This report follows investigations of methods for sealing the ends of stainless steel-uranium oxide fuel pins with the objective to develop an end-capping method that would give consistently good-quality closures in production.

Report discussing studies regarding properties of the zirconium-uranium epsilon phase related to stability and existence range. Data showing this phase's thermodynamic stability is presented as well as the zirconium-uranium constitutional diagram. Oxygen and nitrogen effects on zirconium-uranium alloys and epsilon-phase alloys is included as well as ternary zirconium-uranium-oxygen diagrams.

Thesis discussing the relative yield of neutral pions from elements in a reaction "as a function of the quantum-limit energy (the maximum energy of the quanta in the bremsstrahlung beam) of the Berkeley synchrotron." Interpretation of the results leads to values for the mean free path for absorption of the neutral pions in nuclear matter.

Abstract: "The elastic double scattering of deuterons by complex nuclei has been investigated experimentally. Measurements were made on carbon, aluminum, and copper at around 157 Mev; on lithium, beryllium, and carbon at around 125 Mev; and on carbon and aluminum at 94 Mev. The expected tensor components of the deuteron polarization have not been observed. Measurements have been made of the differential cross section and vector-type polarization as a function of angle for the scattering of deuterons from the above elements, at the above energies. The observed polarizations were larger than would be expected on the basis of the individual nucleon-nucleus interactions. In a second experiment we measured the 169-Mev proton-proton polarization at 10, 15, 22.5, 30, and 35 in the laboratory system. The results indicate that partial waves up to and including L = 3 are important at this energy."

This report presents the best estimate possible on the basis of the available information as to how high an energy would be necessary in order that the gas pressure which could be tolerated would be attainable with present techniques (say 10-(-7) mm Hg.)

Abstract: "The measurement of large, high-frequency, short-pulse currents--ordinarily complicated by inductance, stray magnetic fields, and magnetic forces that tend to disassemble the measuring device--is simplified and made with an average error of 2-1/2% by the use of a specially developed noninductive radial shunt in conjuntion with an oscilloscope. The skin-effect correction is derived theoretically and the accuracy of the method is demonstrated."

Abstract: "The neutrons from the linear pinch in Berkeley have been shown to originate from deuteron collisions with a large net center-of-mass velocity in one direction along the axis of the pinch tube. The interpretation of this result is that the neutron production associated with the pinch is non-thermonuclear in origin. The object of this paper is to review the experimental evidence and discuss a possible source of the neutron production."

A report about elevated-temperature properties of dilute uranium-aluminum and uranium-zirconium alloys. Hot-hardness measurements show that small amounts of wither aluminum or zirconium increase the hardness of uranium at elevated temperatures.

From abstract: "Ninety-two thorium slugs were irradiated in the Hanford piles to study the dimensional stability of the metal. The burnups that were incurred covered the range from 300 to 2800 ppm of the Th232. Slugs with burnups as high as 800 ppm were examined for visual and dimensional changes. The dimensional stability of these slugs was excellent, and no significant corrosion occurred on the aluminum cans. A cursory examination of slugs with burnups of greater than 800 ppm showed no gross dimensional instability."

Abstract. The design, selection, and calculation of the Army Package Power Reactor shielding are described. The APPR-1, a prototype of a package reactor for remote locations, has a primary shield of iron and water. this shield has been adopted to permit fast erection and to provide low transported weight. economically, including transportation cost, the iron water shield is better than a lead water shield and is competitive with a concrete shield for a remote site. Because of the location at Fort Belvoir,Va., the shielding requirements for the APR-1 are considerably more stringent than those for a reactor at a remote base. Since the secondary shielding which surrounds the entire primary system must provide protection for personnel at any location outside the vapor container, concrete is provided for this need.

Abstract: The reactor analysis of the critical experiment and the APPR-1 resulted in a loading of the APPR-1 of 31.096 gm of B-10 with 22.5 kg U-335. This loading will result in adequate reactivity for a core life of 13 MWYR based on uniform burnup of U-335 and B-10. Calculations indicate that five of the seven control rods provided are more than adequate to shut the reactor down at any time. The temperature coefficient of reactivity should be at least -2 x 10-4 [delta] K/0F.

