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: The present invention relates generally to the field of compensation methods for nuclear reactors and, in particular to a method for fail-safe reactivity compensation in solution-type nuclear reactors. In one embodiment, the fail-safe reactivity compensation method of the present invention augments other control methods for a nuclear reactor. In still another embodiment, the fail-safe reactivity compensation method of the present invention permits one to control a nuclear reaction in a nuclear reactor through a method that does not rely on moving components into or out of a reactor core, nor does the method of the present invention rely on the constant repositioning of control rods within a nuclear reactor in order to maintain a critical state.

Abstract: A passive safety system for a nuclear power plant (100) cools a nuclear power plant after shutdown (SCRAM) even when all primary water circulation has been disabled. The system comprises a source of compressed gas (112, 805) that can be its only source of operating energy, a source of water (106, 500), and a plurality of plumbing components. The system is located nearby but outside of the plant where it will not be damaged in the event of an accident inside the plant. In one embodiment, the system is located underground. In another embodiment, the system is portable so that the gas and water are carried in tanks (500, 510) on railroad cars or other wheeled conveyances. The portable system is located above ground, or optionally in a covered trench (705). In an alternative embodiment, only compressed gas is used to cool the plant.

Abstract: A shipping container comprises a tubular or cylindrical shell having a closed end and an open end, a top end-cap removably secured to the open end of the tubular or cylindrical shell, and at least one fuel assembly compartment defined inside the shell. Each fuel assembly compartment includes elastomeric sidewalls and is sized and shaped to receive an unirradiated nuclear fuel assembly through the open end of the shell. The shipping container may further include a divider component, for example having a cross-shaped cross-section with ends of the cross secured to inner walls of the shell, and the divider component and the inner walls of the shell define the fuel assembly compartments. To load, the shipping container is arranged vertically and an unirradiated nuclear fuel assembly is loaded through the open end of the shell into each compartment, after which the open end is closed off by securing the top end-cap.

Abstract: A target shell monitoring device 4 that monitors an attitude and a position of the target shell Tg1, a compression laser output device 5a that irradiates the target shell Tg1 with a compression laser light LS1, and a heating laser output device 6 that irradiates the target shell Tg1 with a heating laser light LS3 following the compression laser light LS1 are provided. The target shell Tg1 has a hollow spherical shell shape, includes an approximately spherical space Sp on an inner side thereof, includes at least one through hole H1 connecting an outer side thereof and the space Sp, and includes, on an outer surface Sf1 thereof, irradiation areas Ar1 and Ar2 to be irradiated with compression laser lights.

Abstract: Illustrative embodiments provide methods and systems for migrating fuel assemblies in a nuclear fission reactor, methods of operating a nuclear fission traveling wave reactor, methods of controlling a nuclear fission traveling wave reactor, systems for controlling a nuclear fission traveling wave reactor, computer software program products for controlling a nuclear fission traveling wave reactor, and nuclear fission traveling wave reactors with systems for migrating fuel assemblies.

Abstract: A method and system for the thermoelectric conversion of nuclear reactor generated heat including upon a nuclear reactor system shutdown event, thermoelectrically converting nuclear reactor generated heat to electrical energy and supplying the electrical energy to a mechanical pump of the nuclear reactor system.

Abstract: The invention relates to nuclear technology, and to irradiation targets and their preparation. One embodiment of the present invention includes a method for preparation of a target containing intermetallic composition of antimony Ti—Sb, Al—Sb, Cu—Sb, or Ni—Sb in order to produce radionuclides (e.g., tin—117m) with a beam of accelerated particles. The intermetallic compounds of antimony can be welded by means of diffusion welding to a copper backing cooled during irradiation on the beam of accelerated particles. Another target can be encapsulated into a shell made of metallic niobium, stainless steel, nickel or titanium cooled outside by water during irradiation. Titanium shell can be plated outside by nickel to avoid interaction with the cooling water.

Abstract: A high-temperature containment-isolation system for transferring heat from a nuclear reactor containment to a high-pressure heat exchanger is presented. The system uses a high-temperature, low-volatility liquid coolant such as a molten salt or a liquid metal, where the coolant flow path provides liquid free surfaces a short distance from the containment penetrations for the reactor hot-leg and the cold-leg, where these liquid free surfaces have a cover gas maintained at a nearly constant pressure and thus prevent high-pressures from being transmitted into the reactor containment, and where the reactor vessel is suspended within a reactor cavity with a plurality of refractory insulator blocks disposed between an actively cooled inner cavity liner and the reactor vessel.

Abstract: A method, system, and apparatus for the thermoelectric conversion of nuclear reactor generated heat including thermoelectrically converting gas cooled nuclear reactor generated heat to electrical energy and supplying the electrical energy to an operation system of the nuclear reactor system.

Abstract: A method, system, and apparatus for the thermal storage of nuclear reactor generated energy including diverting a selected portion of energy from a portion of a nuclear reactor system to an auxiliary thermal reservoir and, responsive to a shutdown event, supplying a portion of the diverted selected portion of energy to an energy conversion system of the nuclear reactor system.

Abstract: A method for monitoring changes in the boron concentration in the coolant of a reactor during a nuclear plant outage that applies temperature compensation to the source range detector output. The method then monitors the compensated output signal to identify changes in the detector count rate above a preselected value.

