The transient aerothermodynamic processes in a gas-cooled reactor are described in a simplified manner to illustrate some of the fundamental physical phenomena involved, to provide some approximate but useful methods of analysis, and to aid in the understanding and use of more complex computer solutions. The transient heat balance equation for an element of a single reactor channel is derived in terms of aerothermodynamic time constants, and typical analytic solutions for transients are presented. This equation is used in generating the time-dependent equation for the channel exhaust gas temperature. The single-channel analysis is extended to multiple channels. A method for determining the approximate transient temperature envelopes for various reactor components is presented. The effects of aerodynamic and thermal coupling between different reactor channels are illustrated. Some of the simplifying assumptions are investigated with respect to the conditions under which they are valid.

Nuclear excavation is the name given to the concept of using large scale nuclear explosion craters for useful projects, such as harbors, canals, and roadway cuts. It is one of the principal applications of the Plowshare Program for industrial, or peaceful, uses of nuclear explosives. Plowshare is sponsored by the U.S. Atomic Energy Commission and is under the technical direction of the Lawrence Radiation Laboratory at Livermore, California. The purpose of this paper is to describe cratering concepts and the present state of nuclear excavation technology. The general nature of the safety hazards associated with nuclear excavation are also discussed.

Recent underground nuclear tests conducted by the U.S. Atomic Energy Commission have yielded data on the effects of contained nuclear explosions in four rock mediums: tuff, alluvium, rock salt, and granite. This report presents and compares data obtained primarily through exploratory mining and drilling into the postshot environment of 35 such events.

Late in 1962, a group in the Computation Division at Lawrence Radiation Laboratory, Livermore, began a study of compiler languages and techniques, the culmination of which was a machine independent FORTRAN written in FORTRAN. The impetus behind this study was a local need to move rapidly and efficiently from one machine to another. A secondary incentive was the need to be able to implement language extensions without the customarily long gestation period. Because of a large inventory of FORTRAN codes at this installation, FORTRAN source language was chosen as standard. Some effort was also expended on a syntax directed compiler written in FORTRAN for FORTRAN. With the knowledge of FORTRAN techniques gained from writing the syntax compiler and translators for other machines, the writing of FORTRAN in FORTRAN was begun.

Calculations of the photonuclear giant resonance according to the Wilkinson model are presented in this report. In this model the giant resonance in the cross section for absorption of gamma rays by nuclei is ascribed to the excitation of large numbers of nucleons in closed shells. The model generally predicts correctly the integrated cross section for the giant resonance, bu the resonance energy is too low. Results are presented in a series of tables and formulas so that the integrated cross section may be calculated for any given nucleus.

In any underground nuclear explosion, the shock front that propagates from the shot point carries with it energy from the explosion, and distributes this energy by doing work on the surrounding material. In the process, the material undergoes changes in both its physical and mechanical states. If enough energy is deposited in the material, it will vaporize or melt thus changing its physical state, or cause it to crush or crack. During the past few years, special computer codes have been developed for predicting the close-in phenomena of underground nuclear explosions using the laws of physics, and the knowledge of the properties of the materials in which the detonations occur. As a consequence, a better understanding of experimental observations and measurements has evolved.

The effects of explosion-induced ground motion must be evaluated in planning and executing any nuclear excavation project. For some projects ground use intensity may dictate the use of less-than-optimum yields to minimize damaging effects. In remote areas, weighing the alternatives of outright purchase of some property or use of smaller yields may be required. The cost of indemnifying owners against damage must be considered in any case. Discussions of the effects of ground motion on three broad types of facilities - engineered structures, residential buildings, and equipment required for the support of nuclear excavation operations - are presented. A method of predicting the response of single- and multi-storied buildings, the response spectrum technique, is discussed, with emphasis on the application of explosion-induced spectra.

LRL has the responsibility of demonstrating the feasibility of a reactor for use as a power plant for a low-altitude, high-Mach-number missile. This reactor is literally a very high power air heater which must work at temperatures in excess of 2000' F. The reactor is exposed to high loads so one of the primary problems is providing high temperature structure. Considerable effort has been devoted to developing ceramic structural elements. One of the materials considered for this purpose is silicon nitride. In ceramic structural elements operating over large temperature ranges, a major problem is coping with thermal stress. In this respect there is a similarity with the radome problem. The work on silicon nitride at LRL consisted of limited fabrication studies (principally for familiarization), measurement of properties of interest to the application, and funding of fabrication scale-up efforts.

A fraction of the energy released by the underground detonation of nuclear explosives is locally deposited as residual thermal energy. An accurate prediction of this usable fraction of the energy released is necessary to evaluate the feasibility of several of the proposed projects in the Plowshare Program. This paper will present a summary of the available data on residual thermal energy from nuclear detonations in three different geological media: tuff, halite, and granodiorite.

The angle errors of a rotary table can be accurately measured by stepping off the angles with an optical caliper and computing table error from (1) the error readings at each angle measured and (2) the cumulative caliper error that will be evident when the circle is closed at 360', eliminating the necessity of adjusting the caliper to the exact setting.

