Abstract: Fuel, heat exchangers, and instrumentation for nuclear reactors are disclosed. A nuclear power system includes a plurality of nuclear fuel elements, each of the nuclear fuel elements including an annulus; and a plurality of heat pipes, each of the plurality of heat pipes configured to pass through the annulus of a respective one of the nuclear fuel elements in conductive thermal contact with the respective nuclear fuel element. A nuclear instrumentation module includes an assembly of optical fibers, each optical fiber comprising one or more sensors and configured for removable installation at one of the plurality of heat pipes. A heat exchanger includes a heat pipe including an evaporating region and a condensing region; and a tube bundle configured to wrap around the condensing region of the heat pipe and including one or more adjacent, parallel tubes, each tube forming a helix that is coaxial to the heat pipe.

Abstract: A travelling wave reactor for a space exploration. A reactor core of the travelling wave reactor is dispersed into several modules in a travelling wave direction; a new reactor is sequentially provided with a starting source module and a plurality of new fuel modules at zero burnup; all the modules are coaxially assembled in the travelling wave direction by means of an assembling parts, and each module further includes a heat pipe; the heat pipe in each module positioned at a front part sequentially passes through all the modules positioned at a rear portion thereof and extends out of the module at a rear end; and after a period of time of burn-up, the reactor core of the travelling wave reactor is provided with the starting source module, a spent fuel module, a critical fuel module and the new fuel module sequentially in the travelling wave direction.

Abstract: A modular nuclear reactor comprises a plurality of sections arranged in a pattern and a side reflector material surrounding the plurality of sections. Each section includes a tank comprising a front plate, a back plate, side plates, a top plate, and a bottom plate. A plurality of grid plates are located within the tank. Each grid plate comprises a plurality of apertures and is vertically separated from an adjacent grid plate. The tank further includes a plurality of fuel elements extending through each grid plate. A plurality of heat pipes extend through each grid plate, the top plate, and an upper reflector. Methods of forming the modular nuclear reactor are also disclosed.

Abstract: A pumped two phase fluid routing system includes an evaporator. The evaporator includes a base portion having an input liquid port for receiving a working fluid and an output liquid port for expelling a liquid. The evaporator also includes a wick portion including a plurality of vapor grooves and a plurality of vapor vents for providing a vapor flow path of a vapor formed within the evaporator. The evaporator further includes a lid portion disposed in close proximity to the wick portion and receiving heat for formation of the vapor, the lid portion having a vapor port for expelling the vapor. The fluid routing system also includes a first liquid line in fluid communication with the base portion for receiving the expelled liquid. The fluid routing system further includes a vapor line in fluid communication with the lid portion for receiving the expelled vapor.

Abstract: Methods and apparatuses are provided for the removal and transportation of thermal energy from a heat source to a distant complex for use in thermochemical cycles or other processes. In one embodiment, an apparatus includes a hybrid heat pipes/thermosyphon intermediate heat exchanger (HPTIHX) system that is divided into three distinct sections, namely: an evaporation chamber, a condensation chamber, and a working fluid transport section of liquid and vapor counter-current flows.

Abstract: Methods and apparatuses are provided for the removal and transportation of thermal energy from a heat source to a distant complex for use in thermochemical cycles or other processes. In one embodiment, an apparatus includes a hybrid heat pipes/thermosyphon intermediate heat exchanger (HPTIHX) system that is divided into three distinct sections, namely: an evaporation chamber, a condensation chamber, and a working fluid transport section of liquid and vapor counter-current flows.

Abstract: Exemplary embodiments provide automated nuclear fission reactors and methods for their operation. Exemplary embodiments and aspects include, without limitation, re-use of nuclear fission fuel, alternate fuels and fuel geometries, modular fuel cores, fast fluid cooling, variable burn-up, programmable nuclear thermostats, fast flux irradiation, temperature-driven surface area/volume ratio neutron absorption, low coolant temperature cores, refueling, and the like.

