The Lawrence Livermore Laboratory has established a training facility for hands-on instruction in various aspects of fissile material control. Eight hemispherical shells of 93% enriched uranium (approximately 23 kg) are used in a configuration convenient for demonstrating the effects of mass, reflectivity, separation, moderation and poison on the state of criticality. Various thicknesses of clear acrylic plastic are used as moderators in the center of the assembly and as reflectors surrounding the fissile material. Assembly is made on a vertical split table which can be manually operated to demonstrate the effect of separation distance between the hemispherical shells. Cadmium sheet is used to study the effect of poisons in isolating masses of fissile material and in isolating fissile material from reflectors. A central void is provided to accommodate a Californium-252 or plutonium-238 beryllium neutron source. Instrumentation for the training facility consists of standard BF/sub 3/ detectors with rare meter and scaler/timer output. Training experiments typically consist of making an approach to critical with the assembly in its optimum configuration and then demonstrating the effect of various parameters on the state of criticality. The effect multiplication constant of the assembly in its optimum configuration (spherical with full moderation and reflection) is …

Transfer coefficients to predict the passage of isotopes from the environment to terrestrial foods have been derived for various radionuclides of importance in the nuclear fuel cycle. These data update and extend previously recommended handbook values. We derive transfer coefficients to terrestrial foods and describe the systematics of the derived transfer coefficients. Suggestions are offered for changes in the values of transfer coefficients to terrestrial foods that now appear in federal regulatory guides. Deficiencies in our present knowledge concerning transfer coefficients and limitations in the use of these values to ensure compliance with radiation protection standards are discussed.

Since September, 1952, Lawrence Livermore Laboratory has conducted pioneering research in applied science. A vital part of this activity has been the development of a variety of high vacuum and ultrahigh vacuum systems. Leaks occur in everything, including vacuum systems. The mass spectrometer leak detection equipment is described.

The rate of pitch-angle scattering in a beam-driven Tokomak is proportional to Z/sub eff/ when neutral deuterium is injected parallel or antiparallel to the toroidal field B/sub T/. The energy spectrum of neutrons produced by D--D or D--T reactions is sensitive to the angular distribution of reacting energetic deuterons so that a measurement of the spectrum may be used to infer Z/sub eff/. Energy spectra of neutrons emitted parallel to B/sub T/ during simultaneous co- and counter-injection were calculated for the case of 120-keV beams by using a PPPL code. The results were then convoluted with spectrometer lineshapes determined experimentally for a system used to measure neutron spectra during a 1.0-s source pulse. Results indicate that Z/sub eff/ in the range of 1 to 4 may be determined with uncertainties of +- 0.25 for D--D plasma and +- 0.5 for D--T plasma, provided the ion temperature T/sub i/ is well known. However, the spectrometer energy resolution is not adequate to determine T/sub i/ directly from a neutron--spectrum measurement. In the absence of accurate T/sub i/ data, the uncertainty in Z/sub eff/ is approximately +- 1. In either case, impurity identification is not established by this type of measurement.

The paper established criteria for the selection of personnel to work on the interactive graphics system and mentions some of human behavioral patterns that are created by the implementation of graphic systems. Some of the social and educational problems associated with the interactive graphics system will be discussed. The project also provided for collecting objective data which would be useful in assessing the benefits of interactive graphics systems.

The optical testing part of the program requires characterizing index homogeneity of large blanks of fluorophosphate glass, optical surface figure and quality of large polished optics and performance of optical coatings such as antireflection, high reflectors and polarizing beam-splitters. For this purpose, a large effort is being expended to upgrade the optical test facilities at Lawrence Livermore Laboratory in preparation for the NOVA optics procurement. (MOW)

Techniques and equipment have been developed to measure in-vessel local void fraction and velocity in a reflood transient test facility. The two impedance sensors, the flag probe and the string probe, have been tested (prototype sensors) in a variety of air-water and steam-water facilities an in all cases acceptable measurement results were obtained.

The magnetic field design and the mechanical design of the TMX magnet system were previously reported by Chen and Hinkle. This paper is a summary of the work that has been accomplished in the two years since then.