Westinghouse Electric Corporation

The United States of America As Represented by the United States

Martin H Cooper

Robert K Sievers

Lyman J Petrosky

William H Kasner

Suresh Krishnaji Bhate

James D Mangus

Delmar R Riffe

Clark E Swenson

Calvin L Kinney

Robert B Tupper

Albert P Ciez

Katherine M Andrews

An alkali metal thermoelectric conversion device formed from a porous tube or plate coated with a thin film of beta-alumina, the porous tube or plate is sintered metal or metal alloy having a coefficient of thermal expansion which approaches that of the beta-alumina to form a mechanically stable device with high electrical output.

High performance thin film alkali metal thermoelectric device

The coolant is circulated thorugh the core of the reactor by a pump between a higher-pressure plenum and a lower-pressure plenum. The impurities are removed by a cold trap between the higher-pressure plenum and the lower-pressure plenum. The trap is an integrated unit including an inner tube and an outer tube defining between them an annulus which contains packing. The outer surface of the outer tube is cooled to a temperature such that the impurities are precipitated from the coolant. Since the packing is coldest on the outside, the precipitation progresses axially upstream to downstream and radially inwardly. The precipitation in the outer part of the annulus insulates the inner part of the annulus thermally so that the reduction of the temperature of the coolant to saturation level in the inner part is delayed precluding premature blocking of the cold trap. The cooled coolant in the annulus also precools the coolant flowing in through the inner tube.

Removal of impurities from coolant of a nuclear reactor

The package includes a body and a closure. A readily breakable electrical oscillatory network sans power supply is physically connected between the body and the closure. The network is tuned to resonate at a predetermined frequency. The package is monitored by a transmitter-receiver when it is distributed to a customer. The transmitter produces pulse signals in a carrier frequency band which overlaps the resonant frequency of the network. During monitoring the package is placed in the field of the transmitter and the oscillatory network is excited to produce a decaying pulse for each transmitter pulse. The receiver is gated during the interval when each transmitter pulse is generated but is receptive of the corresponding decaying pulse from the network. If the package is sealed, the oscillatory network is intact and the receiver receives decaying pulses which produce visual or audible signals. If the package has been opened, the network is broken and no signals are produced.

Package

A self-actuated shutdown system incorporated into a reactivity control assembly in a nuclear reactor includes pumping means for creating an auxiliary downward flow of a portion of the heated coolant exiting from the fuel assemblies disposed adjacent to the control assembly. The shutdown system includes a hollow tubular member which extends through the outlet of the control assembly top nozzle so as to define an outer annular flow channel through the top nozzle outlet separate from an inner flow channel for primary coolant flow through the control assembly. Also, a latching mechanism is disposed in an inner duct of the control assembly and is operable for holding absorber bundles in a raised position in the control assembly and for releasing them to drop them into the core of the reactor for shutdown purposes. The latching mechanism has an inner flow passage extending between and in flow communication with the absorber bundles and the inner flow channel of the top nozzle for accommodating primary coolant flow upwardly through the control assembly. Also, an outer flow passage separate from the inner flow passage extends through the latching mechanism between and in flow communication with the inner duct and the outer flow channel of the top nozzle for accommodating inflow of a portion of the heated coolant from the adjacent fuel assemblies. The latching mechanism contains a magnetic material sensitive to temperature and operable to cause mating or latching together of the components of the latching mechanism when the temperature sensed is below a known temperature and unmating or unlatching thereof when the temperature sensed is above a given temperature. The temperature sensitive magnetic material is positioned in communication with the heated coolant flow through the outer flow passage for directly sensing the temperature thereof. Finally, the pumping means includes a jet induction pump nozzle and diffuser disposed adjacent the bottom nozzle of the control assembly and in flow communication with the inlet thereof. The pump nozzle is operable to create an upward driving flow of primary coolant through the pump diffuser and then to the absorber bundles. The upward driving flow of primary coolant, in turn, creates a suction head within the outer flow channel of the top nozzle and thereby an auxiliary downward flow of the heated coolant portion exiting from the upper end of the adjacent fuel assemblies through the outer flow channel to the pump nozzle via the outer flow passage of the latching mechanism and an annular space between the outer and inner spaced ducts of the control assembly housing. The temperature of the heated coolant exiting from the adjacent fuel assemblies can thereby be sensed directly by the temperature sensitive magnetic material in the latching mechanism.

Self-actuated nuclear reactor shutdown system using induction pump to

A laser welding beam transport system is provided in which the laser beam 14 emanating from the laser generator 10 is expanded in diameter in an expander 16 at a location close to the generator, and then is transported in its expanded diameter to a remote location where the beam is reduced in diameter in a beam reducer 26 at a location close to the welding station 28 for the purpose of maintaining a relatively constant power density of the beam at the station over a significant range of working travel of the working station.

