There has been a great deal of progress in recent years on the development of solid state and KrF lasers, light ion diodes, and heavy ion accelerators for use as drivers in inertial confinement fusion (ICF) facilities. Two relatively new entries in the ICF driver derby are the free electron laser (FEL) and the compact torus (CT). The status and remaining technological challenges of each potential driver are described. The author discusses driver performance criteria for various reactor applications and then gives his informed opinion in a qualitative rating of the six drivers for each application.

Combining direct and thermal power conversion results in a 52% gross plant efficiency with DT fuel and 68% with advanced DD fuel. We maximize the fraction of fusion-yield energy converted to kinetic energy in a liquid-lithium blanket, and use this energy directly with turbine generators to produce electricity. We use the remainder of the energy to produce electricity in a standard Rankine thermal power conversion cycle.

We have carried out further investigations of technical issues associated with using a compact torus (CT) accelerator as a driver for inertial confinement fusion (ICF). In a CT accelerator, a magnetically-confined torus-shaped plasma is compressed, accelerated and focused by two concentric electrodes. Here, we evaluate an accelerator point design with a capacitor bank energy of 9.2 MJ. Modeled by a O-D code, the system produces a xenon plasma ring with a radius of 0.73 cm, a velocity of 4 x 10/sup 7/ m/s, and a mass of 4.4 ..mu..g. The plasma ring energy available for fusion is 3.8 MJ, a 40% driver efficiency. Ablation and magnetic pressures of the point design, a due to CT acceleration, are analyzed. Pulsed-power switching limitations and driver cost analysis are also presented. Our studies confirm the feasibility of producing a ring to induce fusion with acceptable gain. However, some uncertainties must be resolved to establish viability.

The switched-power linac (SPL) concepts are reviewed briefly, and recent work on computer-modelling of the photoemission process at the photocathode and the experimental study of the process are discussed. Work on rf-modelling of the properties of the radial transmission line is outlined. (LEW)

The cooperative program between NRC/ANL and EPRI on the validation of soil-structure interaction analysis methods with actual seismic response data is described. A large scale-model of a containment building has been built by EPRI/Taipower in a highly seismic region of Taiwan. Vibration tests were performed, first on the basemat before the superstructure was built and then on the completed structure. Since its completion, the structure has experienced many earthquakes. The site and structural response to these earthquakes have been recorded with field (surface and downhole) and structural instrumentation. The validation program involves blind predictions of site and structural response during vibration tests and a selected seismic event, and subsequent comparison between the predictions and measurements. The predictive calculations are in progress. The results of the correlation are expected to lead to the evaluation of the methods as to their conservatisms and sensitivities.

The free-electron laser (FEL) simulation code FRED, developed at Lawrence Livermore National Laboratory (LLNL) primarily to model single-pass FEL amplifiers driven by induction linear accelerators, is described. The main emphasis is on the modeling of optical propagation in the laser and on the differences between the requirements for modeling rf-linac-driven vs. induction-linac-driven FELs. Examples of optical guiding and mode cleanup are presented for a 50 ..mu..m FEL.

This paper describes the distribution and chemistry of zeolites in tuffs and in fractures at Yucca Mountain. Samples used in this study were collected from continuously-cored exploratory drill holes. A variety of analytical techniques, including optical petrography, x-ray powder diffraction, electron microanalysis, and x-ray fluorescence, were used to characterize the distribution and chemistry of zeolites in these samples.

Yucca Mountain, in southern Nevada, is being studied by the Nevada Nuclear Waste Storage Investigations (NNWSI) Project as a potential site for an underground high-level nuclear waste repository. The site is within Miocene volcanic rocks that are 1.5 to 4 km thick and range in age from 12.5 to 14 MY. Several holes have been drilled in Yucca Mountain for geologic and hydrologic studies. Drill hole USW G-4, the most recently cored hole within the potential repository block, was chosen for detailed study of fracture-filling minerals because it is closest to the planned NNWSI exploratory shaft. Drill hole USW G-4 was drilled to 914.7 m (3001 ft) and continuously cored from 6.7 m (22 ft) to total depth (TD). The drilling history, lithology of the core, and geophysical logs of the well were published earlier. Because manganese oxides in fractures may act as a natural barrier to radionuclide migration, it is important to determine exactly which manganese minerals are present, in what intervals they occur, and how extensive these fracture coatings are.

For many geologic problems, subsurface observations are available only from a small number of irregularly distributed locations, for example from a handful of drill holes in the region of interest. These observations will be interpolated one way or another, for example by hand-drawn stratigraphic cross-sections, by trend-fitting techniques, or by simple averaging which ignores spatial correlation. In this paper we consider an interpolation technique for such situations which provides, in addition to point estimates, the error estimates which are lacking from other ad hoc methods. The proposed estimator is like a kriging estimator in form, but because direct estimation of the spatial covariance function is not possible the parameters of the estimator are selected by cross-validation. Its use in estimating subsurface stratigraphy at a candidate site for geologic waste repository provides an example.