Abstract: The reactor analysis of the critical experiment and the APPR-1 resulted in a loading of the APPR-1 of 31.096 gm of B-10 with 22.5 kg U-335. This loading will result in adequate reactivity for a core life of 13 MWYR based on uniform burnup of U-335 and B-10. Calculations indicate that five of the seven control rods provided are more than adequate to shut the reactor down at any time. The temperature coefficient of reactivity should be at least -2 x 10-4 [delta] K/0F.

The thermal cycling growth and the accompanying metallographic changes were studied in 300 [degree] C rolled uranium rods up to 3000 cycles. The growth rate was found to decrease at the higher cycling levels. Project-grade material developed substantial porosity during cycling; high purity material showed no evidence of porosity.

The purpose of this report is to provide data pertaining to the corrosion damage incurred in the use of oxalic acid as a cleaning agent for process equipment.

For some time, it has been the opinion of the personnel of this laboratory and other investigators that an appreciable amount of the corrosion observed on stainless steel in nitric acid solutions might be due to the presence of some of the lower oxides of nitrogen; NO-, NO-2, etc. If this assumption is correct, the elimination of these compounds from process solutions should result in a significant increase in the service life of equipment handling nitric acid, such as acid fractionators. Since the corrosion problems experienced in acid fractionators and concentrators are very severe, an investigation of this theory becomes highly desirable. The purpose of this report is to summarize the work performed, to date, by this laboratory in the investigation of the inhibition of nitric acid corrosion of stainless steel.

Twelve uranium-magnesium fuel material samples have been irradiated in the MTR at the request of the Pile metallurgy Unit. These samples were 0.40 inch in diameter by 1.5 inches long and were canned in Zircalloy-2 capsules. The uranium used in these specimens was in the form of chips which packs about 50 volume percent. Six of the samples contained a matrix of pure magnesium and the other six contained an alloy matrix of magnesium - 1.4 weight percent silicon. Two specimens of each matrix material were irradiated to 1000 MWD/T and a like number to 5000 MWD/T. Bend tests were performed on the samples and on unirradiated control samples to secure a measure of the effect of radiation exposure on the physical properties of the material.

With the construction of nuclear reactors, a great deal of emphasis has been placed upon studying the effects of radiation on the solid materials of construction. It has become necessary to consider radiation exposure as an environmental entity along with others so established such as temperature, electrical and mechanical stress, chemical resistance, weather, etc. Problems concerning the study of the behavior of materials that are thus increased when radiation exposure has to be evaluated singly or in combination with one or more of the other environments. This paper presents the general plan of attack being followed to solve such problems that arise when plastics and elastomers are placed in radiation fields. These studies were undertaken for two primary reasons: (1) to obtain engineering data for practical applications of the desirable properties of these materials for such devices as o-rings, gaskets, pipe, and electrical insulation; and (2) to use these data to enable a better understanding of the nature of radiation effects on these materials. The initial phase of the program is the screening of materials by subjecting them to various degrading environments and recording property changes. Thus, with data on how these materials performed, more comprehensive studies could be made …

Prevailing dimensional tolerance for sintered UO₂ reactor fuel components to be enclosed in metal jackets are expensively small. For instance, the PWR fuel pellet, as of November, 1955, consisted of a centerless ground UO₂ cylinder 0.3560" (+0.0005", -0.000") in diameter and 0.3527" (±0.0008") long. This pellet was designed to fit in a Zircaloy tube 0.3585" (+0.0005", -0.0000") inside diameter. The use of UO₂ shapes as pressed, or extruded, and sintered with diameter variations controlled to a tolerance of ±0.003" to ±0.005" would represent a fabrication cost saving worth considering. It is reasonable to assume that the annulus between a sintered UO₂ shape and its container will vary as a function of time of irradiation. Shrinkage from the can walls occurs with relatively low density (i.e., 85% of theoretical) sintered irradiation (cf. MTR Test GEH-4-3C). Contrary to this effect, the thermal expansion coefficient of UO₂ is about twice that of Zircaloy. Of possibly greater significance is the inevitable fractuce of dense UO₂ due to thermal stress. Such cracking effectively relocates the annular heat transfer gap to the interior of the oxide where the higher temperatures enhance the heat transfer coefficient. Thus, possibly the worst condition, with respect to heat transfer, is …

Ultrasonic equipment has been developed for nondestructive testing of Hanford fuel elements. The ultrasonic method has replaced the Frost Test for bonding layer inspection in the Hanford canning line, and provides more accurate and reliable results at lower cost. The method has also been adopted to the testing of new fuel elements for which no other method is available.

