Abstract: Fuel pellets can include a fission material powder, a protective layer coated on the fission material powder, and an oxidation diffusion barrier coated on the protective layer, with the protective layer and oxidation diffusion barrier being formed through ALD to achieve infiltration of the coatings within the fuel pellets.

Abstract: An apparatus for sampling landfill gas from a landfill flowing through a pipe. The apparatus may comprise: an enclosure configured to receive a section of the pipe; a gas sampling port in the section of the pipe; at least one sensor device disposed in a region of the enclosure, the at least one sensor being coupled to the section of the pipe through the gas sampling port; and thermal insulation positioned to retain heat from the section of the pipe in the region of the enclosure. A method of operating a landfill gas recovery system. The method may comprise: flowing gas from a well riser pipe through a sampling subsystem to a collection system; and heating a portion of the sampling subsystem with the gas flowing from the well riser pipe to the collection system.

Abstract: A device for measuring a total gas content of a primary circuit of a PWR nuclear power plant includes a shielding protective cover, and a sampling assembly and a sample measuring assembly that are detachably connected to the shielding protective cover; the sampling assembly includes a sampling bottle; a valve connected to one mouth of the sampling bottle through a pipeline; a second valve connected to the other mouth of the sampling bottle through a pipeline; a first quick female connector connected with the first valve through a pipeline; a second quick female connector connected to the second valve through a pipeline; a balance pipeline, one end being connected to the pipeline between the first valve and the first quick female connector, and the other end being connected to the pipeline between the second valve and the second quick female connector.

Abstract: A method and apparatus for the generative manufacture of a three-dimensional component in a processing chamber, in which the steps “providing a metallic starting material in the processing chamber” and “melting the starting material by means of energy input” are repeated multiple times, wherein a process gas is provided in the processing chamber are disclosed. The method is characterized by the steps: 1) the hydrogen content of the process gas or a sample of the process gas is determined; 2) the oxygen content of the process gas or a sample of the process gas is determined by means of an oxygen sensor and/or the dew point of the process gas or a sample of the process gas is determined; and 3) the values for the oxygen content and/or the dew point determined in step 2 are corrected by means of the value for the hydrogen content determined in step 1.

Abstract: A gases humidification system includes a measuring chamber and a mixing chamber. The mixing chamber has one or more mixing elements that improve a mixing of gases before reaching the measuring chamber. Ultrasonic sensing is used to measure gases properties or characteristics within the measuring chamber. A baffle or a vane may be used to control and direct the gases flow through the mixing chamber as the gases flow moves into the measuring chamber.

Abstract: An environmentally sequestered nuclear spent fuel pool in one embodiment includes sidewalls and a base slab that confine a water impoundment. The pool includes fuel racks containing spent fuel assemblies which heat the water via radioactive decay. A dual liner system enclosing the pool forms an impervious barrier providing redundant provisions for preventing leakage of contaminated pool water into the environment. An interstitial space is formed between the liners which may be maintained at sub-atmospheric pressures by a vacuum pump system that evacuates the space. By maintaining the pressure in the space at a negative pressure with corresponding boiling point less than the temperature of the pool water, any leakage through the inner-most liner into the interstitial space will vaporize and be extracted via the pump for signaling a potential leak in the liner system.

Abstract: Disclosed are a system and method for preventing and monitoring a leakage of water from a tank liner at a storage tank having: a concrete reservoir; the tank liner made up of a wall liner that is formed by coupling a plurality of first panels and is attached to an inner wall of the concrete reservoir, and a floor liner that is formed by coupling a plurality of second panels, is attached to a floor of the concrete reservoir, and is coupled to the wall liner by welding; a leaking water collecting plate formed by welding a plurality of third panels and inserted between the floor liner and the floor of the concrete reservoir; and an edge leaking water collecting channel buried in an edge of the storage tank and configured to collect leaking water discharged between the floor liner and the leaking water collecting plate.

