximately one particle per 10/u² of microscope screen for a 10 minute sampling period. In order to avoid qualitative or quantitative alteration of the aerosol, it was desired that the instrument collect the sample directly on an electron microscope screen rather than on a filter material for subsequent transfer to the screen. This paper summarizes work aimed at the development of such an instrument.

periodically the Industrial Hygiene Unit has the occasion to perform efficiency tests on respiratory protective devices and on filter cartridges used with these units. A study of the relative merits of the flame photometer and conductivity meter was made to determine which is more applicable for the determination of NaCl in filter samples.

The following report studies the dissolution of aluminum-canned thorium, providing results that suggest a dissolution cycle that permits the separation of the canned-slug components.

Abstract: "Aluminum electroplating was studied in a search for new methods of cladding uranium fuel elements. Uranium electroclad with 12 mils of aluminum over a 0.5-mil (or nickel plus copper) electroplate resisted corrosion for more than 100 hr in boiling water. This quality of protection was effected by hot pressing the electroclad uranium with 5.1 tons per sq in. for 5 min at 950 F. The electroclad uranium with hot-pressed samples paralleled those of later experiments with hot-pressed wrought aluminum claddings on uranium. In both cases, the uranium was electroplated with thin (0.5 mil) layers of metals to prevent aluminum-uranium diffusion, to aid bonding, and to assist in corrosion protection. This aluminum electroplating study helped to define the importance of the intermediate coating between the aluminum and the uranium, the effect of good bonds between the various layers, and the effects of hot pressing in protecting uranium with an aluminum cladding."