Abstract: A well logging tool includes a neutron generator having an ion source for ion production by electron impact ionization wherein ionization current trajectory is determined by an electric field and an at least partially misaligned magnetic field. The electric field can be provided by an electrode arrangement having a cathode associated with a field emitter array including a multitude of nanoemitters. The magnetic field can be provided by a permanent magnet incorporated in the neutron generator to act transversely to the electric field in at least part of an ion source chamber in which an ionization current emitted by the field emitter array travels through an ionizable gas. Charged particles traveling through the ionizable gas thus follow respective trajectories that are longer than would be the case in the absence of the magnetic field, thereby increasing ionization probability.

Abstract: A method for producing a reaction product containing 99mTC may include providing 100Mo-metal targets to be irradiated, irradiating the 100Mo-metal target with a proton stream having an energy for the induction of a 100Mo(p, 2n)99mTC core reaction, heating the 100Mo-metal target to over 300° C., recovering incurred 99mTc in a sublimation-extraction process with the aid of oxygen gas which is conducted over the 100 Mo-metal target forming 99mTc-Technetium oxide. Further, a device for producing the reaction product containing 99mTc may include a 100Mo metal target, an acceleration unit for providing a proton stream, which can be directed to the 100Mo-Metal target, such that a 100Mo(p, 2n)99mTC core reaction is induced upon irradiation of the 100Mo-metal target by the proton stream, a gas supply line for conducting oxygen gas onto the irradiated 100Mo-metal target to form 99mTC-Technetium oxide, and a gas discharge line to discharge the sublimated 99mTC-Technetium oxide.

Abstract: This invention generally concerns robotic systems and is specifically concerned with an improved apparatus and method for inspecting nuclear reactor components in limited access areas, such as, the core annulus, core spray and feedwater sparger regions of a nuclear reactor. This invention includes an apparatus for remotely operating and positioning at least one inspection device for inspecting at least one component in an annulus region of a reactor pressure vessel of a nuclear power plant. The apparatus includes a track, a braking system and a frame assembly which has a frame movably connected to the track, at least one mast assembly and at least one mast positioning assembly. The at least one inspection device is attached to the at least one mast assembly. In certain embodiments, the at least one mast assembly includes a mast that is capable of becoming rigidly stable in both an extended tube form and a retracted rolled form.

Abstract: A nuclear power plant control system (3) is provided with detection units (30a to 30d) which detect phenomena that occurs in a nuclear power plant for each of four systems, a trip control device (20) which starts, in the case where a signal that indicates an occurrence of the phenomenon is input from at least a predetermined number of signal lines out of signal lines of two systems, processing corresponding to the phenomenon, and majority circuits (50a and 50b) which are provided for each signal line of the two systems and each output, in the case where the phenomenon is detected by N or more detection units out of the detection units (30a to 30d), a signal that indicates an occurrence of the phenomenon to a corresponding signal line.

Abstract: In a debris trap that may be used in an Emergency Core Cooling System of a nuclear power plant, the filter media is arranged to define both filtration and bypass flowpaths that are in fluid communication with one another. At least initially, each of the filtration and bypass flowpaths are open, and the filtration and bypass flowpaths have relatively low and relatively high head loss, respectively. The debris trap is operative so that flow through the debris trap may passively, and typically gradually, transition from the filtration flowpaths to the bypass flowpath in response to the filter media collecting increasing amounts of debris. More specifically, initially substantially all of the flow may be through the filtration flowpaths, and thereafter the filtration flowpaths may become substantially obstructed so that substantially all of the flow is through the bypass flowpath.

Abstract: A nuclear reactor includes an internal steam generator and a nuclear core disposed in a containment structure. A condenser is disposed outside the containment structure, and includes a condenser inlet line tapping off a steam line connected to the steam generator outside the containment structure, and a condensate injection line conveying condensate from the condenser to the integral steam generator. Isolation valves are located outside the containment structure on a feedwater line, the steam line, and the condensate injection line. The valves have an operating configuration in which the isolation valves on the feedwater and steam lines are open and the isolation valve on the condensate injection line is closed, and a heat removal configuration in which the isolation valves on the feedwater and steam lines are closed and the isolation valve on the condensate injection line is open.

Abstract: The invention relates to a heating rod for a pressurizer of a primary cooling system of a pressurized-water nuclear reactor, the rod comprising a metal outer shell (36) of longitudinally elongate shape having an external surface (62), and a heating element (40) mounted inside the shell (36). It comprises an anti-corrosion coating (60) covering at least part of the external surface (62) of the shell (36).

Abstract: A nuclear fission reactor fuel assembly adapted to permit expansion of the nuclear fuel contained therein. The fuel assembly comprises an enclosure having enclosure walls to sealingly enclose a nuclear fuel foam defining a plurality of interconnected open-cell voids or a plurality of closed-cell voids. The voids permit expansion of the foam toward the voids, which expansion may be due to heat generation and/or fission gas release. The voids shrink or reduce in volume as the foam expands. Pressure on the enclosure walls is substantially reduced because the foam expands toward and even into the voids rather than against the enclosure walls. Thus, the voids provide space into which the foam can expand.