Abstract: A system for determining a concentration of gas in a confined space includes a first frequency generator for generating a first RF signal. A first antenna transmits the first RF signal across the confined space and second antenna receives the first RF signal. First and second RF signal power detectors detect the power of the first RF signal both prior to and after transmission through the confined space. A first comparator circuit determines a concentration of oxygen in the confined space based on the power of the first RF signal prior to transmission through the confined space and the power of the first RF signal received by the second antenna.

Abstract: An apparatus and method are disclosed for sampling and analyzing the exhaust gas or liquid from an internal combustion engine or other device that generates a flow of exhaust gas or liquid during use. The apparatus includes a connector that is adapted to be secured adjacent to an aperture formed through an outlet conduit of an engine or other device that generates a flow of exhaust gas or liquid therethrough during use. A conduit communicates with the connector and is adapted to receive and pass therethrough at least a portion of the exhaust gas or liquid from the outlet conduit. A sensor chamber communicates with the conduit and is adapted to receive and pass therethrough at least a portion of the exhaust gas or liquid from the conduit. A one-way valve only allows the exhaust gas or liquid in the sensor chamber to exit therefrom. Lastly, a sensor senses at least one characteristic of the exhaust gas or liquid in the sensor chamber and generates a signal that is representative of such characteristic.

Abstract: An apparatus adapted to measure gaseous hydrogen concentrations in a mechanical vacuum pump (MVP) gas stream includes connection ports adapted to allow the apparatus to be connected to an MVP system and allow a gas stream sample to be taken from the MVP gas stream. The apparatus further includes a hydrogen concentration analyzer to measure H2 concentrations of the gas stream sample taken from the MVP gas stream.

Abstract: A hydrogen treatment facility for treating hydrogen without using a power source is disposed outside a reactor containment vessel and in an upper portion of a reactor building. A hydrogen detector detecting hydrogen in the reactor building is connected to a control apparatus operated by an independent power source activated at the time of a station black-out. A circulation passage for air circulation generated in the reactor building is disposed in the reactor building and outside the reactor containment vessel. A hydrogen treatment duct connects to the circulation passage and a gangway and a room with equipment. During a severe accident and station black-out and when hydrogen concentration detected by the hydrogen detection apparatus exceeds a set concentration, the hydrogen treatment duct is put in use by the control apparatus. Air containing the hydrogen is introduced into the hydrogen treatment facilities through the hydrogen treatment duct and the circulation passage.

Abstract: Illustrative embodiments provide a nuclear fission reactor, a vented nuclear fission fuel module, methods therefor and a vented nuclear fission fuel module system.

Abstract: A boiling water reactor core power level monitoring system includes a desired length of high dielectric, non-linear material insulated coaxial type cable in close proximity to the reactor core and a time domain reflectometry apparatus configured to measure a temporary characteristic impedance change associated with the coaxial type cable in response to at least one of neutron or gamma irradiation generated via the reactor core.

Abstract: A method for determining a fresh fuel bundle design for a core of a nuclear reactor may include defining a plurality of inputs including user-defined target conditions for evaluating one or more reference fresh fuel bundle designs for each of N bundle groups, and generating a response surface based on making single rod-type changes in each (i,j) rod location of each bundle of a given reference bundle design being evaluated for each of the N bundle groups. A search algorithm may be iterated to evaluate a given combination of multiple rod-type changes made simultaneously across each of the N bundle groups using the generated response surface to determine an accepted fuel bundle design for each of the N bundle groups that satisfies the user-defined target conditions.

Abstract: In the method, a reference core design is generated based on a defined set of limits. The set of limits may include a target hot excess reactivity constraint to be satisfied over a given core energy cycle and a given desired control blade definition that is set for the cycle. A reference core design is generated based on the defined limits. A unique subset of fresh fuel bundles is subject to an iterative improvement process including replacing, at each fuel location, at least one of the current fresh fuel bundles with at least one of the selected fresh fuel bundles, and simulating reactor operation on the reference core design to obtain a plurality of outputs to be ranked based on the defined set of limits. The highest ranked output may represent an accepted core design with set control blade definition that satisfies the target hot excess reactivity constraint.