To properly assess the "sensitivity" of explosives systems under impact conditions we must obtain detailed information on these mechanisms by which explosives are ignited by impact. It is necessary to know which impact conditions represent the greatest hazard to explosive materials, as well as to know for a given impact condition the relative responses of explosives of interest. I should like to describe to you a program sponsored jointly by the Department of Defense and the Atomic Energy Commission to attain this type of information. A wide variety of impact experiments have been conducted using geometrical arrangements of explosive, plastic, and metal which are relatively simple compared to complete ordnance systems. All of these tests have employed billets of explosive fabricated by standard production techniques, and the billets have been sufficiently large that ignition, once started, has something of the same opportunity to grow or decay as in full scale ordnance assemblies. From these relatively simple tests there has accrued much new useful information on the behavior of explosives under impact. With this new information providing a base from which to work, it is hoped that theoretical calculations on impact phenomena will in the future make a bigger contribution to …

Under the stimulus of electronic materials development - particularly thin-film studies - and the need for space environmental simulation chambers, a very rapid increase in the availability of industrial-sized vacuum components and systems operable in the ultrahigh vacuum range has taken place in the last three years. It is the purpose of this paper to explore the design considerations of ultrahigh vacuum systems for metallurgical applications.

During the past five years, potentialities of space travel have greatly increased and new knowledge has become available regarding the nature of cosmic radiation. In the present article the knowledge pertinent to dose evaluation is reviewed for conditions of flight in space in the vicinity of the earth but away from the influence of its atmosphere or magnetic field. Certain properties of the heavy nuclei are also discussed as well as some of the available information on their actual biological effects. Development and completion of the new Heavy Ion Linear Accelerator allows extension of quantitative biological work with these particles. Finally, the statistical nature of the hazard from cosmic radiations and the limitations of space flight due to such rays are discussed.

The problem of photosynthesis is the problem of defining the way in which green plants are able to convert electromagnetic energy into chemical potential in the form of reduced carbon, usually as carbohydrate, and molecular oxygen. The use of tracer carbon, as carbon-14, has made possible considerable progress in the mapping of the routes taken by the carbon atom from CO2 into plant substances. The techniques of separation and identification that have made this progress possible lie largely in the region of chromatography and radioautography involving fractional-gamma amounts of material. A number of proposals have been made about the photochemical act itself. These proposals have led to the development of direct physical tests of their validity, and some results of these will be described.

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 is an attempt to summarize and relate at least some of the material presented in four talks during a symposium on radiobiological studies on yeast, and in addition discuss some related experimental results. The discussion will be divided into two sections: I) a discussion of the various manifestations of radiation damage in yeast; and II) a consideration of modification of these damages by variations of physico-chemical and biological parameters.

The basic investigation of transistor feedback amplifiers has proven mathematically simple and of great practical value. The behavior of single-stage common-emitter amplifiers is described and provides a building block with which cascaded feedback amplifiers can be analyzed and designed. From the results of this analysis the conditions for minimum drift for cascaded single-stages and cascaded loops have been derived.

The method of detecting unpaired electrons in liquid and solid systems by electron spin resonance is discussed. The significance of the hyperfine structure in electron spin resonance is discussed and the possible use of these structural features of the electron spin resonance spectrum to elucidate the nature of the photoproduced unpaired electrons in photosynthesizing systems is introduced.

This report is a comparative cost study of radioactive waste disposal for the Lawrence Radiation Laboratory (UCRL). In particular, it compares the costs of sea disposal in depths of 1000 fathoms and of 2000 fathoms off the California coast with land burial of the wastes at the Hanford Atomic Products Operation (HAPO), Richland, Washington, at the National Reactor Testing Station (NRTS), Idaho Falls, Idaho, or at the Nevada Test Site (NTS), Nevada. In the comparison, the cost of utilizing a commercial waste-disposal firm is also shown as well as a tentative cost of using the Military Sea Transport Service (MSTS).

A method is presented for measuring the average energy of the neutrons from a source. The attenuation of the neutrons by polyethylene is measured by the use of a long counter in good geometry. The attenuation length is a sensitive function of the neutron energy. The average neutron energies from several (o, n) sources have been measured and agree well with values obtained by other techniques.

The last fifteen years have seen the discovery of ten transuranic elements. This paper (presented at the Mendeleev Chemistry Conference in Moscow) deals only with the transplutonium elements, i.e., those elements with atomic number greater than 94. This will be a detailed discussion of the techniques that have been devised for producing and identifying elements 101 and 102 and the possible applications of these methods to elements beyond. There will also be a brief review of the discovery of all the transplutonium elements to show the gradual change in experimental methods from the early days.

It is the purpose of this paper (from a talk given at Mendeleev Chemistry Conference in Moscow) to give a brief progress report on work which is being done on very heavy elements at the Lawrence Radiation Laboratory in Berkeley. The subject matter is divided into three broad classifications. The first classification includes production of the isotopes, the second deals with investigations of their chemical properties and the third includes studies of the nuclear properties.

With the increasing availability of accelerators capable of producing beams of heavy ions it has become useful to know the cross section for a heavy ion to form a compound nucleus by interaction with a target nucleus. The results of calculations based on two simple models are presented here in order to give some idea of the magnitude of this cross section as a function of the energy of the bombarding particle.

This report was prepared at the request of the Subcommittee on Radiochemistry of the Committee on Nuclear Science of the National Research Council as a contribution to a proposed master file on the radiochemistry of all the elements. All known material on the radiochemistry of thorium is included in this report.