Westinghouse Electric Corporation

Westinghouse Electric Company LLC

Other

David F McLaughlin

Richard A Stoltz

Thomas V Congedo

Frank H Ruddy

Edward Jean Lahoda

Thomas S Snyder

David C Grant

William A Byers

Shyam Vasant Dighe

John Bartko

John G Seidel

Arnold H Fero

Wen-Ching Yang

Michael C Skriba

Ernest D Lee

Abdul R Dulloo

William R Gass

Brandon Damon Thomas

Timothy L Francis

Joseph L Gonzalez

John M Iacovino, Jr

Francis Talko

Vanessa R Yochum

Nancy Hamp Ulerich

Vanessa R Youchum

John G Siedel

The present invention relates generally to a process and chemical composition for the removal of adherent niobium-rich second-phase particles (SPPs) from pickled niobium-containing zirconium alloys which includes applying to the alloy surface a chemical composition comprising alkaline hydrogen peroxide; an alkali metal meta-silicate; and a magnesium salt.

Removal of niobium second phase particle deposits from pickled zirconium-niobium alloys

The present invention provides a method for removing niobium-rich second-phase-particle (SPP) deposits from zirconium-niobium alloy components. The method comprises washing a freshly pickled and rinsed zirconium-niobium alloy component with an acidified oxalic acid or ammonium oxalate washing solution. The method of the present invention results in a rapid, efficient and complete removal of surface SPP deposits from the zirconium-niobium alloy component without pitting, leaving behind a clean, shiny surface without the need to use water blasting or mechanical wiping operations.

A fluidized bed reactor ( ) for chemically transforming reactants to generate a desired product, having a hollow, elongated, vertically oriented reactor housing ( ) for confining the reaction and an unobstructed collection path ( ) below the reaction zone for funneling the residue of the process to an exit port ( ). A central gas inlet ( ) proximate the bottom of the reaction zone within the housing directs gas parallel to the vertical axis of the housing to maintain the raw materials in suspension. A plurality of individually controlled peripheral gas jets ( ) positioned at least two elevations along the elongated dimension of the reaction housing ( ), and located circumferentially around the housing ( ) at each elevation, introduce gas at an angle to promote mixing of the entrained materials in suspension. The clog-free collection path ( ) below the reaction zone funnels the residue of the process to an exit port ( ) where it is continuously removed by a screw feeder ( ). A gas sparger ( ) below the reaction zone diverts fine agglomerates of the residue back into the reaction stream to increase the efficiency of the process and minimize the residue.

Fluidized bed reaction design

Detectors are used to monitor the status of spent nuclear fuel storage containers non-invasively while they remain in storage casks. The detectors measure neutron flux and &ggr;-ray flux and may also measure temperature variations of the spent nuclear fuel. The measurements can be accomplished actively or passively, with minimal exposure of individuals to radiation fields or other hazardous conditions. Preferred neutron and &ggr;-ray detectors have a semiconductor active region that is resistant to neutron damage. Incipient structural failures may also be detected using measurements based on electrical continuity, with data being transmitted to an external pickup coil.

In-situ self-powered monitoring of stored spent nuclear fuel

A system for treating contaminated sediments dredged from waterways is disclosed. Dredged sediments are divided into coarse and fine fractions. The coarse fraction is washed to remove contaminants. The fine fraction and the contaminants removed from the coarse fraction are admixed, followed by filtering to produce a dewatered fraction. The dewatered fraction is then melted in a plasma melter to form a molten mass of glass or slag. The molten mass is then cooled to form a stable, low-leachability product. During the plasma melting operation, organic contaminants are destroyed and contaminants such as heavy metals are contained within the matrix of the melted glass or slag. After cooling the melted material may be provided in the form of aggregate, granules or fibers useful for various applications such as road fill, roofing granules and rock wool.

