A conceptual design of a laser fusion power plant is extensively discussed. Recent advances in high gain targets are exploited in the design. A smaller blanket structure is made possible by use of a thick falling region of liquid lithium for a first wall. Major design features of the plant, reactor, and laser systems are described. A parametric analysis of performance and cost vs. design parameters is presented to show feasible design points. A more definitive follow-on conceptual design study is planned. (RME)

The shutdown system for the Clinch River Breeder Reactor (CRBR) includes two independent systems--a primary and a secondary system. The Secondary Control Rod System (SCRS) is a new design which is being developed by General Electric to be independent from the primary system in order to improve overall shutdown reliability by eliminating potential common-mode failures. The paper describes the status of the SCRS design and fabrication and testing activities. Design verification testing on the component level is largely complete. These component tests are covered with emphasis on design impact results. A prototype unit has been manufactured and system level tests in sodium have been initiated.

The first results are given for the conceptual design of a short-wavelength gas laser system suitable for use as a driver (high average power ignition source) for a commercial laser fusion power plant. A comparison of projected overall system efficiencies of photolytically excited oxygen, sulfur, selenium and iodine lasers is described, using a unique windowless laser cavity geometry which will allow scaling of single amplifier modules to 125 kJ per aperture for 1 ns pulses. On the basis of highest projected overall efficiency, a selenium laser is chosen for a conceptual power plant fusion laser system. This laser operates on the 489 nm transauroral transition of selenium, excited by photolytic dissociation of COSe by ultraviolet fluorescence radiation. Power balances and relative costs for optics, electrical power conditioning and flow conditioning of both the laser and fluorescer gas streams are discussed for a system with the following characteristics: 8 operating modules, 2 standby modules, 125 kJ per module, 1.4 pulses per second, 1.4 MW total average power. The technical issues of scaling visible and near-infrared photolytic gas laser systems to this size are discussed.

A series of consistent, versatile, and accurate air-water tests simulating LOCA conditions has been completed on the /sup 1///sub 5/-scale Mark I BWR Pressure Suppression Experimental Facility. Detailed histories of vertical loads on the wetwell are obtained in a carefully scaled three-dimensional system. In particular, variation of hydrodynamic-generated vertical loads with changes in drywell pressurization rate, downcomer submergence, and the vent-line loss coefficient were established. An initial drywell overpressure, which partially preclears the downcomers of water, substantially reduced peak vertical loads.

Nuclear wastes which are logical candidates for deep geologic disposal include commercial (spent fuel, reprocessing) and defense wastes. It is expected that the 5250 metric tons of spent fuel discharged through the end of 1978 would increase to about 100,000 tons by the end of 2000. The individual characteristics of each waste type (spent fuel, solidified waste, defense wastes) are described in turn. (DLC)

A double-peak, energy-dependent Breit-Wigner model of the E1 gamma-ray strength function was applied to nuclei from As to Rh, to predict their neutron capture cross sections and capture gamma-ray spectra. A consistent set of model parameters was obtained in this mass region to describe the step in the low-energy tail of the E1 strength function. This step allows agreement with photonuclear data at high energies, the correct GAMMA/sub gamma/ to be obtained for agreement with neutron capture cross-section data, and the calculation of the observed hardness in the capture gamma-ray spectra. For nuclei at or near the closed, N = 50 shell, however, the double-peak assumption breaks down. In these cases, good results are still obtained if the same set of model parameters is applied, except that the E1 strength function is formulated in terms of the first, narrower peak. 8 figures.

A comparison of some features of the three tokamaks is given. The ORMAK and ISX-A have ceased operation. The ISX-B has completed a checkout phase with studies of circular, ohmically heated plasmas in which it performed much like ISX-A. Shaped and injection heated plasmas are being studied. Diagnostics for mode structures were the usual Mirnov loops for approx.B/sub theta/ and collimated soft x-ray detectors for the internal fluctuations approx.X. The approx.X measurements on ISX-A, and thus far on ISX-B, used only a single x-ray channel which veiwed vertically across the center of a minor cross section. Multiple channels were used on ORMAK in a fashion which permitted m number determinations at several plasma radii. For detailed studies, analog signals were stored on magnetic tape and later digitized for fast Fourier transform analysis.