Laser beam transport system

The nuclear reactor shutdown system comprises a temperature sensitive device connected to a magnetic latch of a neutron absorbing mechanism. The temperature sensitive device is disposed in the neutron absorbing mechanism in such a manner that it is exposed to the reactor coolant so that when the reactor coolant temperature rises above a specific level, the temperature sensitive device will cause the magnetic latch to open and allow neutron absorbing material to enter the reactor core. The temperature sensitive device comprises temperature sensitive material which may be a temperature sensitive resistor sometimes referred to as a thermistor. The thermistor is a device wherein its resistivity significantly increases with increase in its temperature such that when its temperature has significantly increased, the current passing through this system substantially decreases. Therefore, when the nuclear reactor coolant temperature rises significantly, the resistivity in the temperature sensitive material significantly increases to the point where little electricity flows through the circuit thereby causing the magnetic field in the magnetic latch to fall to a level at which the magnetic latch opens thereby inserting neutron absorbing material in the reactor core.

Nuclear reactor shutdown system

An inherent shutdown system for a nuclear reactor having neutron absorbing rods affixed to an armature which is held in an upper position by a magnetic flux flowing through a Curie temperature material. The Curie temperature material is fixedly positioned about the exterior of an inner duct in an annular region through which reactor coolant flows. Elongated fuel rods extending from within the core upwardly toward the Curie temperature material are preferably disposed within the annular region. Upon abnormal conditions which result in high neutron flux and coolant temperature, the Curie material loses its magnetic permeability, breaking the magnetic flux path and allowing the armature and absorber rods to drop into the core, thus shutting down the fissioning reaction. The armature and absorber rods are retrieved by lowering the housing for the electromagnet forming coils which create a magnetic flux path which includes the inner duct wall. The coil housing then is raised, resetting the armature.

A method and apparatus for removing iodine-131 and iodine-125 from a liquid sodium reactor coolant. Non-radioactive iodine is dissolved in hot liquid sodium to increase the total iodine concentration. Subsequent precipitation of the iodine in a cold trap removes both the radioactive iodine isotopes as well as the non-radioactive iodine.

Method and apparatus for removing iodine from a nuclear reactor coolant

A lateral restraint and control system for a nuclear reactor core adaptable to provide an inherent decrease of core reactivity in response to abnormally high reactor coolant fluid temperatures. An electromagnet is associated with structure for radially compressing the core during normal reactor conditions. A portion of the structures forming a magnetic circuit are composed of ferromagnetic material having a curie temperature corresponding to a selected coolant fluid temperature. Upon a selected signal, or inherently upon a preselected rise in coolant temperature, the magnetic force is decreased a given amount sufficient to relieve the compression force so as to allow core radial expansion. The expanded core configuration provides a decreased reactivity, tending to shut down the nuclear reaction.

Magnetic nuclear core restraint and control

A system for reducing the possibility of leakage of fission gases from a nuclear reactor of the gas-cooled type or of a type utilizing a liquid coolant, for example a liquid metal with a cover gas above free surfaces of the coolant. The disclosed system reduces the leakage of fission gases from the cover gas through joints between a pressure vessel and a pressure vessel head in the nuclear reactor by installing an adsorbent material between two seals placed in the joints. This adsorbent material provides sufficient delay time to allow all radioactive isotopes, except long-lived nuclides, to decay to innocuous concentrations before escaping from the pressure vessel.

Adsorption seal for nuclear reactors

A system for removing radioactive fission products from a liquid metal reactor coolant. Isotopic diluents and reacting compounds are added to hot liquid sodium. The reactants isotopically exchange or chemically react with the fission products and are precipitated out of solution in a first cold trap. When the supply of reactants is exhausted, the flow is reversed; the first trap then functions to supply the reactants and the precipitation occurs in a second cold trap. The process operates continuously and reversibly.

Removal of radioactive contamination from a nuclear reactor coolant

A method is disclosed for determining the concentration of fission products in the reactor coolant of a liquid metal cooled nuclear reactor. Reactor coolant is bypassed at constant temperatures and constant velocity through a flow sampling system containing a sampling tube. After a period of time, the sampling tube is isolated and removed from the bypass system; the liquid metal coolant is removed from the tube; and, the radionuclides deposited on the sampling tube are measured by gamma spectroscopy. The concentration of fission products in the reactor coolant is then determined from the measured radioactivity of the deposited nuclides.

Growing community of inventors

Monroeville, PA, United States of America

Martin H Cooper