Conversion of contaminated sediments into useful products by plasma

This invention provides a process wherein hazardous or radioactive wastes in the form of liquids, slurries, or finely divided solids are mixed with finely divided glassformers (silica, alumina, soda, etc.) and injected directly into the plume of a non-transferred arc plasma torch. The extremely high temperatures and heat transfer rates makes it possible to convert the waste-glassformer mixture into a fully vitrified molten glass product in a matter of milliseconds. The molten product may then be collected in a crucible for casting into final wasteform geometry, quenching in water, or further holding time to improve homogeneity and eliminate bubbles.

Plasma vitrification of waste materials

A system for determining depth profiles of concentrations of hazardous elements in soils comprises a neutron source for generating neutrons of a first energy level and irradiating a volume of soil with the neutrons. Nuclear reactions are effected within the soil and gamma radiation is emitted from the soil. The system also includes an array of gamma detectors for detecting gamma radiation emitted from the soil; source electronics for controlling the width of regularly repeated pulses of neutrons generated by the neutron source; detector electronics associated with the gamma detectors for amplifying and digitalizing signals generated by the gamma detectors and storing data representing the digitalized signals; spectral analysis software for analyzing the data and determining the concentrations of selected target elements in the soil; and an acquisition interface module (AIM). The AIM controls the timing of the source and detector electronics such that the neutron source generates neutrons in regularly repeated bursts of a prescribed pulse width and the detectors and detector electronics detect gamma rays during a plurality of time intervals associated with the burst and acquire groups of data. Each group is indicative of a number of gamma rays emitted and their energy levels during a corresponding time interval. The system also includes a mobile platform carrying the neutron source, array of gamma ray detectors and software for determining a depth profile of a target element. Trace elements can also be detected with the disclosed system.

Prompt gamma neutron activation analysis system

This is a method of reducing zirconium chloride to a metal product by introducing zirconium chloride into a molten salt bath containing at least one alkali metal chloride and at least one alkaline earth metal chloride; and electrochemically reducing alkaline earth metal chloride to a metallic alkaline earth metal in the molten salt bath, with the reduced alkaline earth metal reacting with the zirconium chloride to produce zirconium metal. By using this electrochemical-metallothermic reduction, zirconium metal is produced and insoluble subchlorides of zirconium in the metal product are generally avoided. Preferably, the molten salt in the molten salt bath consists essentially of a mixture of lithium chloride, potassium chloride, magnesium chloride and zirconium or hafnium chloride. The method is especially useful as part of a distillation system for separating hafnium from zirconium, possibly after the zirconium chloride is removed from the distillation system, but especially where the distillation system has an alkali metal chloride and alkaline earth metal chloride recirculating solvent and the electrochemical-metallothermic reduction is used to strip the solvent of zirconium chloride. This process can also be used for hafnium and titanium, especially when a powder metal product is desired.

Electrochemical-metallothermic reduction of zirconium in molten salt

A process for producing supported metal catalysts having increased catalytic activity is provided. This process includes the steps of forming a high surface area porous support of a suitable porous material such as alumina or zirconia, dissolving a salt of a selected catalytic metal in an appropriate supercritical fluid solvent, contacting the porous support with the supercritical fluid solution of the catalytic metal salt to impregnate the porous support with the solution so that the catalytic metal salt may be adsorbed on the surfaces of the support, and removing the supercritical fluid solvent by reducing the pressure or increasing the temperature to change the supercritical fluid from the supercritical fluid phase to the gas phase, which may then be recycled for further use. The insoluble catalytic metal salt is deposited in the form of a film on the surfaces of the support. The catalytic metal salt-containing porous support may then be processed conventionally to produce a substantially pure, high activity supported metal catalyst.