Abstract: A sampling system for taking a sample from the atmosphere in a reactor containment of a nuclear plant, includes a sampling line which is connected to a vacuum system and to an analysis system. The sampling line opens into the reactor containment and has a restriction device connected upstream thereof on the gas side for connection to the atmosphere in the reactor containment. A method for taking such a sample is also provided.

Abstract: In the method, a set of limits applicable to a core may be defined, and a test core loading pattern design, to be used for loading the core, may be determined based on the limits. Reactor operation on at least a subset of the core may be simulated to produce a plurality of simulated results. The simulated results may be compared against the limits, and data from the comparison may indicate whether any of the limits were violated by the core during the simulation. A designer or engineer may use the data to modify the test core loading pattern, creating one or more derivative core loading pattern design(s) for simulation and eventual perfection as an acceptable core loading pattern design for the core.

Abstract: In the method, a set of limits are defined and a reference core design is generated based on the limits, and includes an initial loading pattern of current fresh fuel bundles arranged in a plurality of fuel locations. A unique subset of fresh fuel bundles is selected for evaluation as the reference core design is subjected to an iterative improvement process. The iterative process includes replacing, at each fuel location, at least one of the current fresh fuel bundles with at least one of the selected fresh fuel bundles, and simulating reactor operation on the reference core design to obtain a plurality of outputs. The outputs may be ranked based on the defined set of limits, and the highest ranked output may be selected as an accepted core design for the nuclear reactor.

Abstract: A gas sensor includes a semiconductor substrate and a sensing membrane. The sensing membrane is located at the bottom of a recess, which is formed by etching the substrate, and includes a heater, heater extension electrodes, a gas sensitive film, and gas-sensitive-film extension electrodes. A first end of each heater extension electrode is in contact with the heater, and a second end of each heater extension electrode extends outward from the sensing membrane. A first end of each gas-sensitive-film extension electrode is in contact with the gas sensitive film, and a second end of each gas-sensitive-film extension electrode extends outward from the sensing membrane. All of the heater, the heater extension electrodes, and the gas-sensitive-film extension electrodes are made of polycrystalline silicon.

Abstract: The method involves measuring hydrogen permeation in the tubes by mass spectrometry, wherein the tube is inserted into a high or ultrahigh vacuum device in which a mass spectrometer and a total pressure gauge are located. H2 or H2 and inert gas mixtures are circulated inside the tube at the required partial pressure. The tube is then heated and the appearance of H2 outside the tube is observed. The flow thereof inside the tube and emergence time, called permeation time, are determined based on permeation curves. The emergence time of the first microcrack is also determined.

Abstract: A system and method is provided for a continual updating of the optimization of multiple operational control-variables during the operation of a nuclear reactor over a plurality of fuel cycles. A networked computer system includes one or more hosts programmed to execute an optimization process to identify and make changes in quantitative values of operational control-variables that result in improved efficiency and operational flexibility. Optimization and updating of operational control-variables may proceed selectively under manual control for inputting specific optimization constraints and reactor state-point information or may proceed autonomously through a repetitive performing of the optimization process based upon a predetermined user-defined strategy stored on the network.

Abstract: The invention relates to a method of measuring the tritium activity of a drum (1) of radioactive waste containing a quantity of radioactive waste (2) and a free volume, the method consisting of measuring the quantity of 3He produced by the decay of the tritium contained in said radioactive waste during a defined period of time and deducing from it the corresponding activity of the tritium contained in said radioactive waste (2).

Abstract: A method for monitoring and reducing corrosion in furnace boiler tubes measures electrochemical noise associated with corrosion mechanisms while corrosion is occurring at the surface of the tubes as they are exposed to combustion products. This noise is detected using a probe at the boiler waterwall surface that is connected to a corrosion monitor. The monitor contains a computer and software which determines a corrosion rate from the measured electrochemical noise. That rate is compared to a standard to determine if the rate is within acceptable limits. If not, the operator of the furnace or an Adaptive Process Controller (APC) is notified and adjusts one or more burners to change the combustion products that are responsible for the corrosion. Such an adjustment could be made by changing the amount of air or fuel being provided to the burner or other air slots or air ports.

