Westinghouse Electric Corporation

Government of the United States of America, As Represented by the Secretary of Commerce

The United States of America As Represented by the Secretary of

Armand J Panson

John W Ekin

Betty A Blankenship

Michael Troy

John F Jackovitz

Earl A Pantier

Carl A Bergman

A high-T.sub.c superconductor contact unit having low interface resistivity is disclosed, as is a method for making the unit. An inert metal is deposited on the surface of the superconductor, which surface is preferably non-degraded, to form a unit with the surface of the superconductor, and where temperatures as high as 500.degree. C. to 700.degree. C. can be tolerated, the unit is oxygen annealed to establish a still lower surface resistivity between the surface of the high-T.sub.c superconductor and the inert metal, including a low surface resistivity of about 10.sup.-10 .OMEGA.-cm.sup.2 at high-T.sub.c superconductor operating temperatures. The superconductor is a metal-oxide superconductor, and may be rare earth, thallium, or bismuth based.

High T.sub.c superconductor contact unit having low interface resistivity

A process for inhibiting corrosion caused by the presence of coolant water passing through a pressurized water nuclear reactor by the addition of an effective amount of an aqueous solution of zinc borate to the reactor coolant water. The transport of corrosion products and radioactive cobalt ions through the reactor primary circuit, as well as levels of radioactivity within the primary circuit, are reduced.

Process for inhibiting corrosion in a pressurized water nuclear reactor

A high-T.sub.c superconducting unit is disclosed having low contact resistivity between a substantially non-degraded surface of the superconductor and a surface of a contact pad in engagement with the substantially non-degraded surface of the superconductor, with contact resistivity of less than 1000 .mu..OMEGA.-cm.sup.2 at high-T.sub.c superconductor operating temperatures being disclosed.

High T.sub.c superconducting unit having low contact surface resistivity

High-T.sub.c superconductor contact unit having low interface

A low resistivity contact to a high-Tc superconductor is made by forming a contact pad on the surface of an abraded or freshly prepared superconductor by depositing an inert metal on the surface so that a surface resistivity between the surface of the high-Tc superconductor and the pad is established of less than about 1000.mu..OMEGA.-cm.sup.2 at high-Tc superconductor operating temperatures.

High-T.sub.c superconducting unit having low contact surface resistivity

A process is disclosed for determining the dissolved zirconium content of a hydrofluoric acid-nitric acid etching bath for zirconium articles by determining the rise in temperature of a volume of the bath upon immersion therein of a known quantity of zirconium metal, immersing a known quantity of zirconium metal into a portion of the bath, measuring the rise in temperature over a predetermined period of time of said portion, determining the dissolved zirconium content of the bath as a function of the rise in temperature, and treating the bath dependent upon the dissolved zirconium content so determined to be in the bath.

Etching process for zirconium metallic objects

Colloidal corrosion products which are referred to as crud are removed from nuclear reactor coolant streams by suspending zirconium oxide particles in the coolant stream. The crud will be attracted to the surfaces of the zirconia particles and caused to agglomerate thereon. Such zirconia/crud agglomerates may be readily filtered from the coolant. By providing scavenger particles which comprise active areas of zirconia on basically magnetite particles, after the crud is agglomerated to the active zirconia surfaces, the agglomerates may be removed from the coolant utilizing magnetic separation principles.

Reactor coolant crud control by particulate scavenging and filtration

A corrosion inhibiting aqueous steam generation medium for use in the secondary system of a nuclear steam generator comprises from about 5 to 10 ppm boric acid and an equimolar amount of a polyhydric compound, such as a lower alkyl glycol or glycerol, capable of reacting with the boric acid to increase its acid strength and therefore its corrosion inhibiting properties and produce therewith, a volatile diol boric acid complex.

Corrosion inhibiting media for pressurized water reactor steam generators

A process for etching zirconium metallic articles using an aqueous bath of hydrofluoric acid and nitric acid wherein the active hydrofluoric and nitric acid contents of the bath are determined by measurement of the dissolved zirconium content of the bath, and the bath is replenished in acid to give substantially the active hydrofluoric acid concentration and ratio to nitric acid, without removal of dissolved zirconium from the bath, to increase the bath etching life.

Process for etching zirconium metallic objects

A high gradient magnetic filter is enhanced by the electrophoretic effect whereby the range of effectiveness of the conventional high gradient magnetic filter for collecting suspended magnetic solid particles from liquid streams, such as power plant coolant streams, is extended to collect suspended magnetic solid particles of submicron size as well as particulates not susceptible to a magnetic field gradient. A conventional high gradient magnetic filter is connected into a pipeline, through which a liquid stream containing the suspended solid particles to be removed is flowing, so that the filter is electrically insulated from the remainder of the pipeline, and a potential is applied to the filter to polarize same relative to the pipeline with a polarity which is opposite the polarity of the charged particles in the stream which are to be collected.

Augmented high gradient magnetic filter

Uranium ore deposits which contain uranium in the relatively insoluble tetravalent state are readily selectively leached in situ to recover relatively pure uranium compounds, by: (a) passing through the ore deposit a relatively dilute aqueous leach solution of ammonium bicarbonate, ferric ammonium ethylenediaminetetraacetic acid (EDTA), and a source of oxygen, the leach solution converting the tetravalent uranium to hexavalent uranium which readily dissolves in the leach solution; (b) withdrawing the reacted leach solution enriched in dissolved uranium from the ore deposit; and (c) stripping the uranium from the withdrawn leach solution. The stripping of the uranium from the leach solution is preferably accomplished by countercurrent flow of the enriched leach solution to a column of base anion exchange material which preferentially extracts the uranium. Base anion exchange material loaded with uranium is separated from the leach solution and is treated with an aqueous alkaline eluant to extract the uranium and to regenerate the base anion exchange material. The stripped leach solution is adjusted by adding ammonium bicarbonate, peroxide, and ferric ammonium EDTA, and its pH corrected if necessary, and the leach solution is recycled through the ore deposit. The uranium bearing eluant is then acidified and treated with ammonia to precipitate relatively pure ammonium diuranate (ADU).

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Pittsburgh, PA, United States of America

Armand J Panson