Abstract: The object of the invention relates to a neutron source, which contains a proton accelerator for producing a proton beam, and a target arranged in the trajectory of the proton beam exiting the proton accelerator for producing a neutron beam, to which the proton beam arrives in long, typically 0.5 ms-3 ms impulses, and contains a moderator-reflector system arranged in the vicinity of the target and serving for producing a moderated neutron beam, which has at least one moderator, and a reflector surrounding the moderator and the target, characterized by that at least one statistical neutron chopper is arranged to protrude into the at least one moderated neutron beam exiting channel that modulates at least one neutron beam intensity according to a random or pseudo-random sample as a function of time with its neutron transmittance ability varying according to such pattern.

Abstract: Provided are a system and method for reducing the atmospheric release of radioactive materials caused by a severe accident. The system includes a steam generator disposed in a containment building, configured to generate steam by using heat of a coolant heated in a nuclear reactor, and connected to a turbine through a main steam line, a decontamination tank connected to the main steam line through a connection line and containing decontamination water for decontaminating the steam delivered from the steam generator and reducing atmospheric release of radioactive materials when a severe accident occurs, and a depressurizing power generation unit disposed on the connection line and configured to generate emergency power while depressurizing the steam delivered from the steam generator toward the decontamination tank when the severe accident occurs.

Abstract: A safety injection device includes, a cooling water storage section accommodating cooling water injected into the reactor coolant system, a power producing section producing power with steam discharged from the reactor coolant system in case of an accident, a steam supply pipe transmitting steam discharged from the reactor coolant system to the power producing section, a steam discharge pipe discharging steam used to drive the power producing section and a safety injection line supplying cooling water accommodated in the cooling water storage section to the inside of the reactor coolant system. In addition, cooling water accommodated in the cooling water storage section is supplied to the inside of the reactor coolant system, based on the power produced by the power producing section, through a cooling water inlet pipe connecting the cooling water storage section and the power producing section.

Abstract: The present invention relates to a nuclear fuel pellet laminate structure having enhanced thermal conductivity, including a nuclear fuel pellet; and a thermally conductive metal layer disposed above or below the nuclear fuel pellet, and a method for manufacturing the same.

Abstract: A reactor water radioactivity concentration of a nuclear power plant can be predicted with high accuracy. First, a plant state quantity prediction value is calculated by using a physical model that describes plant state quantities of the power plant including a flow rate of feedwater and a metal corrosion product concentration in feedwater of the reactor water is calculated. Next, data for supervised learning is created, and the data for supervised learning includes the previously calculated plant state quantity prediction value and a plant state quantity such as the flow rate of feedwater, the metal corrosion product concentration in feedwater, a metal corrosion product concentration in reactor water, and a radioactive metal corrosion concentration of the reactor water in the reactor as input data and includes a radioactive metal corrosion concentration in the reactor water which is an actual measured value as output data, and a predictive model is trained.

Abstract: A method for calculating a PCI margin associated with a loading pattern of a nuclear reactor including a core into which fuel assemblies are loaded according to the loading pattern is implemented by an electronic system. The fuel assemblies include fuel rods each including fuel pellets of nuclear fuel and a cladding surrounding the pellets. This method includes calculating a reference principal PCI margin for a reference loading pattern of the fuel assemblies in the core; calculating a reference secondary PCI margin for the reference pattern; calculating a modified secondary PCI margin for a modified loading pattern of the fuel assemblies in the core, and calculating a modified principal PCI margin for the modified pattern, depending on a comparison of the modified secondary PCI margin with the reference secondary PCI margin.

Abstract: A method and device for pointing at an object in a Virtual Reality (VR) scene, and a VR apparatus are provided. The method includes sensing a movement of a gamepad from a first position to a second position in a reality scene through an Inertial Measurement Unit (IMU) orientation sensor. The IMU orientation sensor is mounted in the gamepad, and the gamepad is configured to control an object in a VR scene. The method also includes generating a first position vector based on the movement; acquiring a first absolute position coordinate of the second position in the reality scene according to a position coordinate of a starting point in the reality scene and the first position vector; converting the first absolute position coordinate into a first virtual position coordinate in the VR scene; and pointing at a target object located at the first virtual position coordinate in the VR scene.

Abstract: Systems and methods for injecting a carbonate-based sacrificial material into a nuclear reactor containment for containment of molten corium in severe nuclear reactor accidents are disclosed. Molten corium can be quickly cooled and solidified by the endothermic decomposition of the sacrificial material.

Abstract: A data processing device which includes a flexible position input portion for sensing proximity or a touch of an object such as a user's palm and finger. In the case where a first region of the flexible position input portion is held by a user for a certain period, supply of image signals to the first region is selectively stopped.

Abstract: A canister for storing spent nuclear fuel includes an elongated shell, baseplate enclosing the bottom end of the shell, and removable top lid bolted to the shell. The shell may have a dual thickness comprising a lower portion with first thickness and upper portion with greater second thickness by comparison. The upper portion is formed by an annular boss defining a fastening portion of the shell including plural threaded bores for engaging the lid bolting. The fastening portion may protrude radially outwards or inwards in different embodiments. The lid has a mounting flange receiving the bolts and is seated on the top end of shell. The mounting flange does not protrude radially beyond the outer surface of the fastener portion to minimize the diameter of the canister for placement inside an outer radiation shielded overpack or cask for transport/storage. The shell may optionally include cooling fins.