Abstract: Illustrative embodiments provide systems, applications, apparatuses, and methods related to nuclear fission deflagration wave reactor cooling. Illustrative embodiments and aspects include, without limitation, nuclear fission deflagration wave reactors, methods of transferring heat of a nuclear fission deflagration wave reactor, methods of transferring heat from a nuclear fission deflagration wave reactor, methods of transferring heat within a nuclear fission deflagration wave reactor, and the like.

Abstract: Illustrative embodiments provide systems, applications, apparatuses, and methods related to nuclear fission deflagration wave reactor cooling. Illustrative embodiments and aspects include, without limitation, nuclear fission deflagration wave reactors, methods of transferring heat of a nuclear fission deflagration wave reactor, methods of transferring heat from a nuclear fission deflagration wave reactor, methods of transferring heat within a nuclear fission deflagration wave reactor, and the like.

Abstract: A nuclear-engineering installation has a pressurized-water reactor and a degasification system for reactor coolant. The degasification system has a degasification column which is coupled to the primary cooling circuit of the pressurized water reactor and further includes a coolant evaporator with a first heat exchanger and a stripping vapor condenser with a second heat exchanger, wherein a partial flow of the reactor coolant flows through the heat exchanger of the coolant evaporator on the secondary side, and wherein the heat exchanger of the stripping vapor condenser is connected, on the primary side, in a vapor and gas outlet line which is connected to the degasifier column.

Abstract: Illustrative embodiments provide nuclear fission fuel elements, and systems, applications, apparatuses, and methods related thereto. Illustrative embodiments and aspects include, without limitation, nuclear fission fuel elements, heat pipe assemblies, heat pipes, methods of fabricating a nuclear fission fuel element, methods of fabricating a heat pipe assembly, and the like.

Abstract: Illustrative embodiments provide nuclear fission fuel elements, and systems, applications, apparatuses, and methods related thereto. Illustrative embodiments and aspects include, without limitation, nuclear fission fuel elements, heat pipe assemblies, heat pipes, methods of fabricating a nuclear fission fuel element, methods of fabricating a heat pipe assembly, and the like.

Abstract: Method and apparatuses are provided for removing thermal energy from a nuclear reactor, which are fault tolerant. The apparatus includes at least one heat pipe configured to absorb thermal energy produced by the nuclear reactor. In addition, the apparatus includes a first compartment thermally coupled to the at least one heat pipe. The first compartment is configured to contain a first gas. Furthermore, the apparatus includes a second compartment thermally coupled to the at least one heat pipe. The second compartment is configured to contain a second gas and configured to isolate the second gas from the first gas.

Abstract: Methods and apparatuses are provided for removing thermal energy from a nuclear reactor, which are fault tolerant. The apparatus includes at least one heat pipe configured to absorb thermal energy produced by the nuclear reactor. In addition, the apparatus includes a first compartment thermally coupled to the at least one heat pipe. The first compartment is configured to contain a first gas. Furthermore, the apparatus includes a second compartment thermally coupled to the at least one heat pipe. The second compartment is configured to contain a second gas and configured to isolate the second gas from the first gas.

Abstract: A system and method for moving a canister of spent nuclear fuel from a first location, which may be within a nuclear power generation facility to a second location such as a storage cask that is used for short-term or long-term storage of spent nuclear fuel includes a first lifting mechanism for engaging a transfer cask and a second lifting mechanism for engaging and lifting the canister of spent nuclear fuel. Preferably, the method is practiced by first positioning a canister of spent nuclear fuel within the transfer cask and then engaging the transfer cask with the first lifting mechanism. The canister is engaged with the second lifting mechanism. The transfer cask having the canister positioned within is moved to the vicinity of a storage cask, and the canister is lowered from the transfer cask into the storage cask by the second lifting mechanism without disengagement of the first lifting mechanism from the transfer cask.

Abstract: A system (10) for dissipating heat from the interior space (50) of a containment structure (3, 6) for a nuclear reactor (2), for an indefinite time period, comprises a first heat exchanger (15, 15') outside said containment structure (3, 6) which is submerged vertically in a pool (11) associated with the exterior of the top wall (4, 7) of the structure (3, 6), and a second heat exchanger (25) placed in the interior space (50), said first and second heat exchangers (15, 25) being fluid connected to each other in a closed loop circuit (28) with piping (23, 24) containing a thermal carrier fluid. Said pool (11 is provided with a covering (90) defining a first duct (12) in communication with an outside air intake, and a second duct (13) communication with a chimney (14), the interconnection of said ducts (12, 13) being inhibited by the water present in the pool (11) when filled to a predetermined level (9).

