Laser diagnostics for NTP fuel corrosion studies

Viewgraphs and explanations on laser diagnostics for nuclear thermal propulsion (NTP) fuel corrosion studies are presented. Topics covered include: NTP fuels; U-Zr-C system corrosion products; planar laser-induced fluorescence (PLIF); utilization of PLIF for corrosion product characterization of nuclear thermal rocket fuel elements under test; ZrC emission spectrum; and PLIF imaging of ZrC plume

Competitive Effect on the Rate of the Diffusion-Controlled Reaction A+B→C

None available; appears in letters section

Advanced oxidation and reduction processes: Closed-loop applications for mixed waste

At Los Alamos we are engaged in applying innovative oxidation and reduction technologies to the destruction of hazardous organics. Non thermal plasmas and relativistic electron-beams both involve the generation of free radicals and are applicable to a wide variety of mixed waste as closed-loop designs can be easily engineered. Silent discharge plasmas (SDP), long used for the generation of ozone, have been demonstrated in the laboratory to be effective in destroying hazardous organic compounds and offer an altemative to existing post-incineration and off-gas treatments. SDP generates very energetic electrons which efficiently create reactive free radicals, without adding the enthalpy associated with very high gas temperatures. A SDP cell has been used as a second stage to a LANL designed, packed-bed reactor (PBR) and has demonstrated DREs as high as 99.9999% for a variety of combustible liquid and gas-based waste streams containing scintillation fluids, nitrates, PCB surrogates, and both chlorinated and fluorinated solvents. Radiolytic treatment of waste using electron-beams and/or bremsstrahlung can be applied to a wide range of waste media (liquids, sludges, and solids). The efficacy and economy of these systems has been demonstrated for aqueous waste through both laboratory and pilot scale studies. We win present recent experimental and theoretical results for systems using stand alone SDP, combined PBR/SDP, and electron-beam treatment methods

Advanced oxidation and reduction processes: Closed-loop applications for mixed waste

At Los Alamos we are engaged in applying innovative oxidation and reduction technologies to the destruction of hazardous organics. Non thermal plasmas and relativistic electron-beams both involve the generation of free radicals and are applicable to a wide variety of mixed waste as closed-loop designs can be easily engineered. Silent discharge plasmas (SDP), long used for the generation of ozone, have been demonstrated in the laboratory to be effective in destroying hazardous organic compounds and offer an altemative to existing post-incineration and off-gas treatments. SDP generates very energetic electrons which efficiently create reactive free radicals, without adding the enthalpy associated with very high gas temperatures. A SDP cell has been used as a second stage to a LANL designed, packed-bed reactor (PBR) and has demonstrated DREs as high as 99.9999% for a variety of combustible liquid and gas-based waste streams containing scintillation fluids, nitrates, PCB surrogates, and both chlorinated and fluorinated solvents. Radiolytic treatment of waste using electron-beams and/or bremsstrahlung can be applied to a wide range of waste media (liquids, sludges, and solids). The efficacy and economy of these systems has been demonstrated for aqueous waste through both laboratory and pilot scale studies. We win present recent experimental and theoretical results for systems using stand alone SDP, combined PBR/SDP, and electron-beam treatment methods

Simulating beryllium electrorefining with AspenPlus{copyright}

Beryllium is a lightweight, high strength metal with excellent thermal properties. It is a high cost material that has applications in electronics, the space program, and the defense industry. Beryllium is irreplaceable in several defense applications and therefore the US government maintains a reserve supply of several grades of the metal. However, the current defense industry (the largest metallic beryllium user) use has dwindled to the point that the only metallic beryllium producer in the US, Brush Wellman Inc., continually evaluates the profitability of continued production. The production dilemma has been compounded by health concerns associated with the generation of beryllium fines during production. An electrorefining method, previously developed, shows promise for recycling low purity beryllium scraps and produces a high grade material. Recycling and purification can reduce costs and waste disposal problems and increase the beryllium reserves in the event that Brush Wellman discontinues production. In this paper, the authors demonstrate how to use a commercially available process simulator for improving a process to electrorefine both scrap and low purity beryllium into a high purity product

Nonthermal plasma alternative to the incineration of hazardous organic wastes. [Mixtures containing oil and trichloroethylene, carbon tetrachloride and trichloroethane]

We are developing silent discharge plasma (SDP) oxidation technology as an alternative to incineration and as a post-incinerator treatment process for hazardous organic wastes. As an alternative to incineration, SDP apparatus has been coupled to a high-temperature packed-bed reactor, the plasma apparatus serving as a second stage for treating gaseous effluent from the packed bed. As a post- incinerator treatment process, SDP apparatus has been evaluated using a prepared gaseous feed containing hazardous organic compounds which are expected to be found in the machining fluids (trichloroethylene (TCE), carbon tetrachloride (CCl{sub 4}), and trichloroethane (TCA)). In typical tests with the packed-bed reactor alone, we have treated mixtures containing oil and several per cent TCE, TCA, or CCl{sub 4} removing the chlorocarbons to levels of ppm-order for TCA and to order {approximately}100 ppb for TCE and CCl{sub 4}, as measured in the gaseous effluent. In representative stand-alone tests with the SDP reactor, we have removed TCE in the gaseous influent from 1,000 ppm concentrations to around 100 ppb in the gaseous effluent (CCl{sub 4} appears to be more treatment-resistant). The measured figures of merit for the SDP reactor (electrical energy per mass of removed chemical) are 10's of kW-hr/kg for >>99% removal of TCE and 100's of kW-hr/kg for 90% removal of CCl{sub 4}, both being non-optimized cases in terms of waste concentration, carrier gas composition, water content, flow rate, and electrical power. Using combined packed- bed/SDP reactors on chlorocarbon/oil mixtures, several per cent chlorocarbon concentrations have been removed to well below the 100-ppb level overall. We envision eventual reductions to levels of {approximately}10 ppb or less

Fuzzy Set Theory Applied to Measurement Data for Exposure Control in Beryllium Part Manufacturing.

Fuzzy set theory has been applied to some exposure control problems encountered in the machining and the manufacturing of beryllium parts at Los Alamos National Laboratory. A portion of that work is presented here. The major driving force for using fuzzy techniques in this case rather than classical statistical process control is that beryllium exposure is very task dependent and this manufacturing plant is quite atypical. It is feared that standard techniques produce too many false alarms. Our beryllium plant produces parts on a daily basis, but every day is different. Some days many parts are produced and some days only a few. Some times the parts are large and sometimes the parts are small. Some machining cuts are rough and some are fine. These factors and others make it hard to define a typical day. The problem of concern, for this study, is the worker beryllium exposure. Even though the plant is new and very modern and the exposure levels are expected to be well below the required levels, the Department of Energy (DOE), who is our major customer, has demanded that the levels for this plant be well below required levels. The control charts used to monitor this process are expected to answer two questions: (1) Is the process out of Control? Do we need to instigate special controls such as requiring workers to use respirators? (2) Are new, previously untested, controls making a difference? The standard Schewart type control charts, based on consistent plant operating conditions do not adequately answer this question. The approach described here is based upon a fuzzy modification to the Schewart Xbar-R chart. This approach is expected to yield better results than work based upon the classical probabilistic control chart