Abstract: Plurality of layers form a nuclear fission reactor structure, each layer having an inner segment body, an intermediate segment body, and an outer segment body (each segment body separated by an interface). The layers include a plurality of cladding arms having involute curve shapes that spirally radiate outward from a radially inner end to a radially outer end. Chambers in the involute curve shaped cladding arm contain fuel compositions (and/or other materials such as moderators and poisons). The design of the involute curve shaped cladding arms and the composition of the materials conform to neutronic and thermal management requirements for the nuclear fission reactor and are of sufficiently common design and/or have sufficiently few variations as to reduce manufacturing complexity and manufacturing variability.

Abstract: A detection apparatus is a flow and temperature measuring device in the form of a tube having a channel positioned parallel to a coolant flow stream and contains a drogue that is firmly attached to a mount within the channel. The mount has a load detection apparatus firmly imbedded near the flow inlet to the tube. The drogue has at least neutral buoyancy in the fluid at the minimum fluid temperature of interest. A change in the buoyancy of the drogue as a function of temperature and a corresponding change in the strain detection apparatus output in the fluid is determined by a combination of simple physics and calibration measurements. The relationship between changes in strain detection apparatus signal output and flow-rate-induced forces applied to the drogue surface are also determined using a combination of simple physics and calibration measurements. A system and method are also described.

Abstract: A nuclear-power-plant computer-based procedure display device is disposed in a main control room of a nuclear power plant, and includes a operating procedure storage unit that stores a computer-based procedure in which plant operation procedures of the nuclear power plant are divided into procedure steps and listed, a operating procedure display unit that displays the computer-based procedure, and a operating procedure display control unit that controls display of the computer-based procedure. In a case where the procedure step displayed on the operating procedure display unit is selected by an operator, the operating procedure display control unit displays an indication that the procedure step is selected, on the operating procedure display unit.

Abstract: A chemical decontamination reagent containing a reducing agent, a reductive metal ion, and an inorganic acid is provided to remove a radioactive oxide layer on a metal surface. The reagent can dissolve the radioactive oxide layer on the metal surface effectively at a relatively low temperature and enables a simple process of contacting the reagent to the radioactive oxide, thus economically effective in terms of cost and time required for the process. Since the decontamination does not use a conventional organic chelating agent such as oxalic acid, but the reducing agent as a main substance, the residuals of the reducing agent remained after decontamination can be decomposed and removed with an oxidizing agent. Due to the easy decomposition with the chemical decontamination reagent, secondary wastes can be minimized and the radionuclides remained in the decontamination reagent solution can be removed effectively.

Abstract: A system for use in shutting down a nuclear reactor includes a housing that defines a region therein sealed from an ambient environment and a gate member disposed within the region in a manner such that the gate member segregates the region into a first compartment and a second compartment isolated from the first compartment. The gate member is formed from a material having a predetermined melting point. The system further includes a neutron absorbing material disposed within the first compartment and a dispersion mechanism disposed within the region. The dispersion mechanism structured to encourage the neutron absorbing material from the first compartment into the second compartment.

Abstract: A securing device is installable on an outer circumferential surface of a nuclear reactor core shroud and in contact with an inner circumferential surface of a pressure vessel. The securing device includes a base configured for contacting the outer circumferential surface of the nuclear reactor core shroud. The securing device also includes a radial extender including an actuator, a stationary support section fixed to the base and a movable contact section. The radial extender is configured such that the movable contact section is movable along the stationary support section by the actuator to force the movable contact section radially into the inner circumferential surface of the pressure vessel.

Abstract: There is provided a method of producing a radioisotope with a production time shortened. There is provided a producing method of a radioisotope, the method including: irradiating a target substance with a radiation beam; and extracting the radioisotope which is generated by irradiating the target substance and flowing a gas over the substance to transport the radioisotope in gas phase toward an outlet.

Abstract: Technique(s) to mitigate creep and/or cascade failure in high temperature heat pipe reactor cores may include gas loading each heat pipe such that when one or more heat pipes in the heat pipe array fail, the adjacent heat pipes can accommodate added heat load with little change in temperature.

Abstract: The method includes assessing operational characteristics of the fuel assembly, the assessing including determining if the fuel assembly is to be placed in a controlled location in the reactor core, a controlled location being positioned adjacent to a control blade that is to be utilized, and configuring the sidewalls of the outer channel by making at least a first select sidewall of the outer channel a reinforced sidewall, the remaining sidewalls of the outer channel, other than the at least a first select sidewall, being non-reinforced sidewalls. The entirety of the reinforced sidewall as a whole is at least one of thicker and made from a material that is more resistant to radiation-induced deformation as compared to an entirety of the non-reinforced sidewalls.

Abstract: Provided is a target plate for radioisotope production that has sufficient durability and sufficient heat resistance for use in radioisotope production and that is capable of reducing the extent of radioactivation. In a target plate for radioisotope production, a support substrate, which supports a target, includes a graphite film(s). The thermal conductivity in a surface direction of the graphite film(s) is 1200 W/(m·K) or greater, and the thickness of the graphite film(s) is 0.05 ?m or greater and 100 ?m or less.