Abstract: A nuclear reactor including a heat pipe for transferring heat from the reactor pressure vessel to a steam supply vessel is described. More particularly, in one embodiment, the heat pipe includes an evaporator section positioned in the reactor vessel, a condenser section positioned in the steam supply vessel, and an adiabatic section extending between and in flow communication with the evaporator section and the condenser section. The adiabatic section of the heat pipe includes a substantially cylindrical outer sleeve and a substantially cylindrical inner sleeve. An annulus region is formed between the inner and outer sleeves and the annulus region is in flow communication with the steam supply vessel. An insulating layer covers an inner wall of the outer sleeve. A substantially annular wick member is positioned adjacent an inner wall of the inner sleeve, and a steam path is defined by an inner face of the wick member.

Abstract: A nuclear reactor has a containment vessel and a voided calandria space having a plurality of fuel channels therein. A chamber surrounding the calandria space is receptive of a light water moderator and a solid reflector in the chamber surrounds the calandria space. Each fuel channel has a solid fuel matrix having a plurality of coolant holes extending longitudinally therethrough and receptive of light water coolant, a pressure tube surrounding the fuel matrix and a calandria tube surrounding the pressure tube and forming a gap therebetween.

Abstract: A hydrogenous moderated thermionic nuclear reactor operating in the thermal neutron energy region. Thermionic fuel elements are formed from multiple concentric cylinders. The center cylinder is a combination heat pipe and thermionic converter collector. The second cylinder is the converter emitter. The third cylinder is the nuclear fuel. The outer cylinder is the physical barrier between the fuel element and moderator. Between the outer radius of the fuel and outer cylinder is a gap containing multi-foil insulation. The insulation acts as a thermal barrier between the fuel and the outer cylinder and accommodates fuel expansion. This also causes heat flow to be radially inward from the fuel to the center converter/heat pipe.

Abstract: A pneumatic safety system for a nuclear reactor includes a containment vessel containing He.sub.3 at high pressure communicating with a nuclear core by way of a conduit system which includes hollow pipes situated adjacent rods of fissionable material inside the core area. A rupturable diaphragm is interposed in the conduit system and is connected by a plurality of heat-pipes to the core area. The heatpipes respond to changes in core temperature and at a critical temperature cause the diaphragm to rupture thus allowing neutron absorbing gas under high pressure to quickly flood the core shutting down the nuclear reaction.

Abstract: A thermionic electric converter module integrated with heating and cooling heat pipes. Two heat pipes are arranged concentrically, with the annular emitter heat pipe on the outside of the module to isothermally distribute heat from a source located in any direction around the unit to the emitter located on the inside exterior wall of the heat pipe. The exterior wall surface of the collector heat pipe, located inside the annular emitter heat pipe, is separated from the emitter by the thermionic converter's interelectrode gap and serves as the collector of the thermionic converter. The collector heat pipe is of conventional cylindrical configuration and transports the waste heat of the thermionic converter along the unit's axis to a remote location for disposal.

Abstract: Safety equipment is disclosed comprising a three-phase heat pipe for the protection of apparatus from exceeding maximum or minimum safe working temperatures. The heat pipe has a working fluid selected so that it will not function below the desired temperature. A working fluid which has a melting point slightly above the minimum safe temperature of the equipment to be protected is preferred for protecting equipment from exceeding its minimum safe working temperature. This heat pipe may be used to cool an apparatus to a temperature where the heat pipe automatically stops functioning and keeps an apparatus from exceeding its minimum design temperature. A working fluid which has a melting point slightly below the maximum safe temperature is preferred to keep equipment from exceeding its maximum safe working temperature. This heat pipe will be inactive at normal operating temperatures but will release excess heat to cooler surroundings before safe working temperatures are exceeded.