Abstract: An apparatus for treating air containing hydrogen gas used in an area such as an interior of a nuclear reactor containment vessel where hydrogen gas is generated and apt to be accumulated so as to treat rapidly and safely the hydrogen. A treating apparatus (30) for treating air containing hydrogen gas in a nuclear reactor containment vessel, comprises a housing (31) provided with an air intake port (33) and an exhaust port (35) and defining a gas passage therein, a catalyst bed (37) disposed in said gas passage, and a heater (39) disposed in or close to said catalyst bed. The catalyst bed is composed of plate type catalysts, honeycomb type catalysts, or spherical catalysts and activated by being heated with an electric heater. Hydrogen and oxygen in the air containing hydrogen gas flowing in come into contact with the catalyst bed and recombine together such that the hydrogen gas is thus removed from the air.

Abstract: An electrochemical corrosion potential sensor is fabricated by initially joining an electrical conductor to a sensor tip. An electrical cable is joined to the tip conductor. Ceramic powder is fused under heat around the tip conductor to form an integral annular electrically insulating band therearound to insulate the tip from the cable. The band may be formed by plasma spraying, or it may be molded and sintered to seal it to the tip and conductor without brazing. In a preferred embodiment, the band is formed of yttria-stabilized-zirconia or magnesia-stabilized-zirconia.

Abstract: An electrochemical corrosion potential sensor includes a sensor tip electrically joined to a conductor, and a ceramic insulator joined to the tip around the conductor. A sleeve is joined to the insulator around the conductor, and is electrically insulated from the tip by the ceramic insulator. The insulator has an exposed surface axially separating the tip and sleeve, and a ceramic coating is bonded thereto for preventing dissolution of the insulator by reactor water. In a preferred embodiment, the ceramic insulator is sapphire, and the ceramic coating is yttria-stabilized-zirconia or magnesia-stabilized-zirconia which may be plasma sprayed over the insulator.

Abstract: The invention relates to an arrangement for carrying out leak detection of a fuel assembly for a pressurized-water nuclear reactor. A substantially vertical hollow mast means open in both ends houses the fuel assembly to be examined. The fuel assembly is drawn to the inside of the mast means from its lower side. The part of the mast means housing the fuel assembly is lifted to a position in which the fuel assembly is provided near but below the water surface of water inside the nuclear reactor. Water is sucked from a position inside the mast means above the fuel assembly. A gas separating means separates gases present in water sucked from the inside of the mast means. The separated gas is analyzed in a gas analyzing means regarding its amount of gaseous fission products.

Abstract: The method and the device are applicable to the penetrations (2) of a pressurised water nuclear reactor vessel head (1) during operation.The device includes a double circuit for picking off two gas samples (100, 16, 17; 12, 13, 14, 15) and a measurement assembly (18) which regularly compares the content, especially of water vapour, in the two samples picked off. The first sample is taken from the volume of a chamber (7) where the possible leak (10) emerges, and the second in proximity to the head (1) outside the region immediately affected by the leak. The assembly (18) makes it possible to generate (19) an alarm in the event of a leak and to distinguish it from operational alarms.Techniques and means are also provided for determining the flow rate of sweeping in the volume of the chamber (7) and for checking the pick-off and detection systems.

Abstract: A gas injection system of a nuclear power plant including a reactor and a gaseous waste disposal system, comprises a hydrogen injection unit for injecting hydrogen into a reactor of a nuclear power plant, an oxygen injection unit for injecting oxygen into a gaseous waste disposal system in which the oxygen is recombined with the hydrogen passed by way of the reactor, a densitometer for measuring a balance of concentration between the hydrogen and the oxygen in the gaseous waste disposal system, a flowmeter for measuring a flow rate of an exhaust gas of the gaseous waste disposal system, and a controlling unit for controlling the quantities of the hydrogen gas and the oxygen gas.