Recent experiments on low-level irradiation during development raise questions relevant to ICRP Publication 26. Mice and monkeys were studied; the measured endpoint was the radiation-induced loss of female germ cells. Three issues are examined. The first is the numerical value of Q (quality factor) appropriate for low-energy beta rays. Comparisons of tritium with gamma radiation were made under conditions of chronic, low-level exposure, and the relative biological effectiveness (RBE) was found to approach 3. Its bearing on ICRP's recommendations concerning Q applicable to tritium is discussed. Second, female germ cells in squirrel monkeys before birth were discovered to be extraordinarily radiosensitive, more easily destroyed than those of mice. If this holds for other primates too, it has radiation-protection implications hitherto overlooked. Third, the contrast between massive germ-cell loss from chronic exposure in prenatal squirrel monkeys and reported radioresistance of oocytes to acute exposure in rhesus monkeys, unless due to species difference, suggests that during development protracted irradiation may be especially injurious. This also could have important radiation-protection implications and is under investigation. (ERB)

A two year design study has been completed for medical ion accelerators with beams of sufficient range and intensity for therapy. The particles of main interest were ions between carbon and neon, but the generation of proton and neutron beams was studied also. Cyclotrons appear to be good injectors for a heavy ion medical synchrotron, particularly if neutron and/or isotope production is desired as well. They also offer a competitive solution for proton beams of 250 MeV. A superconducting cyclotron design for 380 MeV/u carbon was worked out, but a synchrotron for heavy ion beams of 400 to 600 MeV/u and 5 x 10/sup 9/ particles/sec was found to be more economical and flexible.

The transfer of energy produced by the interaction of the intense pulses of short-ranged fusion microexplosion products with materials is one of the most difficult problems in inertially-confined fusion (ICF) reactor design. The short time and deposition distance for the energy results in local peak power densities on the order of 10/sup 18/ watts/m/sup 3/. High local power densities may cause change of state or spall in the reactor materials. This will limit the structure lifetimes for ICF reactors of economic physical sizes, increasing operating costs including structure replacement and radioactive waste management. Four basic first wall protection methods have evolved: a dry-wall, a wet-wall, a magnetically shielded wall, and a fluid wall. These approaches are distinguished by the way the reactor wall interfaces with fusion debris as well as the way the ambient cavity conditions modify the fusion energy forms and spectra at the first wall. Each of these approaches requires different heat transfer considerations.

Value Engineering, simply defined, is a systematic approach to getting more for your money. It has been used to reduce the cost of a wide variety of products by the D.O.D. and in principle, should be applicable to various phases of the Neutral Beam Program. With respect to R and D, the principles of Value Engineering must be used with caution. They are most effective in evaluating directed development with very specific goals, but can be misleading when considering advanced innovative work.

Published Hugoniot data for UO/sub 2/ is in error, because the measuring techniques used did not resolve the strong multiple-wave shock-structures present. Hence calculations related to liquid metal, fast-breeder-reactor, excursion analyses based on extrapolations of that data are in serious error. The inclined prism, flash gap, and two-stage gas-gun techniques are used to determine shock-compression parameters for UO/sub 2/ to 300 GPa. The Hugoniot elastic limit for UO/sub 2/ was found to be 5.7 GPa. At higher pressure, a plot of shock vs particle velocity displays a discontinuity between 1.0 < U/sub p/ < 1.8 km/s, which appears to be a manifestation of a solid-solid phase transition. For 1.8 < U/sub p/ < 4.0 km/s, the plot is given by U/sub s/ = 5.8 + 1.28 (U/sub p/ - 1.8).

The implementation of a nuclear waste management technology raises several issues concerning the regulation of social risk. This paper presents a decision analytic approach to resolving some of those issues. A methodology for developing a radiological risk measure is presented, and several approaches to defining acceptable levels of that risk measure are considered. The methodology presented is oriented toward the development of radiological performance objectives for use as guidance in the drafting of regulations.

Techniques for producing intense negative ion beams are discussed. These beams are required for intense neutral beam development at energies greater than 150 keV. Handling, acceleration, and stripping of negative ion beams are described.

This paper describes the method used to drive Pockels cells on the 20-arm Shiva laser for inertial confinement fusion research at the Lawrence Livermore Laboratory. Shiva became operational last fall, and has just completed a series of 20-arm target shots. It uses two pockels cell gates in each laser arm for suppression of amplified spontaneous emission (ASE) that can damage or destroy the target before the main pulse arrives. Two additional Pockels cells are used in the preamplification stages, so that a total of 42 cells must be driven by the pulser system.

Thermophysical data are presented for liquid niobium up to approximately 6000/sup 0/K and for liquid lead up to approximately 5000/sup 0/K. These new results are summarized along with previously obtained high temperature data for liquid molybdenum, tantalum, tungsten, and uranium.