Abstract: A reactor steam isolation cooling system includes a containment building surrounding a reactor pressure vessel having a reactor core for generating reactor steam. An isolation pool is disposed outside the containment building and is vented to the atmosphere. An isolation condenser includes a plurality of heat pipes collectively defining at one end thereof a condenser assembly disposed outside the containment building and inside the isolation pool, and at an opposite end thereof an evaporator assembly extending inside the containment building. Reactor steam is selectively channeled to the evaporator assembly for heating a working liquid therein and condensing the reactor steam to form reactor condensate for return to the pressure vessel. The working liquid is vaporized in the evaporator assembly and flows to the condenser assembly wherein it releases heat into the isolation pool with the working condensate therefrom returning to the evaporator assembly.

Abstract: The present invention relates to the retrievable storage of high-level nuclear spent fuel (waste). Such waste, which generates heat as it decays, is packed in sealed containers (2) which are placed in a repository site comprising a tunnel or drift (5) in a geological rock formation (50) for permanent or long-term storage. Elongated, sealed cooling enhancement devices (7) are emplaced in boreholes (8) extending from the inside surfaces (16 a-b) of the drift (5) and carry heat from the location of the waste containers (5) to farther distances in the repository site. Applicable sealed cooling enhancement devices disclosed are heat pipes (7), thermal syphons (307), superconductor rods, and heat pumps (407).

Abstract: A water cooled nuclear reactor comprises a reactor core, a primary water coolant circuit and a pressurizer arranged as an integral unit in a pressure vessel. The pressure vessel is divided into an upper chamber and a lower chamber by a casing, the reactor core and primary coolant circuit are arranged in the lower chamber and the pressuriser is arranged in the upper chamber.A plurality of pipes interconnect a steam space of the pressuriser with an upper portion of the primary coolant circuit via ports in the casing. A plurality of re-entrant surge ports interconnect a water space of the pressuriser with a lower portion of the primary coolant circuit. The surge ports have low flow resistance for water from the water space to the primary coolant circuit and high flow resistance in the opposite direction.

Abstract: Herein disclosed is a dual-tube heat pipe type heat exchanger comprising a heat pipe confined with a working fluid for transferring a heat as a latent heat by repeating evaporations and condensations. The heat pipe includes an outer tube which is disposed within a hot fluid such that its axis is generally horizontal. Further included is an inner tube which is inserted in the outer tube and radially offset upward to substantially contact with the top portion of the inner face of the outer tube and to confine a space between the inner circumference of the outer tube and the outer circumference of the inner tube, thus forming the heat pipe.

Abstract: A liquid accumulator (28) for use in a substantially zero gravity environment which utilizes the surface tension of a liquid to form a meniscus which acts as a gas-liquid interface providing a barrier to the passage or entrainment of a gas into the liquid. The apparatus includes a plurality of tubes (36) for capillary containment of a liquid, a grid member (34) provided with a plurality of holes (one of each tube) for receiving therein in sealing engagement an end of the tube. An opposite end of each of the tubes contains a gas. The apparatus further includes a housing (30) extending circumferentially about the grid member and defining a liquid zone (38) on the side of said grid member opposite said tubes located within the liquid zone and extending partially into each of the tubes is a body of liquid which forms a meniscus (42) in each of the tubes. Fluid communication is provided between the liquid zone of the apparatus and a source of liquid subject to thermal expansion and contraction.

Abstract: A nuclear reactor for generating electricity is disposed underground at the bottom of a vertical hole that can be drilled using conventional drilling technology. The primary coolant of the reactor core is the working fluid in a plurality of thermodynamically coupled heat pipes emplaced in the hole between the heat source at the bottom of the hole and heat exchange means near the surface of the earth. Additionally, the primary coolant (consisting of the working flud in the heat pipes in the reactor core) moderates neutrons and regulates their reactivity, thus keeping the power of the reactor substantially constant. At the end of its useful life, the reactor core may be abandoned in place. Isolation from the atmosphere in case of accident or for abandonment is provided by the operation of explosive closures and mechanical valves emplaced along the hole.

