SYNROC is a titanate-based ceramic waste form being developed to immobilize high-level nuclear reactor wastes. SYNROC-D is a unique variation of SYNROC designed to contain high-level defense wastes, particularly those in storage at the Savannah River Plant (SRP). We review recent research and development on SYNROC-D processing options and report on work in progress on various unit operations. The overall immobilization process can be divided into three general parts: (1) slurry preparation (formulation, reactant addition and blending); (2) powder processing (spray drying, calcination/redox control); and (3) mineralization (densification). Powder processing research is directed toward development of a slurry-fed, fluidized-bed calciner based on the ICPP design. Densification research is focused on use of hot isostatic pressing (HIP) or hot uniaxial pressing (HUP). The successful use of both have been demonstrated.

In the Tandem Mirror Experiment Upgrade (TMX-U), the formation of a thermal barrier and the potential plugging of ion end loss were achieved at central-cell densities up to 2 x 10/sup 12/ cm/sup -3/. The presence of a thermal barrier was confirmed by direct measurement, and ion axial-confinement times in the range 50 to 100 ms were measured. The ECRH in the end cells (a) initiates plasma startup, (b) generates hot, mirror-confined electrons to form thermal barriers, and (c) creates the plugging potential for central-cell ions. The ECRH system consists of four 200 kW, 28 GHz gyrotrons each feeding power to a separate heating location (two in each end plug). Fundamental heating is used at the potential plug, and second harmonic is used in the thermal barrier. Hot-electron plasmas are produced at total end-cell antenna power levels up to 300 kW. Strong single-pass absorption and net hot-electron heating efficiencies exceeding 40% are observed. Hot-electron parameters achieved are: n/sub eh//n/sub et/ up to 0.8, volume-average beta <..beta..> approx. = 0.15, and T/sub x/ (x-ray tail above 40 keV) in the range 75 to 200 keV.

The Rocky Flats Plant is introducing the use of dicesium hexachloroplutonate (DCHP) into the Molten Salt Extraction Process (MSE). DCHP (Cs/sub 2/PuCl/sub 6/) extracts americium from molten plutonium metal into a molten calcium chloride matrix. The DCHP is produced by precipitating plutonium (IV) from hydrochloric acid with cesium chloride. Before production of the DCHP began, we performed a pilot-scale test to determine yields, track impurities, and test filtrate recovery for the proposed process. In the course of this study, we determined that impure plutonium oxide (0.80 g/g) dissolved in concentrated HCl is an acceptable source of plutonium for the DCHP. We also determined that dissolved oxide and chloride anion exchange eluate can be mixed for DCHP preparation. We found that DCHP yields average 92-95% at 8M total chloride and are independent of sparging rate and time. Furthermore, we found that drying at 150/degree/C for 5 hr gives <0.1% water in the DCHP only if it is preceeded by extensive air drying. Finally, we proved the efficiency of chloride anion exchange for the recovery of above-discard plutonium from the filtrate. 11 refs., 1 fig., 11 tabs.

Induction linear accelerators (LIAs) are inherently capable of accelerating several thousand amperes of /approximately/ 50-ns duration pulses to > 100 MeV. In this paper we report progress and status in the areas of duty factor and stray power management. These technologies are vital if LIAs are to attain high average power operation. 13 figs.

The overall objective of this research project is to develop a technical basis for flexible piping designs which will improve piping reliability and minimize the use of pipe supports, snubbers, and pipe whip restraints. The current study was conducted to establish the necessary groundwork based on the piping reliability analysis. A confirmatory piping reliability assessment indicated that removing rigid supports and snubbers tends to either improve or affect very little the piping reliability. A couple of changes to be implemented in Regulatory Guide (RG) 1.61 and RG 1.122 aimed at more flexible piping design were investigated. It was concluded that these changes substantially reduce calculated piping responses and allows piping redesigns with significant reduction in number of supports and snubbers without violating ASME code requirements.

This paper discusses a perspective which we have developed on the problem of demonstrating compliance of high-level waste repositories with system performance standards. Our viewpoint arises from two primary concerns - first, that the US Environmental Protection Agency's proposed environmental standard for high-level waste disposal appears to require demonstrations of compliance which are incompatible with scientific knowledge, and, second, that the federal agencies involved in the licensing process may not appreciate fully the extent of unquantifiable and uresolvable uncertainty in repository performance-assessment models. We propose a general approach to demonstrations of compliance which we feel is compatible with the kinds of technical information that will be available for judging repository performance. Our approach emphasizes the importance of investigation alternative conceptual models and lines of reasoning in evaluating repository performance and the importance of subjective scientific judgment in the desision-making process. 24 references, 1 figure.

The D phi experiment is a recently approved effort at FERMILAB to study proton-antiproton collisions at 2 TeV. A powerful new detector has been designed for this experiment and is described. The D phi detector has been designed to optimize its discovery potential in the mass range where deviations from the Standard Model might be expected to manifest themselves. Rather than discussing the detector's response to particular hypothetical new states (Higgses, squarks, etc.), we focus here on more technical capabilities (leptons, jets, etc.). After a brief physics summary to motivate our technical choices, we consider the detector design subsystem by subsystem. 9 references.

Article evaluating the selectivity of compounds originally identified as inhibitors of poly(ADP-ribose) polymerase on members of the three classes of enzymes. The results suggest that micromolar levels of the benzamides in the culture medium should allow selective inhibition of poly(ADP-ribose) metabolism in intact cells. Furthermore, comparative quantitative inhibition studies should prove useful for assigning the biological effects of these inhibitors as an effect on either poly(ADP-ribose) or mono(ADP-ribose) metabolism.