As recommended in a previous report a study of the NO₂ and HNO₃ exposures of plant personnel in the 224 U Building has been made. Concentrations of NO₂ and HNO₃ from the 224 U roof stack, in the concentrator cells, and in the calcining pot rooms have been determined. The problems have been outlined and recommendations have been made for its alleviation.

When water is used as a coolant in any heat-producing process, the purity of the cooling water is of considerable importance, both from the standpoint of build-up of deposited solids inside the cooling tubes, and as an indication of corrosion of the tubes or any other materials with which the water comes in contact. The first problem has long been recognized, and is generally solved by pretreatment of the water. Efficient treatment can reduce the total solids content to less than 0.1 ppm, and the concentration of individual elements to the order of 0.01 ppm. If water of this purity is used, the analysis of the input and output stresses can result in some useful information. The input stream analysis, of course, is direct measure of the quality of the original cooling water, and frequent analysis by a reasonably fast method can be used to keep pretreatment under control. But of even greater significance is the difference in the impurity content of input and output streams. In a simple, straight-through system the difference generally will be negligible. If a closed, recirculating system is considered, however, with the coolant water circulating through the process to be cooled and then through a …

Gradual corrosion and mechanical wear of equipment over a period of years has affected the seals and gasketing of the electric pot calcining equipment in the 224-U Building Cell E to such an extent that the desirable vacuum cannot be maintained in the pots. Air contamination has been gradually increasing, and this, together with a lowering of the mask working limits, has made it necessary to require personnel to wear assault masks continuously. Indications are that, with the increased production now required, the level of air contamination will continue to rise unless measures are taken to prevent it. The Manufacturing Department has requested that a project be established to reduce the contamination level. Several items of improvement are listed for consideration including, in general, the electric pot agitation and sealing, semi-automatic pot unloaders, cell ventilation and air locks, and the nitric acid off-gas system and stacks. Because of the urgency of improving the conditions, the project, at first, is to provide for immediate improvements for the electrical pot agitation, the pot cover leakage, and the nitric acid off-gas system and stack. Additional study will be required to determine the extent of the ventilation and semi-automatic unloading improvements required.

The Redox process uses or produces only a very few materials that are hazardous for reasons other than radioactivity. The conditions under which these materials become hazardous were carefully taken into consideration in the development of the process and design of the equipment. A considerable about of information on the hazardous properties of the process materials was obtained so that the pertinent material could be incorporated into the process specifications. Providing the equipment is operating properly and the process is being carried out within specification limits, no hazardous conditions can be created by the process. The purpose of this report is to assemble in a single, readily available document all of the information on the normal concentration limits and safe handling procedures needed to adequately control the use and storage of these materials. This report should be helpful in preparing safety bulletins and provide guidance in case of unusual incidents, malfunctioning of equipment, or contemplated changes in either the process or equipment. It is important to remember that a maximum allowable concentration (MAC) is only a limit on the concentration of a toxic material which cannot be exceeded in the air to which workers are constantly exposed to every working …

It was shown that without further major development the detectors proposed for the Body Monitor can be expected to detect 0.02 microcurie of plutonium at the center of the chest cavity. This is the permissible body burden of insoluble forms of plutonium. The detection level can be decreased by decreasing the background counting rate. Decreases in the background can reasonably be expected; it should be possible to detect a small fraction of the permissible body burden. If it can be shown, as suggested by other work, that americium will remain with plutonium, then within at least a few months after entry into the body it should be possible to measure the plutonium by detection of rays from Am²⁴¹.