Abstract: In a liquid metal heat transport system including a source of thaw heat for use in a space reactor power system, the thaw flow throttle or control comprises a fluid passage having forward and reverse flow sections and a partition having a plurality of bleed holes therein to enable fluid flow between the forward and reverse sections. The flow throttle is positioned in the system relatively far from the source of thaw heat.

Abstract: A nuclear reactor installation located in the cavity of a pressure vessel comprises a nuclear reactor with a core traversed from top to bottom by a cooling gas, a plurality of main loops consisting of heat exchangers and blowers, together with auxiliary loops for the removal of decay heat. According to the invention, the auxiliary loops contain no heat exchangers but a bundle of heat pipes independent of each other, the heat absorbing part of which is arranged in the pressure vessel cavity. As a heat sink, an external cooling water loop is provided for each bundle of heat pipes in which water is circulated. The cooling water is recooled in a cooling tower. In a preferred embodiment the heat transferring part of the heat pipes of each bundle terminates in an external water reservoir to which the cooling water loop is connected. For a certain period of time, in case of a sufficient volume of water, the decay heat may be removed only by evaporation from the water reservoir.

Abstract: A thermionic energy conversion system assembly is described which comprises a fissionable nuclear fuel which surrounds a cylindrical arrangement of thermionic emitter electrodes which surround corresponding collector electrodes, which in turn surround a cylindrical container of a heat sink material, such as lithium hydride, which can absorb large amounts of waste heat energy through a phase change. The heat sink material may also act as a nuclear moderator to reduce the amount of required nuclear fuel. A heat pipe is enclosed within the container of heat sink material to remove waste heat stored in the material. A thermionic energy conversion module is described which comprises 100 stacked-in-series thermionic converter assemblies. A complete space-based thermionic nuclear reactor is described which comprises an array of 91 thermionic converter modules wherein the heat pipes connect to a lithium hydride radiation shield which acts as a further heat sink.

Abstract: Apparatus for the isothermal transfer of heat from a heat source to a heat absorber, the heat source and the heat absorber being enclosed within a container. A heat transfer working medium (e.g., a volatile liquid) is enclosed within the container and is capable of being efficiently vaporized on the surface of the heat source, being conveyed to the heat absorber, being condensed thereon, and being returned to the heat source. The quantity of the heat transfer medium contained in the container is sufficient to permit vaporization thereof on the surface of the heat source. A method of isothermal heat transfer is also disclosed.

Abstract: The electromagnetic device is suitable for use in actuating a pressurized water reactor control bar. It comprises a shaft and a fluid-tight casing in which are movable longitudinally a first and a second sets of grippers for gripping the shaft, staggered in the longitudinal direction. The first set of grippers is associated with a movable pole co-operating with a holding coil, carried by the casing and movable by energization and de-energization of the coil between a position in which the first set of grippers holds the shaft and a position in which it releases it. The second set of grippers is associated with a movable plunger co-operating with a transfer coil and movable by energization and de-energization of the transfer coil to and from a position in abutment against an other pole. The other pole is movable between two positions spaced apart by a given step.

Abstract: The disclosure is directed to an apparatus and method for determining the content and distribution of a thermal neutron absorbing material within an object. Neutrons having an energy higher than thermal neutrons are generated and thermalized. The thermal neutrons are detected and counted. The object is placed between the neutron generator and the neutron detector. The reduction in the neutron flux corresponds to the amount of thermal neutron absorbing material in the object. The object is advanced past the neutron generator and neutron detector to obtain neutron flux data for each segment of the object. The object may comprise a space reactor heat pipe and the thermal neutron absorbing material may comprise lithium.

Abstract: The invention relates to a pool-type fission reactor power plant design having a reactor vessel containing a primary coolant (such as liquid sodium), and a steam expansion device powered by a pressurized water/steam coolant system. Heat pipe means are disposed between the primary and water coolants to complete the heat transfer therebetween. The heat pipes are vertically oriented, penetrating the reactor deck and being directly submerged in the primary coolant. A U-tube or line passes through each heat pipe, extended over most of the length of the heat pipe and having its walls spaced from but closely proximate to and generally facing the surrounding walls of the heat pipe. The water/steam coolant loop includes each U-tube and the steam expansion device. A heat transfer medium (such as mercury) fills each of the heat pipes.