Abstract: A method and an apparatus for measuring the degree of intergranular stress corrosion cracking protection in the area of the core shroud weldments. Electrochemical potential sensors are attached to the shroud wall and the upper core spray line at locations near the actual weld surface of concern to ensure the accuracy of the electrochemical potential measurements. A working electrode doped or coated with noble metal and a reference electrode are implanted into the reactor core shroud. A throughhole is drilled or machined into the shroud wall at an elevation just below the top guide support ring, i.e., near the core shroud weldments. Then a plug containing the working and reference electrodes is inserted into the throughhole.

Abstract: A method for mitigating crack initiation and propagation on the surface of metal components in a water-cooled nuclear reactor. An electrically insulating coating is applied on the surfaces of IGSCC-susceptible reactor components. The preferred electrically insulating material is yttria-stabilized zirconia. The presence of an electrically insulating coating on the surface of the metal components shifts the corrosion potential in the negative direction without the addition of hydrogen and in the absence of noble metal catalyst. Corrosion potentials .ltoreq.-0.5 V.sub.she can be achieved even at high oxidant concentrations and in the absence of hydrogen.

Abstract: A process and system for the rapid concentration, separation and measurement of Kr-85 and Xe-133. By measuring the amount of Kr-85 radioisotope which is present, false positive signals for the vacuum sipping process can be eliminated. The fission gases are trapped by passing the recirculating gas stream through an adsorbing media. During this process, a known mixture of nonradioactive krypton and xenon is added to the gas stream which enters a thermal conductivity (TC) detector to calibrate the latter. The trapped gases are desorbed and injected into the inlet of a separating column. The column discharges into the TC detector. The TC detector discharge is diverted for counting to an evacuated beta detector chamber during the time that krypton is sensed by the TC detector. Any minute amount of Kr-85 is captured in the chamber, free of Xe-133. The detector discharge is diverted for counting to another evacuated beta detector chamber during the time that xenon is sensed by the TC detector.

Abstract: This invention concerns a plant diagnosis apparatus which comprises a first detecting unit for detecting a state of devices constituting a circulating system in which a fluid circulates and a second detecting unit for detecting a quality of the above-mentioned circulating fluid or a quality of the atmosphere surrounding the above-mentioned circulating system, and a unit for diagnosing the circulating system by output of the first and second detecting units, and therefore can diagnose anomaly of facilities such as a nuclear power plant with high reliability and rapidity.

Abstract: A system for continuously monitoring the concentration of tritium in an aqueous stream. The system pumps a sample of the stream to magnesium-filled combustion tube which reduces the sample to extract hydrogen gas. The hydrogen gas is then sent to an isotope separation device where it is separated into two groups of isotopes: a first group of isotopes containing concentrations of deuterium and tritium, and a second group of isotopes having substantially no deuterium and tritium. The first group of isotopes containing concentrations of deuterium and tritium is then passed through a tritium detector that produces an output proportional to the concentration of tritium detected. Preferably, the detection system also includes the necessary automation and data collection equipment and instrumentation for continuously monitoring an aqueous stream.

Abstract: A method and apparatus of sensing obstructions in a tubular nuclear fuel rod or the like is disclosed. A nozzle is positioned to engage one end of the fuel rod in an air tight sealed relationship. A first gas flows through the nozzle and then into and through the fuel rod. The pressure is sensed and compared with a standardized pressure to determine any excess back pressure in the nozzle indicating an obstruction present therein.

Abstract: An electrode probe suited for employment as an electrical potential reference electrode in an aqueous, high pressure, high temperature, and high radiation field environment such as the core of a nuclear reactor is described. The electrode is a brazed and welded assembly consisting of only ceramic and metal parts including a sapphire base which is brazed to a kovar/stainless steel housing, welded in turn, to a coaxial cable assembly for signal transfer. The base incorporates an integrally formed pedestal through which a conductor wire extends and over which is positioned a selectively coated cylindrically shaped sealing retainer. The device is particularly suited for employment with a silver/silver chloride electrode system.