Catalyst preparation using supercritical solvent

Removal of aluminum and iron impurities is accomplished using an absorbing column containing potassium or sodium chloride, producing an aluminum and iron chloride-rich bottoms product and purified Zr(Hf)Cl.sub.4 vapor at the top of the column. This invention is a continuous process for removing impurities of iron or aluminum chloride or both from vaporous zirconium chloride (or hafnium chloride or a mixture thereof). When iron is being removed from zirconium tetrachloride using potassium chloride, the process comprises: introducing impure zirconium chloride vapor into a middle portion of an absorbing column containing a potassium chloride-containing molten salt phase, the molten salt phase absorbing the iron chloride impurity to produce a zirconium chloride vapor stripped of iron chloride in the top portion of the column; introducing potassium chloride into a top portion of the column; controlling the top portion of the column to between 300.degree.-375.degree. C.; heating a bottom portion of the column to 450.degree.-550.degree. C. to vaporize zirconium chloride from the molten salt; withdrawing molten salt substantially free of zirconium and hafnium chloride from the bottom portion of the column; and withdrawing zirconium chloride vapor substantially free of iron chloride impurity from the top of the column. Similarly, hafnium or hafnium-zirconium mixtures can be substituted for zirconium, or aluminum or iron-aluminum can removed rather than iron, or sodium chloride or sodium potassium chloride mixtures can be substituted for potassium chloride.

Molten salt scrubbing of zirconium or hafnium tetrachloride

Improvements are described to a process in which the extractive distillation separation of zirconium or hafnium may be accomplished using mixtures of fused alkali metal or alkali metal and alkaline earth chlorides as the solvent. The solvent composition is adjusted to provide a low-melting eutectic, permitting recirculation of the stripped solvent in the liquid phase, as well as reducing the temperature required for thermal stripping (reducing the corrosivity of the fluid). Stripping of the bottoms is accomplished at least partially by direct electrolysis of the bottoms stream, producing the zirconium-free salt recycle stream to be transferred to the top of the column, and at least partially eliminating the need for chemical reduction of the tetrachlorides to metal (a costly process generating undersirable waste streams). Regeneration of the reflux is accomplished in a presurized condenser system, of one or more stages, with all material transport to be done in either the liquid or vapor states.

Molten salt extractive distillation process for zirconium-hafnium

This is an improved method for separating hafnium from zirconium of the type where a complex of zirconium and hafnium chlorides and phosphorus oxychloride is prepared from zirconium-hafnium chloride and the complex is introduced into a distillation column, with the improvement comprising: electrochemical breaking of the zirconium of hafnium chloride complex taken from said distillation column to separate product from the complex. The electrochemical breaking of the complex, possibly by reducing zirconium or hafnium, is done in a molten salt bath. Preferably, the molten salt in said molten salt bath consists principally of a mixture of alkali metal and alkaline earth metal chlorides and zirconium or hafnium chloride. The product can be either chloride, metal, or mixed metal and subchloride for further processing.

Electrochemical decomposition of complexes of zirconium or hafnium

This is a zirconium-hafnium separation process utilizing a complex of zirconium-hafnium chlorides and phosphorus oxychloride. The complex is introduced into a distillation column and a hafnium chloride enriched stream is taken from the top of the column and a zirconium chloride enriched stream is taken from the bottom of the column. In particular, the invention utilizes prepurification of the zirconium-hafnium chlorides prior to introduction of the complex into the distillation column to substantially eliminate iron chloride; thus, the buildup of iron chloride in the distillation column is substantially eliminated and the column can be operated in a continuous stable, and efficient manner.

Preparation of complexes of zirconium and hafnium tetrachlorides with

This is a process for removing phosphorus oxychloride from a complex of zirconium or hafnium chloride and phosphorus oxychloride utilizing a lithium-potassium chloride molten salt absorber vessel displacing phosphorous oxychloride from the complex, with a condenser which has the complex of zirconium or hafnium chloride and phosphorus oxychloride as the condensing fluid to scrub zirconium or hafnium chloride from the phosphorus oxychloride vapor released from the complex. The process uses at least one separate vessel to strip the zirconium or hafnium chloride from the lithium-potassium chloride molten salt.

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Oakmont, PA, United States of America

David F McLaughlin