Abstract: A laser using heat and thermionic electrical output from a nuclear reactor in which heat generated by the reactor is utilized to vaporize metal lasants. Voltage output from a thermionic converter is used to create an electric discharge in the metal vapors. In one embodiment the laser vapors are excited by a discharge only. The second embodiment utilizes fission coatings on the inside of heat pipes, in which fission fragment excitation and ionization is employed in addition to a discharge. Both embodiments provide efficient laser systems that are capable of many years of operation without servicing. Metal excimers are the most efficient electronic transition lasers known with output in the visible wavelengths. Use of metal excimers, in addition to their efficiency and wavelengths, allows utilization of reactor waste heat which plagues many nuclear pumped laser concepts.

Abstract: The invention relates to a fast neutron nuclear reactor equipped with residual power removal devices.Each device comprises an evaporator incorporating a bundle of tubes in glove finger-like form immersed in the liquid metal contained in the reactor vessel, an adiabatic collector constituted by a pipe traversing the slab sealing the reactor vessel and a condenser in which the heat transfer fluid, such as mercury, contained in said device is condensed by heat exchange with the atmospheric air sucked in through the chimney or flue.Application to fast neutron nuclear reactors.

Abstract: An improved passive cooling arrangement is disclosed for maintaining adjacent or related components of a nuclear reactor within specified temperature differences. Specifically, heat pipes are operatively interposed between the components, with the vaporizing section of the heat pipe proximate the hot component operable to cool it and the primary condensing section of the heat pipe proximate the other and cooler component operable to heat it. Each heat pipe further has a secondary condensing section that is located outwardly beyond the reactor confinement and in a secondary heat sink, such as air ambient the containment, that is cooler than the other reactor component. Means such as shrouding normally isolated the secondary condensing section from effective heat transfer with the heat sink, but a sensor responds to overheat conditions of the reactor to open the shrouding, which thereby increases the cooling capacity of the heat pipe.

Abstract: A system for producing process heat which employs a high temperature gas cooled nuclear reactor and is adapted to provide process heat at temperatures higher than the reactor core temperature. The system includes a closed secondary loop having a working fluid heated to a first temperature by the coolant of the reactor core in an intermediate heat exchanger, and has a heat pump connected in the secondary loop which increases the temperature of the working fluid to a temperature above the core coolant temperature. Steam in an independent closed nuclear steam supply circuit is heated directly by the core coolant in a steam generator and provides steam for make-up driving power to the heat pump in the secondary loop. The steam supply circuit also supplies additional steam to generate electric power and process steam. The size of the intermediate heat exchanger is minimized to enable maximum utilization of the steam supply circuit.

Abstract: A heat pipe configuration for use in a magnetic field environment of a fusion reactor. Heat pipes for operation in a magnetic field when liquid metal working fluids are used are optimized by flattening of the heat pipes having an unobstructed annulus which significantly reduces the adverse side region effect of the prior known cylindrically configured heat pipes. The flattened heat pipes operating in a magnetic field can remove 2--3 times the heat as a cylindrical heat pipe of the same cross sectional area.

Abstract: Apparatus for homogenizing the circumferential temperatures of the vertically axes ferrule of a component passing through the upper slab of a nuclear reactor, wherein it comprises at least one assembly forming a heat pipe describing the entire circumference of said ferrule in order to ensure the homogenization of the temperatures of said ferrule level with the assembly, means for fixing the assembly or assemblies forming the heat pipe on the inner face of the ferrule and means for ensuring a thermal contact between the assembly or assemblies forming the heat pipe and the said ferrule.

Abstract: A heat transfer system for a nuclear reactor. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.

Abstract: A fast nuclear reactor is described which comprises a conical reactor core surrounding an embedded array of heat pipes of, per se, novel structure, carrying either moderator or nuclear fuel material as part of their working fluid. This reactor system is self-regulating, because an excessive increase in reactivity drives the fuel or moderator working fluid out of the conical core region, thereby reducing reactivity. The heat pipes are protected against burnout by a novel heat pipe envelope shape and internal wicking structure designed to increase the working fluid circulation speed with increasing heat transfer loads.