Abstract: The present invention is addressed to an electrode for evaluating electrochemical potentials which has a robust structure particularly suiting it for employment within the rigorous environment of the reactor core of a nuclear power facility. The electrode of the present invention is comprised of five major segments: a metal cap electrode, an elongate annular metal jacket, an alumina retainer (i.e. an insulator), an annular metal transition sleeve, and a positioning and signal transfer assembly. The metal cap electrode has a tip and annulus extending therefrom formed from sidewalls having an interior surface. The elongate annular metal jacket has an annular retainer securing mouth at one end and an outlet at its opposite end. The alumina retainer has a recessed cap securing portion nestably secured to a portion of said cap electrode interior sidewall surface, and an oppositely-disposed recessed jacket securing portion nestably secured to the interior of said annular jacket retainer securing mouth.

Abstract: A container for electrochemical reactants for an electrode is provided, as well as electrodes employing the same. The electrodes can withstand the rigorous environment of a nuclear reactor core. The design of the container reduces stresses in the electrode and significantly improves its reliability. The container has a generally cylindrical member of an insulator. The member has a base region with a cut-out extending therethrough. Sidewall means extend from the base to define a cavity for containing electrochemical reactants, e.g., silver chloride. An insert of an insulator at one end mates with the cut-out and at another end mates with and is brazed to a cap for the container. The insert has a second sidewall means for holding the electrochemical reactants, and is shaped to fit within the first sidewall means. The base of the insert and the the cut-out are metallized for acceptance of a silver base.

Abstract: Measurement values of conductivity of pH of water in the primary cooling water system of a boiling water atomic power plant are input through on-line and the measurement values of conductivity and pH at times of measurement when water quality changes are compared with values at the time of normal operation. Tendencies to increase or decrease the conductivity and pH are combined to prepare one diagnosis data, and causes of anomaly in progress in component apparatus members are discriminated and diagnosed by the diagnosis data. By using a correlation between logarithm of conductivity and pH in preparing the diagnosis data from combinations of conductivity and pH, causes of anomaly can be diagnosed more accurated.

Abstract: In a system for detecting abnormal movement of a part of a gas-cooled nuclear reactor, for example abnormal tilting of a boiler unit caused by failure of a boiler support, a tracer material is released into the gas coolant path in response to the movement. The releasing of the material may be effected by causing a gas canister to be pierced as a result of the movement. The presence of the tracer material in the coolant is detected by the coolant monitoring system.

Abstract: A container for electrochemical reactants for an electrode is provided, as well as electrodes employing the same. The electrodes can withstand the rigorous environment of a nuclear reactor core. The design of the container reduces stresses in the electrode and significantly improves its reliability. The container has a generally cylindrical member of an insulator. The member has a base region whose outer surface is a surface attachment region. The base region has an annular channel for a lead. The base region also has a generally conical cut-out. Sidewall means extend from said base to define a cavity for containing electrochemical reactants, e.g., silver chloride. A generally conical insert of an insulator mates with the cut-out. The outer surface of the insert, cut-out, and surface attachment region is metallized, and the insert is set in place by brazing. In the electrode the lead is in electrical contact with the apex of the insert.

Abstract: A system for detecting steam voids or bubbles within a reactor coolant system. A dynamic pressure transducer detects pressure fluctuations in the coolant system and produces signals representative of steam voids within the system. The signals produced by the transducer are conditioned and applied as an input to a microprocessor along with other inputs representative of other operating parameters for the reactor coolant system. The microprocessor adjusts the signals representative of steam voids within the system and displays same to the operator.

Abstract: An apparatus for testing, in situ, highly irradiated specimens at high temperature transients is provided. A specimen, which has a thermocouple device attached thereto, is manipulated into test position in a sealed quartz heating tube by a robot. An induction coil around a heating portion of the tube is powered by a radio frequency generator to heat the specimen. Sensors are connected to monitor the temperatures of the specimen and the induction coil. A quench chamber is located below the heating portion to permit rapid cooling of the specimen which is moved into this quench chamber once it is heated to a critical temperature. A vacuum pump is connected to the apparatus to collect any released fission gases which are analyzed at a remote location.