The three-phase region of various mixtures of D/sub 2/, DT, and T/sub 2/ has been investigated through plots of temperature and pressure vs time. The liquid surface for a temperature-vs-composition plot is obtained from the points of first freezing. The solid surface is obtained from the points of first melting after a quick freeze. All components appear miscible in both liquid and solid phases from 17 to 22 K. From analogy to H-T systems, the chemical equilibria in these D-T systems were assumed to be the same at experimental temperatures as at room temperature. The Raoult's-law total pressure is calculated from an analysis of all six species; the experimental pressure is at the most 3.5% higher than the Raoult's-law pressure. Raoult's law is used to obtain gas-phase compositions; the phase diagram shows a maximum temperature difference of 0.15 K between the gas and solid surfaces. As an example for 50-50 mole % of liquid D-T at about 19.7 K, the gas will contain about 42% T and the solid 52%. Codes giving the equilibrium vapor pressures of pure components for both the solid and liquid from 4 to 30 K are listed.

Lead-tin plating can be rapidly and uniformly applied to a 0.25 in. square copper conductor. Such plating can be used as solder with a minimum flux requirement. In the range studied, the tin content of the coating can be controlled. It varies directly with the tin content of the bath and amperage and inversely with the temperature.

The new two-phase heat transfer medium proposed is a mixture of potassium droplets and helium which permits blanket operation at hih temperature and low pressure, while maintaining acceptable pumping power requirements, coolant ducting size, and blanket structure fractions. A two-phase flow model is described. The helium pumping power and the primary heat transfer loop are discussed. (MOW)

Precision gravity methods provide new information regarding geothermal reservoir mechanisms and depletion. This paper discusses the principles of present interpretations and early conclusions from two producing geothermal fields, Wairakei, in New Zealand, and The Geysers, California. 4 refs., 4 figs.

This paper is concerned with the optimal time to commence extraction of energy from a hot-water geothermal reservoir. The economic models that we have presented in the past have the common characteristics that the extraction program starts immediately (see References 1 and 2). Based on this assumption, we determined optimal extraction strategies and planning horizons such that the present values of total profits were maximized. In this study we relax the requirement that extraction be undertaken immediately, seeking instead the delay in starting time that along with the other decision variables maximizes the present value of total profits over the economic life of the reservoir. Of course, optimal starting time, economic life of the reservoir, optimal extraction rate, and optimal injection temperature are interrelated, and therefore, we analyze their effect on the overall planning strategy simultaneously. 4 refs.

Work over the past year has concentrated on three areas: 1) to implement a concept of vertical equilibrium in geothermal modeling, 2) to improve the matrix equation solution technique for both two- and three-dimensional models, which improvements this report describes in detail, and 3) to apply a vertical equilibrium, areal model to the Wairakei, New Zealand geothermal field. The steady-state modeling indicates that large regions in the reservoir probably had a small steam cap prior to exploitation. Furthermore, transient simulations indicate that leakage into the reservoir is significant; that is, the Wairakei reservoir is not a closed system. The most difficult part of history matching at Wairakei is adjusting permeabilities in order to remove enough mass from storage (as opposed to leakage) and reproduce the observed pressure decline trends. 5 refs.

The experimental well, HGP-A, drilled under the auspices of the Hawaii Geothermal Project, is located on the island of Hawaii near the eastern rift of Kilauea volcano. Drilling was completed to a depth of 6450 feet in April 1976. The well is cased to 2230 feet below the surface, which is 600 feet above sea level, with a slotted liner running from the end of the casing to bottomhole. Cuttings and core samples obtained during drilling indicate that the region is composed of volcanic basalt with a profile that contains a zone of open fractures (3300-4500 feet) and a zone of partially sealed fractures (4500-6450 feet) as shown in Figure 1. Conclusions from preliminary test results and analyses: the Kapho Geothermal Reservoir is liquid-dominated, with permeability thickness of ~ 1000 md-ft, very high temperatures ~ 350°C, high formation pressure ~ 2000 psi, slightly brackish water, and high silica content, and is potentially large; the HGP-A Geothermal Well borehole contains steam and water at saturation during flash; flashing occurs in formation; the well has high wellhead pressures ~ 160 psi at 50 Klb/hr steam, probably has severe skin damage, and potential power output ~ 3.5 MWe; the well’s producing regions are …

A well interference testing program of the Salton Sea Geothermal reservoir is being conducted as part of a resource evaluation study by the Earth Sciences Geothermal Industrial Support Program of the Lawrence Livermore Laboratory. Studies to date indicate the reservoir rock to be composed of layered sequences of shales and sands. Wells involved in the testing program are being used in support of, or are in the vicinity of, the MAGMA-SDG&E Geothermal Loop Experimental Facility (GLEF), located in the Salton Sea Geothermal Field (SSGF). Between these wells, a shale layer has been correlated which appears to divide the reservoir into an upper and lower portion. Other thick sand and shale sequences may provide additional stratification. This report describes work in progress on a well testing program designed to determine the horizontal and vertical transmissivity and storage parameters between wells in the vicinity of the GLEF. These tests are being conducted with the cooperation and support of Magma Power Company and San Diego Gas and Electric Company. 3 figs., 4 refs.