Abstract: A high voltage multitube alkali metal thermal electric convertor having a plurality of closely packed tubular cells disposed in a tube sheet in a vessel and electrically connected in series, the tube sheet dividing the vessel into a high pressure high temperature portion having a wick and heater disposed therein and a low pressure low temperature portion having a wick disposed in a condenser from which heat is removed; a pump for transferring liquid metal therebetween and a tab on a wick disposed in the tubular cell to remove excess liquid metal and prevent shorting between the cells.

Abstract: A melt replenishment system for dendritic web growth having a pellet feed arrangement, which distributes equal amounts of feed material to a pair of feed tubes in communication with opposite ends of a crucible to maintain a melt pool at a constant level and a cover gas system, which keeps the feed tubes flowing and helps maintain thermal consistency within the melt.

Abstract: A test apparatus for studying the behavior of chemical reactants is disclosed.

Abstract: A nuclear reactor such as a pressurized water reactor has an integrated head package providing structural support and increasing shielding leading toward the vessel head. A reactor vessel head engages the reactor vessel, and a control rod guide mechanism over the vessel head raises and lowers control rods in certain of the thimble tubes, traversing penetrations in the reactor vessel head, and being coupled to the control rods. An instrumentation tube structure includes instrumentation tubes with sensors movable into certain thimble tubes disposed in the fuel assemblies. Couplings for the sensors also traverse penetrations in the reactor vessel head. A shroud is attached over the reactor vessel head and encloses the control rod guide mechanism and at least a portion of the instrumentation tubes when retracted.

Abstract: Nickel (or other transition metal) contaminated with about 5 ppm technetium is decontaminated by dissolving the nickel and the technetium into an aqueous acid solution while introducing a graphite or activated carbon powder into the acid to immediately adsorb the dissolving technetium. The technetium-contaminated powder is separated from the aqueous acid solution and the nickel is then electrowon from the solution. The depleted acid solution is then recycled back to the dissolution step.

Abstract: A sublimer assembly vaporizes zirconium tetrachloride in a Kroll reduction process. A retort for vaporizing the feed has a sidewall extending from a bottom wall with a peripheral heater adjacent to the sidewall and an internal heater extending through the retort. Substantial contact between the feed and the surfaces of the internal heater and retort sidewall is maintained so that the vaporization rate tends to cycle and the time required to vaporize the feed may be substantially reduced.

Abstract: A solid oxide fuel cell generator has a pair of spaced apart tubesheets in a housing. At least two intermediate barrier walls are between the tubesheets and define a generator chamber between two intermediate buffer chambers. An array of fuel cells have tubes with open ends engaging the tubesheets. Tubular, axially elongated electrochemical cells are supported on the tubes in the generator chamber. Fuel gas and oxidant gas are preheated in the intermediate chambers by the gases flowing on the other side of the tubes.Gas leakage around the tubes through the tubesheets is permitted. The buffer chambers reentrain the leaked fuel gas for reintroduction to the generator chamber.

Abstract: This is an improved method of fabricating Zircaloy-4 strip. The method is of the type wherein Zircaloy-4 material is vacuum melted, forged, hot reduced, beta-annealed, quenched, hot rolled, subjected to a post-hot-roll anneal and then reduced by at least two cold rolling steps, including a final cold rolling to final size, with intermediate annealing between the cold rolling steps and with a final anneal after the last cold rolling step. The improvement comprises: (a) utilizing a maximum processing temperature of 620.degree. C. between the quenching and the final cold rolling to final size; (b) utilizing a maximum intermediate annealing temperature of 520.degree. C.; and (c) utilizing hot rolling, post-hot-roll annealing, intermediate annealing and final annealing time-temperature combinations to give an A parameter of between 4.times.10.sup.-19 and 7.times.10.sup.

Abstract: Technetium is separated from nickel by electro-refining contaminated nickel. Electrorefining controls the electrolyte solution oxidation potential to selectively reduce the technetium from the metallic feedstock solution from Tc(VII) to Tc(IV) forcing it to report to the anodic slimes and thereby preventing it from reporting to the cathodic metal product. This method eliminates the need for peripheral decontamination processes such as solvent extraction to remove the technetium prior to nickel electrorefining. These methods are particularly useful for remediating nickel contaminated by radio-contaminants such as technetium and actinides.

Abstract: A nuclear reactor having a chemical decontamination system is provided in which every piece of decontamination equipment which processes radioactive materials is located within a decontamination building. The decontamination system is designed to provide for adequate protection for personnel safety and also incorporates a modular design for equipment transportation and storage.

Abstract: 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.

Abstract: Two alternate, mutually exclusive, methods of removing radio contaminants from metal are taught based respectively on electrowinning or electrorefining of the base metal. The alternative using electrorefining controls the anolyte oxidation potential to selectively reduce the technetium in the metallic feedstock solution from Tc(VII) to Tc(IV) forcing it to report to the anodic slimes preventing it from reporting to the cathodic metal product. This method eliminates the need for peripheral decontamination processes such as solvent extraction and/or ion exchange to remove the technetium prior to nickel electrorefining. The other alternative method combines solvent extraction with electrowinning. By oxidizing technetium to the heptavalent state and by using mixtures of tri-n-octyalphosphine oxide and di-2-ethyl phosphoric acid in aliphatic hydrocarbon carriers to extract the radio contaminants prior to electrowinning, the background metal may be recovered for beneficial reuse.