Abstract: This system measures tritium on-line and collects tritium from a flowing inert gas stream. It separates the tritium from other non-hydrogen isotope contaminating gases, whether radioactive or not. The collecting portion of the system is constructed of various zirconium alloys called getters. These alloys adsorb tritium in any of its forms at one temperature and at a higher temperature release it as a gas. The system consists of four on-line getters and heaters, two ion chamber detectors, two collection getters, and two guard getters. When the incoming gas stream is valved through the on-line getters, 99.9% of it is adsorbed and the remainder continues to the guard getter where traces of tritium not collected earlier are adsorbed. The inert gas stream then exits the system to the decay chamber.Once the on-line getter has collected tritium for a predetermined time, it is valved off and the next on-line getter is valved on.

Abstract: A conductivity probe able to withstand high water temperatures and pressures, and intense nuclear radiation is suitable for use within the core of the nuclear reactor. The probe is made with a ceramic insulator, such as sapphire, and a central electrode that is mounted on the insulator. A sleeve that supports the insulator and the central electrode is made from metals having a coefficient of thermal expansion compatible with the coefficient of thermal expansion of the insulator, such as Kovar. The central electrode and sleeve are bonded to the insulator by a brazed compressive seal that protects an internal conductor in the probe from intrusion of the reactor water. A counter electrode made from a corrosion resistant metal, such as Kovar, is attached to the sleeve so that it extends over the central electrode a fixed, spaced distance. A positioning and signal transfer arrangement operatively supports the sleeve and conveys electrical signals to and from the two electrodes.

Abstract: An electrode probe suited for employment as a reference electrode in a high pressure, high temperature, and high radiation field environment such as adjacent the core of a nuclear reactor is described. The electrode is a brazed and welded assembly consisting of only ceramic and metal parts including a sapphire crucible which is brazed to a kovar/stainless steel housing, welded in turn, to a coaxial cable assembly for signal transfer. The crucible incorporates an integrally formed pedestal through which a conductor wire extends and over which is positioned a selectively coated cylindrically shaped sealing retainer. The device is particularly suited for employment with a silver/silver chloride electrode system.

Abstract: This invention comprises electrochemical analytical devices capable of performing electrolysis in multiple pulse modes. It relates to a method of quantitative analysis and equipment for performing quantitative analysis which uses a combinaiton of these pulse modes to realize the measurement of concentrations of multiple substances to be measured, occurring in the test solution to be measured and also a nuclear reactor water quality control system employing such a quantitative analysis method.

Abstract: An atmospheric tritium sampler is provided which uses a carrier gas comprised of hydrogen gas and a diluting gas, mixed in a nonexplosive concentration. Sample air and carrier gas are drawn into and mixed in a manifold. A regulator meters the carrier gas flow to the manifold. The air sample/carrier gas mixture is pulled through a first moisture trap which adsorbs water from the air sample. The mixture then passes through a combustion chamber where hydrogen gas in the form of H.sub.2 or HT is combusted into water. The manufactured water is transported by the air stream to a second moisture trap where it is adsorbed. The air is then discharged back into the atmosphere by means of a pump.

Abstract: Apparatus and method determine the concentration of an individual component, such as water vapor, of a multi-component mixture, such as a gaseous mixture for cooling a nuclear reactor. A hygrometer apparatus includes an infrared source for producing a broadband infrared energy beam that includes a strong water vapor absorption band and a weak water vapor absorption region. The beam is chopped to select infrared pulses. A temporally first pulse has a wavelength in the weakly absorbing region, a temporally second pulse has a wavelength in the strong band and a temporally third pulse has a wavlength in the weakly absorbing region. A fourth reference pulse representing background radiation is interposed in such chopped pulses.

Abstract: A device for detecting the presence of a gaseous phase in the tank of a nuclear reactor closed by a cover on which a plurality of vertical tubes are fixed for adapting the control rod actuating mechanism of the reactor, the adapter tubes not provided with mechanisms being closed by a plug. A plurality of ultrasonic emitter-receivers are fixed to the upper surface of the plugs of at least a part of the adapter tubes, so that each emitter-receiver directs an ultrasonic beam to the inside of the tank parallel to the axis of the corresponding tube, the latter being provided with at least one reflector placed inside the tube in the path of the ultrasonic beam. The invention is especially applicable to reactors cooled by pressurized water.