Two types of direct converters at up to 100 keV were tested. A beam direct converter was tested on a reduced area TFTR source at the Lawrence Berkeley Laboratory (LBL). After surface conditioning and outgassing, the efficiency was over 60% at the beginning of a pulse. During a pulse, the efficiency decreased as the gas density built up. A single-stage plasma direct converter with immersed grids is being tested on a steady-state ion beam with 6 kW of beam power. The power density at the grids can be varied by adjusting the beam focus. Recovery efficiencies over 70% are measured and we are now studying various loss mechanisms.

A crossed molecular beam study was made of the reactions of U with inorganic oxidizers (O/sub 2/, NO, SO/sub 2/, N/sub 2/O, CO/sub 2/), water, alcohols, acetone, and halogenated methanes. Results show that U in the gas phase behaves very much like most other heavy metals, and may be called a heavy Ba or Sn atom. 8 figures. (DLC)

A brief history of Decontamination and Decommissioning (D and D) experience at the Idaho National Engineering Laboratory is presented as an introduction to the status of current projects. Details are then presented as an introduction to the status of current projects. Details are then presented on a project to remove sodium from some major components of the Hallam reactor and on the Organic Moderated Reactor Experiment (OMRE) decommissioning project. Cost, schedule, waste volume, and other technical data from these projects are presented. In addition, a brief summary of the future INEL D and D program is presented.

Recent results obtained by using a 10 channel, filtered XRD detector system to record sub-keV x-ray emission from laser-irradiated targets are reported. Targets materials were Be, Al, Ti, Sn, Au and U, with Z ranging from 4 to 92. Targets were irradiated with 1ns FWHM, 1.06 ..mu..m wavelength pulses at an intensity of 5 x 10/sup 14/ W/cm/sup 2/. Time-resolved x-ray emission pulses show systematic and striking variations with Z. These variations can most probably be attributed to the onset of inhibited electron conduction. Time-integrated x-ray yields are obtained as a function of target Z as well as calculated charge states anti Z, indicating the type of physical processes that give rise to the x-ray emission. Typical sub-keV x-ray spectra are presented; in some cases such as Ti where prominent lines are present, the charge state of the plasma can be directly deduced from line ratios, agreement with numerical simulation is very good.

Advanced imaging methods have been evaluated for the purpose of constructing images of objects from ultrasonic data. Feasibility of imaging surfaces which are off-normal to the sound beam has been established. Laboratory results are presented which show a complete image of a typical core component. Using the previous system developed for under sodium viewing (USV), only normal surfaces of this object could be imaged. Using advanced methods, surfaces up to 60 degrees off-normal have been imaged. Details of equipment and procedures used for this image construction are described. Additional work on high temperature transducers, electronics, and signal analysis is required in order to adapt the off-normal viewing process described here to an eventual USV application.

A high-speed rotating shutter was designed to operate in a 10/sup -6/ Torr vacuum at the optical focus of a laser spatial filter. The shutter is basically a wheel, with a single 3 x 10-mm slot at the perimeter, which rotates with a peripheral speed of 1 km/s. The motor to drive the rotating wheel is magnetically suspended and synchronously wound. The wheel achieves a 4 ..mu..s opening time and a timing accuracy of better than 0.2 ..mu..s. (MOW)

Shiva is a 20 beam Nd:Glass Laser and Target Irradiation Facility at the Lawrence Livermore Laboratory. The laser system and integrated target facility evolved during the last year from a large, untested, experimental laser system to a target irradiation facility which has provided significant laser driven inertial confinement fusion data. The operation of the facility is discussed.

Different chemical pretreatments and filtration methods were evaluated as a possible means of clarifying and improving the injectivity of hypersaline brines. Six different downflow media combinations were evaluated over three geopressurized sites, using test data from 4 inch diameter filters. Also, tests were conducted with one hollow fiber ultrafilter unit and two types of disposable cartridge filters. The test procedures are mentioned briefly. (MHR)

RELAP4 is a computer code which can be used for the transient therm~l hydraulic analysis of light water reactors and related systems .. Various versions of the RELAP4 code are widely used throughout the world for experimental system analysis, reactor design,and nuclear system safety studies. RELAP4/MOD6 includes many new analytical models which were developed primarily for the analysis of the reflood phase of a PWR loss-of-coolant accident (LOCA) transient. The key feature forming the basis for the MOD6 reflood calculation is a unique moving finite differenced heat conductor. This paper will describe the development and application of the moving heat conductor mesh for use in reflood analysis.

To satisfy a broad range of control-analysis and data-acquisition requirements for Shiva, a hierarchical, computer-based, modular-distributed control system was designed. This system handles the more than 3000 control elements and 1000 data acquisition units in a severe high-voltage, high-current environment. The control system design gives one a flexible and reliable configuration to meet the development milestones for Shiva within critical time limits.