Abstract: A process for manufacturing a lithium alloy, metal sulfide cell tape casts slurried alloy powders in an organic solvent containing a dissolved thermoplastic organic binder onto casting surfaces. The organic solvent is then evaporated to produce a flexible tape removable adhering to the casting surface. The tape is densified to increase its green strength and then peeled from the casting surface. The tape is laminated with a separator containing a lithium salt electrolyte and a metal sulfide electrode to form a green cell. The binder is evaporated from the green cell at a temperature lower than the melting temperature of the lithium salt electrolyte. Lithium alloy, metal sulfide and separator powders may be tape cast.

Abstract: A scrub solution is made up for use in starting up a hafnium liquid-liquid extraction system. An aqueous zirconium oxychloride-containing solution is contacted with methyl isobutyl ketone containing less than 1 Molar thiocyanic acid. The aqueous solution is maintained at a chloride concentration of 1.6 to 3.5 Normal (as HCl) by addition of concentrated hydrochloric acid. Ammonium thiocyanate is added to the acidified aqueous stream to produce thiocyanic acid. The high acidity of the aqueous solution drives the thiocyanic acid into the methyl isobutyl ketone without the chloride anions having a depressing affect on the transfer. The thiocyanic acid-containing MIBK may then be used as a scrubbing solvent to start up the hafnium extraction system.

Abstract: A process for producing nuclear grade zirconium and a liquid-liquid separation circuit for separating zirconium from hafnium are provided. The process employs an aqueous feed of ZrOCl.sub.2 in the presence of thiocyanate, an organic solvent and acid and a series of high mass transfer efficiency pulse columns in which are conducted the iron extraction, hafnium extraction, zirconium stripping, hafnium scrubbing and zirconium and hafnium thiocyanate recovery processes required to produce substantially hafnium-free nuclear grade zirconium. A feed zone mixer-settler separates thiocyanate and zirconium injection points and permits the prestripping of zirconium prior to the main stripping operation. All of the scrubbed solvent and the thiocyanate are regenerated. Higher concentrations, smaller flows, and compact equipment result in the present process requiring substantially reduced in-process inventories as compared to previously known Zr/Hf separation processes.

Abstract: A sublimer-reactor system for reducing Group IVB metals with magnesium has a sublimer spaced from a reactor with a gas flow control valve in piping interconnecting them. A load cell weighs the feed in the sublimer and outputs a signal to the control valve to control the vapor flow of feed vapors to the reactor.

Abstract: A primary coolant circuit for cooling a nuclear reactor has wetted mechanically stressed nickel base alloy components such as Alloy 600 tubes in steam generators having oxidized surfaces comprising 1-10 w/o zinc, which tubes are inhibited against primary water stress corrosion cracking. The crack initiation times may be delayed by a factor of two in pressurized water nuclear reactors.

Abstract: A vapor stream from a sand chlorinator containing principally zirconium tetrachloride, hafnium tetrachloride and silicon tetrachloride contaminated with ferric chloride is purified by cooling the vapor to a temperature of about 335.degree. C. to about 600.degree. C. The cooled vapors flow through a gaseous diffusion separative barrier where a silicon tetrachloride vapor stream contaminated with metal chlorides flows from the separative barrier as a "fast" stream; ferric chloride is adsorbed by the separative barrier; and a vapor stream principally containing zirconium tetrachloride, hafnium tetrachloride and silicon tetrachloride is screened by the separative barrier.

Abstract: A zirconium sponge contaminated with unreacted magnesium and by-product magnesium which is produced as a regulus in a Kroll reduction process is purified by:distilling the magnesium and magnesium chloride from the regulus at a temperature of above about 800.degree. C. and at a pressure less than about 10 mmHg;condensing the magnesium and the magnesium chloride;backfilling the sysem with a gas; andrecirculating the gas between a vessel containing the purified zirconium sponge and a condenser containing the magnesium and magnesium chloride.In preferred practice, the recirculating gas is an inert gas such as argon or helium and the system is backfilled during the distillation step.The zirconium sponge is purified in shorter times and adsorbs less impurities from the air in subsequent handling.

Abstract: Utilization of inherent fractional distillation of magnesium and magnesium chloride in reduction to sponge metal in a vacuum distillation furnace of zirconium and/or hafnium or other refractory metal tetrachloride by the Kroll process, to separate magnesium from magnesium chloride and metal subchlorides so the magnesium can be recycled in the process substantially free of the magnesium chloride and metal subchlorides. The magnesium vapor from the distillation furnace is recovered and condensed separately from the magnesium chloride and refractory metal sub-chloride vapors.